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TEXT-BOOK OF PALEONTOLOGY
MACMILLAN AND CO., Limitkd
LONDON • BOMBAY • CALCUTTA
MELBOURNE
THE MACMILLAN COMPANY
NKW YOHK • BOSTON • CHICAGO
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THE MACMILLAN CO. OF CANADA, Limited
TORONTO
TEXT-BOOK
OF
PALEONTOLOGY
EDITED BY
CHARLES R. EASTMAN, A.M., Ph.D.
PROFESSOR OF PALKONTOLOGY IN THE UNIVERSITY OF PITTSBURGH
AND CURATOR AT THE CARNEGIE MUSEUM, PITTSBURGH
ADAPTED FROM THE GERMAN OF
KARL A. VON ZITTEL
LATE PROFESSOR OF GEOLOGY AND PALEONTOLOGY IN THE UNIVERSITY OF MUNICH
SECOND EDITION REVISED AND ENLARGED BY THE EDITOR IN COLLABORATION
WITH THE FOLLOWING -NAMED SPECIALISTS:
B. S. BASSLER, W. T. CALMAN, A. H. CLARK, H. L. CLARK, J. M. CLARKE,
J. A. CUSHMAN, W. H. DALL, A. HANDLIRSCH, R. T. JACKSON, A. PETRUNKEVITCH, P. E. RAYMOND,
R. RUEDEMANN, C. SCHUCHERT, J. P. SMITH. F. SPRINGER, T. W. VAUGHAN, C. D. WALCOTT
VOL. I.
WITH ABOUT 1600 ILLUSTRATIONS
MACMILLAN AND CO., LIMITED
ST. MARTIN'S STREET, LONDON
1913
COPYRIGHT
'There is nothing good in this world but that which is true." — Diderot.
First Edition, 1900
Second Edition, 1913
EDITOES PREFACE TO THE SECOND EDITION
A NEW English edition of von Zittel's Text-hook of Fakontology having been
called for, advantage was taken of the opportunity to prepare a thorough-
going revision of the first volume, in order that an adequate account might
be incorporated of the new knowledge that has been gained during recent
years.
Towards this end, a number of specialists were invited to collaborate Avith
the Editor in preparing a fresh treatment of the leading groups of Inverte-
brates, and the jDresent work bears witness to the generous response that was
made to this invitation. Many parts of the work have been entirely re-
written, others have been emended, rearranged and enlarged, and the
classification in various places has been very considerably altered. The new
work, therefore, cannot Avith either justice or propriety be called von
Zittel's Text-book, being in eifect a composite production ; and 3'^et in scope
and style it is modelled after the well-known G erman original.
The names of the difterent collaborators appear on the title-page, and the
sections that have been revised or rewritten are credited in the body of the
work to the specialists responsible for them. To all of his collaborators
the Editor desires to otter grateful acknowledgments, and to express the
sense of his own personal indebtedness to them for the large service they have
rendered, and for many individual courtesies.
To his friend and former associate at Harvard, Doctor Robert Tracy
Jackson, the Editor is under an obligation greater than can be adequately
acknowledged ; for besides having contributed practically a fresh account of
the Echini, Dr. Jackson has carefully read the proofs of the entire work, and
has offered in many places most valuable suggestions and emendations. Like
several of the other collaborators, also, he has fui'nished the originals for a
number of new figures. The total number of fresh illustrations has thus been
sensibly increased. It is hoped that the large amount of painstaking work
which has been bestowed upon the present treatise will be found to yield
returns in increased value and usefulness among students of Paleontology
generally.
CHARLES R. EASTMAN.
Carnegie Museum, Pittsburgh,
Pennsylvania, June 5, 1913.
V
LIST OF COLLABOEATORS FOR THE
SECOND EDITION
Dr. Joseph Augustus Cushman, Foraminifera.
Dr. T. Wayland Yaughan, Adino::oa.
Dr. Rudolf Ruedemaxn, GraptolUoidea.'
Mr. Frank Springer, Cystoidea, Blastoidea, Crinoidea.
Dr. Arthur Hobart Clark, Post-Paleozoic Crinoidea.
Dr. Hubert Lyman Clark, Asteroidea, Holothuroidea .
Dr. Robert Tracy Jackson, EcJiinoidea.
Dr. Ray S. Bassler, Brijozoa.
Prof. Charles Schuchert, Brachiopoda.
Dr. William Healy Dall, Pelecypoda, Gastropoda (pars).
Prof. JAiiES Perrin Smith, Ammonoidea.
Dr. Percy E. Raymond, TriloUta.
Dr. Charles D. AValcott, TriloUta (jMrs), Arachnida (pars).
Dr. liAY S. Bassler, Branchiopoda, Ostracoda.
Dr. William T. Calman, Girripedia, Malacostracu.
Dr. John M. Clarke, Phyllocarida, Arachnida.
Dr. Alexander Petrunkevitch, Evnholohranchiata, Myriapoda.
Dr. Anton Handlirsch, Tnsecta.
VI
OEIGINAL AUTHOR'S PREFACE
Die englische Ausgabe meiner Gruiidziige der Palaeontologie hat ein vom
deutschen Original in verschiedener Hinsicht abweichende Gestalt erhalten.
Dei" Herausgeber, meiu Freund imd ehemaliger Schiiler Dr. Eastman, suchte
mit meiner Zustimmung eine Anzahl der hervorragendsten Specialisteu fiir
die Bearbeitune; einzelner Thierclassen zu gewinnen. Dadurch erfuhr das
Werk eine griindliche und sachkundige Ueberarbeitung, welche sich namentlich
im Detail vortheilhaft geltend macht und mancherlei Irrthiimer der deutschen
Ausgabe beseitigte.' Fiir diese miihevolle und aufopfernde Arbeit bin ich den
Mitarbeitern des Text-Book zu grossem Dank verpflichtet.
Allerdings wurde durch die Betheiligung einer grosseren Anzahl von
Autoren, deren Anschauungen in systematischen Fragen nicht immer unter
einander und mit denen des Autors der deutschen Ausgabe in Einklang standen,
die Einheitlichkeit des AVerkes nicht unerheblich gestort und auch der urspriing-
liche Umfano- verschiedener Abschnitte bedeutend iiberschritten : allein diese
Nachtheile diirften durch die sorgfiiltigere Durcharbeitung des eigentlichen
Stotfes reichlich ausgeglichen sein.
Die Revision der Crinoideen hatte der verstorbene Herr Charles Wachsrmith,
jene der Asteroideen tukI Echinoideen Herr IF. Percy Sladen iibernommen.
Abgesehen von einigen Abiinderungen, welche mehr terminologische als
sachliche Fragen betreflen, wurde in diesen Abtheilungen eine weit voll-
standigere Aufziihlung und Charakterisierung der fossilen Gattungen durch-
gefiihrt, als in der deutschen Ausgabe. AVeitergehende Umgestaltung erfuhr
die Classe der Bryozoen durch Herrn E. 0. JJlrich. Die paliiozoischen Formen
sind von diesem ausgezeichneten Kenner mit einer Ausfiihrlichkeit behandelt,
welche nicht ganz mit der Darstellung anderer Abtheilungen in Einklang
steht. Auch die Transferierung der bereits bei den Korallen abgehandelten
Chaetetiden und Fistuliporiden zu den Bryozoen und die dadurch veranlasste
doppelte Darstellung derselben ist eine Incongruenz, welche sich nur durch die
Meinungsverschiedenheit iiber die zoologische Stellung dieser ausgestorbenen
Organismen entschuldigen liisst.
Eine durchgreifende Umarbeitung haben die Brachiopodeu durch Herrn
Charles Schuchert erfahren. Wiihrend sich die deutsche Ausgabe mehr auf die
vii
viii TEXT-BOOK OF PALEONTOLOGY
AVerke unci Anschauungen von Thomas Davidson stiitzt, folgt die englische
Uebersetzung sowohl in der Auftassung der Gattungen und Familien, als auch
in den systematischen Principien den neusten Arbeiten von James Hall, J. M.
Clarice, und C. E. Beecher. Die systematischen Hauptgruppen sollen liier
zugleich entwicklungsgeschichtlichen Phasen entsprechen und das ganze
System den Anforderungen des biogenetischen Grundgesetzes geniigen. Von
jihnlichen Gesichtspunkten wurden auch Professor Beecher bei der Bearbeitung
der Trilobiten i;nd Professor Hyatt bei jener der Cephalopoden geleitet. Es
ist mir zweifelhaft, ob die Zeit zu einer durchgreifenden Reform der bio-
logischen Systematik, bei welcher weniger morphologische und vergleichend-
anatomische Merkmale, als embryologische und phylogenetische Gesichtspunkte
im Vordergrund stehen, jetzt schon gekommen ist ; allein jedenfalls sucht die
in Nord Amerika gegenwartig herrschende Stromung auf einem neuen AVeg
zur AVahrheit zu gelangen und eine die genealogischen Beziehungen deutlicher
Avieclerspiegelnde Systematik zu erzielen.
Bei den Pelecyi^oden hat Herr Dr. JF. H. Ball die durch Neumayr eingef iihrten
und in den Grundziigen mit einigen Modificationen angenommenen Gruppen
durch seine eigene, auf hingjiihrige Spezialuntersuchungen basirte Eintheilung
ersetzt. Die Scaphopoden, Amphineuren, Gastropoden und Pteropoden
wurden von Herrn Professor H. A. Pilsbry, die Crustaceen mit Ausnahme der
Trilobiten und einiger anderer Gruppen von Professor /. ^S'. Kingsley, und die
iibrigen Arthropoden von meinem langjahrigen Mitarbeiter und Freund
Professor S. H. Scudder in sachkundigster AA^eise durchgesehen.
Fiir den wichtigen Abschnitt der Cephalopoden tragt Herr Professor
Alpheus Hyatt die Verantwortlichkeit. Hier treten die Differenzen mit der
deutschen Ausgabe am auffallendsten zu Tage, vertritt doch dieser Autor am
entschiedensten die moderne Richtung in Amerika. Obwohl meine An-
schauungen iiber verschiedene Grundprinzipien der S^^stematik, namentlich
liber Abgrenzung von Familien, Gattungen und Arten von denen meines
amerikanischen Collegen abweichen, so glaubte ich doch einem so hervorra-
genden Kenner der fossilen Cephalopoden bei der Bearbeitung des von ihm
iibernommen Abschnittes vollig freie Hand lassen zu miissen. Das Text-
BoOK ist dadurch um eine werthvolle Originalarbeit bereichert worden, welche
viele bis jetzt noch nicht verofFentlichte Thatsachen enthiilt.
Zu ganz besonderem Dank bin ich dem Herausgeber der englischen
Ausgabe Herrn Dr. C. E. Eastman verpflichtet. Er hat keine Miihe gescheut,
das AYerk mit den neusten Ergebnissen der palaontologischen Forschung in
Einklang zu bringen vuid den Fortgang derselben zu fordern.
Dr. KARL A. von ZITTEL.
MuxcHEN, im Septciabcr 1899.
EDITOR'S PREFACE TO THE FIRST EDITION
The Grundziige cler Palaeontologie, which forms the basis of the present work,
was published in the spring of 1895, only a short time after the completion
of the fifth and last volume of Professor von Zittel's celebrated Handhuch der
Palaeontologie. Of the latter, an excellent translation exists in French by
Barrois ; but English-speaking students are Avithout either an independent
treatise on Paleontology or translation from any foreign work, which is
comparable in scop6 and character to the writings of von Zittel.
With the hope of supplying this deficiency the Editor undertook the task
of rendering the GrundzUge into English. It was at first intended to bring
out a strictly literal translation, but with the Author's consent this plan was
modified in important respects which should be clearly understood by all.
The chapters on Protozoa and Coelenterata stand here essentially as in the
original, but nearly all the remaining chapters have been remodelled, enlarged,
and brought as nearly as possible up to date by a selected body of experts.
The greater part of the work is therefore a composite production, and
from the nature of the case some incongruities in style and treatment are to
be expected. For all the collaborators to have adhered to uniform limits of
altei'ation and expansion would have been impossible. It will be found,
therefore, that some portions of the revised text are not sensibly different
from the original while others are changed very radically, and a few chapters,
notably the Molluscoidea, Mollusca, and Trilobites, are entirely rewritten. An
effort has been made throughout to adapt the text more especially to the
needs of Anglo-American students, and the bibliographies have l)een enlarged
with similar intent.
For all changes in the classification over the original the revisers of the
different sections are responsible ; but although radical departures have been
made with the Author's sanction, one must by no means presume he is thereby
committed to all the innovations which are set forth. How far and Avhether
in all cases the system has been improved must be left for experience to
detei'mine. The Author's graciousness, however, in yielding his own prefer-
ences on systematic points will be apparent on reading his annexed preface.
Due acknowledgments are rendered the collaborators in the Author's
ix
X TEXT-BOOK OF PALEONTOLOGY
pi'eface, and also in footnotes at the end of the several chapters. Their
names are enumerated below in the order of their respective sections, and the
Editor begs to express at this time a sense of his profound appreciation of the
services that have been so generously rendered. For the many personal
courtesies extended, he would return to each of them his sincere and hearty
thanks.
LIST OF COLLABORATORS
^Ii'. Charles "Wachsjiuth, Crinoidea, Blastoidea.
Mr. W. Percy Slauen, Asterozoa, Echinozoa.
Dr. George Jennings Hinde, Vermes.
Mv. Edward O. Ulrich, Bryozoa, Ostracoda.
Mr. Charles Schuchert, Brachiofoda.
Dr. William H. Dall, Pelecijpoda.
Prof. Henry A. Pilsbry, Gastropoda.
Prof. Alpheus Hyatt, Cephalopoda.
Prof. Charles E. Beecher, TrUohita.
Prof. John M. Clarke, Eucrustacea (pars), Acerafa (jxirs).
Prof. John S. Kingsley, Eucrustacea {pars), Accrata (pars).
Prof. Samuel H. Scudder, Insecta.
The Editor is also greatly indebted to his friend Dr. John C. Merriam,
who undertook the translation of the entire chapter on Mollusca, a very
laborious work. Dr. Merriam's assistance has been further enlisted in the
translation of the second volume, which will be devoted exclusively to the
Vertebrates. Dr. August F. Foerste was kind enough to furnish a transla-
tion of the chapter on Insects, and various friends have assisted in correcting
proofs. For the compilation of the index the Editor is indebted to Miss
Elizabeth B. Bryant, a former student of his at Eadcliffe College, and to
his brother, Mr. David P. Eastman.
CHARLES R. EASTMAN.
Harvard University,
Scptemher 15, 1899.
CONTENTS
INTRODUCTION
Definition and Scope of Paleontology
PACK
1
PHYLUM I.
Protozoa
17
PHYLUM IL
COELENTERATA (Zoopliytes) .
46
PHYLUM m.
Vermes (Worms)
135
PHYLUM IV.
Echinodermata
143
PHYLUM V.
MOLLUSCOIDEA
. 314
PHYLUM VL
Mollusc A
421
PHYLUM VIL
Arthropod A (Articulates)
690
INDEX
,i=^
XI
823
INTRODUCTION
DEFINITION AND SCOPE OF PALEONTOLOGY
Paleontology (Aoyos twv TraAatwi' m'TOH') is the science which treats of
the life which has existed on the globe during former geological periods. It
deals with all questions concerning the structure, classification, relationships,
descent, conditions of existence, and distribution in time and space of the
ancient inhabitants of the earth, as well as with those theories of organic and
cosmogonic evolution which result from such inquiries.
Under the term of fossils are understood all remains or traces of plants
and animals which have lived before the beginning of the present geological
period, and have become preserved in the rocks. The criterion which
determines the fossil character of organic remains is the geological age of the
formation in which they occur, whereas their mode and state of preservation,
or the fact of their belonging to extinct or to still living species, are merely
incidental considerations. Although fossils have, as a rule, undergone more
or less radical changes during the process of fossilisation, and are usually
transformed into mineral substances, nevertheless, under exceptionally
favourable conditions (as in frozen ground, amber, resin, peat, etc.), plants
and animals may be preserved through geological periods in a practically
unaltered state. Carcasses of mammoths and rhinoceroses entombed in the
frozen mud-cliffs of Siberia, and inclusions of insects, spiders and plants in
amber are none the less genuine fossils, in spite of their having sustained no
trace whatever of mineral infiltration.
A considerable number of plants and animals occurring as fossils in Tertiary
and Pleistocene formations belong to still living species; while, on the other
hand, the remains of forms which have become extinct during historical times
(Rhytina, Alca, Didus, Pezophaps, etc.) can no more be classed as fossils in the
true sense of the word than all such recent organisms as may chance to
become buried in deposits now forming under the present prevailing orographic
and climatal conditions.
The changes which organic bodies undergo during the process of fossilisa-
tion are partly chemical and partly mechanical in their nature.^ According
as certain portions of the original substance are removed, or are replaced atom
' Wlbitc, Charles A., Couditious of preservation of invertebrate fossils. Bull. U.S. Geo), and
Geog. Survey Territ., 1880, vol. v., p. 133. Trabucco, G., La Petrificazione. Pavia, 1887.
VOX. I. B
2 ELEMENTS OF PALEONTOLOGY
for atom by foreign matter, the result may be either carbonisation, decom-
position, total dissipation, or petrifaction.
Carbonisation is a deoxidising process taking place under water or with
limited access of air, and especially common among i^lants. Fossil wood and
other vegetable matter abound in peat, lignite and bituminous coal, the
leaves being transformed into a thin flake of carbon, on Avhich often the finest
venation is still discernible. In some cases chitinous animal structures also
become carbonised, as in insects, crustaceans and graptolites.
Decomposition as a rule effectually destroys all organic carbon and nitrogen
compounds. AYith few exceptions, therefore, animals without hard parts,
such as worms, infusorians, naked mollusca, most hydrozoa, many anthozoa,
and the embryos of vertebrates, leave no traces behind in the rocks. Horn,
hair, chitin and similar structures are likewise totally destroyed during the
fossilisation process, while only under especially favourable conditions, as
in ice or in frozen soil, muscular and epidermal tissues remain unchanged ;
or else, through the taking up of lime phosphate in argillaceous and calcareous
deposits, undergo a sort of petrifaction, in which the finer structure is but
little altered.^ Even the conservable hard parts of animal bodies are deprived
of their organic compounds ; bones give tip their fats and oils, and the shells
of mollusks, echinoderms and crustaceans lose their pigments and soft sub-
stratum. The hard portions, which first become more or less porous through
loss of their organic constituents, next suffer the gradual disintegration of
their inorganic compounds, and finally undergo dissolution, reabsorption,
or petrifaction.
Petrifaction. — In this process foreign substances soluble in water (chiefly
calcium carbonate and silica, more rarely pyrites, iron oxyhydrate and other
salts) impregnate and completely fill all original cavities as well as those
formed subsequently by decay. Chemical metamorphism takes place
occasionally, when, owing to the decomposition of certain inorganic con-
stituents, the original molecules become replaced by those of other substances.
For instance, we find quartz pseudomorphs after calcareous tests and skeletal
parts, and conversely, calcite pseudomorphs after silica, as in certain sponges.
Wherever the space originally occupied by soft parts, as, for example, the
interior of a shell or other hollow body, becomes filled up with infiltrating
ooze, while the shell itself or the enclosing wall decays, there is produced a
cast of the interior, which in most cases (especially where the shell is thin, as in
ammonites, brachiopods, certain mollusks and crustaceans) preserves an exact
copy of the original form, and is susceptible of as accurate determination as
the real object. Not infrequently fossil organisms leave molds or imprints of
their shells or skeletons — very rarely of their whole bodies — in the rocks.
Sometimes, indeed, their presence is indicated merely by tracks or footprints.
Fossils are often distorted by mechanical agencies, such as faulting, folding,
crushing, and other deformations of the country rock. Such cases require
especial attention, and due caution must be observed in their determination.
Paleontology and Biology. — Although the fossil remains of ancient
life-forms yield but a fragmentary record of themselves, are almost never
perfectly preserved, and are usually more or less altered in appearance, yet
on the whole, they readily fit into place in the great framework of zoological
^ Reis, Olio, Cber ]>etrilicirte Muskulatur. Arch. Miki'os. Anat., vols. xli. xliv. Hi., — ])ccm,
B., Preservation of nuiscle-fibres in sharks. Amer. Geol., 1902, vol. xxx.
INTEODUCTION 3
and botanical classifications. Notwithstanding all their differences, their
general structure is similar to that of recent organisms, and their identification
requires the most careful comparison with nearly related plants and animals.
The methods of paleontological research do not differ from those employed
by the zoologist and botanist, excepting, of course, that the paleontologist is
restricted to those parts which are alone capable of preservation, and must
reconstruct the missing soft parts ideally from analogy with recent forms. It
is, nevertheless, incumbent on the paleontologist to obtain all possible informa-
tion from the material such as it is, aided by every means he can devise ; and
hence his investigations do not cease with an examination of the external,
macroscopic characters, but must be extended to the finer microscopic and
histological as well. In numerous instances paleontology has anticipated
zoology and botany by important histological discoveries ; in the branch of
vertebrate comparative anatomy, for example, through the exhaustive study
of conservable hard parts, such as the teeth, skeleton, dermal covering, etc.,
this science has been elevated to its present high standard chiefly by paleon-
tologists (Cuvier, Owen, Huxley, H. von Meyer, Riitimeyer, Marsh, Cope,
Osborn and others). The principle of correlation of parts, first applied with
such eminent success by Cuvier, according to which all parts of an organism
stand in certain fixed relationships to one another, so that one organ cannot
vary without a corresponding variation taking place in the others, is now
worked out not only for the whole group of vertebrates, but for invertebrates
as well ; and its elaboration is such that frequently a single bone, tooth,
plate, carapace, shell -fragment and the like, is sufficient for us to form a
tolerably accurate concept of the entire creature. It is therefore clear that
in so far as paleontology has to deal with the study and classification of fossil
organisms, it is no other than a part of zoology, comparative anatomy and
botany, and hence may be very properly divided into Paleozoology and Faleo-
hotany. Paleontology has vastly increased the subject - matter of the two
biological sciences, has filled up innumerable gaps in the system, and has
infinitely enriched our knowledge of the variety and complexity of plant and
animal organisation. In almost every class of both kingdoms where preserva-
tion is possible, the number of fossil forms considerably exceeds the recent.
A natural classification of the Foraminifera, sponges, corals, echinoderms,
mollusks, vertebrates, and of the vascular cryptogams, cycads and conifers,
would be utterly inconceivable without taking paleontological evidence into
account, since in certain classes (brachiopods, cephalopods, reptiles, mammals)
the number of extinct fossil forms may be ten, a hundred, or even a thousand-
fold greater than the living, and this proportion is steadily increasing in
favour of paleontology, as fresh discoveries are made in various parts of the
world.
Paleontology and. Geology. — Although as a biological science paleon-
tology does not differ essentially from botany and zoology, yet its connection
with geology is none the less intimate, and consequently it has been cultivated
quite as assiduously by geologists as by biologists. The material is brought
to light almost wholly by geologists or by geological collectors, who obtain it
from the stratified rocks of the earth's crust — that is to say, rocks which have
been formed by the subaqueous deposition of sediment, or have been built up
from detritus on dry land by aerial agency. The distribution of fossils
throughout stratified rocks is by no means promiscuous, neither do all rocks
4 ELEMENTS OF PALEONTOLOGY
contain the same species ; but on the contrary, each separate stratigraphical-
complex, and frequently even single beds and layers, are characterised by
certain particular assemblages of fossils. The older the rock, the-more strikingly
different from recent organisms are its fossil remains ; the younger the forma-
tion, the greater is their resemblance. Now, since experience shows that
contemporaneous deposits which have been laid down under similar conditions
(as, for example, in salt or in fresh water) contain identical or at least very
similar fossils, the latter furnish us with an infallible guide, taken together
with the local stratigraphic succession, for determining the relative age of a
givea formation. Furthermore, a knowledge of the fossils occurring in homo-
taxial deposits enables us to reconstruct the various paleofaunas and paleo-
flloras which have existed on our planet at different periods in its history.
Having determined the chronological succession of the clastic rocks by means
of their superimposition and their characteristic or index-fossils, the}^ may be
divided up into still smaller series, each one of which is characterised by a
particular assemblage of organic remains. In the main, then, paleontology is
the ultimate foundation of historical geology.
Excluding the oldest metamorphic rocks (gneiss, mica schists, phyllites,
etc.) which are destitute of fossils, and concerning whose origin there is still
great difference of opinion, the total thickness of the sedimentary rocks
amounts to 20,000 — 30,000 metres. The building up of this prodigious
pile of rock must have extended over an inconceivably long time, whose dura-
tion cannot even approximately be estimated, since we are without data as
to the rate of deposition in former periods, and since the beginning, culmina-
tion and end of geological epochs cannot be correlated Avith astronomical
events.
Since, however, the earth has been inhabited in former times by very
different creatures from those now living ; since successive paleofaunas and
paleofloras follow one another everywhere in the same order ; and since,
furthermore, in certain formations the greater part or even the total number
of species appear and disappear in a body, so that one fauna or flora is
replaced almost in its entirety by the next following ; it is obvious that the
sedimentary rocks may be subdivided into a number of longer and shorter
time measures, which may be designated by particular names. The beginning
and end of such periods (group, system or formation, series or section, stage,
zone or bed) is usuall}'^ indicated by local interruptions in the deposition,
occasioned by variations in sea-level, volcanic eruptions, or by other causes ;
and such disturbances are usually accompanied by changes in the flora and
fauna. The now generally accepted subdivision of the secondary rocks is
represented in the table on page 5, in which it should be noted that only the
first three columns are of universal significance, while the last two apply only
to European countries.
The rocks of the Archaean Group amount to 40,000 — 60,000 metres in
thickness. They belong to the oldest and longest period in the history of
our planet, and are remarkable for their schistose and crystalline structure, as
well as for the total absence of fossils. In order of stratigraphy, gneiss com-
prises for the most part the oldest ; mica, chlorite, and talc-schists the middle ;
and phyllites (primitive schists) the youngest division of this group. The
so-called fossil organism, Eozoon, occurring in gneiss, has been proved to be of
inorganic nature.
INTRODUCTION
'
Clyi 5 4^CA^^vi
1
Eras
Epochs (Etages)
renous j>
Cenozoic Group
Quarternary
System
Alluvium
Recent Deposits
Diluvium
(Pleistocene)
Postjjlacial Series
Glacial ,,
Preglacial ,,
Tertiary System
- 1
o
to
Pliocene
Miocene
Upper or Sicilian (Sicilien)
Middle or Astian (Astien)
Lower or Plaisancian (Messinien)
Pontian Series (Pontien)
Sarinatian ,, (Sarniatieu)
Tortonian ,, (Tortonien)
Helvetian ,, (Helvetien)
Bunligalian Series (Burdigalien)
Aquitanian ,, (Aquitanien)
Oligocene
Upper or Rupelian (Stanipien)
Lower or Lattortian (Tongrien)
Eocene
Bartonian Series (Bartonien)
Parisian ,, (Lutetien)
Ypresian ,, (Ypresien)
Landenian ,, (Landenien)
! Cretaceous
Upper Cretaceous
Danian Series (Danien)
Senonian ,, (Senonien)
Turonian ,, (Turonien)
Ceuomanian Series (Cenoraanien)
z Group
System
Lower Cretaceous
Gault Series (Albien)
Aptian and Urgonian Series (Aptien, Urgonien)
Barremian Series (Barremien)
Neocomian and Wealden Series (Neocomieu)
\
Upper Jurassic
(Malm)
Tithoiiian and Portland Series (Portlandien)
Kininieridgian ,, (Kinimeridgieii)
Coralliau . ,, (Sequanien)
Oxfordian ,, (Oxfordien)
Kellaway „ (Callovien)
•g Jurassic System i
Middle Jurassic
(Dogger)
Bath or Great Oolite Series (Bathonien)
Bajeux or Inferior Oolite Series (Bajocien)
o
m
Lower Jurassic
(Lias)
Toarcian Series (Toarcien)
Charniouthian Series (Charmouthien)
Sinemnrian ,, (Sineniurien)
Hettangian ,, (Hettangien)
Upper Triassic
(Keuper)
Rliaetic Stage (Rhaetien)
Noric ,, (Norien)
Carinthian ,, (Carnien)
Triassic System
Middle Triassic
(Muschelkalk)
Ladinian Series (Ladinien)
Virglorian ,, (Virglorien)
Lower Triassic
(Bunter Sandstein)
WerfPiiian Series (Wertenien, or
Weitenian Series Scythien)
Paleozoic Group
Permian System
(Dyas)
Carboniferous
System
Devonian
System
Zechstein
Rothliegendes
Thuringian Series (Thnringien)
Saxonian or Penjabian (Saxonien)
Artinsk or Antunian (Autunien)
Coal Measures
Urahan or Stepnanian (Ouralien)
Muscovian or Westplialian (Moscovien)
Lower Carboniferous
(Culm)
Dinantian Series or Culm (Dinantien)
Upper Devonian
Painennian Series (Famennien)
Frasniaii ,, (Frasnien)
Middle Devonian
Givetian ,, (Givetien)
Eifelian Series (Eifelien)
Lower Devonian
Coblenzian Series (Cbblentzien)
Gedinnian ,, (Gedinnieu)
Silurian System
Silurian
Ludlow Series "4
Wen lock ,, HGothlandien)
Llandovery Series J
Ordovician
(Lower Silurian)
Bala or Caradoc Series ^
Llandeilo ,, V (Ordovicien)
Arenig ,, )
Cambrian
System
Upper Cambrian
S^og'T" (Potsdamien)
Middle Cambrian
Menevian Series (Acadien)
Lower Cambrian
Harlech Series (Georgien)
Arch-
aean
Group
Primitive Scliist
System
Gneiss System
' Phyllite (Primitive Schists,
Mica and Chlorite Schists,
etc.)
Gneiss
Precambrian Series (Algonkien)
6 ELEMENTS OF PALEONTOLOGY
The Paleozoic or Friinary Group comprises the Cambrian, Ordovician,
Sihirian, Devonian, Carboniferous and Permian systems, each of which is
made up of a great number of series, stages and zones. In the Cambrian
crustaceans, trilobites, brachiopods and worms predominate, associated with a
few echinoderms, coelenterates, sponges and poorly preserved algae. In the
Silurian system most classes of the animal kingdom are represented with the
exception of amphibians, reptiles, birds and mammals, while the flora still
consists of algae. Marine invertebrates are very abundant, especially crus-
taceans, mollusks, echinoderms and coelenterates, while only a few frag-
mentary fish-remains indicate the presence of vertebrates. All the species
and nearly all the genera have since become extinct, and belong for the most
part to extinct families and orders. During the Devonian, Carboniferous and
Permian systems, the same classes of animals continue as a body, but are
represented by frequently difterent families and genera. Fishes develop a great
variety of forms in the Devonian, amphibians (Stegocephalia) make their
appearance in the Carboniferous, and reptiles in the Permian. The flora
consists chiefly of vascular cryptogams, together with a few conifers and
cycads.
The Mesozoic Group comprises three systems — the Triassic, Jurassic and
Cretaceous. Many of the widely distributed Paleozoic types (Tetracoralla,
graptolites, crinoids, cystids, blastoids, brachiopods, trilobites) have either wholly
or in greater part disappeared, while others (cephalopods, lamellibranchs, sea-
urchins) are replaced by very different genera and families. Vertebrates are
remarkable for the gigantic size attained by amphibians (Labyrinthodonta) and
many reptiles, as well as for the wonderful variety of the latter. Birds appear
for the first time in the Upper Jurassic (Arckaeojyteri/x), and mammals
towards the close of the Triassic, being represented by diminutive, probably
marsupial types. During the Triassic and Jurassic periods, vascular crypto-
gams, conifers and cycads remain the dominant plant-forms, dicotyledons not
occurring until the middle Cretaceous.
The Cenozoic Group comprises the Tertiary and post-Tertiary or Quaternary
systems. Among the invertebrates, ammonites, belemnites, Rudistae and
most of the Crinoidea have now passed away. Amphibians and reptiles have
greatly declined, and, like the invertebrates, are represented by still living
orders. On the other hand, birds, and particularly mammals, attain a
wide distribution ; the latter class branches out in such manifold variety, and
experiences such rapid development during Cenozoic time, that it alone
furnishes us with the principal index-fossils of this era. From now on the
flora consists chiefly of dicotjdedonous plants.
Paleontology and Physical Geography. — Not only do fossils con-
stitute the very foundation of historical geology, but they furnish us in
addition with valuable information respecting the origin of the rocks in
which they occur, the former distribution of land and water, climatal
conditions, and the facts of geographical distribution in former periods. By
means of analogy with recent species we are able in most cases readily to
determine whether fossil forms pertain to land, fresh, brackish or salt water
species, whence it is apparent under what conditions the strata were deposited.
The distribution of marine and fresh-water formations helps us to certain
conclusions respecting the extent of former seas and land areas. Deep-sea,
shallow water, and littoral deposits are readily distinguishable by means of
INTRODUCTION 7
their fossil organisms. By fossils, also, even the climatal conditions of
former periods are indicated with great fidelity. The luxurious and uniform
development of cryptogams over the face of the globe during Carboniferous
time presupposes a warm, moist climate, little varying with latitude ; tropical
dicotyledons occurring in the Cretaceous and Tertiary deposits of Greenland, or
coral-reefs extending into high latitudes during the Paleozoic era, prove Avith
equal certainty the prevalence of amilder climate and higheroceanic temperature
in earlier times ; while again, the remains of reindeer, the lemming, musk-ox,
polar fox, and other arctic animals in the diluvium of Central Europe testify
to a period of glaciation with reduced mean annual temperature.
The geographical distribution of fossil organisms proves that the regions
and provinces occupied by recent plants and animals are to a certain extent
identical with those existing in the Tertiary, and that life has been subject to
the same distributional laws in the past as in the present. Nearly all recent
forms are the obvious descendants of extinct creatures which formerly
occupied the same region. For example, the fossil mammals, birds and
reptiles of Diluvial time in Europe, Asia, Australia, North and South America,
are scarcely distinguishable from forms now inhabiting the same continents.
The ancestral homes of marsupials and edentates were perpetuated in
Australia and South America until as recently as the Diluvial epoch, and
during the later Tertiary, Europe, Asia and America formed but a single
zoological province; inhabited by the ancestors of forms now living in the
northern hemisphere. An understanding of the physical conditions which
have governed the perpetuation of recent plants and animals in their respective
provinces {succession of similar types) would be utterly impossible without a
knowledge of their distribution in former times. In like manner, our know-
ledge of the distribution of land and water, of prevailing climatal conditions,
oceanic currents, etc., of earlier periods depends chiefly upon evidence derived
from fossils.
Paleontology and Embryology. — To trace the development of living
plants and animals through all stages from the one-celled egg onward to
final dissolution, is the task of Embryology and Ontogeny. At the present
moment, botanists and zoologists are devoting their most scrutinising attention
to embryological investigations, which latter accordingly exert a powerful
influence on the progress of biology, and particularly on the classification.
The fact that every individual, species and genus of a whole group of plants
and animals passes through nearly the same course of development, at least
in the primary stages, and that all embryos belonging to a given order or
class resemble one another so closely, up to a certain stage, that they cannot
be told apart, has revealed unexpected affinities among forms diftering very
considerably in the adult stage. Cirripedes, for example, which were formerly
mistaken for shell-bearing mollusks, develop from the same Nauplius-larvae
as the Copepoda, Branchiopoda and Osti'acoda, although the mature individuals
belonging to these orders of crustaceans possess but little common resemblance.
Likewise, the whole group of vertebrate embryos can hardly be distinguished
from one another in the earliest stages, and only very gradually assume the
characteristic features pertaining to class and order.
The results of embryological inquiry have a most important bearing on
paleontology. Numerous fossil forms are known, which, in comparison with
recent related organisms, exhibit embryonic, or at least larval or adolescent
8 ELEMENTS OF PALEONTOLOGY
characteristics. Examples of such primitive or embryonic types are especi-
ally common in vertebrates, for the reason that here the skeleton becomes
ossified very early in life, and hence the immature stages of the recent can be
directly compared with adult fossil forms. Now, observation has shown that
in most of the older fossil fishes and reptiles, the vertebral column never
passed beyond an embryonic stage, but remained in a cartilaginous or
incompletely ossified condition through life. The Paleozoic amphibians
(Stegocephalia) probably breathed by means of both gills and lungs through-
out life, whereas most recent amphibians lose their gills comparatively early
(Caducibranchia), and breathe wholly by lungs. Many fossil reptiles and
mammals retain certain skeletal peculiarities permanently, while allied recent
forms exhibit them only in embryonic stages. The skull in most of the older
fossil reptiles and mammals closely corresponds in form and structui^e with
that in embryos of recent related types. In the oldest fossil artiodactyls
the palm-bones are all completely separated, while in recent ruminants this
division continues only during the embryonic stage, being followed by a
fusion of the two median metapodals, together with a reduction of the laterals.
Among invertebrates, also, fossil embryonic types are by no means uncommon.
The Paleozoic Beliimridae find their counterpart in the larvae of the common
Limulus ; many fossil sea-urchins are characterised by linear ambulacra, while
recent related forms, although developing petaloid radii in the adult stage,
pass through the linear phase during adolescence. Many fossil crinoids re-
semble the young of the living genus Antedon ; and, according to Jackson,
recent echinoids, oysters and pectens exhibit in their nepionic stages certain
characters peculiar to the adults of Paleozoic genera.
The so-called fossil generalised or comprehensive types, which unite in one and
the same form characters which, in geologically later, or recent descendants,
have become distributed among different genera and families, are in reality
merely primitive or immature types which have stopped short of the higher
differentiation attained by their descendants. Generalised types always
precede more highly specialised ; and properties that were originally distri-
butive among older forms are never reunited in geologically younger species
or genera. Trilobites, amphibians and reptiles of the Paleozoic and Mesozoic
eras, and early Tertiary mammals belong almost exclusively to the category
of generalised types.
In certain groups of vertebrates, and especially of mammals (Ungulata,
Carnivora), the chronological succession of genera is so closely paralleled by
the successive stages of development in the life-history of their descendants,
that to a certain extent the ontogeny of the individual is a representment of
a long chronological series of fossil forms. This truth furnishes a strong
foundation for the biogenetic law, enunciated in various terms by Geoffroy St.
Hilaire, Serres, Meckel, Fritz Miiller and others, and recently more precisely
formulated by Haeckel, as follows : The developmental history or ontogeny
of an individual is merely a short and simplified repetition or recapitulation of
the slow (perhaps extending over thousands of years) process of evolution of
the species and of the whole branch.
The biogenetic law has since been found to hold true not only for verte-
brates, but also for invertebrates, including even wholly extinct types. In
ammonites, for instance, the primary or innermost whorls always differ from
the outer in their greater simplicity of suture, and in their lesser ornamenta-
INTEODUCTION 9
tioii. Very often a coiT6S})ondence is observable with geologically older forms ;
and it is a well-known fact that all ammonites pass through early stages which
resemble, at least so far as chambering of the shell is concerned, Paleozoic
goniatites. A comparison of the inner whorls of an ammonite with its corre-
sponding goniatitic form, or with older ammonites, seldom fails to reveal
ties of kinship not otherwise discernible. Beecher has shown that nearly
every stage in the development of arm-supports in recent brachiopods corre-
sponds to conditions of the adult in some fossil genus ; and further, that the
chronological succession of the latter is to a certain degree identical with the
successive ontogenetic stages of recent foi-ms.
The relation of rudimentary or degradational organs occurring in recent forms
to those of the fossil ancestors of the latter is of extreme significance. By
rudimentary organs are meant certain structures (as, for example, limbs,
parts of limbs, organs of sense, respiration, digestion, reproduction, etc.),
which are still indicated by atrophied remains, but whose physiological
functions, and hence their utility to the organism, have wholly disappeared.
Rudimentary organs are, as a rule, either normally developed in an embryonic
stage, or at least more strongly than in the adult individual, owing to a
process of degeneration, or retrogressive development. The fossil progenitors
of forms possessing vestigial structures are almost always characterised by
a full development, of the respective parts. The lateral metacarpals and
metatarsals in the horse and most ruminants, for example, are indicated only
by rudimentary side-splints ; but in an embryonic stage they are much more
strongly developed, and in related fossil forms they occur as normal bones,
carrying toes like the other metapodals, and serving for locomotion and
support. The wrist and metacarpal bones in birds have also suffered degenera-
tion, as is evident from a comparison with embryos and with older forms
(Archaeopteryx), which exhibit a much higher development. In like manner,
the teeth of birds have also become degenerated. In only a few forms
(parrots, ostriches) are faint dental ridges discernible during embryonic stages ;
but in all known Mesozoic birds the teeth are well developed and remain
functional throughout life. Similarly, teeth are developed duriug embryonic
stages in the baleen whale, but subsequently become atrophied ; while in the
older fossil Cetacea teeth are always present. Other instances of this
nature are to be met with in great profusion, both among vertebrates and
invertebrates.
The biogenetic law is, however, not infrequently obscured, for the reason
that two closely related forms may not develop in exactly the same manner ;
embryos of the one type may be affected by peculiar accelerating impulses
which are not shared by those of the other, and in consequence the first may
pass through certain stages very rapidly, or may even omit them altogether.
In this way the historical or palingenetic record contained in the development
of every individual may be to a large extent veiled, suppressed or rendei-ed
unintelligible ; and this phenomenon of inexact parallelism {coenogene&is) is
especially common in highly differentiated types, where the embryo passes
through a multitude of phases.
Paleontology and Phylogeny. — While conceding that by means of
embryological investigations zoologists and botanists are able to trace the
gradual development and differentiation of an organism through all its various
stages, and thereupon to construct a tree of descent (phylogeny) founded upon
10 ELEMENTS OF PALEONTOLOGY
the successive phases of growth, nevertheless such hypothetical genealogies
can only be relied upon as truthful when they are substantiated by paleonto-
logical facts. And only in cases where the different ontogenetic stages are
I'epresented by corresponding fossil primitive or generalised types, which
appear in the same chronological order, and clothe the supposititious ancestral
tree with real forms, can the truthfulness of the latter be said to have been
established. This requirement paleontology is from the nature of things
unable to satisfy except .in a few instances ; but a multitude of other facts
testifies to the blood-kinship between morphologically similar fossil and recent
organisms, and points to the direct descent of the younger from the older
forms.
Geology proves conclusively that of the numerous floras and faunas which
lie buried in the rocks, those which are most nearly of the same geological
age bear the greatest resemblance to each other. It often happens that species
and genera occurring in a given formation reappear in the next following with
scarcely any perceptible changes, so that the doctrine of the gradual trans-
formation and transmutation of older forms is irresistibly forced upon one,
while the faunas and floras of later periods assert themselves as the obvious
descendants of the more ancient. Other weighty evidence for the progressive
evolution of organisms is afforded by fossil transitional series, of which a
considerable number are known, notwithstanding the imperfection of the
paleontological record. By transitional series are meant a greater or less
number of similar forms occurring through several successive horizons, and
constituting a practically unbroken morphic chain. Often the dift'erences
between individuals belonging to different periods are so slight that we can
hardly assign to them the value of a variety. But let a number of such
mutations occur in succession, the end-members of the series become finally
so divergent as to constitute distinct species and genera. The most striking
and most numerous examples of transitional series naturally occur in types
peculiarly well fitted for preservation, such as mollusks, brachiopods, sea-
urchins, corals and vertebrates. Particularly remarkable among mollusks
are the closely linked transitional series in ammonites. Among vertebrates
transmutation proceeded far more rapidly than among invertebrates, and
accordingly, the successive members of a series are usually so divergent as to
require their assignment to separate genera.
With increasing abundance of paleontological material, the more numerous
and more complete are the series of intermediate forms which are brought to
light. But the more extended our knowledge of transitional series the greater
is the difficulty we encounter in defining our conception of species. "While the
older disciples of the Linnean and Cuvierian schools contended that each
separate species was created with a certain definite sum of fixed characters,
and remained incapable of any extensive modifications ; on the other hand,
those holding to the Darwinian theory of evolution look upon varieties,
species, subgenera, genera, families, orders, classes and phyla merely as
arbitrary yet useful and convenient distinctions, corresponding to the state of
our information at the present time ; it being assumed that by means of
gradual transmutation during the course of ages all organisms have become
evolved from a single primitive cell, or from a few primitive types.
According to the Linne-Cuvier doctrine, a species is composed of individuals
which are directly descended from one another, or from common ancestors,
INTRODUCTION 11
and which resemble their progenitors as much as they resemble each other.
Members of one and the same species interbreed, b\it individuals belonging
to diiferent species do not cross, or when they do, produce infertile or
imperfectly fertile offspring.
According to the theory of descent no sharp specific distinctions can be
drawn, but all individuals are assigned to the same species which share a
number of essential features in common, and which are not connected with
neighbouring groups by means of intermediate types. It is plain that this
definition is open to considerable laxity of interpretation, and inasmuch as
the direct descent of individuals belonging to a given species cannot always (in
paleontology never) be determined on experimental grounds, systematists
are rarely agreed in regard to the precise limitations of species, genera and
families.
The doctrine of the invariability of species received powerful support from
the cataclysmic theory of Cuvier, which maintained that each period in the
earth's history is marked by distinctively characteristic faunas and floras ; that
no species is common to two successive periods ; that tremendous convulsions
of nature (cataclysms) occurred at the close of each cycle, and annihilated the
whole organic world ; and that by means of special creative acts, the renovated
earth became time and again populated with new animals and plants which bore
absolutely no connection with either previous or subsequently introduced types.
Cuvier's cataclysmic theory may be regarded at the present day as com-
pletely ovei'thrown, inasmuch as the modern school of geology, following the
leadership of Sir Charles Lyell, has demonstrated conclusively that the earth
has proceeded from one stage to another during the course of its development
only with the utmost slowness ; that the same forces and laws which regulate
the world of to-day have operated likewise in primeval times ; and that
geological periods are by no means abruptly set off from one another, but are
linked together by innumerable transitional stages.
The theory of the descendant origin of organic forms, Avhich was advanced
as early as 1802 by J. B. Lamarck and Geoftroy St. Hilaire, and was supported
by Goethe, Oken and Meckel in Germany, kept winning continually more
adherents, yet it was not until the latter half of the nineteenth century that
its universal significance was insisted on by Charles Darwin and his school.
Paleontology, as already remarked, contributes a great deal of extremely
weighty evidence in favour of the theory of descent ; the series of intermediate
forms, often traceable through several successive formations ; the presence of
primitive and generalised types ; the parallelism between ontogeny and the
chronological succession of related fossil forms ; the similarity between floras
and faunas of approximately the same age ; the correspondence in the
geographical distribution of recent organisms with that of their progenitors ;
and a host of other facts are explicable only by means of the theory of descent.
The causes of variation and transformation were attributed by Lamarck
chiefly to the use and disuse of organs ; secondly, to the effect of changes in
external conditions ; and lastly, to a supposed inherent tendency toward
valuation and perfection existing in each individual. According to Lamarck,
new characters brought about by these influences are transmitted to descend-
ants through inheritance, and become permanently established in the I'ace.
Geoffroy St. Hilaire maintained the same principles on the whole, but ascribed
the chief causes of variation of species to the influence of environment.
12 ELEMENTS OF PALEONTOLOGY
The Darwinian theory of natural selection is based upon the property
common to all organisms of acquiring ancestral characteristics through heredity,
and of transmitting them in turn to their progeny ; and also on the adapta-
bility of organisms to particular external conditions, by means of which
variations are brought about. Since in the struggle for existence only those
individuals which are the best adapted — that is to say, those possessing the
most advantageous modifications — survive, nature is continually exercising,
according to Darwin, a most rigorous selection which operates toward the
increase and perfection of useful variations. Through the constant accumula-
tion of originally slight yet serviceable modifications, and through the perpetual
transmission of the same from one generation to another, there are produced
first of all new varieties, then species, and eventually genera, families and orders.
The zoological and botanical classifications are, according to Darwin, merely an
expression of genealogical facts, exhibiting the remoter and closer ties of
consanguinity which exist among different organic forms.
Darwin's explanation of the origin of species by the addition of the
agency of natural selection to the Lamarckian factors of variation and
inheritance found in Wallace, Huxley, Haeckel and others, zealous and
ingenious supporters, although on other sides it encountered vehement
opposition. Moritz Wagner regarded free intercrossing as an insurmountable
obstacle to the establishment of new modifications, and contended that the
isolation of a few individuals, a condition which would occur most frequently
during migrations, was a necessary postulate in accounting for the origin of
each new variety or species. As will be stated presently, the principle of
isolation, slightly modified, has been applied by other writers. Bronn, Niigeli
and A. Braun raised the objection to Darwin's theory of natural selection
that many organs are entirely useless to the individual, and therefore natural
selection, which depends upon the principle of utility, could neither have
produced such organs nor could have modified them in any way. Niigeli
assumed that, in addition to natural selection, a certain resident tendency
toward perfection, inherent in every individual, takes part in conditioning
the growth of morphological characters. Every variation brought about
by external or internal agencies is at once in the nature of a differentiation,
a step forward in the division of labour, and consequently an advancement.
Weismann endeavoured in a similar manner to supplement Darwin's theory
of selection by his hypothesis of the continuity of germ-plasm. According to
Weismann, germ-matter is of itself capable of producing all variations that
are useful to an organism. Only that which exists in the original plasm or in
the sexual elements as embryonic rudiments can be transmitted to offspring
and become further acted upon and developed by natural selection, according
to Weismann's theory. The continuity, that is to say, the perpetual trans-
mission of a portion of the germ-plasm from parent to offspring, forms a
necessary postulate to the theory of descent.
AVeismann originally attributed only a subordinate influence to the
action of physical environment as a cause of variations, and particularly
denied the inheritance of acquired characters. But in his later writings,
he is inclined to admit that somatic variations due to environmental influences
may be transmitted to the offspring, and endeavours to explain this with the
help of his germ-plasm hypothesis. Thus he approaches in a way the opinion
of his opponents, the so-called Neo-Lamarckian school (represented by Herbert
INTRODUCTION 13
Spencer, Cope, Hyatt, Osborn, Semper, Claus, Roux and others), which ranges
itself more and more on the side of Lamarckian ideas, and ascribes to the use
and disuse of organs, and to external conditions, a very considerable influence
in effecting the transformation of organic forms. AVhile, on the one hand.
Semper, Locard and Clessin undertake to prove the direct action of environ-
ment on mollusks in a number of instances ; on the other hand. Cope, Osborn,
Roux and others, emphasise the effect of use and disuse, and abundance or
scantiness of food-supply. Adequate nourishment and exercise increase the
development of a given organ, while physical conditions determine its form.
Since like causes produce like effects in the animate as well as in the inanimate
world, it is obvious that similar organs must be developed in a variety of plant
and animal forms wherever they are subjected to similar external conditions,
and especially to the same physical agencies. A convenient explanation is
thus found for the phenomena of parallelism, or " convergence," which are
in nowise related to one another by inheritance. The analogous swimming-
organs of fishes, ichthyosaurians and whales, or the analogoiis limb-structure
in long-legged ruminants, the horse, elephant and carnivora, are due to
adaptation to external conditions and to use ; the same explanation also
accounts for the like form of sternum in bats, birds and Pferosauria, or for the
spindle-shaped body characteristic of most rapid-swimming fishes, reptiles and
aquatic mammals, oi; for the similar form of jaw possessed by marsupials and
various orders of Placentalia. These are all instances of [)arallelism, in which
it often happens that two fundamentally different forms acquire the same
outward shape, or become provided with similar or analogous organs. Kineto-
genesis, or the process of a gradual transformation of parts, especially parts
belonging to the internal skeleton, skull and limbs, is very ingeniously
interpreted by Cope as having been accomplished in mammals through the
agency of mechanical conditions, use and food. The same author has also
traced the line of progressive modification in fossil genera as exemplified by
numerous series of intermediate forms.
In sharp contrast to all these opinions is the " mutation theory " of de
Vries. The latter attempts to show that new species of plants are formed
by what he calls mutations. It should be noted that this term is used in a
different sense from the same word as mentioned on p. 10, being equivalent to
saltatioii, used previously for the same thing. Mutations, in de Vries's sense,
are more or less strongly marked deviations from the normal type, appearing
rather suddenly ; and de Vries claims that only these are capable of being
bred true by pedigree-culture, and that they alone lead to the origin of new
species. What he actually did was to demonstrate that it is possible, by
pedigree-culture, to produce true breeding forms (species) out of mutations,
but he failed to see that the essential factor in this process is not the quality
of the material he worked with (i.e. the mutations), but that it is the pedigree-
culture, and that this corresponds to the well-known factors of selection and
isolation.
The latter principle, originally introduced, as has already been stated, by
Moritz Wagner, has recently been put forward by other writers (Baur,
Ortmann, Gulick, etc.) as a factor which causes the differentiation of one
species into several co-existing species (" process of speciation," 0. F. Cook).
While it is admitted that the Lamarckian factors of variation and inheritance
and the Darwinian factor of natural selection, are real and actual, it is
14 ELEMENTS OF PALEONTOLOGY
evident that these are not sufficient for the understanding of the whole of the
evolutionary process. They are capable of explaining the transformation of
one existing form into one other form, but fail to account for the fact that
often two or more different forms have originated from a single ancestral type.
Isolation, biological or ecological separation, or habitudinal segregation, are
synonymous terms applied to a fourth factor, which is important for render-
ing the process of speciation more intelligible. These terms signify that
the descendants of one ancestral form living amid a definite set of ecological
(or environmental) conditions, begin to adapt themselves to different sets of
conditions, as a result of which they become ecologically separated or segregated.
Each group of descendants consequently becomes subject to different influences
of environment, and in responding to such develops along different lines, the
divergence becoming finally so great as to be of specific value.
According to the view that has just been stated, it is necessary to
recognise that the whole process of evolution is a very complex one ; that it
is the ultimate outcome of a number of factors, each of which has its owii
special efficacy, and may be sometimes antagonistic to the others ; and that of
the various factors engaged the following four are the most potent and most
essential : variation, inheritance, natural selection and separation. This view is
perhaps to be regarded as the most satisfactory explanation of the organic
world and its upbuilding that has yet been 2:)ut forward. Nevertheless, though
it cannot be gainsaid that the four operative principles just mentioned are
actively at work, it is difficult sometimes to trace their causes. This is
particularly true of those factors known as variation and inheritance. As to
the former of these factors, the rival hypotheses of the Lamarck-Darwinian
and of the Weismannian school are contradictory with reference to the cause
of inheritable variation. With regard to the cause of inheritance, important
discoveries, such as the Mendelian law, have been made, but these are too far-
reaching to permit of a satisfactory account in limited space.
Life-Period and Extinction of Species. — Observation shows that
different organisms are by no means equally susceptible to impulses received
from the outer world. Many fossil genera remain almost wholly unchanged
throughout a number of formations (Foraminifera, Cidaris, Nautilus, Lingula,
Terebratula, Insectivora),and hence may be designated as j^ersisfent or conservative
types, in contradistinction to variable types. The latter pass through rapid changes
at the beginning of their career, develop a great variety of forms, and send out
branches and off-shoots in all directions up to a certain point ; they may then die
out after a comparatively short period of ascendency (Nummulites, Graptolites,
Cystids, Blastoids, Tetracoralla, Perischoechinoida, Trilobitae, Eudistae, Ichthy o-
sauria, Pterosauria, Dinosauria, Amblypoda, Toxodontia, etc.), or in some cases
may even continue on to the present day with undiminished vitality (Spatangidae,
Clypeastridae, many land and fresh-water mollusks, crabs, lizards, snakes,
ruminants, apes). Not infrequently types that were originally variable pass
over gradually into persistent ; their power of adaptation dwindles, they grow
less plastic, become incapable of sending off new varieties, species or genera,
and as the less vigorous of their numl)er become worsted one after another, they
finally stand out as isolated relics of antiquity (Isocrinus, Hatteria, Tapirns,
Equus, etc.) in the midst of rehabilitated surroundings. A one-sided develop-
ment in a certain direction, excessive size, abnormal (hypertrophic) jDeculiarities,
or too high specialisation of organs, is as a rule injurious to the form and
INTRODUCTION 15
leads usually to its extermination. Many groups remarkable for their
extreme diflerentiation (Dinosauria, Pterosauria, Amblypoda, Toxodontia,
etc.) have become extinct probably for this reason, since, having advanced so
far in a single limited direction, adaptation in other directions was no longer
possible.
Persistent types seldom produce a large number of species during a single
geological period ; types that start up suddenly and proceed to vary rapidly
as a rule soon die out ; while groups that develop slowly and steadily usually
contain in their growth the promise of great longevity.
Some very ancient types have persisted to the present day in highly
saline lakes, or in salt pans, in acid, alkaline, very cold or otherwise unnatural
situations. These represent dominant types of past ages which, vigorous and
adaptable, when forced by internal specific pressure due to the enormous
increase in the numbers of individuals were able to invade and adapt them-
selves to physically and chemically unfavourable localities. The subsequent
development of other types, younger and more vigorous, has extirpated them
from all the more desirable situations, though these types have not proved
sufficiently adaptable or vigorous entirely to exterminate them.
The fauna of the ocean deeps and of biologicall}^ unfavourable situations
generally is, therefore, a curious composite of the more vigorous and adapt-
able types of animal life from the Cambrian to the present day, including
forms which were dominant in all earlier epochs, as well as forms derived directly
from recent ancestors.
For the extinction of many plants (Sigillaria, Lepidodendron, Cordaites) and
animals (Blastoids, Tetracoralla, Trilobites, Ammonites, Rudistae, Ichthyosaurs,
etc.) of former periods no adequate explanation has as yet been found. Changes
in external conditions, especially such as regards the distribution of land and
water, climatal conditions, saltness of the water, volcanic eruptions, paucity of
food-supply, the encroachments of natural enemies, and diseases, may have
led to the extinction of certain forms, but such conjectures signally fail to
account for the disappearance of an entire species or particular groups of
organisms. Oftentimes extinction seems to have been caused merely by
superannuation. Long-lived forms belong for the most part to persistent
types whose range of species is limited. Their reproductive functions have
declined, and like an individual in its senescence, they evince the symptoms of
decrepitude and old age. Darwin attributes the extinction of less well-adapted
organisms to the struggle for existence ; but since, according to the theory of
natural selection, new species arise only with extreme slowness by means of
the gradual accumulation of useful variations, and since in like manner their
less successful competitors are only very gradually crowded out, we should
expect to find in the rocks, siipposing that the paleontological record were in
any degree perfect, all manner of extinct intermediate forms, and we should be
able, at least for those groups especially liable to conservation, to build up
complete ancestral trees. But as observation shows, not only do most plants
and animals now living in a wild state adhere to their peculiar characteristics
with great tenacity, exhibiting barely appreciable changes even in the course
of himdreds or thousands of years, but, furthermore, fossil species remain
within the limits of a single geological period fairly constant. With the
beginning of a new epoch or period, however, which is usually indicated
in the section by lithologic changes, a greater or less number of species either
16 ELEMENTS OF PALEONTOLOGY
entirely disappears, or is replaced by closely related, but at the same time
more or less different forms. Obviously, therefore, there have been periods
when the process of transformation and the vi^eeding out of organisms were
greatly accelerated, and following upon these reconstructive periods long
intervals of repose have ensued, during which intervals species have retained
their characteristic forms with but little variation. The fact that evolution
has advanced by occasional bounds or leaps stands, however, in nowise contra-
dictory to the theory of descent.
T^e whole animate community at any point on the earth's surface rests
normally in a state of equilibrium, the balance being maintained by the com-
bined activity of all ranks and members of society. For the preservation of
this balance nature practises a most rigid domestic economy. Every plant
depends upon particular conditions of soil, food, temperature, moisture and
other requisites for its support ; and these conditions govern its distribution
and increase in the last degree. Every plant controls the destiny of all
animals subsisting upon it ; their numbers multiply with its increase, and
wane with its decrease. The fate of these creatures determines that of their
natural enemies, who stand in similar relationships to still remoter circles ;
and hence no form can overstride the bounds set for it by the general balance
without disturbing the whole general system of economy. Let the flora or fauna
of a given region become altered by the extinction of a number of species, or
by the introduction of new and more powerful competitors, the balance is
immediately upset. In the first instance vacant places must be filled up, and
in the second, room must be made for the newcomers at the expense of the
settled community. Thus, wherever climatal, orographic, or other changes
are instrumental in bringing about the extermination of large numbers of
plants and animals during the lapse of a geological period, a state of inequi-
librium must necessarily result. But thereupon the struggle for existence
is waged with unwonted severity among the survivors, until finally a
readjustment is established, and a pause in the formation of new species ensues.
The whole course of evolution in the organic world during past geological
periods indicates not only definite progression in all branches of the animal
and vegetable kingdoms up to their present state, but also a more perfected
specialisation. Granting that the theory of descent is true, and that all
organisms have developed from a single primitive cell, or from a few primitive
ground-types, then every new growth and differentiation must stand for im-
provement and progress, leading gradually to the development of more or less
highly specialised organs, and to a division of labour in their physiological
functions ; the higher the degree in which this is manifested, and the more
conformably to apparent purpose and utility that each organ fulfils its
functions, the more perfect is the organism, as we conventionally term it.
Evolution in the organic world has not advanced in a simple, straightforward
direction, but its course has been exceedingly complicated and circuitous.
The biological systems, accordingly, do not suggest to us the similitude of a
ladder with its numerous rounds, hwt rather that of an enormously ramifying
tree, whose topmost twigs represent the youngest, and, on the whole, the
most perfect forms of every branch. The root, trunk, and a goodly portion
of the upper limbs lie buried in the earth ; and only the ultimate green
shoots, the last and most highly differentiated members of long ancestral
lines, blossom forth in the world of to-day.
Phylum I. PROTOZOA.
Protozoa are unicellular organisms with bodies consisting of sarcode (proto-
}Dlasm), usually very minute, frequently microscopic in size, and without
differentiated tissues or organs. They are water-inhabitants, take in nourish-
ing matter either at any point on the periphery of the body whatsoever, or
through a so-called mouth (ci/fosiome), and reject the undigested portions either
from any part of the body whatsoever, or from a definite point called the anal
aperture {cijtopyge). The contractile sarcode almost invariably contains one
or more nuclei, and exhibits considerable diversity of structure and differentia-
tion. Locomotion is Accomplished by means of vibratile' cilia, flagella, pseudo-
podia or irregular processes of the periphery. Reproduction takes place by
means of budding or self-division, which latter process is often preceded by a
temporary conjugation of two individuals. Protozoa are divided into four
classes, only the first-named of which is known to occur in the fossil state :
Sarcodina, Flagellata, Infusoria and Gregarina.
Class 1. SARCODINA.
Frotozoa with or without a test, liaving in fully developed individuals tvell
characterised pseudopodia, either digitate, reticulate or radiate, with or without axial
filaments.
Subclass 1. RHIZOPODA.
Sarcodina either naked or ivith a definite test, the pseudopodia either lohose or
reticulate ; the adult form is amoeboid.
Order 1. AMOEBIDA.
The animals constituting this order do not occur as fossils. There are
found, however, in chalk and many marine limestones minute calcareous
bodies resembling coccoliths, such as are present in vast quantities in deep-sea
ooze of existing oceans.^
^ To the Amoebida were formerly assigned bj' Huxley and Haeckel the so-called Bathyhius, a
reticulated colloidal substance composed of anastomosing strands, occurring at great depths in the
Atlantic Ocean. Sir Wyville Thomson and Moebius regarded it as a precipitate of calcium sulphate,
intermingled with decomposed organic matter. In deep-sea ooze, which consists chiefly of lime
carbonate, as well as in Bathyhiiis, great quantities of minute calcareous Ijodies of various shapes
are found, such as also occur as an essential constituent of chalk, marls and most marine lime-
stones belonging to older geological periods (cf. C. W. G'ainhel, Neues Jahrbuch fiir Mineralogie,
1870, p. 753). Ehrenberg termed these bodies morpholites, and regarded tlieni as inorganic in
VOL. I 17 C
18 PROTOZOA— RHIZOPODA phvlu.m i
Order 2. FORAMINIFERA dOrbigny.
Rhizopoda usually with a test ivhich is typically calcareous hut may he siliceous
or agglutinated ; consisting of one or more chamhers ; pseudopodia reticulate.
The Foraminifera are for the most part minute animals varying in size
from a fraction of a millimetre to several millimetres in length, but may
develop a test several inches across ; these, however, are rare exceptions. A
few species occur in fresh or brackish water, but the great majority live in
the ocean. They are found at all depths, but are most frequent at moderate
depths in the ocean basins, where they form characteristic deposits — the
so-called "globigerina ooze." In the vicinity of tropical coral islands many
species occur in great abundance.
The animal itself is a single-celled form with one or many nuclei, as will
be later explained. The test, in many cases at least, is really an internal
structure, as the thin film of protoplasm which covers it in the perforate
forms, and probably in others, is capable of secreting the material of the test
to repair fractures and the like.
nature. Huxley (Journal Microscop. Science, 1868, YIII. No. 6) and Haeckel (Jeuaische Zeit-
scbrift, 1870, V. 3, p. IS) regarde<l them at first as portions of Bathi/bius, and designated
them coccoliths (Fig. 1). The simple, disklike varieties, convex on the upper side and concave on
the lower, were termed discoliths (Fig. 1, c) ; while those composed of two closely applied disks
of different sizes, resembling cuff-buttons in profile, were referred to as cyatholiths (Fig. 1, a, b).
Coccoliths are only visible umler powers of 800 to 1000 diameters, and exhibit, as a rule, a number
of zones differing in their retractive indices, which are disposed about a single, double or star-
. , , ,, g shaped central granule. Fre-
^.JL-^^ quently large numbers of cocco-
yr,,^^-^^v. %p Wihs become aggregated to-
W H^^^^^ \ gether in the form of freely
suspended spherules or cocco-
a i -Will Ml l|U|' ^''
i #«vil m ll\ ^K/§g?^.'S'J.^2^ x^/^ spheres {Fig. 2). Besides cocco-
i-.iisy vv vj ASS-^ri?^ ^ liths, other minute, rod-shaped,
'. 5 m©//i mil fill \^^,
calcareous bodies are sometimes
Fro. l,rt, ;;.—Coecoi(7/is (6V-t//(o/(7/(x) from the Atlantic Ocean ; upper sur- met with, which are charac-
face and in prottle (after Haeckel) . ^ . .. ,- terised by a discoidal or cruci-
Fio. 1, c.—Cocxoliths (Disrohths) from the Adriatic bea ; upper surface <•„„,„ „„i„„„„„ „ *. 4. i
and in protile (after O. ScliniKlt). form enlargement at one end.
Fio. 2.— Cocco-fji/icces fiom the Atlantic Ocean (after Haeckel). inese are called rhabdoliths
Fio. 3.— iJ/i«Mn/it/is from the Adriatic Sea (after O. Schmidt). All figures (Fig. 3), and their nodular
iiias^nilied 70(1 diameters. aggregations r/uthdospheres.
Wyville Thomson, Carter and
Murray would identify coccospheres as unicellular algae, or as sporangia of algae, while Haeckel
creates for them a special group, '' Calcocytae" and assigns them provisionally to the Protophytes.
According to Harting, however, the action of ammonia generated by the decomposition of albumin-
ous matter held in solution in lime sulphate or lime chloride, causes the separation out of minute
calcareous disks which bear a striking resemblance to coccoliths. Hence it would appear that
the formation of excessively fine divided particles of lime in the sea should take place wherever
there are decomposing albuminous or nitrogenous substances present, and the calcium sulphate
held in solution in the water becomes precipitated as calcium carbonate.
^ Literature: d'Orbigny, A., Foraminiferes fossiles du bassin tertiare de Yienne. Paris, 1846.
— Ehrenherg, O. O., Mikrogeologie, 1854, and Abhaiidlungen der Preu.ss. Akad. Wi.ss., 1839. —
Schidtze, Max, Ueber den Orgauismus der Polythalaiiiien. Leipzig, li^A.-^Cuipenter, W. B.,
Introduction to the Study of the Foraminifera. Ray Society, \^Q2.—Reuss, E. A., Numerous
Reports in Sitzungsberichte der Wiener Akademie, from 1860 onwards. — Schwager, Conrad,
Saggio di una classificazione dei Foraminiferi. Boljet. Coniitato Geol., 1876. — Brady, W. B.,
Monograph of Carboniferous and Permian Foraminifera. Palaeontograph. Soc, 1876. — Brady,
IF. />'?, Report on the Foraminifera, Scieut. Results Challenger Exped. , Zoology, XL, 1884. —
Sherborn, V. />. , Index to the Genera and Species of the Foraminifera. Smith. Misc. Coll.,
1895, vol. xxxvii. — Egger, J. G., Foraminiferen der Seewener Kreideschichten. Sitzber. Bayer.
Akad. Wi.ss., 1909, No! 11. — Schelhoien, E., Monographic der Fusulinen. Palaeontogr. 1908-1912,
vols. Iv., lix.
ORDER ir FOEAMTNIFERA 19
Comparatively little is known concerning the animal of the Foraminifera
except in certain littoral species. As single-celled animals the Foraminifera
are especially interesting, and their structures do not need explanation on the
basis of organs or tissues. There is much beauty in the curves of the test
and in its ornamentation, the patterns of the latter being often very inti'icate.
Throughout the group of Foraminifera there is a nearly complete series,
from a simple gelatinous covering of the cell in some of the fresh-water forms
to the complex calcareous test of the higher groups. The fresh-water forms,
while not considered in the systematic part of this treatise, are nevertheless of
especial interest on account of their primitive characters. In Myxotheca the
simplest sort of covering is found, a gelatinous test which is flexible, so that
it takes the shape of the changing form of the cell. There is here also no
definite aperture, the pseudopodia being pushed through at any point. In
others of the fresh-water forms the test may be of flexible chitinous material,
but has a definite shape when the animal is at rest and usually one or more
definite and permanent orifices.
In the marine species, which form the basis of the present work, there is
usually a definite, specific form to the test, and the aperture is permanent.
The materials used in making the test may be grouped in two classes: (1)
those derived from foreign sources, and (2) those secreted by the animal itself.
The foreign materials are derived from the bottom on which the animal lives,
and therefore even in the same species found under diff'erent conditions there
is some variation in the character of the materials used. In general, however,
there seems to be a certain amount of selective power on the part of certain
forms, and such characters have been used as of generic rank in systematic
work. The foreign material most frequently used is the mud or sand of the
ocean bottom, but certain forms use sponge spicules, either making them into
a soft felted mass (Pilulina) or arranging them in a definite manner and firmly
cemented {Technitella). Other foraminiferal tests may be used, as may various
small bodies which come within the range of the animals. The cement in the
agglutinated tests may be chitinous, of iron oxide, or calcareous.
Of these calcareous tests two sorts have been recognised, one with a definite
aperture or series of apertures and with minute pores (the perforate group),
the other with a definite aperture or series of apertures but without minute
pores (the porcellanous group). By many writers the latter group, represented
by the Miliolidae, has been held to be primitive and a group which had not
developed perforations.. On the other hand, certain evidence, such as the
perforate condition of the early chamber of Peneroplis and other genera, would
indicate that they are derived from the perforate group, and that the lack of
pores instead of being a primitive condition may in reality be a specialised
one derived from a condition in which pores were developed throughout the
life of the individual.
In general the test of the Foraminifera may be single-chambered or many-
chambered. Contrary to the impression given by certain works on the group,
the process of adding chambers in the Foraminifera, while superficially like
budding or gemmation, is not necessarily or usually accompanied by nuclear
divisions. That is, instead of the new chambers being potential individuals
they are simply integral parts of one cell, and in the uninucleate form the
single nucleus is found in about numerically the middle chamber. In the
process of adding a new chamber a portion of the protoplasm is protruded
20 PEOTOZOA— EHIZOPODA phylum i
from the aperture and a new chamber wall then formed about it. In some
cases a complete wall is formed with each newly added chamber, but in others
the adjacent parts of previous chambers form the inner walls of the new
chamber, and new walls are formed only on the free ])arts of the protoplasmic
mass. In the open tubular test, such as Astrorhim or Hyperammina, increase
in the protoplasmic body is accompanied by addition of material at the open
end of the tube and an increase in size results. In single-chambered types,
such as Lagena, the manner of increase in size is problematical, if there be any
at all. In such forms the entire test may be made in its completed form at
once after division, as is the case in certain of the fresh-water Rhizopods.
In the tests having more than a single chamber the apertures of the first-
formed chambers become internal as a rule, and a complexity of relations to
the outside medium is thus brought about. One of the simplest arrangements
of the chambers is a linear series. Such an arrangement is seen in lieophax
and Hormosina. Another very common plan of arrangement is a planospiral,
as in Ammodiscus. This may be varied by having the revolving line in a spire
and then the whole test becomes trochoid, as in Trochammina. Another
common arrangement is a biserial one, the chambers being on opposite sides
of the axis, as in Teztularia. These four plans or some modification of them
are the characteristic arrangements for the chambers in most of the secreted
tests. Oftentimes more than one plan of arrangement enters into the forma-
tion of the test. Dimorphism was used for this, but that term has been used
elsewhere with a very difi'erent meaning. As here viewed, this life-history
with several distinct methods of growth has a deeper significance than has
usually been attached to it. It seems to have a definite phylogenetic bearing
in each particular group. The term " dimorphism " would hardly cover the
case iu some genera, where eight or more distinct stages may be made out,
each with its characteristic form of chamber, yet all appearing successively in
a single test.
The number of chambers in the complex tests varies from a few to a great
many. Where the size of the test becomes considerable and the chambers
correspondingly large, the chamber is often divided up in various ways into
chamberlets, as in Orhitolites. In such cases the adjoining chamberlets are
usually in free communication with one another. The walls of the chamber-
lets give additional strength in many forms in which they are developed.
Another characteristic modification in some genera is the development of
labyrinthic structures in the interior of the chambers. Such structures are
seen in Cydammina, Haplostiche, Fahnlaria, etc. In general, it seems to be a
mark of the culmination of certain lines in development, and many of the
genera which developed such labyrinthic structures are now extinct. From
the appearance of a series of such tests of one species at diti'erent stages in
development, it would seem as though this labyrinthic condition was developed
as a secondary growth in the chamber. One of its uses may be to give added
strength to the test, but this does not always seem to be the case, for it may
occur in tests which are characterised by thick walls.
The aperture in a given species seems to be rather constant when the
development is understood. Much has been written upon this subject ;
apertural characters have been i;sed by some authors as a basis for systematic
work, and discarded by others as very variable. In a few specimens it may
seem at first sight as though the apertural characters were very variable, but
ORDER II FORAMINIFERA 21
with a large series showing difterent stages in development another phase of
the matter is presented. In certain cases there is a very decided change
in the condition of the aperture, but these changes appear at different stages
in the life-history, and all may be seen by cutting back a single full-grown
individual. In general, it has seemed from recent studies that apertural
characters, when studied in large series, are a rather dependable set for
systematic work, and this is true in the Miliolidae and Lagenidae especially.
In many species teeth of various sorts are developed in the aperture, and
these teeth are subject to various modifications. It can be demonstrated
that these modifications occur in a definite sequence, and that this sequence is
important from a phylogenetic point of view.
In a considerable number of genera a definite tubular neck is developed,
with the aperture at its end. This neck is seen in many genera in a great
many modifications, and in Lagena the tube may be inverted and be directed
into the chamber of the test.
It is obvious that a very long slit-like aperture may be a source of weak-
ness to the test, especially when it is at the edge of a thin chamber. Usually
in such cases, as in Orhitolites, the animal changes its aperture from a single
one in each chamber to a considerable number. This is often coincident with
the development of chamberlets, but not invariably so, for multiple apertures
occur in Peneroplis where there are no chamberlets.
Many of the tests of the Foraminifera are beautifull}'' ornamented. Eaised
costae, striations, knobs, spines and punctate areas form the main types of orna-
mentation. Several of these or combinations of them may occur in a single
sjjecies, the form of the ornamentation often changing as the chambers of the
test are developed. Certain of the simpler forms of ornamentation may occur
as parallelisms in widely separated groups. As a rule, the proloculum and
early chambers are smooth and unornamented, but there are certain exceptions,
as in Nodosaria, for example, where in some species ornamentation may occur
on the first chamber. In specialised genera it is not uncommon to find certain
of the species with the early portion of the test ornamented, but the last-
formed chambers with a loss of ornamentation and a consequent development
of smooth chambers. On the other hand, there may be a thickening of the
test from without and the covering of the chambers already formed with a
secondary growth, often spinose. Such a condition is seen in some species of
BuUmina.
Ordinarily the diff'erent parts of the test are connected with one another
by the previous apertures, but in some cases, notably in Polystomella, there is
a secondary canal system which is very complex and runs to all the parts.
This has been worked out by Carpenter and others in detail.
For many of the Foraminifera two distinct phases have been discovered.
One of these, the microspheric form, has a proloculum or first chamber of
much smaller size than the other — the megalospheric form. These two forms
are to be looked for in all species.
The microspheric form (Fig. 4, B) has a number of nuclei, often a larger
number than there are chambers, scattered irregularly through the protoplasm
of the body. There seems to be a rather definite relation between the size of
the nuclei and the size of the chamber in which they occur, the larger nuclei
being in the larger chambers and the reverse. Apparently these nuclei simply
divide in their i-eproduction during the growth of the test.
22
PEOTOZOA—EHIZOPODA
PHYLUM I
Fig. 4.
BiluculinahraO n'l Schlumb. Recent ; Bay of Biscay.
A, Small form with megasphere. B, Large form with
microsphere. 15/^ (after Schlumberger).
in having a single nucleus
When the animal attains its adult stage there is a great increase in the
number of pseudopodia, and the entire protoplasm either leaves the test and
accumulates about the exterior or is
drawn into the outer chambers.
Finally, each nucleus gathers a mass
of protoplasm about itself and secretes
the proloculum of a new test. This
newly formed proloculum is of the
larger type and is the first chamber
of the megalospheric form, instead of
being of the same size as that of the
microspheric parent from which it was
derived. The megalospheric form (Fig.
4, A) differs from the microspheric form
This does not divide, but moves along as new
chambers are added,
keeping in about the
middle chamber nu-
merically. Nucleoli
appear in increasing
numbers as the growth
continues, and finally
the whole nucleus
breaks down and a great
number of minute nuclei
appear. These draw
about themselves por-
tions of the protoplas-
mic mass and then di-
vide by mitotic division.
Finall}^, the mass leaves
the test in the form of
zoospores. These are
then supposed to con-
jugate and to give rise
to the small proloculum
of the microspheric
form, thus completing
the life cycle, although
the actual process of
conjugation has not de-
finitely been observed in
this group. The empty
tests left behind must
form a large propor-
tion of the dredged
Foraminifera. The
two forms may be dis-
tinguished by the size
of the proloculum and, when sufficiently known, by other characters as well.
Pig. 5.
Deep-sea ooze iiiagiiilied 700 diameters, u, Bnthyhiiis witli Coccolith.s ;
h, Individual Discoliths and Cyatholiths ; c, Coccos])heres ; d, Olohkierina ;
(', Ghthiiiertnn witli luirsted test; /, Textnlnr'ui; ij, (/, Radiolariu ; li, i,
Diatoms; 1:, 1, Sponge spicules ; in, Mineral fragment.
ORDER II
FORAMINIFERA
23
The microsiaheric form is thus the result of a conjugation or sexual process,
while the megalospheric form is the result of simple division or an asexual
process. As a rule the megalospheric form is by far the most common, and
in many species the microspheric form is very rare, or even as yet unknown.
The microspheric form, while it starts as a smaller individual, in most cases
attains a much larger size than the megalospheric, as might be suspected from
the nature of the reproductive processes by which it is formed. In species
where there are definite stages in development it is usually the microspheric
form which repeats these most fully, these stages being reduced or entirely
skipped in the megalospheric form of the species.
In some cases the megalospheric form may give rise to a group of megalo-
spheric young instead of to zoospores. On the whole, the life cycle agrees well
with the alternation of generations as seen in certain other groups of animals.
of preparec
light under
laria, (:!iibigcriiui. and 7.
Specimen
transmitted
P'lo. 6.
1 White Chalk from Meudon, as seen in
power of 300 diameters, showing Tcxtn-
Thin slice of Pliinerkalk from Bolieniia,
viewed in transmitted light under power of
50 diameters, showing sections of Nodosarin,
RMaUa, Frondiciihirin, and numerous iso-
lated GUibigerind chambers.
The vast majority of Foraminifera are marine in habit. They occur in
shallow water bordering the coasts, sometimes attached to algae, sometimes
creeping on the bottom. A few genera are extraordinarily abundant in the
open sea, being found at different depths as free-swimming forms, and also on
the floor of the ocean. Enormous quantities of their remains are spread over
vast tracts of the sea-bottom, and down to a depth of 2300 fathoms they
remain an essential constituent of the deep-sea ooze. This is a finely divided
agglomeration of decomposed calcareous substances, such as the shells of
mollusks, corals, bryozoans, coccoliths, radiolarians, diatoms, sponges and
Foraminifera. Of the latter, certain genera are remarkable for their extra-
ordinary abundance (Globirjerina, Orbulina, Pulvinulina, Biloculina) (Fig. 5).
In the Atlantic and Pacific Oceans Globigerina ooze is the prevailing deep-
sea deposit ; in the North Sea, along the coast of Norway, Biloculina ooze.
Numerous limestones and marls of older geological periods exhibit great
24 PROTOZOA— RH I ZOPODA phylum i
similarity in structure and chemical composition to the now forming deep-sea
oozes. White Chalk (Fig. 6) is clearly a variety of abyssal ooze, from which
siliceous constituents have become segregated out, and in which Textnlaria
predominate instead of Globigerina. Certain of the Eocene limestones of the
Paris basin are composed almost exclusively of the tests of Miliolidac, while
others are made up of Alveolinae and Nimimulifes. During the Carboniferous
period the chief role as rock-building organisms was played by Fusnlina.
Many dense, apparently homogeneous, or even semi-crystalline limestones of
various ages, when examined microscopically in thin sections, are seen to be
composed in large part of Foraminifera and other organic bodies (Fig. 7).
Fossil Foraminifera are best preserved, being usually detachable from the
matrix, and at the same time occur most abundantly, in unconsolidated marls
and clays which are interbedded with calcareous strata, or in limestones of a
chalky or earthy character.
The tests of Foraminifera were first discovered by Janus Plancus, in 1730,
on the beach of Rimini, and in the following year they were found by Beccari
in the Pliocene of Bologna. They were long considered to be shells of
mollusks, and were described by Breyn, Soldani, Fichtel, d'Orbigny and
others as Cephalopoda foraminifera, in distinction from Cephalopoda siphonifera.
Dujardin, in 1835, was the first to recognise their true character as belonging
to the Rhizopoda.
Family 1. Gromidae.
Test chitinous with an aperture at one or both ends for the pseicdopodia.
The animals belonging to this family are mostly fresh-water species and
their occurrence as fossils is unknown.
Family 2. Astrorhizidae Brady.
Test composed of agglutinated material for the most part, occasionally with a
chitinous inner layer, consisting of a chamber with several openings or a tubular
test open at both ends ; or in certain forms of a closed chamber with a single
aperture. Throughout the family the test is not divided into a series of chambers.
Recent and veiy abundant at depth. Fossil in Paleozoic and later
formations.
Subfamily A. Astrorhizinae Brady.
Test consisting usually of a tube open at both ends or ivith several tubes entering
a central chamber ; in some species with the tube branching.
The genera Astrorhiza, lihabdatamina, Marsipella, Jiathysiphon and
Bhizammina make up this subfamily. Apparently fossil since the Upper
Jurassic and common in Recent.
Subfamily B. Saccammininae Brady.
Test consisting of a single chamber, or group of superficially attached chambers.
The walls made up for the most part of ((gglufinatrd material ; apertures sometimes
numerous but usually single ; tests free or attached.
ORDER 11 FOEAMINIFERA 25
Saccammina Sars. (Fig. 8). Shell thick, with labyriiithiform interior ;
spherical, pear-shaped or fusiform, with tubular prolongations at one or both
ends ; sometimes united together in chains. Ordovician (Ayrshire), Devonian
(Canada), Carboniferous and Recent. Entire strata of Carboniferous rock
near Elfhills, Northumberland, are built up by S. carteri Brady.
Large-sized species of Astrorhiza, Psammosphaera, Saccammina, Hyperammina,
and Pihahclammina are described by Hausler from the Upper Jurassic (Trans-
versarius beds) of Switzerland.
Thurammina Brady. Test free, monothalamous, irregularly spheroidal,
usually with excrescences or sjiiny processes. Upper Jui'assic and Recent.
Subfamily C. Hyperammininae.
Test consisting of a globular proloculum- and a more or less elongated, some-
times branching portion, but not divided into chambers; free or attached wall
of various agglutinated materials.
The genera Hyperammina, Saccorhiza, Tolypammina, Ammolagena, Jaculella
and Sagenina make up this subfamily. Some of these occur as fossils.
Subfamily D. Ammodiscinae Cuslimaii.
Test composed of a globular proloculum and long undivided tube, closely coiled,
either planospirally or in changing planes or to form a spiral test ; wall of fine
sand with much cement.
Ammodiscus Reuss. Test free, composed of a proloculum and long
coiled tubular chamber. Carboniferous to Recent.
Family 3. Lituolidae Brady.
Test composed of a.gghdinated material for the most part ; consisting of two or
more chambers ; arranged in a linear, coiled or irregular series ; apertures usually
one to each chamber, but sometimes more.
The tests included in. this family all have the wall composed of ag-
glutinated material with a varying amount of cement in the different genera.
Throughout the family as here used the tests are composed of two or more
chambers and a definite proloculum is apparent. Usually the tests are
composed of a series of chambers.
Subfamily A. Aschemonellinae Ciishman.
Test composed of agglutinated material, divided irregularly into chambers toifhout
a definite plan of arrangement.
Subfamily B. Reophacinae Cushman.
Test of agglutinated material, sand grains, sponge spicules, etc., with a varying
amount of cement, chambers in a linear series, aperture single at the distal end of
the last -formed chamber.
lleophax Montfort. Test free, composed of a lineal series of chambers,
26
PEOTOZOA— RHIZOPODA
PHYLUM I
joined end to end in nearly a straight line, curved but not coiled, wall
coarsely arenaceous, chambers undivided, aperture simple and terminal.
Carboniferous to Recent.
Haplostiche Reuss (Fig. 9). Test similar to Beophax but the chaAibers
divided into labyrinthic cavities, aperture in adult made up of several pores
or dendritic. Jurassic to Recent.
Subfamily C Trochamjiininae Brady.
Test composed of several chamhers, either in a planospiral coil, trochoid or other-
wise arranged ; trail composed of sand grains of varying degrees of coarseness
cemented with a ccdcareons or ferruginous cement ; free or attached.
Trochamminoidcs Cushm. (Trochammina Reuss, pars) (Fig. 10). Test free,
composed of several coils, each constricted into a number of chamber - like
portions with large openings between ; wall of fine sand and yellowish-brown
0
A, SiMvainiiiiiin cmirri
Brady. Carboniferous Lime-
stone ; Elfhills, Northum-
berlaiul. i/j. B, Fractured
Fig. 9.
Hdjihisliclie
/((I/ /((itt Schwa-
g e V. U p p e r
Jurassic (Im-
iressa clay) ;
Fi(i. 10.
Fig. 11.
Lititohi (Ihijilo-
FlG. M
jilimuinium) i rreiju-
Placop.Hlliin
/■(istnitu Quenst.
sp. Upper ,) ur-
assic (luipressa
Triichuiiiininn pro-
ti'u.i Karrer. Vienna
sandstone(Senouian); laris Roeiuer. Sea- clay) ; Reiehen-
test, filled with interior cal- Gruibingen, Hiittel dorf, near phiten - Pliiner ; bach, Wurtteni-
cite. "Vj (after Brady). Wiirtteinbers. Vienna. Knindorf, Bohemia. berg.
cement, aperture simple at the end of the last-formed chamber. Lias to
Recent.
Ammohaculites Cushm. {Haplophragmium Reuss, pars) (Fig. 11). Test free,
chambered, early portion close-coiled in one plane, later portion uncoiled and
made up of a more or less linear series of chambers ; wall coarsely arenaceous,
fairly thick ; aperture single, at the centre of the terminal face of the uncoiled
portion, but in the coiled portion at the base of the apertural face. Carboni-
ferous to Recent, particularly abundant in the Jurassic and Cretaceous.
Flacopsilina d'Orb. (Fig. 12). Test rugose, arenaceous, attached, and
divided into pyriform or spherical chambers, Avhich are joined in chains or are
irregularly united. Lias to Recent.
Sublainily D. Neusininae Cusluu;
111.
Test arenaceous with some chitin, broad and fiaftened, of many rliamhers, early
portion coiled, later chambers broad and spreading ; sides with elongated chitinous
filaments.
Here is placed the single recent genus Neusina Goes.
Fig. 13.
Orbitolina eoncava Lam.
ORDER II FORAMINIFEEA 27
Subfamily E. Orbitolininae.
Test siliceous, imperforate, crateriform and composed of concentric annuli which
are partitioned off into numerous chambers.
Orbitolina Lam. (Fig. 13). Test composed of agglu-
tinated sandy particles ; bowl - shaped to depressed
conical ; upper surface convex, lower slightly concave ;
externally smooth or with concentric bands. Test
composed of multilocular rings, the chambers com-
municating with one another on all sides by pores.
The outer portion of each chamber is subdivided by
two secondary partitions disposed at right angles to cenomanian ; Urscheiau,
, , -^-^ '- , -jiT 1 TT Bavarian Alps, a, Inferior
each other. Very abundant in the Lower and Upper surface; 6, Superior sur-
Cretaceous. 0. lenticularis and 0. eoncava Lam. fenLVgedT"''''''' '''^'°°
Family 4. Textulariidae Schiiltze.
Test either arenaceous or calcareous, perforate, the chambers usually numerous,
essentially biserial or triserial, or in some genera spirally arranged.
The family Textulariidae is apparently the most primitive, after the
Lituolidae. A number of the genera are wholly or in part composed of
species with arenaceous tests, which is in itself a primitive character in the
group. In many species both the microspheric and megalospheric forms
are known. In the microspheric form, which repeats most completely the
phylogenetic characters, a coiled early development succeeding the proloculum
is commonly found. This stage may be compared to the entire development
of such a genus as Haplophragmoides in the Lituolidae.
Subfamily A. SriROPLECTiNAE Cuslnnaii.
Test either coarsely arenaceous or ralcareous, or even hyaline, the early chambers
following the proloculum closely coiled, the later chambers biserial, occasionally tending
to become uniserial in the last developed chambers.
This subfamily includes the single genus Spiroplecta Ehrb., which in its
developmental stages connects the Textulariidae with the Lituolidae. Its de-
velopment is primitive in that the stages are seen in both the microspheric
and megalospheric forms of the species, and are of comparatively long duration.
Cretaceous and post-Tertiary.
Subfamily B. Textularinae Brady.
Test typically biserial, early portion in microspheric form often with a few coiled
chambers, followed by biserial ones, later chambers varioicsly modified in different
genera, uniserial, broadly extended, etc. JFall either arenaceous or calcareous and
hyaline, perforate ; aperture single, or in a few cases, many present in a single
chamber.
Textularia Defr. (Fig. 14, A). Test usually elongated, straight, tapering,
or turbinated. Chambers biserial, alternating and communicating with each
28
PEOTOZOA— HHIZOPODA
PHYLUM I
other by means of slit-like apertures. Carboniferous to Recent. Extremely-
abundant in the AVhite Chalk. •
Fig. 14.
A, Textularla glohifnu Reuss. Upper Cretaceous (Senoniau) ; Pattena\ier Stollen, ne;a- Traunstein, Bavaria.
L', BoIU-ina iricrassata Reuss. Upper Cretaceous; Gdtzreuther Graben, near Siegsdorf, Bavaria, r, J'lecunium
<lihl,osum d'Orb. Plioceue ; Sienna, Italy. D, Grammostomum (l-idt:uliiin) (immen d'Orb. Recent; Cuba. E,
'Oaudryhm rugom d'Orb. Upper Cretaceous. Gotzreuther Graben, near Siegsdorf. F, Clavullna communis
d'Orb. Miocene ; Baden, near Vienna.
Bolivina d'Orb. (Fig. 14, B). Test biserial throughout, aperture elongate,
Ffo. 15.
A, BuUmlmi buchlana d'Orb. Miocene (Leitliakalk)
Same locality. C, Climaram;m,ina texttilarijbrmis Miiller.
Xussdorf, near Vienna. B, BiiUmina piipoides d'Ovb.
Carboniferous Limestone; IJugno, Russia. Longi-
tudinal section, ^"/i (after Moller). D, Vlimiwammina pyrifonnh (Miiller). Carboniferous Limestone ; Sloboda,
Rus.sia. 20/j (after Moller). E, yali'iilina .'•2^. Eocene (Calcaire Grossier) ; Grignon, near Paris. F, retnilajis
conica Ehrbg. Carboniferous Limestone; Bachtin, Russia, ao/j (after Moller). G, Ehrenbergina serrata
Reuss. Miocene ; Baden, near Vienna.
usually wider at one end, hyaline in young, thickened -with age.
to Recent.
Cretaceous
ORDER n FORAMINIFERA 29
Clwiacammina Brady (Crihrostomum Moller), (Fig. 15, C, D). Test
arenaceous with calcareous basis. Chambers biserial, rectilinear. Oral aper-
ture jiorous. Abundant in Carboniferous Limestone (cf. Bigenerina d'Orb.).
Subfamily C. Verneuilininae Cushman.
Test at first triserial, later biserial or even uniserial in some genera.
Gaudryina d'Orb. (Fig. 14, E). Test free, early portion triserial, later
chambers arranged biserially, wall usually arenaceous.
Clavulina d'Orb. (Fig. 14, F). Test at first triserial, latest developed
portion uniserial. Eocene to Recent.
Valvulina d'Orb. (Fig. 15, U). Test arenaceous with calcareous basis.
Chambers in triple series arranged in screw-like spiral. Carboniferous to
Recent.
Tetrataxis Ehrbg. (Fig. 15, F). Test calcareous, conical. Alternating
chambers arranged in a turbinate spire. Carboniferous Limestone.
Subfamily D. Bdlimininae Brady.
Test composed of chambers in an elongate spiral, aperture elongate, loop-shaped,
usucdli/ oblique, test calcareotis, hyaline in young.
Bulimina d'Orb. > (Fig. 15, A, B). Test calcareous, the alternating
chambers arranged in an elongated spire. Triassic to Recent.
Subfamily E. Cassidulininae Brady.
Test with the chambers biserial but combined with a spiral or volute arrangement
making a complex test.
Ehrenbergina Henss (Fig. 15, G). Test calcareous, the alternating biserial
segments either completely or only partially coiled. Tertiary and Recent.
Oassidulina d'Orb. Tertiary and Recent.
Family 5. Chilostomellidae.
Test calcareous, finely perforate, composed of numerous chambers, following each
other from the same end of the long axis, or alternately from the two ends, or
in cycles of three.
The genera Ellipsoidina Seg., Chilostomella and Allomorphina Reuss compose
this family. Cretaceous to Recent.
Family 6. Lagenidae Carpenter.
Test calcareous, vitreous, finely perforated, one or more chambers placed in a
straigld line, coiled or variously arranged.
Subfamily A. Lageninae Brady.
Test monothalamous, flash-like.
Lagena Walker (Fig. 16, A). Test single-chambered, spherical, ovate or
flask-shaped, with terminal oral aperture. Silurian to Recent.
30
PROTOZOA— EHIZOPODA
PHYLUM I
Subfamily B. Nodosarinae Brady.
Test either coiled or uniserial, or a modification of one or the other.
Nodosaria Lam. (Fig. 1 6, B). Test rod-shaped ; chambers arranged in
a linear series and set off from one another by constrictions ; oral aperture
round, terminal. Abundant and widely distributed from Silurian to Recent.
Fig. 16.
A, Lagena semhtrlata Williamson. Antwerp Crag (Pliocene); Antwerj). B, Nodosaria npinicusfa d'Orb.
Tegel (Miocene); Baden, ne.ar Vienna, i \ Brntalina rieguiis d'Orh. Same locality. D, CristellariarotulataLia.m.
Scapliiten-PUiner (Tnronian) ; Bohemia. E, i'ayinulina recta Beuss. Neocondan ; Salzgitter, Hanover. F,
LiwjuVuM coitata d'Orb. Tegel (Miocene) ; Baden, near Vienna.
Dentalina d'Orb, (Fig. 16, C). Like the preceding, but test slightly
arcuate. Carboniferous to Recent.
Lingulina d'Orb. (Fig. 16, F). Test rectilinear, compressed; segments
regularly attached ; aperture terminal, slit-like. Trias to Recent.
Glandulina d'Orb. (Fig. 17, A). Test abbreviate, ovate; segments united
in rectilinear series, half embracing one another. General aperture round,
terminal, tubiform. Trias to Recent.
Vaginulina d'Orb. (Fig. 16, E). Test rectilinear, laterally compressed;
segments flattened, with obliquely directed septa. Trias to Recent.
M ar g i n u I i n a
d'Orb. Early portion
arched or helicoid,
later segments recti-
linear. Terminal
aperture slit - like.
Trias to Recent.
Cristellaria Lam.
(Fig. 16, B). Test
regularly planospiral,
with convolutions
completely envelop-
ing one another. Ter-
minal aperture round.
Trias to Recent.
Frondirularia Defr. (Fig. 1 7, D). Test extremely compressed and foliately
expanded in a single plane ; chambers reflexed and laterally embracing one
another. Terminal aperture round. Trias to Recent.
Fio. IT. •
A, (llandidiiia inflata Bornem. Septarienthon (Oligocene) ; Hermsdorf.
]1, Polymorjjliina hijial<i Williamson. Recent ; German Ocean. C, Ditnorpliina
sp. Pliocene; Sienna, Italy. D, Frundicniaria iiohlfitsui, Renss. Scaphiten-
Pliincr ; Diihnen, Westphalia. E, Uvinerlna prjgmara d'Orb. Tegel (Miocene) ;
Baden, near Vienna.
ORDER II
FORAMINIFERA
31
Subfamily (!. Polymorphininae Brady.
Test composed of chambers arranged spirally or irregidarly about the long axis ;
aperture usually radiate.
Polymorphina d'Orb. (Fig. 17, B). Segments irregularly helicoid, or
arranged biserially, more or less enveloping one another and variable in shape.
Terminal aperture round. Trias to Recent.
Dimnrphina d'Orb. (Fig. 17, C). Early chambers irregularly or triserially
arranged, later ones following in rectilinear fashion. Cretaceous to Recent.
Subfamily D. Uvigerininae Cushmaii.
I'est composed of chambers arranged triserially about the long axis ; aperture
usually simple, with a definite neck and a phialine lip.
Uvigerina d'Orb. (Fig. 17, E). Segments dissimilar, disposed in triple
series, and spirally wound like a gastropod shell. Eocene to Recent.
Subfamily E. Eamulininae Brady.
Test composed of chambers with long tubulariform tubes.
Bamulina Rupert Jones. Test branching, consisting of rounded chambers
joined by stolon-like' tubes. Recent, and possibly also represented in the
Cretaceous.
Family 7. Globigerinidae Carpenter.
Test free, calcareous, perforated by coarse tubules ; monothalamous or poly-
thalamous ; chambers globular, either irregularly disposed or imperfectly spiral.
Of the two principal genera belonging to this family, Orbulina d'Orb. (Fig.
18, A) is unilocular, and Globigerina d'Orb. (Fig. 18, 6') is multilocular. The
individual chambers
usually open into a
common central
canal. In both
genera the test is
often covered with
extremely delicate
calcareous spines,
which, however, are
very easily broken
off, and are never
preserved intact in
the fossil state.
Both these genera
are excessively abundant in existing oceans (Globigerina doze) ; they occur
sparingly in the Trias and throughout the Mesozoic, first becoming important
during the late Tertiary.
Sphaeroidina d'Orb. (Fig. 18, B). Characters few, so coiled as to form a
nearly globular test ; aperture with a valvular lip. Cretaceous to Recent.
Fig. is.
A, OrhuUna universa Lam. Pliocene ; Sienna, Italy. B, Sphaeroidina
ausfriaca d'Orb. Miocene Tegel ; Baden, near Vienna. C, Glohlijerina con-
glomerata Schwager. Pliocene ; Kar Nikobar Island, a, Inferior surface ;
'/, Superior surface ; c, Portion of periphery ; il, Transverse section enlarged.
32
PEOTOZOA— RHIZOPODA
PHYLUM I
Family 8. Rotalidae Carpenter.
Test calcareous, perforate, free or adherent, ti/pically spiral at least in the young.
Subfamily A. Spirillinixae Braclj^
Test a fat spiral, without divisions, free or attached.
Spirillina Ehrenberg. Test a planospiral undivided tube, free or attached.
Miocene to Recent.
Subfamily B. Rotalinae Carpenter.
Test calcareous, rarely arenaceous or siliceous, finely or coarsely perforated,
frequently with intermediate skeleton, free or adherent, turbinate or discoidal in
contour. Segments usually arranged in an elongated spire, although in some forms
irregularly disposed.
Discorbina Parker and Jones (Fig. 19, A, B). Test coarsely perforated,
Fio. 111.
A, Discorbina (Asterigerina) planorbis d'Orb. Miocene (Leithakalk) ; Nussdorf, near Vieuna. B, Discorbina
sp. Recent, a, Under side ; b, Upper side ; c, Lateral view ; d. Median section. '/, VlanorJmlina mediter-
ranensis d'Orb. Recent ; Mediterranean, a, Inferior surface ; b, Superior surface ; c, Transvei'.se section.
turbinoid ; lower surface broad and Hat ; umbilicus often filled with deposit
of intermediate skeleton. Cretaceous to Recent.
(■ D
Fig. 2t).
A, Rotalia beccari Lin. Pliocene: Sienna, Italy. B, ridvlnuUna jiartschi d'Orb. Miocene (Tegel) ; Baden,
near Vienna. C, Kiidolhurn ilnnderi Miiller. Carboniferous Limestone; Russia. '-O/i. D, Endvthyra piirm
Moller. Lower Carboniferous ; Russia. Longitudinal section, lof/j.
PlanorbuUna Parker and Jones (Fig. 19 C). Test coarsely perforated, com-
planate, usually attached, upper and lower surfaces dissimilar : early segments
ORDER II FORAMINIFERA 33
arranged in a depressed spire, subsequently becoming cyclical. Lias to
Recent. Various subgenera, named by d'Orbigny Tnmcatulina, Anomalina,
Planulina, etc., are based upon slight modifications in form.
Rotalia Lam. (Fig. 20 A). Test finely perforated, with segments in turbinoid
spire. Septa composed of two slightly separated lamellae, with anastomosing
canals occupying the intermediate space. Base often thickened by supplemental
skeleton. (?) Silurian. Upper Jura to Eecent.
Pulvimdina Parker and Jones (Fig. 20 B).
Rotaliform, but septa simple without being per-
forated by a canal system. Lower Lias to Recent.
Endothjra Phill. (Fig. 20 C, D). Test cal-
careous, composed of an external coarsely per-
forated and an internal compact layer, the latter
finely granular ; segments numerous, coiled in
an irregular spiral, terminal chamber opening by yig. -n.
several apertures. Abundant in Lower Carbon- caicarina mhntmpoides Lam. upper
iferous, and existing at the present day, ac- S'^tianT" (^""'^'"'^^'^^^ = Macstricht,
cording to Brady.
Caicarina d'Orb. (Fig. 21). Test discoidal, with dissimilar upper and lower
surfaces ; chambers spirally coiled. Exterior encrusted with a supplemental
skeleton which fills up all depressions and forms spinous or spur-like processes
traversed by coarse .canals. Upper Cretaceous to Recent ■ very abundant in
Maestricht Chalk.
Sulifjuuily C. TiNOPORlNAE Brady.
Test of irregularly massed chambers, the early ones more or less distinctly spiral
in their arrangement, nsxially loithout a general aperture.
Tinoporus Montf. Patellina Williamson.
The Recent genera Carpenteria Gray, Eupertia Jones, etc., are distinguished
by their extremely irregular, coarsely perforated and usually adherent tests,
which sometimes attain considerable size and often contain agglutinated,
sandy or various other foreign particles. Thalamopora Roemer, occurring in
the Cretaceous, probably also belongs to this subfamily.
Family 9. Nummulitidae.
Test calcareous, finely tubulated, polythalamous, free, spiral, usually bilaterally
symmetrical.
Subfamily A. Fusulininae Brady.
Test fusiform or subglobular chambers extending from pole to pole, each convolu-
tion completely covering the preceding whorls.
Schwagerina Moller. Test spherical, finely perforated. Primary and
secondary septa simple, thin, straight ; secondary chamberlets communicating
with the next following principal chamber by means of a basal aperture.
Abundant in Lower Carboniferous rocks of Japan, China, Sumatra, North
America and Russia.
VOL. I D
34
PEOTOZOA— RHIZOPODA
PHYLUM I
Fusulina Fischer (Fig. 22). Test fusiform, laterally elongated like
Alveolina, coarsely perforated. Septa of principal chambers undulating, and
D
^S^'i
Fig. 22.
A, Fusulmn ciilindrica Fisch. Carboniferous Limestone : Sarani.sk, Russia. Natural size. B, C, Same
species showing various cross-sections enlarged. D, Enlarged section showing chambers communicating by
means of foramina (n, b).
united so as to form secondary chamberlets. Excessively abundant in
the Lower Carboniferous of Europe (Russia), Asia and North America.
Fig. 23.
Polydomdla crispa Lam.
Pliocene ; Sienna, Italy.
(Highly magnified.)
Subfamily B. Polystomellinae Brady.
Test Ulaterally symmetrical, nautiloid, the more complex
specimens with a well-developed secondary canal system.
Polystomella Lamarck (Fig. 23). Test regular, equi-
lateral, nautiloid, final whorl alone visible from the
exterior. Jurassic to Recent.
Subfamily C. Nummulitinae Brady.
Test lens-shaped or flattened, higher forms with complex secondary caned system.
Archaediscus Brady. Test lenticular, unsymmetrical, spirally coiled. The
segments irregularly constricted and expanded so as to form chambers. Septa
and canal-system wanting. Lower Carboniferous.
Fig. 24.
A mphistcgiiia hauerl d'( )rb.
Miocene (Leithakalk); Nuss-
dorf, near Vienna, a, Exterior
views, enlarged ; /), Natural
size ; c, Median section,
greatly enlarged ; d, Trans-
verse section, greatly en-
larged.
Fig. 25.
Opereuliiia compluntda (Bast.). Miocene; Bor-
deaux, a, Natural size ; b, c, Median and longi-
tudinal sections, greatly enlarged.
Pig. 20.
Heterosti'dina costata
Miocene (Leithakalk) :
dorf, near Vienna.
d'Orb.
Nuss-
Amphistegina d'Orb. (Fig. 24). Test lenticular, slightly inequilateral,
spirally rolled. Whorls divided into chambers by numerous single septa in
ORDER II FORAMINIFERA 35
which canals ai'e not present; solid wedge-shaped deposit of intermediate
<'&«^, „\^
Fig. 27.
a d
Nummulifes r.fr. luaisanus Dfr. Eocene ; Kressenberj^, Upper Bavaria. Several times enlarged.
a, Mari;inal cord with canal-system ; h, Septal plane with interseptal canal-system ; c, Interior of chamber ;
(I, Finely perforate periphery ; e, Small pillars of intermediate skeleton.
skeleton near the umbilicus. On one side the volutions completely enclose
one another as far as the centre, on the other they overlap
only partially by means of alar prolongations extending in-
wards. Chambers communicate with each other by means
of a slit along the basis. Miocene to Recent. Particularly
abundant in Miocene.
Operculina d'Orb. (Fig. 25). Test discoidal, complanate,
composed of three to six rapidly expanding spiral whorls,
which are polythalamous and non-involute. Septa and
marginal cord traversed by a direct canal-system, which gives
off numerous branches. Cretaceous to Recent. Particularly
abundant in Eocene.
Heterostegina d'Orb. (Fig. 26). Like Operculina, but with chambers sub
divided by secondary septa into chamberlets. Tertiary and Recent.
Fig; 28;
Nummulites (Assi-
Una) exjmnens Sow.
Eocene ; Pyrenees.
C 3 c 1 2 Fig. 29.
A '^~, Nummulites (jizchcnslsEhThg. Eocene; Libyan Desert. Natural size. .4 =*, Specimen with eroded peri-
pheral portion, showing arrangement of septa. i}i2, Nummulites laevigatus Lam. Calcaire Grossier ; Paris.
Natural size. B3, Portion of same enlarged. 6'i2j Nummulites ramondl Defr. Eocene (Nummulitic lime-
stone) ; Pyrenees. Natural size. C'3, Enlarged section.
Nummulites Lam. (Phacites Blumenb. ; Lenticulites Lam.) (Figs. 27-29). Test
36
PEOTOZO A— RHIZOPODA
PHYLUM I
symmetrically lenticular or discoidal, composed of numerous spirally arranged
polythalamous volutions, and usually with columnar intermediate skeleton,
which forms small excrescences on the periphery. The septa and marginal
cord contain a coarse, anastomosing canal-system, as in Operculina. Primordial
chamber spherical, sometimes large, sometimes exceedingly minute in size.
The whorls either merely embrace one another {Assilina) (Fig. 28), or they
completely envelop one another by means of alar prolongations reaching
inwards to the centre (Nwrnnulina).
The septa are pierced in the median
plane by an oblique slit-like aper-
ture, and also extend into the saddle-
shaped alar prolongations of the
chambers. They are directed in
the groups Eadiatae and Stria fae in
straight or slightly curved lines
(Figs. 27 and 29, C) ; in the
Simiafae they follow meandering
courses (Fig. 29, A) ; and in the
Eeticulatae (Fig. 29, B) they form
Pjq 3q an interlacing network by means
A, Nummnlitic limestone with horizontal sections of oi Connecting prOCeSSCS. The rami-
N cUstans Fusch Peyrehorade, in the Pyrenees. B, fications of these lateral prOCeSSCS
Nummnlitic limestone showing sections of N. lucasanus _ -i
Defr. zakophane in the Carpathians. ( Jilet cloisomiaire) may be readily
seen on fracturing a portion of the
test, and are a valuable aid in the determination of species. The oldest
Nummulites {N. pristinus Brady) occur very sparsely in the Carboniferous
limestone and Upper Jurassic, but are distinguished from the typical later
forms by the absence of an interior canal-system in the marginal cord. The
typical Nummulites which are so characteristic of the Eocene (Nummnlitic
limestone) in Europe, North Africa, Asia and Central America, often build up
massive formations. The largest species (iV. gizehensis Ehrbg., N'. orhiculatus
Schafh.) attain a diameter of 60 mm. ; the smallest species does not exceed
2 mm. ; recent representatives comparatively scarce.
Subfamily D. Cycloclypeinae Brady.
I'est flat with a thickened centre, or lens-shaped, consisting of a disc of chambers
arranged in concentric annuli with peripheral thickenings, septa double with inter-
septal canals.
OrUtoides d'Orb. (Hymenocyclus Bronn ; Lycophrys Monti.) (Fig. 31). Test
discoidal, with circular or stellate contour, often bent, exterior smooth or with
radial striae, and composed of numerous concentric annuli disposed about a
primordial spiral of three to five whorls. The rings are divided by transverse
partitions into small rectangular chambers, and the septa and marginal cord
are traversed by canals. Superimposed over the median series of principal
chambers on both sides are several layers of flattened secondary chamberlets,
which are likewise disposed in concentric rings. Very abundant in the Eocene,
associated with Nummulites ; rare in Upper Cretaceous and Miocene.
Cycloclypeus Carp. Miocene and Recent.
ORDER II
FOEAMINIFEEA
37
Dawson, Carpenter and various other authors have referred the so-called
Eosoon occurring in crystalline limestone of the Archaean (Laurentian) period
to the Foraminifera ; but the elaborate investigations of Mobius have shown
"'''•« in, Ita n. del.
Fic. 31.
A, Orh'tto'uhs papyraeta Boubee. Eocene (Perniginous sandstone) ; Kressenberg, Upper Bavaria, (Greatly
enlarged), i Median chambers ; ~ Lateral chambers ; ■i Compacc pillars of intermediate skeleton. B. Portion of
median transverse section, liighly magnified; -Lateral chambers with perforate walls; "i Canal - system of
cyclical marginal cord ; s Tubules connecting adjacent chambers. C, Periphery and profile of same, natural
size. D, OrhitoUles tencUa Giimbel. Eocene ; Kressenberg, (Natural size). E, OrhUoides variecostata Giinibel.
Eocene ; San Martino, near Verona. (Natural size.) F, OrhUoides eiihippium Sow, Eocene ; Kressenberg,
(Natural size.)
that neither Eozoon nor Archaeosphaerina can be regarded as organic structures,
being merely mineral segregations.
Family 10. Miliolidae Carpenter.
Test of one or more chamhers, calcareous and porcellanons, sometimes covered with
sand, usnally imperforate, hut in some forms with the early chambers distinctly
perforate.
Subfamily A. Cornuspirinae Cushman.
Test planospiral, usually of a prolocidum and long coiled
single chamber.
Cornuspira Schultze (Fig. 32). Test composed of numer-
ous piano-spiral convolutions ; oi'al aperture simple, terminal;
monothalamous. Lias to Kecent.
Pi(i. 32.
Cornuspinx polygyra
Reuss. Oligocene ;
Hungary.
Subfamily B. Nubeculariinae Brady.
Test irregular and asymmetrical, the apertures variously placed.
Nubecidaria Defrance. Test at first coiled, later tubular or irregular ;
attached. Liassic to Recent.
38
PEOTOZOA— RHIZOPODA
PHYLUM I
Subfamily C. Hauerininae Brady.
First-formed part of test Cornuspira-like, later chambers spiral or otherwise
arranged, apertures single.
Ophthalmidium, Kiibler. Early chambers like Cornuspira, later ones two
or more to a convolution. Liassic to Recent.
Hauerina d'Orbigny. Early chambers Milioline, later ones planospiral with
two or more chambers to a convolution. Cretaceous to Recent.
Subfamily D. Miliolinae Brady.
Test at first spiral, then each whorl divided typically into two chambers, later
chambers more numerous in the whorl or uniserial.
Miliola Lam. (Figs. 33, 34). Chambers disposed in coil -shaped loops
about a few spirally wound primordial chambers. Each chamber in the
A Jl
Fig. 33.
A, Bilondina inornnta d'Orb. From tlie Miocene Tegel ; Baden, near Vienna. B, Trilnculina gUilm d'Orb.
Oligocene sand from Astrupp. C, Spirnloculinn hadetisii d'Orb. Miocene Tegel ; Baden, near Vienna. D, Quin-
queloruUna auxoruw d'Orb. Eocene (Calcaire Grossier) ; Grignon, near Paris.
adult forms a half coil. Terminal pseudopodial aperture either curving
in the form of a crescent about a tooth-like projection, or branching den-
dritically (Lacazina). Forms having all the segments disposed in a single
plane, and all externally visible, are grouped together in the genus Spirolocu-
lina d'Orbigny ; with all the segments completely enveloping one another,
Biloculina d'Orb. ; segments disposed in three or in five diiTerent planes,
Miliolina Will. ( = Trilocu-
•= =^ Una and Quinqueloculina
d'Orb.). The great variety
and profusion of these
genera combine to
them some of the
important of the
building Foraminifera.
Massive beds of Eocene
limestone (Paris basin,
Pyrenees) are made up of
Miliola remains ; at the
present day calcareous
deposits are being formed
by Biloculina in the North Sea west of the coast of Norway. Miliola first
makes its appearance in the Trias, and attains its maximum development
in the Tertiary and Recent periods.
Fio. 34.
A, Longitudinal section of
Biloculina inornata d'Orb.
(enlarged). B, Transverse
section of Quinqueloculina
saxorum d'Orb. (enlarged).
make
most
rock-
FiG. 3S.
Fabularia dis-
colithcs Defr.
Eocene (Calcairo
Grossier); Paris.
Fio. 36.
Vertehralina wm-
cnmata d'Orb.
Recent ; Mi'di-
terranean.
ORDER II
FORAMINIFEEA
39
Fabularia Defr. (Fig. 35). Like BUoculina, but relatively larger. General
aperture cribriform ; chambers not an empty cavity, but filled with porcell-
anous or calcareous matter, and perforated by numerous anastomosing canals
which are directed parallel with the axis of convolution. Abundant in the
Eocene of the Paris basin.
Vertebralina d'Orb. (Fig. 36). First-formed portion of test consisting of
coil-shaped loops, the segments afterwards becoming joined in rectilinear
series. Tertiary and Recent.
Idalina Schlumb. Last -formed chamber completely enveloping all pre-
ceding ones. Cretaceous.
Subfamily E. Peneroplinae Brady.
Test planospiral or cyclical, and bilaterally symmetrical ; apertures many.
Peneroplis Montf. (Fig. 37). Test discoidal, complanate, polythalamous ;
direction of growth primarily spiral, gradually becoming rectilinear, while
rapidly increasing in width. Septa perforated by numerous pores. Tertiary
and Recent.
''^'EWM
^Ei
aS^
Fid. 37.
PeiicroplU plawitus
Montfort. Rpccnt ;
Mediterranean.
Fig. 38.
Orhicul ina nummi.f-
malis d'Orhigny. Plio-
cene ; Sienna, Italy.
Fir.. 39.
A, OrhitoUfcs complanafa Lam. Eocene (Cal-
caire Grossier) ; Paris. B, Portion of same en-
larged.
Orbiculina Lam. (Fig. 38). Test discoidal, first -formed portion spiral,
afterwards becoming annular ; polythalamous ; septation regular, chambers
subdivided ; septa and walls of segments perforate. Tertiary and Recent.
Orbitolifes Lam. (Fig. 39). Test discoidal, circular in outline, both surfaces
slightly concave in the middle, attaining comparatively lai'ge size, and com-
posed of segments which are arranged concentrically about a few spirally
coiled primordial chambers. Septa radially disposed, and perforated by
symmetrically placed pores. In the more complicated forms the principal
segments are invested with a superficial multilocular layer, the chambers of
which are also arranged in concentric rings and communicate with the
principal segments by means of pores. An important rock-building genus,
ranging from the Lias onward. 0. praecursor and 0. circumvulva Giimbel are
Jurassic, 0. macropora d'Orb. Cretaceous, and 0. complanata Lam. Tertiary
species.
Subfamily F. Alveolininae Brady.
Test spiral, elongated in the direction of the axis of coiling ; chambers divided
into secondary chamberlets.
Alveolina d'Orb. (Borelis Montf.) (Fig. 40). Test fusiform, elliptical or
spherical, usually elongated in the axis of convolution, and composed of
40 PROTOZOA— EHIZOPODA phylum i
spirally wound segments which completely envelop one another. Each seg-
ment is partitioned off into long, narrow chambers by septa arranged at right
angles to the axis, and these are subdivided into chamberlets by a second
set of septa running transversely to the first set. Each of the secondary
chamberlets communicates with the adjacent primary chamber by means of a
single round aperture. In
certain Recent species the
secondary chamberlets are
also subdivided. The
genus begins in the Ceno-
manian, continues in ex-
^^'■- ^'^- traordinary profusion, and
^it>eoHwr/|o.srfa'Orb. Eocene (Calcaire Grossior) ; Paris. -^.Frontal becOmes a mOSt important
aspect. B, Test laid open so as to sliow contormation of mteruir ; . . i
considera»)iy enlarged. rock-builder in the Eoceue.
It is especially abundant
in the Calcaire Grossier of the Paris basin, the Alveolina limestone of Istria,
Dalmatia, Greece and the Libyan Desert.
Subfamily G. Keramosphaerinae Brady.
Test spherical, chamhers arranged in concentric layers.
Keramosphaera Brady. Test spherical, chambers more or less irregular,
in concentric layers. Recent.
Range and Distribution of Fossil Foraminifera.
More than 2000 species of Foraminifera have been described, of which
number about two-thii'ds are known in a fossil state. The longevity of
certain genera and species is remarkable, many of them persisting, according
to Parker, Jones, Brady and others, throughout a number of formations of
various ages.
The earliest forms occur very sparingly in the Silurian of St. Petersburg,
Siberia and Scotland. They are for the most part poorly preserved, those
from Petersburg being recognisable only as glauconitic casts, belonging in
part to siliceous shell-bearing genera (Placopsilina, Saccamina), and in part to
vitreo-perforate genera (Nodosaria, Lagena, Glohigerina, Botalia). The Devonian
is also very poor in Foraminifera remains ; but, on the other hand, the Carboni-
ferous yields an abundant and considerably varied fauna ; in fact, certain
genera (Fusulina, Schwagerina, Saccamina, Endothijra) build up limestone de-
posits occasionally of great thickness. Numerous representatives of the
Lagenidae {Nodosaria, Dentalina, etc.), Textalariidae, Eotalidae, and even the
Nummiditidae accompany the rock-building forms, and continue for the most
part throughout the Permian. Except in the Alps, the Triassic is almost
destitute of Foraminifera, and even the pure limestones and dolomites of the
Alpine Trias have usually become so altered by metamorphism as to render
the recognition of tests wellnigh impossible. Notwithstanding, Globigerina
limestone has been discovered in the Upper Triassic of the Northern Alps,
and tests of Crisfellaria, Margimdina, Glohigerina, Tcxtularia, Biloculina, etc., are
found in the St. Cassian beds.
Certain argillaceous and calcareous strata of the Lias and Jura contain
vast quantities of minute, vitreo-perforate or siliceous Foraminifera. In the
ORDER III
EADIOLARIA
41
Cretaceous, Textularia, Botalia, Cristellaria, Glohigerina, Miliola and coccoliths are
essential constituents of the White Chalk. Individual beds of the Maestricht
Chalk consist almost entirely of Calcarina remains ; in the Urgo-Aptian Orhi-
tolina is the chief rock-builder ; in the Upper Cretaceous Alveolina.
The maximum development of the Foraminifera occurs in the Tertiary
period. Massive beds of the Eocene Calcaire Grossier of the Paris basin and
in the Pyrenees are composed of Miliolidae remains ; other Eocene limestones
consist of Alveolina, Operculina, Orhitolites and OrUtoides aggregations. But of
far greater geological importance are the NummuUtes, which occur in incredible
abundance in the Eocene and Oligocene Nummulites-formations of the Medi-
terranean district, Asia Minor and Eastern Asia.
During the late Tertiaiy the NummuUtes almost entirely disappear ; only
Amphistegina continues as an occasional rock-builder, and from the middle
and later Tertiary on, the Foraminifera fauna remains very nearly the same
as now.
Table showing Geological Eange of the Foraminifera
Families
3
c
.S
'H
o
>
Q
2
c
O
g
3
>-5
3
O
<p
6
1
>>
u
H
a
Gromidae
Astrorhizidae
Lituolidae
Tcrdulariidae
ChilostomeUidae
Lagenidae
GJohigerinidae
Rotalidae
Nummulitidae
Miliolidae
1
1
j
1
[Tlie foregoing chapter on Foraminifera has been revised for the present work by Dr.
Joseph A. Ciishiiian of the Boston Society of Natural History, Boston, Mass. — Editor.]
Order 3. RADIOL ARIA Muller.^
{Fohjcystina Ehrenberg. )
Marine Bhizopoda emitting fine, filiform, radially directed pseudopodia, tvith
central capsule and extra- cap sidum, and usually with delicate siliceous skeleton.
The sarcode body of the Radiolarians is differentiated into (1) an inner
central sphere or capsule of tough gelatinous-like protoplasm containing one or
^ Literature : Ehrenberg, O., Mikrogeologie, 1854 ; also memoirs on Radiolaria from Barbados,
in Abhandl. Akad. Wiss. Berlin, 1872, 1875.— HaecM, E., Die Radiolarien, 1862.— /c^ewt, Report
on tile Radiolaria, in Scient. Results Challenger Exped., Zool., vol. xviii., 1887.^ — Hertwig, R., Der
42
PROTOZOA— RHIZOPODA
PHYLUM I
more nuclei, vacuoles, alveoles, granules, oil -globules and sometimes crystals
and surrounded by a capsule-membrane perforated by pores or pylae ; and
(2) an outer jelly-like extra-capsulum, the sarcode of which emits pseudopodia.
The individuals lead usually an isolated existence, and are only rarely united
in colonies.
Most Eadiolarians secrete skeletons composed of either bars or spicules of
acanthine (an organic substance allied to horn or chitin) or silica, or they build
an exceedingly delicate lattice-work composed of transparent amorphous silica.
Only the latter forms are known in a fossil state, and owing to their minute
size, are commonly indiscernible except with the aid of the microscope.
Haeckel divides the Radiolaria into four suborders, as follows : —
A. Acantharia. — Capsule-membrane uniformly perforated ; skeleton com-
posed of acanthinic spicules. Unknown in fossil state.
B, Spumellaria. — Capsule-membrane single, pores distributed all over;
skeleton siliceous, spherical or discoidal, sometimes wanting (Fig. 43).
Fio. 41.
Silurian and Devonian Radiolarians : A, Cenospliaera macro'pora Rlist. Ordovician ; Cabrieres, Langiiedoc.
B, Stiiuriilonche micTopora, Rlist. Ordovician ; Cabrieres. C, Caryosphaera groddecld Riist. Upper l)e\'onian ;
Schiibenholz, near Elbingerode, Harz Mountains. D, Lithocampe tschernytschewii Riist. Devonian ; Ural.
Magnified 100 to 120 diameters (after Riist).
C. Nasselaria. — Capsule-membrane single, perforated only about the oral
pole ; skeleton siliceous, helmet- or cap-shaped, conformation of poles dissimilar
(Figs. 44, 45).
D. Fhaeodaria. — Capsule-membrane double, perforated by one main opening
prolonged into a tubulus, and by a few smaller accessory openings. A dark
pigment body (phaeodiuni) constantly present in extra-capsular sarcode. Skeleton
commonly consisting of hollow siliceous spicules disposed in flask-shaped or
variously shaped frameworks. Unknown in fossil state.
Radiolarians are exclusively marine organisms, and are found at all bathy-
metric zones. They occur in vast numbers, especially in tropical seas,
swimming on the surface, as well as at medium and even abysmal depths.
Particularly between 2000 and 4000 fathoms in depth, extensive deposits of
" Radiolarian mud " have been found, the composition of which is largely silica
with a small percentage of carbonate of lime.
Organismus der Radiolarien. Jenaische Denkschr., 1879, vol. ii. — Stohr, E., Die Radiolarieii- Fauna
von Grotte in Sicilieu. Palaeoiitogr., 1880, vol. xxvi. — Rust, D., Radiolarien aus Gesteinen des
Jura. Palaeoutogr., 1885, vol. xxxi. — Idem, op. cit., vols, xxxiv. xxxviii. and Iv. — Dreycr, F., Die
Tripoli von Caltanisetta. Jenaiselie Zeitsclir. f. Naturvv., 1890, vol. xxiv. — Cayeux, L., Les Preuves de
I'existence d'organismes dans le Precambrien. Bull. Soc. Geol. France, 1894, vol. xxii. — Vinussa
de Regny, P. E., Radiolarie delle flaniti titoniane di Carpena (Spezia). Palaeont. Italica, 1899, vol.
iv. — Hinde, G. J., Radiolaria in Devonian Rocks of New South Wales. Quart. Journ. Geol. Soc.,
London, 1899, vol. Iv. — Idem, Radiolaria from the Triassie of the Dutch East India Archipelago.
Jaarl). Mijnwezen Nederl. Ooost India, 1908, vol. xxxvii. — Squinahol, S., Radiolarie eretacce degli
Euganee. Padova, 1904. — Princqd, P., C'ontributo alio studio dei radiolari niiocenioi italiani.
Boll. Soc. Geol. Ital., 1910. vol. xxviii.
ORDER III
RADIOLAEIA 43
The diversity of form exhibited by Eadiolarians is very remarkable, and
.1 /; c D
Fro. 42.
Carboniferous, Jurassic, and Cretaceous Radiolarians : A, Stauracontium inaequah RUst. Carboniferous ;
Sicily. B, Troehodiscus nicholsovi Riist. Carboniferous ; Harz. C, Xiphmlictya acuUi Riist. In coprolite
from Lias ; Ilsede, Hanover. D, Hyinenvutrum rotiindum Rust. In coprolite from Cretaceous ; Zilli, Saxony.
the identification of their microscopic siliceous skeletons is impossible without
the aid of special literature. Contrary to formerly current ideas, the geological
antiquity of the
Radiolarians is very
great ; and they also
play an important
part m
position
siliceous
the com-
of many
and cal-
careous-siliceous
rocks (quartzites,
hornstone, jasper,
phyllites, Aptychen-
schiefer, etc.). Ac-
cording to Barrois
they are the oldest
known animal or-
ganisms, since the
Spumellaria (Mono-
sphaeroidae) occur
plentifully in the
bituminous quartz-
ites of Brittany,
interbedded with
pre - Cambrian
gneiss.
Although the
group is still very
imperfectly known,
yet, according to
Riist, fossil Badio-
laria are by no
means less abundant and
Recent and Tertiary Spumellarians : A, Actinomma (isteracanthium Haeck.
Recent; Messina. B, Stylodictyaimdti.^pina "Hueck. Recent ; Messina. C, Helio-
disaus humboldti Elirbg. Barbados eartli (Miocene) ; Barbados. D, Haliomma
dixiphos Elirbj^. Miocene marl ; Caltanisetta, Sicily. E, Astroinvin aristutelis
Ehrbs. Miocene ; Barbados.
less diversified than the Becent. Only in exceptional
44.
PROTOZOA— EHIZOPODA
PHTLUM I
instances (Miocene of Barbados, Oran, Sicily) have
unaltered, and still consist of amori^hous silica. I
has usually become dissipated in the matrix, being
iron, or some colouring agent ; in other cases the
Pio. 44.
Recent and Tertiary Nasselarians : A, Podocyrtis schomburgki Ehrbg.
Tertiary marl; Barbados. B, Cyrtocalpis amphora Haeclv. Recent;
Messina. C, ISothnjocainpe liexathahvniia Haeck. Recent; Mediterranean.
D, Pdalospyris fuveolata Mhrhg. Tertiary marl ; Barbados.
the skeletons been preserved
n the older rocks the silica
replaced by lime carbonate,
quartz has become crypto-
crystalline, or replaced by
a calcite pseudomorph.
The Cambrian GrifFel-
schiefer of Sonneberg in
Thuringia contain poorly
■ preserved Sphaeroidea ; the
usually dark, though some-
times red or light-coloured
Ordovician strata of Lan-
genstriegis in Saxony, and
of Rehau and Steben in
Franconia, the red jasper
of Abington, Scotland,
and the Ordovician sili-
ceous rocks of Cabrieres
in Languedoc, are more or
less rich in Radiolarian
remains belonging exclusively to the Spumellaria (Fig. H, A, B).
From the Devonian jasper of Siberia, the siliceous schists of Hesse and
Nassau, and the manganiferous quartzite of Elbingerode in the Harz, and
other places, Riist has described forty-six Spumellarian species and seventeen
Nasselarian (Cyrtoidea). The Lower Carboniferous quartzites, phyllites,
adinole and jaspers from the Harz (Culm formation), Ural district and Sicily
have yielded 155 species, of which thirty-six belong to the Nasselaria. In
general the Paleozoic Kadiolarians are remarkable for their relatively large
size and excellent preservation.
The Triassic appears to be destitute of Radiolarians except in the Alps,
where they are abun-
^ AT*
D
E
dant in the hornstone
and siliceous lime-
stone of the Buchen-
stein beds of Hungary,
and occur less fre-
quently in the Rei-
fling limestones, in
the Wengen beds of
Storzic in Carniola,
in the marls of St.
Cassian, and in the
siliceous limestone of
the Rothelstein, near Aussee, etc. They are usually associated here with
the remains of Sponges and Foraminifera. In the silicified coprolites of
the Lias, found at Ilsede, Hanover, Radiolarians are very common; they
are somewhat less frequent in the limestones of the Lower Lias on the
Schafberg in Upper Austria. Certain hornstone beds of Middle Jurassic
age, found at Piszke, Hungary, the Upper Jurassic pudding-stones of
Fifi. 45.
Tertiary Nasselarians from Barbados : .-I, Antlwcyrtis mespilus Elirbg. B,
Lychnocaniu7)i hiceriia Ehrbg. C, Diclyomitramovfgdljieri Elirbg. D, Eucyr-
tidium degans Ehrbg. E, Ptcrocodon campana Ehrbg.
ORDER III RADIOLARIA 45
Cittiglio, near Laveno on Lago Maggiore, and numerous Tithonian jaspars, as
well as the Alpine Aptyclius beds, are charged with Radiolarians ; here the
Nasselaria are nearly as plentiful as the Sjnimellaria. The Lower Cretaceous
(Neocomian) of Gardenazza has yielded but few forms. On the other hand,
coprolites from the Gault, found near Zilli in Saxony, and Lower Cretaceous
clay marls in Manitoba, Canada, as well as from Upper Cretaceous marls of
Haldem in Westphalia, and Vordorf in Brunswick, contain excellently preserved
skeletons in greater or less abundance. Even the flinty concretions of the
Upper Chalk sometimes contain them, although in a poor state of preservation.
Certain Eocene hornstones in Italy, according to Pantanelli, are filled with
Radiolarian remains, while in the Flysch they are also very profuse in some
localities, although usually poorly preserved.
By far the most noted occurrence of fossil Radiolarians is in the siliceous
" Barbados earth," of Miocene age, in which Foraminifera are also very con-
spicuous ; while the " tripoli " of Grotte, Caltanisetta and Girgenti in Sicily,
of Oran, Aegina, Zante, the Nikobar Islands and other localities (Miocene and
Pliocene), is scarcely less noteworthy. Ehrenberg has described 278 species
from Barbados alone, and from Sicily Stohr has described 118 species, most of
which belong to still extant Spumellarian, Nasselarian and Phaeodarian genera.
Phylum II. COELENTERATA.
CoELENTERATES 01" Zoophytes are free-swimming or attached aquatic animals
of very variable form and size. They diflfer from the Protozoa in having
multicellular bodies with distinct organs ; and from all higher classes in the
absence of a definite body-cavity. In the subphylum Porifera there is a
simple or usually complex system of digestive sacs, with inhalent pores in the
body wall and one or many exhalent pores or oscula, and no stinging cells or
tentacles. The two other subphyla, Cnidaria and Ctenophora, exhibit a more
or less pronounced radial symmetry, have no inhalent pores and no special
exhalent opening in the body wall, but a large mouth opening conducts into a
gastrovascular cavity. Food is taken in and the excreta and sexual elements
are voided through the mouth opening. Stinging. cells and usually tentacles
are present in the two last-named divisions.
The body consists of two layers of cells — an ectoderm and entoderm —
and usually also a third layer, the mesoderm. The ectoderm in the Cnidaria
often secretes a calcareous or horny skeleton, but in the Porifera the horny,
siliceous or calcareous skeletal elements are the product of the mesoderm.
Reproduction is either sexual or asexual, or, in the Hydrozoa, an alterna-
tion of generations may occur. The process of budding or self-division gives
rise to polyzooid colonies, in which the zooids subsist in intimate relationships
with one another, and sometimes institute a physiological division of labour.
R. Leuckart was the first to recognise the Coelenterates as constituting a
distinct structural type of animals and separated them from the Echinoderms,
with which the older systematists had associated them under the general term
of Radiates or Actinozoa. The Coelenterates are divided into three principal
groups or subphyla : Porifera, Cnidaria and Ctenophora. Of these only the first
two have skeletons and have left traces in the rocks.
Subphylum I. Porifera Hogg.
The Porifera or Sponges are sessile, aquatic animals of extremely variable
form. The body consists of a single layer of pavement-cells forming the
ectoderm, a single layer of collared epithelial cells constituting the entoderm,
and usually a strongly developed mesoderm, which latter comprises the bulk of
the soft parts (including all the organs, muscles, sexual elements and nerves),
and almost invariably secretes a hard skeleton. The latter may consist of
horny sponge-fibres, or of regularly disposed siliceous or calcareous skeletal
elements. The whole body is ramified by a canal-system, and the outer
epithelial layer is perforated by countless minute, dermal pores for the entrance
of water ladeu with food-particles. The pores communicate by means of fine
46
CLASS I SPONGIAE 47
iiicurrent canals with subdermal ciliated chambers, from which larger excurrent
canals conduct the water and food or excreta through the body, and generally
open into a wide, exhalent opening called the cloaca or paragaster. Stinging
cells, tentacles and radial mesenteries are absent. The Porifera comprise but
one class, the Sponges.
Class 1. SPONGIAE. Sponges.^
Sponges are remarkable for their extreme variability in external form
and size ; they lead either an isolated existence, or are united in colonies of
cylindrical, tubulate, pyriform, fungus-like, bulbous, spherical, compressed,
foliate, umbel-, bowl- or beaker-shaped, or of botryoidal form. They are long-
or short-stemmed, or a peduncle may. be absent ; sometimes the stock is
branching, and the arms may be either separate or interlaced so as to form
networks. Nothing is less stable than the outer conformation, which varies
excessively according to the situation and other physical conditions, and
whose systematic importance, accordingly, is very slight. The size is also
extremely variable, ranging from that of a pin-head to 1| metres in diameter.
Sponges are invariably sessile in habit, being attached either by means of
a stem or a bundle of anchoring spicules, or they may be simply encrusting
at the base.
s- '■ The canal-system by which the whole body is traversed, is extremely com-
plicated in thick-walled, but simple in thin-walled sponges. A distinction is
recognised between incurrent or inhalent, and excurrent or exhalent canals.
In the terminology proposed by Rauff, inhalent canals are designated as
epirrhysa, and exhalent canals as aporrhysa ; the former terminate on the
periphery in ostia (not to be confounded with the finer dermal pores), while
the latter terminate on the cloacal surface in postica (again not to be con-
founded with gastral pores). Postica are usually larger than ostia, and
differ from them in form and arrangement.
1 Literature : ^. Ou recent Sponges : —
Schmidt 0.,Die Spougien des Adriatischen Meeres. Leipzic, 1864-66. — Idem, Die Spongien der
Kiiste von Algier. Leipzic, 1868. — Idem, Die Spougien des Meerbu&ens von Mexico. Jena, 1879-80.
— Haeckel, E., Die Kalkschwiimme, 1872. — Schulze, Fr. E., Untersuchungeu liber den Bau
und die Entvvicklung der Spongien. Zeitschr. f. wiss. ZooL, 1876-80, vols, xxvii. - xxx. —
Report on the Hexactiuellida. Scieut. Results Challenger Exped., Zool., vol. xxi., 1887. —
Vosmaer, G. G. J., Spongien {Porifera), in Bronn's Classen und Ordnungen des Tierreichs,
2nd ed., 1882-87, vol. iii. — Lendeiifeld, R., A Monograph of the Horny Sponges. London, 1889.
B. On fossil Sponges : —
Gold/uss, A., Petrefacta Germaniae, vol. i., 1826-33. — Michelin, H., Iconographie zoophyto-
logique, 1840-47. — -Fromentel, E. de, Introduction a I'etude des t'ponges fossiles. Mem. Soc. Linn.
Normandie, 1859, vol. xi. — Roemer, F. A., Die Spongitarien des norddeutschen Kreidegebirges.
Palaeontographica, 1864, vol. xiii. — Zittel, K. A., Ueber Coeloptychium. Abhandl. k. bayer.
Akad., 1876, vol. xiii. — Studien iiber fossilen Spongien, i., ii., iii., ibid., 1877, vol. xiii. (translated
by Dallas in Annals and Mag. of Nat. Hist, for 1877, 1878, 1879). — Beitriige zur Systematik der
fossilen Spongien, i., ii., iii., Neues Jahrb. fvir Mineral. 1877, 1878, 1879. — Quenstedt F. A.,
Petrefacteukunde Deutschlands, 1877, vol. v.—Sollas, W. J., Quart. Journ. Geol. Soc. 1877-80,
vols, xxxiii. - xxxvi. — Rinde, G. J., Catalogue of fossil Sponges of British Museum, London,
1883. — Monograph of British fossil sponges ; Palaeontographical Society, 1887, 1888, 1893. —
Rauff, H., Palaeospongiologie ; Palaeontographica, 1893 - 94, vols, xl., xli. (contains full
bibliography). — Schrammen, A., Beitrag zur Kenntniss der obersenonen Tetractinelliden. Mittheil.
Roemer. Museum Hildesheim, 1899-1903, Nos. 10, 14, 15, 19.— Hall, J. and Clarke, J. M.,
A Memoir on the Palaeozoic reticulate Sponges constituting tl^e family Dictyospongidae. N. Y.
State Mus. Mem. ii., 1898. Earlier contributions by same authors in 15th and 16th Reports N. Y.
State Geologist, 1895-96. — Schrammen, A., Kieselspongien der oberen Kreide von Nordwestdeutsch-
land. Palaeontogr. 1910, Supplem. vol. v. — Kolb, R., Kieselspongien des schwabischen weissen
Jura. Oj). cit., 1911, vol. Ivii.
48 COELENTERATA— PORIFERA phylum ii
The water enters through the dermal pores, and passes through the
incurrent canals into ciliated chambers, which are lined with epithelial cells.
From these it is conveyed through all parts of the body by means of the
frequently branching excurrent canals, which open into a sac-like, tube-like
or funnel-shaped cloaca. The exhalent opening of the latter is termed the
osculum. Extremely thin-walled sponges have no cloaca, osculum or branch-
ing canal-system, but the excurrent canals terminate directly in small openings
situated on the upper surface of the body. The cloaca when present is often
of considerable depth, although sometimes shalloAV, or reduced to a mere sac-like
prolongation of the osculum. Forms with a large and deep cloaca are regarded
as single individuals, those with numerous cloacae and oscula as colonies. But
since all the cloacae of a colony communicate by means of canals, while the
oscula are never surrounded by a crown of tentacles, it is often difficult to
distinguish between large excurrent canals and true cloaca, and hence also
between individuals and colonies,
Eeproduction is either sexual or asexual. In the first process the fertilised
ova complete a tolerably regular segmentation, develop into a gastrula, pass
out through the osculum, and attach themselves to some foreign object.
Asexual reproduction takes place by budding, the young buds remaining
attached to the parent individual, and thus giving rise to colonies. Re-
production by means of fission forming new colonies is of rare occurrence.
The great majority of sponges secrete a skeleton composed either of horny
fibres or of siliceous or calcareous spicules, or they incorporate foreign bodies
into their framework. Only a few Recent forms {Myxospongiae) are without
a skeleton. In the horny sponges (Ceratospongiae) the skeleton consists of
anastomosing and reticulated fibres of spongin, an organic nitrogen compound
resembling silk. The fibres are either solid, or they contain an axial canal,
which is sometimes cored with foreign bodies, such as sand-grains, fragments
of sponge-spicules, foraminifers, radiolarians, etc.
Siliceous spicules are sometimes encased in horny fibres, sometimes occur
detached in the cellular tissues, or are interlaced and consolidated with one
another in various ways to form a supporting framework. In each genus the
skeleton is composed of but a single type, or at the most of but a few regularly
repeated varieties of siliceous bodies, which are called the skeletal elements. In
addition to these there occur more or less abundantly, especially on the outer
surface and in the cloacal and canal walls, extremely delicate flesh-spicules,
usually of small size and of great diversity of form. The flesh-spicules are as
a rule destroyed during fossilisation. All the siliceous skeletal elements are
secreted by nucleated cells, and are composed of concentric layers of colloidal
silica, deposited usually about a slender axial canal. In some spicules, notably
those having spherical or stellate contours, the axial canal is wanting. It is
very delicate in fresh spicules, but becomes enlarged by maceration, and in
fossil specimens it is often coarsely calibrated.
The multitudinous varieties of siliceous skeletal elements (Fig. 46) may
be grouped into a few fundamental types, as follows : —
(a) Uniaxial spicules or monaxons (Fig. 46 ^"^") and (^^~^^). Straight or
bent, smooth, prickly or knotty, bevelled, sharpened or truncated needles,
rods, hooks, clasps, pins and anchors (ampJddiscs). They invariably contain
an axial canal, which may be either entirely sealed up, or open at one or at
both ends.
CLASS I
SPONGIAE
49
(b) Tetraxial spicules or tetraxons (Fig. 46 ^''). The normal form is
characterised by four equal rays intersecting like the bisectrices of the plane
angles of a regular tetrahedron. Triaxial forms result from the occasional
abortion of one of the rays. One of the rays may become elongated or other-
wise modified so as to form anchors (triaens) with three simple or furcate hooks
(Fig. 46 i8-23^_ Three of the rays may be numerously divided or foliately
expanded so as to produce forms resemlDling thumb-tacks {frichotriaens, phyllo-
triaens) ; atrophy of the fourth ray in the last-named form reduces the spicule
to a delicate siliceous disk (Fig. 46 ^^). A peculiar forking of the shaft gives
rise to candelabras or ampJdtriaens, while other modifications may produce
umbellate spicules (Fig. 46 -^), etc.
Certain skeletal elements of the Lithistids (Figs. 48-63) may be regarded
as irregular tetraxons (desmoms), in which the extremities of the four rays are
Fl<i. 46.
Various forms of Sponge spicules from the Upper Cretaceous of Haldem, Westphalia ; iiiagnifieil 25 diameters.
1-6, Uniaxial rods and needles. 7-9, Uniaxial siliceous elements with coarse axial canals. 10-13, Uniaxial
cylinders and spheres. 14, Microspined sjjicule. 15, Clasp-hook flesh-spicule. 16, Bispatulate liesh-spicule.
17, Regular four-rayed spicule (chevaux de frise). lS-21, Trifid anchor-shaped spicules. i;'2-23, Anchors with
furcate head-rays. 24-2.5, Irregular four-rayed skeletal elements. 20, Umbel-shaped spicule. 27, Six-rayed
spicule. 28, Polyaxial siliceous disk.
prolonged in knotty, root-like excrescences, or in which, owing to the un-
symmetrical growth, branching or atrophy of one or more of the arms,
extremely irregular forms are produced ; for these a special terminology has
been devised by Rauff.
(c) Hexactinellid spicules (hexadins or triaxons) (Figs. 65-70). The
ground-form is an axial cross with six equal arms intersecting at right angles
like the axes of a regular octahedron. Atrophy of one or more of the rays
may result in pentaxial, tetraxial, triaxial, or even clavate forms, without their
real character becoming entirely obliterated. Bifurcation or other modifica-
tions of a number or of all the rays produce beautifully formed siliceous
structures highly characteristic of the group Hexadinellida, which resemble
candelabras, double-headed anchors, fir-trees, pitch-forks, rosettes, etc. The
fusion of juxtaposed hexactins produces more or less symmetrical latticeworks
with cubical interstices.
VOL. I E
50 COELENTERATA— PORIFERA phylum i
(d) Anaxial or polyaxial bodies of spherical, cylindrical, stellate or
discoidal shape, which are not derivable from either of the three ground-forms,
occur in only a few varieties of recent and fossil siliceous sponges.
Calcareous skeletal elements are much less complicated, and are genei'ally
smaller and more perishable than the siliceous. Their form is either triaxial
(triods), tetraxial (tetraxons\ or nail -shaped (inonaxons). The triaxial and
tetraxial spicules are very rarely forked or otherwise modified. Each skeletal
element behaves optically like a single calcite crystal ; axial canals are absent.
The skeletal elements in sponges are arranged chiefly with reference to the
circulation of water through the canal-systems. In thin- walled forms they are
more or less closely crowded together, and are often regularly oriented in the
soft parts ; in other forms they are encased in horny fibres, or are packed in
between the canals ; in still others they are united to form an irregular frame-
work, or may be welded together in a regularly reticulated scaffolding.
The horny fibres are totally destroyed during fossilisation ; calcareous
spicules are often wholly or partially dissolved, or are replaced by infiltrating
lime carbonate, and assume a dense fibrous appearance (Pharetrones). Like-
wise in siliceous sponges the skeletal elements are rarely preserved unaltered ;
as a rule the originally colloidal silica becomes crystalline, or is dissolved and
removed. The cavities thus formed may subsequently become filled with
infiltrating quartz, limonite or most commonly with lime carbonate. In
this manner the skeletons of fossil siliceous sponges are converted into calcite,
and, contrariwise, spicules that were originally calcareous may become silicified.
Hence the distinction between siliceous and calcareous sponges in the fossil
state depends entirely upon morphological characters, and not at all upon the
chemical composition of the preserved parts.
Sponges are divided into four subclasses : Myxospongiae, Ceratospoiigiae,
Silicisponcjiae and Calcispongiae. The latter 'group stands in sharp contrast to
the other three, which are connected by intermediate forms, and constitute
together a 'group of equal value with the calcareous sponges. Skeletal
elements are absent in the Myxospongiae, whose bodies are composed entirely
of soft cellular tissues. The Cerafospongiae also lack imperishable hard parts,
the spongin fibres being entirely destroyed during fossilisation. The reputed
horny sponges from the Trias (BhizocoraUum), Jura and Cretaceous (Spongites,
Saxonicus, Paramudra, etc.) are either of inorganic nature or are zoologically
indeterminate. All fossil sponges, therefore, belong either to the Silicispongiae
or the Calcispongiae. The oldest forms are found in the Cambrian ; in the
Trias, Jura and Cretaceous they are very abundant.
Subclass 3. SILICISPONGIAE. Siliceous sponges.
Skeleton composed either exclusively of siliceous elements, or of horny fihres enclos-
ing siliceous spicules.
Order 1. MONACTINELLIDA Zittel.
(Monaxonia F. E. Schulze.)
All skeletal elements uniaxial.
The Monacfiiu'llida include the majority of existing marine sponges, most
of which occur at moderate depths ; and also the few fresh-water forms
ORDER II
SILICISPONGIAE— TETRACTINELLIDA
51
(Spongilla) that are known. The skeleton, as a rule, is composed like that
of the horny sponges, of anastomosing spongin fibres, which either encase
rod-like spicules, or contain quantities of uniaxial siliceous elements ; some-
times the latter are also present in the soft parts. In each genus there are
usually either one or but few varieties of siliceous elements present, which are uni-
formly distributed throughout the body. Needles, hooks, crotchets, cylinders,
spindles, amphidiscs and the like occur in great diversity. Owing to the
decomposition of the horny fibres during fossilisation, and the fact that the
skeletal elements are never fused together, the latter become detached and
scattered in all directions. While Monactinellid spicules are very common
in certain formations, they are rarely united in the form of coherent
skeletons, and are only capable of generic determination when their form is
sufficiently characteristic, as in Benieria, Esperia, etc. The basal beds of the
Alpine Lias often contain considerable hornstone, which is sometimes com-
pletely filled with rod-shaped spicules. In various Cretaceous and Tertiary
horizons Monactinellid spicules are also enormously abundant. Hinde has
described a Climacosjwngia from the Silurian of Tennessee, in which the
skeleton consists of spicules arranged in longitudinal rows, and connected by
transversely disposed elements. The spicules were probably originally
enclosed in horny fibres. The Clionidae secrete pin-shaped siliceous elements
which are also encased in horny fibres, and Eecent sponges of this family
bore labyrinthic passages in the shells of mollusks. Fossil sponge-borings are
also common. Detached spicules of Benieria, Axinella and HajMstion have
been described by Hinde from the English Carboniferous Limestone.
Order 2. TETRACTINELLIDA Marshall.
{Tetraxonia F. E. Schulze.)
Skeleton composed of regidar fetraxons which are generally combined loith uni-
axial, polyaxial or heteraxial siliceous bodies. The
skeletal elements occur detached throughout the soft
parts, and are never united to form a connected frame-
work.
The most common forms of skeletal elements
are normal tetraxons, anchors with simple or
furcate prongs, spheres and stellate bodies. In
certain genera (Geodia) the large anchors and
cylinders are disposed in radiately arranged fasci-
cles, and are surrounded by a thick layer of
anaxial spheres.
Detached Tetractinellid spicules associated
with Monactinellids occur more or less abundantly
in the Carboniferous Limestone, the Alpine Infra-
Lias, the English Neocomain, the Deister Sand-
stone (Hils), the Upper Cretaceous of Haldem
and Coesfeld in Westphalia, and in the Tertiary
and Pleistocene formations. The skeletal elements are preserved in their
natural position in the genera Ophiraphidifes Carter ; Tethyopsis Zittel (Fig. 47),
Pachastrella Schmidt, Stolleya and Cephaloraphidites Schrammen.
Fig. 47.
Tethyopsis steinmanni Zittel. Upper-
Cretaceous ; Ahlten, Hanover, i^/i.
52
COELENTERATA— PORIFERA
PHYLUM II
Order 3. LITHISTIDA Schmidt.
Massive, thick-walled, siliceous sponges, usually with complicated canal-system.
Skeleton composed of irregular tetraxons or monaxons (desmoms) which develop
nodose or root-like branches either at the extremities or all along the shaft, and are
firmly united hy zygosis. Symmetrical, tetraxial, uniaxial or polyaxial dermal and
flesh-spicules also present.
The Lithistids are closely related to the Tetractinellids, and in the
opinion of many zoologists, should be embraced in the same order with them.
The Lithistids are peculiarly well adapted for preservation, owing to the
massive stony character of their skeletons ; and their remains occasionally
form thick deposits, especially in the Jurassic and Cretaceous. Their outer
configuration is extremely variable ; most commonly it is crateriform,
cup-shaped, pyriform, globular, bulbous or plate-like ; while the body is
attached either by the base or by means of a peduncle. The canal-system
varies greatly in difterent genera, but is usually well developed and more or
less complicated. The four-rayed skeletal elements are interlocked by means
of the root-like branching ends of the rays, and the points of intersection
(nodes) with the ends of adjacent uniaxial spicules are thickened into balls.
The usually irregular uniaxial skeletal elements are interlaced on all sides by
means of root-like processes. Dermal and flesh-spicules are preserved only
under exceptionally favourable conditions, but are invariably present in
recent genera, and furnish valuable differential characters. The classification
of fossil Lithistids is based wholly upon the skeletal elements and canal-
systems. Five principal groups are recognised, whose subdivision into
families need not concern us at present : — Tetracladina, Eutaxicladina, Anomo-
cladina, Megamorina, and Rhizomorina. Existing Lithistids occur most abun-
dantly at depths ranging between 100 and 400 metres, but are occasionally
found as deep as 1800 metres.
Suborder 1. TETRACLADINA Zittel.
Skeletal elements composed of four usually equal rays, each of which encloses an
axial canal, and has extremities terminating in root-like strands or processes ; the
spicules are intertwined
to form an open mesh-
work. Dermal spicules
either grapnel-like te-
traxons, frequently with
furcate prongs, or dis-
coidal with entire or
lohate margin ; or they
are nail - shaped or
cylindrical monaxons.
The skeletal ele-
ments of the Tetra-
cladina are usually
symmetrical tetrax-
ons, whose four smooth, more rarely tuberculate or knotty rays intersect ap-
proximately at an angle of 109i". They occur in the Cambrian and Silurian,
Fio. 48.
Aulocopixim aii,ranU)nn OsviaXA. Diluvium; Sadovvitz, Silesia, a, Example
in 1/2 natural size ; //, Skeleton magnitled 00 diameters.
ORDER III
SILICISPONGIAE— LITHISTIDA
53
are very scarce in the Upper Jurassic (Protetraclis), but abundant in the
Cretaceous, Tertiary and Recent periods.
A'ulocopium Oswald (Fig. 48). Hemispherical or bowl-shaped with short
peduncle ; inferior surface covered with a dense, wrinkled, siliceous skin.
Fig. 49.
Callopegma acaule Zitt. Senonian ; Ahlten, Hanover ; a, Specimen in •*/4 natural size ; h, Skeleton magnified
^o/i ; c, Portion of periphery, ^/j ; d, Same magnified 40/i, and showing anchors with furcate head-rays.
Cloaca central ; sponge body with numerous arched canals parallel to contour
of periphery, and with finer radial canals leading from exterior to cloaca.
Skeleton composed of irregular smooth-rayed tetraclons with root-like branch-
ing extremities, disposed in rows parallel to the radial canals. Occurs (usually
replaced by calcite) in the Ordovician of the Russian Baltic Sea Provinces,
B
Fig. 60.
Phymatella tuherosa (Queiistedt). Quadratenlvreide,
('Upper Senonian) ; Linden, near Hanover, a, Sponge,
1/2 natural size ; b, Outer surface, i/i ! ''i Slceletal element,
sw/i ; d, Spicules from stalk portion, 50/i.
Fig. 51.
Siphonia tulipa Zitt. Greensand ; Blackdown.
A, Longitudinal section, natural size. JS, Sponge
with jieduncle and root, 1/2 natural, size (after
Sowerby).
Ordovician of Illinois, and Silurian of Gotland. Also in erratic blocks on the
plains of Northern Germany, usually chalcedonised.
Archaeoscyphia Hinde. Cambrian.
Callopegma Zittel (Fig. 49). Bowl- or funnel-shaped, short-stemmed, thick-
walled. External surface perforated by smaller, internal by larger canal-openings
54
COELENTERATA— PORIFERA
PHYLUM II
(ostia and postica). Skeleton composed of smooth-rayed tetraclons, the digitate
extremities of which are inflated into balls. Dermal spicules in the form of
anchors and rods. Upper Cretaceous.
Phymatdla Zittel (Fig. 50). Upper Cretaceous.
Polymaraphinina, Sollasella, Pseudoplocoscyphia and Craterella Schramm en.
Upper Cretaceous.
Fig. 53.
Skeletal element of Jerea
qvensteiUi, Zittel, showing
brandling extremities of
rays. Qnadratenkreide; Lin-
den, near Hanover. ■''Vi.
Fig. 54.
Zittel.
Plintlwsella squamosa
Skeleton mai;nified 80 diameters.
Senonian ; Ahlten, Hanover.
Fig. [>2.
Jerea pyriformis Lamx.
Greensand ; Kelheim, Ba-
varia, i/o natural size.
Siphonia Park.
(Fig. 51). Fig-, pear-
or apple-shaped, with
a long or short ped-
uncle. Body with
deep cloaca, into
which arched canals
running parallel with
the periphery, to-
gether with numerous
fine radial canals, con-
duct. Skeleton com-
posed of smooth-rayed, branching dichotriders. Dermal spicules in the form
of monaxons and grapnels. Abundant in Middle and Upper Cretaceous.
Hallirhoa Lamx. Like the preceding, but invariably short -stemmed.
Body pyriform and lobate, owing to a number of deep constrictions.
Cenomanian.
Jerea Lamx. (Figs. 52, 53). Body pyriform, flask-shaped or cylindrical,
with truncate or depressed summit, in which a number of tube-like canals,
vertical in the central portion but arched in the peripheral, terminate. Cross-
ing the latter are finer radial canals. Skeleton composed of tetraclons and
dichotriders. Common in Middle and Upper Cretaceous.
Bhaijadinia rimo.'^a Roemer.
natural size ; h, Skeleton, 40/j
Spicule of dermal layer, -I'V]-
Pio. 55.
Senonian ; Alilten, Hanover, a, Sponge,
c, Lobate disk from dennal layer, -lO/i ;
ORDER III
SILICISPONGIAE— LITHISTIDA
55
Polyjerea From. ; Astrodadia, Thecosiphonia, Colymmatina Zitt. ; Twronia Mich. •
Plinthosella Zitt. (Fig. 54). Cretaceous. Discodermia Boc. ; Bhacodiscula Zitt.,
etc. Cretaceous and Tertiary.
Ehagadinia Zittel (Fig. 55). Auricular, plate- or bowl- shaped, short-
stemmed. Both surfaces traversed by irregular branching furrows, in which
the canalicular ostia are situated. Skeletal elements four-rayed, sometimes
uniformly or only distally covered with tuberculous knobs, and with digitate
extremities. Dermal spicules in the form of six-lobed disks, provided with a
short shaft, and minute, multifid tetraclons. Upper Cretaceous.
Suborder 2. EUTAXICLADINA EauflF.
Skeleton composed of four-rayed spicules with three equoMy developed simple or
bifurcate rays which terminate distally in root-like fibres ; and one abbreviate, inflated
fourth ray {ennomoclon). Axial canals probably in all of the rays. Skeletal elements
invariably arranged in either parallel or alternating roivs, and united by zygosis into
a network with triangular or irregular meshes ; spicular nodes greatly inflated.
Nearly all the genera are Silurian ; a few [Mastosia, Lecanella) occur in the
Upper Jurassic.
Fic. 56.
Astylospongia praemorsa (Goldf.). In erratic block from Mecklenburg, a, Sponge, partially cut into, natural
size; 6, Skeleton, 1-/1 ; c, Portion of same highly magnified.
Astylospongia Eoem. (Figs. 56, 57a). Spherical, with shallow depression on
the summit ; base evenly rounded, unattached ; probably fastened by means
of anchoring fibres. Large-sized canals directed parallel to perii:)hery in the
outer portion of the body, vertical in central
portions ; besides these there are numerous fine
radial canals which terminate in pores all
over the periphery. Skeletal elements with
four smooth elongated rays, one or all of
which branch dichotomously just above the
junction with the shorter arm. Spicular
nodes thickened into large knots. Ordovician
of the Eussian Baltic Sea Provinces, and ment of i/i/irfj«, so/^ (after Rauff).
Silurian of Sweden and North America (not-
ably in Tennessee), usually chalcedonised. Also in erratics in the Diluvium
of Northern Germany.
'MJ
Fio. 57.
Detached skeletal element of Astylo-
spongia, 120/1 ; &> Detached skeletal ele-
56
COELENTERATA— POEIFERA
PHYLUM II
Caryosjmigia, Caiyospongia RaufF. Ordovician and Silurian ; Europe.
Palaeomanon Roem. {AsUjlomanon EaufF). Like Astylospongia, but bowl-
shaped, with shallower and wider cloacal depression. Entire surface covered
with pores. Silurian ; North America. P. cmtera Roem.
Caryomanon, Caiyomanon Rauff. Silurian ; North America.
Hindia Duncan (Fig. blh). Body spherical, with perforate periphery,
traces of attachment wanting. All canals radiate from the centre outAvard.
Skeletal elements composed of three simple rays beset with prickly tubercles,
and a reduced button-like fourth arm. All spicules regularly disposed in rows
parallel with the radial canals. Silurian ; North America.
Neohindia Schrammen. Upper Cretaceous ; Germany.
Suborder 3. ANOMOCLADINA Zittel.
(Didymmorina RaufF. )
Skeletal elements composed of short, smooth rays with spheriailly inflated ends
which give off three, four or more simple or digitate branches ; the latter are united
by zygosis with processes of adjacent rays ; axial canals simple. Dermal spicules
rod-shaped monaxons. Upper Silurian to Recent.
Anomoclonella, Pycnopegma RaufF. Silurian ; North America.
Cylindrophyma Zittel (Fig. 58). Body cylindrical, thick- walled, attached ;
cloaca wide and tube-like, receiving numerous radial canals, and extending
FlQ. 58.
Cylindrophyma milleporata (Goldfuss). Upper White Jura ; Hoclistriiss. A, Two s])ocinieii.s, 1/2 natural size.
J}, Skeleton magnified 30 diameters. C, Detached skeletal element of Cylindrophyma, B^/j (after Raufl').
down as far as the base. External surface perforated by fine ostia. Common
in Upper Jurassic.
Melonella Zittel. Skeleton apple-shaped or hemispherical, with broad base,
or provided with very short i)eduncle ; base covered with wrinkled siliceous
skin. Cloaca deep, funnel-shaped. Coarser canals arched, parallel with peri-
phery ; finer incurrent canals radially directed. Upper Jurassic. M. radiata
(Quenstedt).
ORDER III
SILICISPONGIAE— LITHISTIDA
57
Rauff. Silurian. Megalithista Zittel. Upper Jurassic
Spoiige-body cylindrical, simple or branching,
a number of larger canals running parallel
b
Suborder 4. MEGAMORINA Zittel.
{Rhabdomorina Rauff. )
Usually large-sized, elongated, smooth, bent, loosely interlocking, irregularly
branching, or only terminally forked skeletal elements with simple axial canals ;
interspersed among tvhich small, radiciform, numerously branching elements
{rhizomorins) are occasionally jiresent. Dermal spicules uniaxial or grapnel-shaped.
Ordovician, Silurian, Carboniferous, Jurassic, Cretaceous and Recent.
Saccospongia
Nattheim.
Doryderma Zittel (Fig. 59).
pyriform or compressed, with
with the body
axis, and numer-
ous smaller radial
canals. Skeletal
elements large,
bent and divided
into two or more
simple branches.
Dermal spicules
in the form of
three - fluked an-
chors. Upper
Cretaceous ; Nor-
thern Germany,
England and
France. Accord-
ing to Hinde, also
Carboniferous.
Carterella Zittel; Asteroderma Schrammen. Cretaceous.
Isorhaphinia Zittel. Sub - cylindrical, pedunculate, with wide cloaca
reaching nearly to the base. Skeletal elements large, slightly bent, rod-
shaped, inflated at the ends, rarely dichotomously branching. They are
associated in bundles, and so interlocked at their extremities as to form
an open meshwork. Cretaceous. /. texta (Roemer).
Fig. 59.
Doryderma dlchotoma (Roemer). Upper Cretaceous, a, Sponge, natural size ; 6,
Dermal layer, 2/^ ; c. Bundle of skeletal elements, lo/j ; rf, Skeletal element and
several dermal spicules with furcate, anchor-shaped head-rays, ■^o/i.
Suborder 5. RHIZOMORINA Zittel.
Skeletal elements small, composed of four or of three principal rays, or simple and
irregular, with numerous pjrojecting spines or tubercles ; axial canal simple or branching.
Dermal spicules monaxons, tetraxons or similar 'to those of the skeleton. Chiefly
Jurassic, Cretaceous and Recent.
Nipterella Hinde. Cambrian.
Cnemidiastrum Zittel {Cnemidium, p. p. Goldf.) (Fig. 60). Turbinate or
bowl-shaped, with deep cloaca. Walls thick, perforated by numerous radial
canals disposed in tiers one over another, thus forming vertical fissures which
often divide toward the exterior. Skeletal elements irregularly branching,
entirely beset with blunt spiny processes. Abundant in the Upper Jurassic
58
COELENTERATA— PORIFEEA
PHYLUM II
Spongitenkalk of South Germany, the skeletons being almost invariably
replaced by calcite. C. rinmlosum Goldf. According to Hinde also present
in the Carboniferous Limestone of Ireland.
Fig. 60.
Cnemidiastrum, stellatum (Goldfiiss). Upper Jurassic Spongiten-
kalk ; Hossingen, Wiirttemberg. a, Sponge, V2 natural size ; b,
Vertical tangential section, showing radial canals In vertical clefts ;
c, Skeletal elements, 6"/^.
Fig. 61.
Skeleton of Jercica polystovia
(Roem.). Upper Cretaceous ; Alilten,
Hanover. BO/j,
Hyalotragos Zittel. Bowl-, plate- or funnel-shaped, with short peduncle.
Depression in summit perforated by the ostia of numerous short canals. ■ Ex-
ternal surface finely perforate, or covered by a smooth or wrinkled dermal
layer. Skeletal elements irregular, Avith numerous branches beset with points,
but with few spines. Very abundant in Upper Jurassic Spongitenkalk. H.
patella (Goldfuss).
Fig. 02.
Cheiic)idoponifungiformisLa,mx. Senonian ;
Chatellerault, Touraine. ^/j natural size.
Fig. 63.
Verruculina auriformis (Roemer). Quadratenkreiiie;
Linden, near Hanover. 2/3 natural size.
Flatychonia Zittel. Leaf- or ear-shaped, irregularly undulating, covered on
both surfaces with fine pores. Skeletal elements resembling those of Hyalo-
tragos. Upper Jurassic. P. vagans (Quenstedt).
Jereica Zittel (Fig. 61). Sponge cylindrical, turbinate,"pyriform or club-
ORDER IV SILIOISPONGIAE— HEXACTINELLIDA 59
shaped, with short peduncle. Summit truncated or with shallow depression,
perforated by the postica of vertical excurrent canals. Exterior perforated by
ostia of the finer radial incurrent canals. Skeletal elements root-like, bent,
irregularly branching, with numerous short lateral processes. Upper
Cretaceous. /. polysloma (Roemer) ; /. punctata (Goldfuss).
Chenendopora Lamx. (Fig. 62). Goblet-, funnel- or bowl-shaped, with
peduncle. Cloaca deep, perforated by postica of fine canals. Skeletal
elements numerously branched and containing branching axial canal. Upper
Cretaceous.
Verrucidina Zitt. (Fig. 63). Foliate-, funnel-, ear- or bowl-shaped, short-
stemmed or sessile. Ostia on the upper surface surrounded by slight, collar-
like elevations. Middle (Gault) and Upper Cretaceous.
Amphithelion Zitt. Like the preceding, but with both ostia and postica
terminating in bosses. Cretaceous.
Other genera : Scytalia, Coelocorypha, Stachyspongia, Fachinion, Seliscothon
Zittel ; Megarliiza and Leiochonia Schrammen, etc., in the Middle and Upper
Cretaceous.
Order 4. HEXACTINELLIDA O. Schmidt.
(Triaxonia F. E. Schulze.)
Siliceous sponges with six-rayed skeletal elements, the rays being normally disposed
in three axes intersecting at right angles, and containing axial canals ; elements either
detached or fused together so as to form a lattice-like mesh. Dermal and flesh spicules
exceedingly variable in form, but invariably six-rayed.
Next to the Lithistida, the HexactinelUda are the most abundant of the fossil
siliceous sponges. They are extraordinarily variable in form, and are often
anchored by a tuft or " rope " of long, slender, vitreous fibres, or are attached
directly by the base. The walls are thin as a rule, and enclose usually a wide
cloaca ; the canal-system is consequently much simpler than in the Lithistida.,
being made up merely of short tubes which penetrate the walls more or less
deeply on both sides, and generally end blindly. Sometimes the sponge is
entirely composed of thin-walled tubes which twine about one another irregu-
larly and produce a system of lacunar interstices (intercanals) of greater or
less size.
The skeletal elements proper are distinguished by their considerably larger
size and simple form from the usually minute, astonishingly variable and
delicate flesh-spicules ; the latter, unfortunately, are seldom preserved in the
fossil state. The skeletal elements occur detached in the soft parts in the
Lyssacina group, or are partially or irregularly cemented together ; in the
Dictyonina group, on the other hand, they are regularly united in such manner
that the rays of proximate elements are all closely applied against one another,
and are surrounded by a continuous siliceous envelope. In this way a more
or less symmetrical lattice-work with cubical meshes is produced, in which,
however, the fusion of juxtaposed elements is indicated in that each ray con-
tains two distinct axial canals. The junction of the rays at the central node
of each element is usually inflated, but is sometimes sculptured in such manner
as to enclose a hollow octahedron (lantern nodes, lychnisks). The exterior of
the skeleton is often covered by a dermal layer composed of irregular hexactins.
60 COELENTERATA— PORIFERA phylum ii
in which the externally directed ray has become atrophied ; or a dense siliceous
envelope is secreted, in which stellate hexactins with reduced outwardly
and inwardly directed rays (stauractins) are embedded in greater or lesser
profusion.
The Hexadinellida of the present day are distributed chiefly over the greater
depths of the ocean beyond the hundred-fathom line (200 to 3000 fathoms).
They occur fossil principally in deep-sea deposits, and make their first appear-
ance in the Cambrian ; their period of greatest development coincides with
Jurassic and Cretaceous time.
Suhorder 1. LYSSACINA Zittel.
Skeletal elements either entirely detached, or only partially and in an irregidar
fashion cemented together. Root-iv^t often present.
The Lyssacina are poorly adapted for preservation in the fossil state, since
the skeletal elements are but rarely cemented together to form a connected
framework, and the flesh-spicules are invariably destroyed. Notwithstanding,
complete sponges composed of large-sized detached hexactins have been found
in Paleozoic formations, and also in the Upper Jurassic of Streitberg; and,
indeed, the oldest sponges that can be determined with certainty all belong to
the Lyssacina.
Family 1. Protospongidae Hinde.
Thin-walled, sack-, tube-like or spherical sponges, with walls composed of a single
layer of crnciform tetraxial spicules (stauractins), arranged so as to form quadrate
and suhquadrate meshes. Elements non-fasciculate. The reticulation formed by the
larger elements is divided into secondary squares by smaller spicides, so that the m.esh-
work is constituted of several series of squares. Cambrian and Ordovician.
To this family belong the genera Protospongia Salter, and Phormosella Hinde.
Family 2. Dictyospongidae Hall.
Usually large, funnel-shaped, cylindrical or prismatic sponges, whose thin tvalls
are frequently diversified by ridges and prominences. Skeletal framework very regular,
and composed of larger and smaller quadrate meshes situated one within the other.
Framework formed by bundles of slender spicules. Chiefly in Devonian (Chemung)
and Lower Carboniferous (Keokuk) of North America, and Devonian of Europe.
Subfamily 1. Dictyospongiinae Hall and Clarke.
Dictyospongia Hall and Clarke. Smooth, obconical or subcylindrical
sponges devoid of nodes, ridges or other ornamentation ; base furnished with
a tuft of long, straight, anchoring spicules. Silurian and Devonian.
Hydnoceras Conrad (Fig. 64). Obconical more or less rapidly expanding
sponges with eight prism-faces and nodes in horizontal and vertical rows. Base
with short tuft of anchoring spicules. Devonian and Carboniferous.
Lysactinella Girty ; Hydriodictya, Prismodictya, Gongylospongia, -Botryodictya,
Helicodictya, Bhabdosispongia, Ceratodictya, Clathrospongia, Lebedictya Hall and
Clarke. Chemung Group ; New York.
ORDER IV SILICISPONGIAE— HEXACTINELLIDA 61
Subfamily 2. Thtsanodictyinae Hall and Clarke.
Thysanodidya Hall and Clarke. Subcylindrical or tapering Dictyosponges
with prominent projecting, rectangularly reticulating spicular bands or lamellae
forming series of fenestrated quadrules upon the surface. Base with basal
disk or broad obcone. Devonian.
Phragmodidya Hall ; Arystidida, Adoeodidya, Griphodidya Hall and Clarke.
Upper Devonian and Lower Carboniferous.
Subfamily 3. Calathospongiinae Hall and Clarke.
Calathospongia Hall and Clarke. Stout subcylindrical cups with truncated
bases, probably attached by the basal margins ; contracted mesially and more
or less expanded at the aperture. Surface without
nodes. Carboniferous.
Clepsydrospongia Hall and Clarke. Thamnodidya,
Cleodidya Hall.
Subfamily 4. Physospongiinae Hall and Clarke.
Physospongia Hall.' Keokuk group. Roemeri-
spongia Hall and Clarke. Eifel Devonian. (' ,,'-
Subfamily 5. Hyphantaeniinae Hall and Clarke.
Hyphantaenia (Uphantaenia) Vanuxem. Large,
circular and shallow saucer-shaped cups, composed
of two series of intersecting spicular straps, one
radiating, the other concentric. Chemung Group ;
New York.
Fio. 04.
Subfamily 6. HalLODICTYINAE Hall and Clarke. Hydiwceras hathensis Hail and
•' ClarkR. Cliemung Group' ; Bath,
Hallodidya Hall and Clarke. Adinodidya, Crypto- of .stronj;- iwdes and iHieiy reticu-
didya Hall. Chemung Group ; New York. ciadcer"''"'' ''' ^"''"' """^ ""^
Subfamily 7. Aglithodictyinae Hall and Clarke.
Aglithodidya Hall and Clarke. Chemung Group ; New York.
Family 3. Plectospongidae Eauff.
Thin-ioalled tubes with skeleton composed of a regular framework made up of an
ascending and approximately ring-like series of spicules ; the latter form rectangular
to quadrate, hut not very symmetrical meshes. Spicular rays^ fasciculate. Ordovician
and Silurian.
Cyathophycus Walcott ; PalaeosaccMS, Acanthodidya Hinde. Ordovician.
Pledoderma Hinde. Silurian.
62
COELENTEEATA— PORIFEEA
PHYLUM II
Genera incertae sedis.
Pattersonia Miller {Strohilospongia Beecher). In form of large botryoidal
clumps. Brachiospongia Marsh. Vase-like sponges Avith broad inferior margin
prolonged into a number of hollow arms. Ordovician of North America.
These, together with Amphispongia Salter, and Astroconia Sollas, from the
Silurian of England, represent extinct families of the Lyssacina.
Fyriionema M'Coy (Acestra Eoem.) Fascicles of long, stout spicules,
supposed to be root-tufts. Silurian,
Hyalostelia Zitt. (Acanthospongia Young). Skeletal elements relatively large,
in the form of regular hexactins and stellate bodies with reduced vertical ray,
and with inflated nodes.
Root-tuft composed of elon-
gated, slightly bent fibres,
sometimes terminating in
four recurved rays. Cam-
brian to Lower Carboni-
ferous ; Great Britain.
Holasterella Carter;
Spiradinella (Fig. 65), and
Acanthactinella Hinde, are
allied genera occurring in
the Lower Carboniferous
of Great Britain.
ThoUasterella Hinde (Fig.
Fio. 66.
Thnliastcrella gracilis
Hinde. Carboniferous
Limestone ; Dairy, Ayr-
shire. Dermal layer with
fused stellate spicules,
5/i (after Hinde).
■ S^^SB^^^^
Fig. 65
Spiractinella wriciMil (Carter).
Carboniferous Limestone ; Sligo,
Ireland. A, Normal hexactin. B,
Hexactin with forked rays, 5/j
(after Hinde).
Fig. 67.
AsteractineUa expansa Hinde.
Carboniferous Limestone ;
Dairy, Ayrshire. Skeletal
element, 5/j (after Hinde).
Fig. 68.
Astraeospongia meniscus Roemer.
Silurian ; Tennessee. A, Sponge, in
profile, 2/3 natural size. B, IJpper
surface of same.
66), from the Carboniferous, has thin walls composed of a layer of robust,
irregularly amalgamated hexactins. As a rule, two of the rays lying in the
same plane divide dichotomously from the nodes outward, so as to produce
a six-armed instead of a four-armed cross. In AsteractineUa Hinde (Fig. 67),
all of the rays lying in the same plane divide in two or more branches, thus
giving rise to many-rayed, extremely diverse, stellate and corolla-like bodies.
Carboniferous ; Ayrshire.
Astraeospongia Roem. (Fig. 68). Thick-walled, depressed, bowl-shaped,
upper surface concave, lower convex, without traces of attachment. Skeleton
composed of relatively' large, homogeneous, uncemented cruciform spicules ;
six of the rays are disposed in the same plane, while the two rays projected
at right angles to these are reduced to short, button-like prominences. Common
in Silurian of Tennessee and Devonian of the Eifel.
ORDER IV
SILICISPONGIAE— HEXACTINELLIDA
63
According to Hinde, Tholiasterella and Asteradinella constitute a distinct
order (Heteradinellidae), and Astraeospongia is made the type of the order
OctadinelUdae. These two groups may perhaps best be regarded as aberrant
Hexactinellids, in which sui:)ernumerary rays are produced by branching.
Suborder 2. DICTYONINA Zittel.
Skeletal spicules cemented to form a continuous framework in sncli a way that
every arm of a
hexactin is applied
to the corresponding
arm of an adjacent
spicule, and both
rays become en-
veloped in a common
siliceous covering.
Boot-tuft absent.
The Dictyonina
are probably de-
scendants of the
Lyssacina (possi-
bly from Proto-
spongia- and Dictyo-
phyton-Wke forms).
They appear first
in the Trias, and
play a prominent
role as rock-builders in the Jurassic and Cretaceous. Their lattice-like skeletons
are frequently replaced by calcite, or are dissolved away and merely indicated
by cavities. The more important fossil
forms are divided into the following
families.
Family 1. Craticularidae Rauff. (Eure-
tidae p. p., Zittel non Schulze.)
Cup-shaped, cylindrical, branching or
flattened sponges. Spicular nodes solid.
External surface without distinct dermal
layer, but protected by a thickening of the
outer skeletal layer, and occasionally covered
with a delicate tveb of cemented spicules.
Canals simple, blindly terminating in the
skeleton. Jurassic.
Fig. 69.
Tremadictyon retimdatum (Goldf.). Upper Jurassic ; Streitberg, Pranconia. a,
Sponge, "-^/g natural size ; h, Enlarged portion of outer surface witliout dermal layer ;
c, Portion with well-preserved dermal layer, 3/j ; d, Skeleton, 12/^.
Fio. 70.
Craiicidaria -paradoxa (Miinster). Upper Jurassic ;
Muggeudorf, Franconia. a, Sponge, 1/3 natural size ;
6, Latticed skeleton, 12/1 ; c, Tliickened dermal layer.
Tremadictyon Zitt. (Fig. 69). Cup-,
plate-shaped or cylindrical, with wide
cloaca. Canal-openings on both sides in alternating rows. Base nodular ;
exterior veiled over with delicate net-work of amalgamated hexactins, extend-
ing even across canal pores. Skeletal framework with more or less irregular
cubical meshes. Very common in Upper Jurassic.
Craticularia Zitt. (Fig. 70). Funnel-shaped, cylindrical or flattened;
64
COELENTEEATA— PORIFERA
PHYLUM II
simple or branching. Canal - openings on both surfaces either round or
elliptical, and regularly distributed in vertical and horizontal rows. Canals
short, ending blindly. Jurassic, Cretaceous and Miocene.
Sporadopyle Zitt. Cup- to funnel-shaped or conical, occasionally branching.
Canal -openings on the outer surface irregularly distributed, or arranged in
quincunx ; on the cloacal surface in vertical rows. Upper Jurassic. S. ohliqua
(Goldfuss).
Sphenaulax Zittel, Ferrucocoelia Etallon. Jurassic. Polyosepia Schrammen.
Upper Cretaceous.
Family 2. Ooscinoporidae Zittel.
Cahjcoid, heaker-like, lohafe, branching or stellately convoluted sponges, ivifh thin
toalls perforated on both sides by numerous canal-openings arranged in alternating
rows; canals short, ending
blindly. Framework com-
pact, with fine meshes;
dermal layer replaced by
thickening of the outermost
skeletal layer. Spicular
nodes solid, more rarely
p>erforate. Cretaceous.
Leptophragma Zitt.
Beaker - shaped, with
root - like attachment.
AValls thin, covered on
both sides with small
canal-openings arranged
in alternating rows.
Mesh-work very closely
woven, spicular nodes
solid. Middle and
Upper Cretaceous.
Pleurostoma Eoem. ; Guettardia Mich. ; Balantionella Schrammen. Cretaceous.
Coscinopora Goldf. (Fig. 71). Beaker-like, Avith branching roots. Ostia
small, round and in alternating rows. Skeletal elements in part with
perforated intersection nodes". Root consisting of long siliceous fibres. Dermal
layer formed by the thickening and fusion of outermost hexactins. Cretaceous.
Coscinopora infiindiMMformis Golclf. Upper Cretaceous ; Coesfekl, West-
phalia, a, Complete specimen, i/o natural size ; h, Outer surface, natural
size ; c, Same, 3/j ; d, Skeleton of cup, 12/1 ; e. Skeleton of root, I'-^/j.
Family 3. Staurodermidae Zittel.
Turbinate, funnel-shaped or cylindrical, more rarely branching or in clumps.
Ostia and postica irregularly distributed, or in alternating rotvs. Skeletal frametvork
more or less regular; intersection nodes thick or octahedrally excavated. The
outer or both surfaces of the wall provided with large, stellate spicules (stauractins),
tohich differ from those of the rest of the skeleton, and are either but loosely cemented
together or are embedded in a continuous siliceous skin. Jurassic and Cretaceous.
Cypellia Zitt. (Fig. 72). Top-shaped, bow-shaped or branching, without
root. Canals irregularly distributed, crooked, and branched. Lattice
skeleton with irregular meshes, intersection nodes perforated. Dermal layer
OKUER IV
SILICISPONGIAE— HEXACTINELLIDA
65
composed of large, foui"-rayed stauractins embedded in a thin, continuous or
perforated skin. Very common in Upper Jurassic Spongitenkalk.
Stauroderma Zitt. Funnel-shaped or plate-like, with broad and shallow
cloaca, into which the large, round postica of short canals open. Inner and
outer surfaces provided with dermal layer, in which stellate spicules are
embedded with reduced externally and internally directed rays. Upper
Jurassic.
Casearia Quenst. Cylindrical, with numerous annular constrictions.
Cloaca deep, tubiform; dermal layer relatively thick, and made up of
cemented stellate spicules. Upper Jurassic. C. articulafa (Goldfuss).
Porospongia d'Orb. (Fig. 73). Compressed and expanded, more rai-ely
bulbous or cylindrical. Superior surface pitted with large exhalent apertures
of short, blindly terminating cloacae, and covered over with a dense or finely
perforate siliceous skin, in which cruciform spicules and regular hexactins are
k -^^^
k' ^^te^^ss - jSi^2liiSi>
Flfi. 72.
Cypellia rufiosa (Goldfuss). Upper Jurassic ; Streit-
berg, Franconia. a, Sponge, 1/2 natural size ; b, c,
Dermal layer, i-/x.
Fig. 73. «
Porospongia i»y)?'cssa (Goldfuss). Upper Jurassic ;
Muggenrtorf, Franconia. a, Fragment in natural size ;
6, Dermal layer, "/i ; c. Skeleton, 12/j.
embedded. Lattice skeleton with cubical meshes ; intersection nodes imper-
forate. Upper Jurassic.
Family 4. Ventriculitidae Toulmin Smith.
IFall intricately convoluted ; folds radially disposed, generally vertical in direc-
tion. Radial canals ending hlindhj. Longitudinal furrows developed along folds of
the wall, and either open, or partially covered over with a dermal layer, which is usnally
formed by thickening of the outer skeletal layer. Skeletal frametvork with octahedrally
perforated nodes. Roots consisting of elongated siliceous fibres united by transverse
bridges and without axial canals. Jurassic and Cretaceous.
Pachyteichisma Zittel (Fig. 74). Turbinate or bowl-shaped, with very thick,
convoluted wall. Folds separated on outer surface by deeply incised furrows,
on inner surface by shallow furrows. Framework extremely regular. Eoot
and dermal layer absent. Upper Jurassic.
Ventriculites Mantell (Fig. 75). Bowl-, plate-, beaker-, funnel-shaped, or
cylindrical, with wide cloaca. Wall thin, convoluted ; folds separated on both
sides by closely crowded longitudinal furrows. Lattice-work of skeleton more
VOL. I F
66
COELENTERATA— POEIFERA
PHYLUM II
or less regular ; outer layer thickened ; roots present. Common in Middle
and Upper Cretaceous.
Fio. 74.
Pachyicich-isma carteri Zittel. Upper
Jurassic ; Hohenpolz, Frauconia. a,
Sponge, 1/2 natural size ; b, Skeleton, 12/j.
Fig. 75.
Ventriculites striatus Smith. Quadra tenkreide ; Linden,
near Hanover, a, Sponge, i/.j natural size ; b, Transverse
section, i/x ; c. Skeleton, 12/1.
Fig. 76.
Coeloptycldum agan-oirhs Goldf. Upper Cretaceous ; Vordorf, near Brunswick. A, Top view. /;, Profilo.
C, Under surface, 2/3 natural size. D, Skeleton, co/j.
Schizorhahdus, EJdzopoterion, PolyUastidmm Zittel ; Sporadoscinia Pomel ;
ORDER IV
SILICISPONGIAE— HEXACTINELLIDA
67
Lepidospongia Roemer ; Leiostracosia, Pledodermafium, Microhlastidium Schram-
men, etc. Cretaceous.
Family 5. Ooeloptychidae Zittel.
Umbel- or mushroom-shaped, with stalk. Wall thin, deeply folded. Convolutions
radially arranged, becoming furcate toward periphery of umbel, and exposed on lower
surface. Marginal and
upper surface enveloped
with porous dermal layer
entirely covering the folds.
Ostia only- on under side
of umbel, situated on
backs of the folds. Frame-
work very regidar ; inter-
section nodes octahedral,
perforated ; rays of hex-
actins provided with
slender, thorny processes. PlocoscvphiapertusaGem.\ GreensancUCenomanian); Bauowitz, Kunsary.
^ ' , 1 ■ rt,lFragment in natural size Wh, Dermal layer, five times enlarged ; c, Skeleton
LoetoptyC Ilium of interior, i^/ii; d, Outward portion of skeleton, la/j.
Goldf. (Fig. 76), oc-
curring in the Upper Cretaceous of Northern Germany, England, and Southern
Russia, is the solitary genus.
Family 6. Maeandrospongidae Zittel.
Sponge body consisting of thin-walled, intricately labyrinthine, and partially
amalgamated tubes or foliae, which form tuberous, pyriform, beaker-shaped, or bush-
like branching stocks.
Between the tubes are
cavities and interstices
of considerable size,
which constitute the so-
called inter canalicular
system. Four canals
faintly developed. Der-
mal layer absent, or re-
presented by a continuous
silicious superficial skin.
Abundant in the Cre-
taceous, and also re-
presented by numerous
recent genera.
Plocoscyphia Reuss
Becksla sokdandi Schliit. Quadratenkreide ; Coesfeld, Westphalia. A, CPiq 77) CluniD-like
Sponge body, 1/2 natural size ; 0, Ostia of radial canals ; /, Hollow, root-like , * ,
processes of wall. B, Skeleton, 50/j. Or bulboUS StOcks con-
sisting of labyrinthic,
anastomosing tubes or foliae. Walls of tubes thin, perforated by numerous
small ostia. Latticed skeleton, intersection nodes solid or perforate. Cre-
taceous.
Fig. 78.
Becksia Schliiter (Fig. 78).
The thin walls of the shallow, beaker-like
68
COELENTERATA— PORIFERA •
PHYLUM II
sponge are composed of vertical tubes having a radial disposition and fused
with one another along the sides. Between the tubes are large interstices ;
near the base the tubes develop hollow, spinous processes. Lattice skeleton very
regular, exactly similar to Coeloptijchmm. Upper Cretaceous ; Westphalia.
Tremabolites Zitt. ; Etheridgia Tate ; Zittelispongia SinzofF, etc. Upper
Cretaceous.
Camerospongia d'Orb. (Fig. 79). Globular, sub-globulai-, or pyriform.
Fig. 79.
Camerospongia fiingiformis
(Goldfuss). Planerkalk ; Oppeln,
Silesia. Is'atural size.
Fig. so.
Cystispongia lursa Quenst. Cuvieri-Planer (Turonian) ; Salz-
gitter, Hanover, o, Sponge, natural size ; b, Dermal layer with
underlying skeletal framework ; c, Skeleton, i2/j.
Upper half of the body enveloped by smooth siliceous skin, and with large
circular depression on the summit ; lower half marked by undulating ridges
and furrows, and passing gradually into a stem. Interior of sponge body
consists of thin-walled, labyrinthous tubes. Upper Cretaceous.
Cystispongia Roem. (Fig. 80). Like the preceding, but with dense siliceous
skin punctured by large, irregularly shaped apertures, uniformly enveloping
the whole sponge body. Body composed entirely of tubes. Cretaceous and
still living.
Subclass 4. CALCISPONGIAE. Calcareous Sponges.
Skeleton composed of calcareous spicules of three-rayed, four-rayed, or uniaxial types.
The external form of the Calcisponges is quite as variable as that of the
siliceous sponges, and reminds one particularly of the Lithistida. Like the
Lithistids, too, the thick-walled Leucones and Pharetrones have a canal-system
consisting of a central cavity into which radial excurrent canals conduct ;
while the numerous tributaries of the latter end in ciliated chambers which
are fed by fine incurrent canals. In the Sycones the wall is perforated by
simple radial tubes, but in the thin-walled Ascones it is pierced by mere holes.
The calcareous skeletal elements lie free in the soft parts, sometimes
forming but a single layer disposed in the same plane {Ascones) ; sometimes
their disposition is more or less distinctly radial, following the canal courses
(Sycones) ; sometimes they are irregularly crowded together (Leucones) ; and
ORDER I
CALCISPONGIAE— PHARETRONES
69
\
^
sometimes they are closely opposed in the form of solid anastomosing fibres
(Pharetrones). Regular triaxial spicules are of the most common occurrence,
next monaxial spicules, sharpened on both sides, and
more rarely four-rayed spicules.
Owing to the ready solubility of the skeletal elements
in calcareous sponges, they are usually but poorly pre-
served in the fossil state, and are ill-adapted for micro-
scopical investigation. The three -rayed and rod-shaped
spicules which are united in fibres are seldom distinctly
recognisable as such, since, as a rule, they are either
wholly or partially dissolved, and are converted into
homogeneous or crystalline fibres of calcite (Fig. 84) ; in
these minute threads of calcite may be seen radiating
in all directions from numerous centres of crystallisation. Sometimes such
calcareous skeletons afterwards become silicified. It is clear, therefore, that
the present chemical composition of a fossil sponge furnishes us no clue in
regard to its original chai-acter, since during the process of fossilisation a
Fig. 81.
Triaxial skeletal elements
of a Recent Ascon, 50/j.
Fio. 82.
Fibres of a Pharetrone, composed of three-
FiG. S3.
Fic;. 84.
Fibres of fossil calcareous
Solid fibres of fossil calcar-
rayed spicules. Peronidella cylindrica (Gold- eous sponge with partially sponge altered by crystallisa
fuss). Upper Jurassic, *o/i. preserved spicules, ''o/j. tion, -JO/i
siliceous skeleton may become converted into a calcareous, and a calcareous
into a siliceous.
Of the four orders of calcareous sponges — PharetroneS, Sycones, Ascones, and
Leucones — only the first two are of practical importance to the paleontologist,
traces of the others being either wanting or extremely fragmentary.
Order 1. PHARETRONES Zittel.
JFall thick ; canal system like that of the Lithistida, though sometimes indistinct
and apparently absent. Spicules arranged in solid anastomosing fibres ; a smooth or
corrugated dermal layer frequently present. Devonian to Cretaceous ; unknown in
Tertiary and Recent.
Eudea Lamx. Cylindrical or club-shaped, usually simple, rarely branching.
Cloaca narrow, tubiform, extending to the base, and terminating above in a
round osculum. Dermal layer smooth, perforated by ostia of short canals.
Triassic and Jurassic. E. clavafa Lamx.
Peronidella Zitt, (Peronella Zitt. non Gray ; Siphonocoelia, Polycoelia From.),
(Figs. 85, 86). Thick - walled, cylindrical, simple or branching. Cloaca
tubiform, extending to the base ; base sometimes covered by a dense dermal
layer. The rest of the exterior finely perforate. A distinct canal-system
70
COELENTERATA— PORIFERA
PHYLUM II
absent. The coarse, anastomosing skeletal fibres composed of closely packed
three-rayed and one-rayed spicules. Sparse in Devonian (P. constrida Sandb.) ;
common in Trias, Jurassic, and Cretaceous.
Fig. 85.
Peronidella cylin-
drica (Miinst.).
Upper Jura. ; Miig-
gendorf. x i/o.
Fig. 86.
Peronidella dvmosa (From.).
Hils ; Berklingeii, Bruns-
wick. Natural .size.
Fig. 87.
Corynella quensiedti Zitt. Coral - Rag ; Natt-
heiin. o, Sponge, natural size ; h, Skeletal
fibres, 4/i.
EusiphoneUa Zitt. (Fig. 88). Similar to preceding, but thin-walled, with
broad cloaca extending to
the base, into which con-
duct radial canals ar-
ranged in vei'tical rows.
External surface per-
forate. Upper Jurassic.
Corynella Zitt, (Fig,
87), Knob-like, cylindri-
cal, or top-shaped, thick-
walled, simple, or com-
posite. Cloaca funnel -
shaped, shallow, terminat-
ing below (in a series of
vertical branching tubes ; exhalent aperture often surrounded with radially
diverging furrows. Ostia
EusiphoneUa hronni
(Miinst.). Coral-Rag ;
Natthelm. Natural
size.
Oculospongia tu-
hulifem (Goldf.).
Kreidetuff ; Mae-
stricht. Natural
size.
Fig. 90.
Stellisponyia glomerata
(Quenst.). Coral - Rag ;
Nattheim. Natural size.
conducting
into
numer-
ously branching radial
canals, which unite again
in larger excurrent canals,
and open into the cloaca.
Common in Trias, Jur-
assic, and Cretaceous.
Stellispongia d'Orb,
(Fig, 90). Usually com-
j)osite stocks made up of
hemispherical, or short
pear-shaped persons, with Upper surface, natural size
base enveloped by com-
pact dermal layer. Summit dome-shaped, with shallow cloaca surrounded by
radial furrows ; radial and vertical canals terminating along sides and basis of
Fig. 01.
Elasmostoma acatirnaiyo Roem.
Hils ; Berkliugeu, Brunswick.
Fig. 92,
Ehaphido neina farringdonense
(Sliarpe). Lower Cretaceous
(Aptian) ; Farringdon, Berkshire.
2/3 natural size.
ORDER II
CALCISPONGIAE— SYCONES
71
cloaca. Skeleton constituted of short, blunt, and bent uniaxial, and also of
three- and four-rayed spicules. Triassic and Jurassic.
Holcospongia Hinde. Jurassic and Cretaceous. Sestromodella Zittel. Trias
to Cretaceous. Sympella Zittel. Cretaceous. Oculospongia (Fig. 89) and
Diplostoma From. Cretaceous.
Elasmostoma From. (Fig. 91). Foliate-, ear-, or funnel-shaped. Upper {i.e.
inner) surface covered with smooth dermal layer, in which large shallow oscula
are situated ; under surface cribriform. Cretaceous.
Bhaphidonema Hinde (Fig. 92). Beaker-, funnel-, or twisted leaf-shaped.
Inner or upper surface smooth, with very small oscula or pores. Outer surface
rough, cribriform. Canal-system indistinct. Trias, Jurassic, Cretaceous.
Pachytylodia Zitt. Funnel-shaped, thick-walled ; base with smooth dermal
layer; oscula present here, but absent on other parts of the exterior. Skeleton
composed of very coarse, anastomosing fibres. Cretaceous. P. iiifundibuliformis
(Goldfuss).
Order 2. SYCONES Haeckel.
JFalls traversed by simple canals disposed radially with reference to the cloaca
arid opening into it. Skeletal elements very regularly arranged.
Mostly small delicate forms inhabiting shallow water.
Frotosycon Zitt., from the Upper Jurassic of Streitberg, is a small, cylin-
drical, or conical form agreeing with living Sycons in the arrangement of its
radial canals.
To the Sycons, RaufF assigns also the calcareous sponge Sphinctozoa described
by Steinmann (Jahrb. f. Mine- a
ralog. 1882, II. p. 139), which is
distinguished from all other
Calcisponges by having a most
remarkable segmentation, such
as occurs in the Lithistid genus
Casearia.
The oldest Sycons
Sollasia, Amblysiphonella
Sehargasia Steinm., from
Carboniferous Limestone
Asturias. In the Triassic of
St. Cassian and Seelandalp,
near Schluderbach in Tyrol,
are found Colospongia Laube,
Thaumastocoelia and Cryptocoelia Steinmann. Thalamopora Roemer and Barroisia
Steinm., occur in the Lower and Middle Cretaceous.
Barroisia {Ventriculites Zitt. non Defr. ; Sphaerocoelia Steinm.) (Fig. 93).
Occurs sometimes as simple, cylindrical, or clavate individuals, and again in
the form of bushy stocks. Outer surface frequently constricted, summit
arched, with osculum in the centre, cloaca tubiform. The cylindrical indi-
viduals are composed of thin-walled, hemispherical, or compressed segments,
which are so arranged that the roof of one segment serves also as the floor of
the next following. The wall is everywhere perforated by simple radial canals,
are
and
the
of
Fig. 93.
Barroisia anastomans (Mantell). Aptian ; Parringdon, Berk-
shire. A, Bush -like colony, one branch sliced open ; natural
size. B, Individual cut through obliquely, 5/2 ; «, Junction of
two segments ; B, Cloaca ; 0, Osculum ; d, Radial canals. C, D,
Three-rayed skeletal spicules, 36/j and '-/i (after Steinmann).
72 COELENTERATA— PORIFERA phylum ii
and is made up of fibres composed of three-rayed spicules, B. helvetica (Lor.).
Aptian ; La Presta, Switzerland.
Appendix to Sponges.
Incertae sedis.
Family. Receptaculitidae Roemer.i
This singular group which ranges throughout the Ordovician, Silurian,
and Devonian systems, consists of globular, cup-, or platter - shaped bodies
containing a central cavity, and whose wall is composed of elements arranged
in quincunxial order. The substance of the wall is thought by Hinde to have
been siliceous ; calcareous according to Rauff ; aragonite according to Giimbel ;
calcite or chitinous according to Billings, either aragonite or chitinous in the
opinion of Girty. The elements lying on the outer or under side of the wall
have been usually described as consisting of small rhomboidal plates having
four transverse rays disposed crosswise, and one inwardly directed ray ; but
Girty has found evidence that the spicular summit plates are infiltrations of
the rhombic pits of the outer surface, and the radial pillars or spicules are
infiltrations filling radial tubes.
The systematic position of these problematic fossils is wholly conjectural.
Giimbel assigns them to the calcareous algae (Dactijloporidae), and others to
the Foraminifera and Sponges. Hinde has referred them to the Hexadinellida,
but the observations of Rauff and Girty as to the original calcareous and
chitinous composition of the wall disprove this inference.
Eeceptaculites Defrance. Spherical or pyriform bodies, with a central closed
cavity. Ordovician to Carboniferous. Europe, America and Australia.
Ischadites Murchison {Didyocrinites Conrad ; Dkfi/ocrimis Hall). Conical or
ovate bodies, inclosing a central cavity, with a small summit aperture and
lacking an inner layer. Ordovician to Devonian ; Europe and America.
Here are also referred Cijdocrinus Eichwald ; Pasceolus Billings ; Pohjgono-
sphaerifes Roemer; Cermiites Meek and Worthen; Lepidolites a,nd Anomalospongia
(Anomaloides) Ulrich.
Range and Distribution of Fossil Sponges.
The phylogeny of the Myxosfongiae, Ceratospongiae and a part of the Silici-
spongiae, owing to their' perishable organisation, remains involved in doubt.
1 Salter, J. ir., Canadian Orgauic Remains, Dec. 1, 1859.— ^a?Z, /., Pal. N. Y., vol. i., 1847 ;
Geological Report of Wisconsin, 1862 ; Sixteentli Rept. N. Y. State Cabinet Nat. Hist., 1863 ;
Twelfth Rept. State Geologist of Indiana, 1883 ; Palaeontology of New York, vol. iii., 1859 ;
Eleventh Rept. State Geologist of Indiana, 1882 ; Second Ann. Rep. N. Y. State Geologist, 1883 ;
Palaeontology of New York, vol. vL, 1887. — Ulrich, E. O., Jour. Cincinnati Soc. Nat. Hist., vol. i.,
1871; vol. ii., 1879. — Owen, J). J)., Geol. Report Iowa, Wisconsin and Illinois, 1844; Geol.
Survey of Wisconsin, Iowa and Minnesota, 1852.— Billinffs, E., Palaeozoic Fossils, vol. i., 1865 ;
Canadian Naturalist and Geologist, second ser., vol. ii., 1865 — Meek and Worthen, Geol. Survey of
Illinois, vol. iii., 1868. — Gilmhel, C. IT., Abhaudl. der k. bayr. Akad. Wisseusch., vol. xii., 1875. —
R.oemer, F., Lethaea Palaeozoica, 1880.— Hinde, G. J., Quart. Jour. Geol. Soc. London, vol. xl.,
1884. — James, J. F., Jour. Cincinuati Soc. Nat. Hist., vol. viii., 1885 ; vol. xiv., 1891. — Walcott,C. D.,
Mon. U. S. Geol. Surv., vol. viii., 188^.— Whitfidd, R. P., Geology of Wisconsin, vol. iv., 1884.—
Rauff, II., Zeit.schr. deut.sch. geol. Gesellsch., vol. .\i., 1888. — Nicholson and L>/dekker, Manual of
Palaeontology, vol. ii., 1889 Wiuchell and Srlnteliert, Geol. of Minnesota, vol. iii., pt. 1, Pal.
18^5— Ulrich, E. ()., ibid., ]\ 68.— Girl i/, G. I/., Fourteenth Ann. Rept. N. Y. State Geologist
for 1894, 1895. — Welli^r, S., Geol. Survey'of New Jersey, Rept. on Pal., vol. iii., 1903.
RANGE OF FOSSIL SPONGES 73
Nevertheless, isolated spicules prove the existence of Monactinellids and
Tetractinellids in Paleozoic seas ; while in the Trias, Jura and Cretaceous
these forms become important rock-builders, and play an active part in the
formation of hornstone, chalcedony and flint. In the Tertiary, spicules refer-
able to existing genera are common.
The former distribution of the three best preserved sponge groups — the
Lithistids, Hexactinellids, and Calcisponges — is noteworthy. The living repre-
sentatives of the first two orders inhabit deep or moderately deep water, while
the calcareous sponges predominate in shallow waters bordering the coast.
And hence, since fossil Calcisponges likewise occur almost entirely in marly,
clayey, or sandy strata of undoubted littoral origin, and are absent in lime-
stones where Lithistids and Hexactinellids predominate, it is plain that the
distribution of both fossil and Eecent sponges has been occasioned by like
physical conditions.
In the Cambrian occur the Lithistid genera Archaeoscyphia and Nipferella,
and in the Ordovician and Silurian of Europe and North America are found
a number of Tetradadina (Aulocopium) and Eutaxicladina forms (Astylospongia,
Palaeomanon, Hindia), together with a few Rhizomorina. In the Carboniferous
Rliizomorina and Megamorina are sparsely represented ; but in the Upper
Jurassic, and especially in the Spongitenkalk of Franconia, Swabia, Switzer-
land, and the Krakau district, the Lithistids exhibit an astonishing develop-
ment, and occasionally" form thick beds. They occur only sparingly in the
Lower Cretaceous, but are abundant in the Planer, Greensand and Upper
Cretaceous of Northern Germany, Bohemia, Poland, Galicia, Southern Russia,
England and France. The Tertiary being nearly everywhere made up of
shallow-water formations, the absence of Lithistids and Hexactinellids is not
surprising. They persist locally, however, as in the Upper Miocene of Bologna
and in the Province of Oran in Northern Africa.
The range of the HexadinelUda is in every respect similar to that of the
Lithistida. Beginning in the Upper Cambrian, they are represented in the
Ordovician and Silurian by peculiarly modified Lyssacina forms (^Protospongia,
Phormosella, Cyathophycus, Palaeosaccus, Pledoderma, Pattersonia, Bradiiospongia,
Didyophytoii, Astraeospongia). The same group continues also through the
Devonian, where Dictyophyton and its associates are conspicuous for their wide-
spread distribution in North America. A few aberrant Lyssacina, which Hinde
designates as Heteradinellidae, are found in the Carboniferous. During the
Mesozoic and Cenozoic eras the distribution of the HexadinelUda is nearly
identical with that of the Lithistida ; although here and there beds occur
which are charged principally with Hexactinellids, and others chiefly with
Lithistids.
Very diff'erent conditions are presented by the Calcisponges, among which
only the Pharetrones and Sycons are of geological importance. The oldest
calcareous sponges occur very sparsely indeed in the Middle Devonian and
Carboniferous Limestone. They appear in considerable diversity in the Alpine
Trias (St. Cassian and Seelandalp), but outside the Alps are almost wholly
absent. In the Jurassic they occur in marly beds of the Dogger (Ranville,
Swabia), and also in certain facies of the Malm (Terrain a Chailles, Coral-Rag
of Nattheim, Sontheim, etc.) in Southern Germany and Switzerland.
The Lower Cretaceous, particularly the Neocomian of Brunswick, the
Swiss Jura, and the Paris Basin, as well as the Aptian of La Presta, near
74 COELENTERATA— CNIDARIA phylum ii
Neuchatel, and Farringdon, Berkshire ; and also the Middle Cretaceous (Ceno-
manian) of Essen, Le Mans, and Havre, are characterised by an abundance of
well-preserved Pharetrones, and a lesser number of Sphinctozooid Sycons. In
the Tertiary, however, both groups are wanting, although the existence of
calcareous sponges is still indicated by occasional detached triactins. The
Pharetrones apparently become extinct at the close of the Cretaceous.
SuBPHYLUM II. Cnidaria.
The Cnidaria or Nematophora have a radially symmetrical body, and a
terminal mouth -opening suiTOunded by fleshy tentacles. In the ectoderm
(sometimes also in the entoderm) cnidoblasts are common, from the contents
of which thread-cells (nematoci/sts) filled with an urticating fluid and containing
a hollow, spirally coiled thread, are developed. Each cnidoblast possesses a
fine superficial process (cnidocil), which is very sensitive to mechanical stimuli.
The polyp wall typically consists of three layers : an outer ectoderm, an inner
endoderm, and a middle mesogloea. The mesogloea is sometimes entirely
absent, but the ectoderm and entoderm are strongly developed. The ectoderm
frequently secretes a calcareous or horny skeleton, and both ectoderm and
entoderm are concerned in the production of muscles and nerves. The sexual
organs are the product of the entoderm.
The Cnidaria are divided into two classes : Anthozoa and Hydrozoa. The
latter are undoubtedly the more primitive group, but it will be convenient to
treat of the Anthozoa first in the present work.
Class 1. ANTHOZOA = ACTINOZO A. Coral Polyps.^
Usually sessile, cylindrical polyps, possessing a mouth surrounded hy tentacles,
oesophagus, and gastrovascular cavity. The latter is divided by numerous vertical
partitions (mesenteric folds) into a system of radially disposed pouches. A calcareous
or horny skeleton is freqitently developed. Simple or forming colonies.
The simple polyp zooids have the form of a cylindrical or conical tube
at the distal end of which is situated a muscular disk perforated centrally by
^ Literature : Milne Edioards, H., et Ilaime, J., Histoire naturelle des coralliaires, 3 vols, and
atlas. Paris, 1857-60. — Idem, Monograplue des polypiers fossiles des terrains paleozoiques. Arch, du
Museum, Paris, vol. v., 1851. — Idem, Monograph of the British Fossil Corals. Palaeontogr. Soc,
1849-64. — Fromentel, E. de. Introduction a I'^tude des polypiers fossiles. Paris, 1858-61. — Idem,
Paleoutologie frangaise ; 1861 and later. — Reuss, A. E., Articles in Sitzber. Akad. Wiss. Wien, 1859,
1864, 1865, 1870 ; also Denkschr. vols, vii., xxiii., xxviii., xxix., xxxi., xxxiii. — Duncan, P. M., British
Fossil Corals, 2d ser. Palaeontogr. Soc. 1865-69, and 1872. — Idem, Revision of the Families and
Genera of the Sclerodermic Zoantharia or Madreporaria. Journ. Linn. Soc. Zoology, 1885, vol.
xviii. — Kohy, F., Monographic des polypiers jurassiques de la Suisse. Abhandl. Schweiz. Pal. Ges.,
1880-94, vols. vii. -xxii. — Pratz, E., Ueber Septalstructur. Palaeontogr. 1882, vol. xxix. — Koch,
G. von. Die ungeschlechtliche Verniehrung der palaozoischen Korallen. — Ibid., 1883, vol. xxix. —
Quenstedi, F. A., Petrefactenkunde Deutsclilauds, 1889, vol. vii. — Koby, F., Monographic des poly-
piers cretaces de la Suisse. Alihandl. Schweiz. Pal. Ges. 1896-98, vols, xxii.-xxiv. — Ogiivie- Gordon,
Maria M., Korallen der Stramberger Schichten. Palaeoutographica, Supp. II., 1897. — Idem,
Systematic Study of Madreporarian Types of Corals. Phil. Trans. Roy. Soc. London, 1897, ser.
B, vol. clxxxvii. — Gregory, J. W., 1'he Corals, Jurassic Fauna of Cutch. Palaeontol. Indica, 1900,
ser. 2, vol. ix., pt. 2. — Vaughan, T. Wayland, Eocene and Lower Oligoceue Coral J^'aunas of the
United States. Mon. xxxix, U.S. Geol. Survey, 1900. — Idem, Critical Review of the Literature on
•the simple Genera of the Madreporaria Fuiigi<la. Proc. U.S. Nat. Mus., 1905, vol. xxviii. —
Duerden, J. E., West Indian Madreporai'ian polyi^s. Mem. Nat. Acad., 1902, vol. \\\\.—Idem,
CLASS I
ANTHOZOA
75
the slit-like or oval fissure of the mouth. The oral disk is fiu-nished with a ring
of tentacles round its margin, and opens into a membranous oesophageal tube
conducting into the gastric cavity. The outer covering of the body, the parts
of which are designated as wall, oral disk, and pedal disk, are constituted of
ectoderm and entoderm, between which is a thin layer of mesoderm (mesogloea).
Six, eight, or more radially disposed vertical partitions {mesenteries), (Figs. 94,
95), projecting inwardly from the body-wall, divide the gastric cavity into a
series of radiating compartments {mesenteric pouches). The mesenteries are
continuous upwardly with the hollow, muscular tentacles ; while the generative
organs are attached to their faces near the lower end of the body. The
mesenteries are covered on both sides with muscular tissues, and bear mesen-
teric filaments on their curled inner edges. On one side of the mesenteries
the muscle fibres are transversely directed, on the other longitudinally. The
longitudinal system is usually considerably folded and thickened ; and the
disposition of these
muscular portions is of
great importance from a
systematic standpoint,
since it reveals the
bilateral symmetry of
many Anthozoans, and
enables one readily to
identify the antimeres.
If a polyp individual be
cut in two by a plane
passing through the Pi^. 94,
longer axis of the Diagrammatic section of
month nnpnina thpn in *''^*' ^°*^ P^'"'^'* °* ^" '^'^*°'
mOUtn-Openmg, tnen, in coraUa(Alcyonimn). sc.Oeso-
the OctOCOralla (Fig phagus ; 1 2 3 4 Mesen-
. ^ '^. tenes of the left side (alter
94), the mesenteries 01 r. Hertwig).
the right half will have
all the muscular thickenings disposed on the right-hand side, and those of the
left on the left-hand side. In the Hexacoralla (Fig. 95) the mesenteries are
grouped in pairs, with the muscular thickenings of any pair facing each other.
Two pairs, however (those corresponding with the opposite extremities of the
longitudinal mouth), form often an exception to this rule, since these have the
muscular thickenings placed on opposite sides. These are called the directive
mesenteries, and serve to indicate the longitudinal axis of the body.
Only a few Anthozoa have permanently soft bodies ; the majority secreting
calcareous, horny, or partly horny and partly calcareous structures, termed the
skeleton or corallum. The simplest form of corallum is that composed of
microscopic, round, cylindrical, acerate, or tuberculated spicules of carbonate
Diagrammatic section of the soft parts of
a HexacomUa. In the upper half (above the
line a — 6) the section passes through oeso-
phagus s ; in the lower half, beneath the
same. Corallum indicated by heavy lines,
r, directive mesenteries.
Morphology of tlie Madreporaria. A series of papers in Ann. and Mag. Nat. Hist., ser. 7, vols, ix.,
X., xi., xvii.,xviii. (1902-1906), and Biol. Bull.,vols. vii. and ix. (1904-1905).— /rfem, Recent Eesults on
the Morphology and Development of Coral Polyps. Smithsonian Miscellaneons Collections, Quart. Iss.,
1904, vol. xlvii. — Felix, J., Die Anthozoen der Gosan Schichten in den Ostalpen. Palaeontographica,
1903, vol. xlix. Numerons other papers, especially in Zeitsch. deutsch. geol. Gesellsch. — Carruthers,
R. a., The primary Septal Plan of the Rugosa. Ann. and Mag. Nat. Hist. 1906, ser. 7, vol. xviii.—
Gordon, G. E., Studies on early Stages in Paleozoic corals. Am. Jour. Sci., 1906, vol. xxi. — Broimi,
T. C, Studies on the Morphology and Development of certain Rugose Corals. Ann. N.Y. Acad. Sci.,
1909, vol. xix.
76
COELENTERATA— CNIDARIA
PHYLUM II
of lime, which are developed in great quantities and remain detached in the
soft parts (many Alcyonaria). In a number of forms {Corallium, Mopsea,
Tubipora) the spicules are firmly cemented together by means of a calcareous
or horny connective substance, in such a manner as to form tubes (Tubipora),
or, when the secretion takes place chiefly at the base, a sclerobase, or axis.
Surrounding the axis is the soft coenosarc in which the polyps of the colony
are embedded (Fig. 96). In some cases the sclerobase is composed entirely of
horny matter without admixture of calcareous secretions. In the so-called
"stone corals" (Fig. 97) a consistent calcareous skeleton is formed by the
outer surface of the ectoderm. At the base of the polyp between each pair
of mesenteries, the infolded ectoderm secretes small, round, oval or irregular
calcareous bodies (sderites) ; these are opposed against one another in radial
directions, and as others are successively laid down on top of them, upright
Fk:. 96.
Corallium, rubrum Lam. (after Lacaze-Dutliiers).
Branch of red coral of commerce laid open along the axis,
and showing three polyps in section embedded in lleshy
coeiio.sarc.
Fig. 97.
Astroides calycularis (Lamx.). Mediterranean
(alter Lacaze - Duthiers). Enlarged longitudinal
.section of polyp with calcareous skeleton. te,
Tentacles ; oc, Oesojjhagus ; me, Mesentery ; loc,
Mesenteric pouches ; cue, Coenosarc ; spt, Septum ;
col. Columella.
partitions or septa are built up. Early in development also, after fixation of
the larva, the basal plate becomes calcified, owing to the secretion by the outer
surface of the ectoderm of numerous minute calcareous granules [calicoblasts).
The septa, however, grow considerably above the base, and become lodged in
the vertical interspaces between the mesenteries. In the same manner, within
the soft body-wall, a calcareous secretion may take place, binding the outer
borders of the septa together, and known as the wall or theca. Both septa and
theca are composed of minute, densely crowded calcareous bodies, in which
delicate calcareous fibres may be seen radiating in all directions from a central
dark space. And since all the calcareous bodies forming the sejDta have a
radial disposition, the calcification-centres as seen in transverse sections form
.a dark, mostly interrupted and occasionally jagged median line, from which
bundles of minute fibres radiate outward in all directions. Similar calcification-
centres may also be found in the theca. Sometimes the median dark line is
uiiinterrnpted and divides the septum into two separate lamellae.
CLASS I
ANTHOZOA
77
The interstices between the sclerites forming the septa are either com-
pletely filled with carbonate of lime (Aporosa), or there remain larger or
smaller porous spaces (Perforata) ; in many cases, in fact, the septa are
represented by a loose network of sclerites piled up vertically, or merely by
vertically directed spines.
The number of septa and of tentacles is either equal to the number of
pairs of mesenteries (when only entocoelic septa are present), or double that
of the pairs of mesenteries (when both exocoelic and entocoelic septa and
tentacles are present), and is somewhat uniform throughout species, genera
and higher groups. The number, Avidth and mode of formation of the
septa furnish important systematic characters. As the locus of the origin of
the septa succeeding the primaries may conform to one of several plans, this
character is used in determining the major groups. The upper edges of the
septa are sometimes smooth, sometimes
serrated or granulated ; and they extend
from the central depression to or through
the walls of the theca, either obliquely or
in a curved line. This open, central depres-
sion, formed by the superior edges of the
septa, is known as the calice or calyx.
The sides of the septa are rarely smooth,
but are commonly granulated or furnished
with rows of small prominences ; occasion-
ally they are provided with well-marked
vertical cross-bars (carinae). When the
projections on the sides of the septa are
in the form of conical or cylindrical trans-
verse bars, they are termed sijnapticulae.
Frequently the synapticulae of two adjacent
septa become joined together; sometimes
whole rows of them are fused together
to form perpendicular bars, thus greatly
strengthening the septal framework. In
some corals (athecalia) the development of tabulae
synapticulae is such as to render an outer
wall superfluous. With the upward growth of the polyp, the theca gradually
becomes elevated, and its lower portions, as their occupation by the soft parts
ceases, may be partitioned off by numerous horizontal or oblique calcareous
plates which bridge over the interseptal spaces. These structures are known as
dissepiments and tabulae. The tabulae are often nothing but highly developed
dissepiments, being distinguished from the latter merely by the fact that they
extend across between the septa at the same level ; sometimes they are
perfectly horizontal, sometimes they are arched or funnel-shaped (Fig. 98),
and sometimes incomplete. Dissepiments and tabulae are most strongly
developed in cylindrical forms, and frequently fill the included space within
the theca with a vesicular or cellular tissue.
When a number or when all of the septa are produced as far as the centre
of the calice, their inner edges may become twisted so as to form an axial
structure, known as a pseudocolumella. Sometimes, however, a true columella
is present ; this may be either a compact, styliform or foliaceous structure, or
Fig. 98.
Lithostrotion
wnrtini B. and H.
Longitudinal sec-
tion showing
Fio. 99.
CixryophylUa cijathns Sol.
Corallum split open longi-
tudinally ; true columella
in the centre, surrounded
by a cycle of pali.
78 COELENTERATA— CNIDAEIA phylum ii
may be composed of a bundle of styliform or twisted rods (Fig. 99), or of thin
lamellae. It extends from the floor of the visceral chamber to the bottom of
the calice, into which it projects for a greater or less distance. The structures
known as pali are narrow vertical plates which are inserted between the colu-
mella and the inner ends of the septa in one or more cycles (Fig. 99).
The outer wall or theca is often formed by the secretion of a particular
ring-like fold of the ectoderm, and is constituted of distinct sclerites, having
separate calcification-centres, and connecting the outer borders of the septa
(euthecalia). In many cases the peripheral edges of the septa become thickened
and laterally fused to form a spurious theca (pseudothecalia) ; and occasionally
the dissepiments lying in a certain zone become united so as to form an inner
wall within the true theca. The epitheca is a usually smooth, sometimes corru-
gated, superficial calcareous investment, which, according to Koch, is merely a
prolongation of the basal plate, and is secreted by the outer surface of the
ectoderm, which is reflected over the top of the corallum. The epitheca is
deposited either directly upon the septa, or upon the theca, or, when the septa
are produced outwards so as to form exothecal lamellae or ribs (cosfae), the
theca and epitheca are separated. Exothecal lamellae, not corresponding in
position to the septa, are called pseudocostae or rugae.
New individuals or colonies commonly originate by sexual reproduction.
Following fertilisation and segmentation of the ova, ciliated larvae are born,
which swim about for a time, become fixed, and develop into simple polyp
individuals. Vegetative or asexual increase by two sharply defined processes,
namely, budding (or gemmation) and fission, assumes a great importance among
Anthozoans, resulting in the production of colonies or stocks, often of large
size and exceeding complexity of form.
New corallites are produced either within or without the calice of the
parent polyp. In extra-calicinal gemmation the buds are thrown out either
from the sides of the polyp (lateral gemmation), or are formed in the common
calcareous matrix which unites the various corallites of a colony (coenemhymal
and costal gemmation). In both cases the new corallites may diverge from one
another, being attached to the parent corallum only at the base, or they may
grow up closely opposed to the latter and to one another, so that the thecae
are in contact on all sides. In this way branched, dendroid or massive and
knob-like ("astraeiform") compound coralla are formed. A less common
mode of increase is by hasal or sfolonal gemmation. In this process the wall of
the original polyp sends out creeping prolongations (stolons) or basal expansions,
from which new corallites arise. In calicinal gemmation buds are produced
within the calice of the parent corallite, according to one or the other of the
following methods : either certain particular septa become enlarged and pro-
duced so as finally to enclose a new calicinal disk (septal gemmation) ; or tabulae
are produced upwards in the form of pockets, from which new corallites are
developed {tabular gemmation). In both septal and tabular gemmation, a portion
of the parent corallite including a part of the original wall is concerned in the
formation of buds ; while the septa or modified tabulae are converted into
portions of the new thecae, from which new septa then begin to grow inwards
towards the centre.
A peculiar kind of calicinal gemmation is that known as rejuvenescence. In
this method only one bud is formed within the parent calice, but it enlarges
until it completely fills the latter. By the indefinite repetition of this process, a
CLASS I ANTHOZOA 79
corallum is formed, consisting of a succession of cups placed one within the other,
of which only the youngest and uppermost is occupied by the living animal.
The beginning of reproduction by fission is marked by an elongation or
distortion of the parent calice, accompanied by the contraction of the Avail at
opposite points along the margin. The constriction may proceed until it
divides the oral disk into two halves ; or two opposite septa may unite to form
a new theca. By this method branching, massive or " astraeiform " colonies
are produced, which do not differ essentially from those formed by budding.
Frequently, however, individuals formed by fission become only imperfectly
separated, remaining proximally more or less closely confluent. In such cases
the calices form continuous, straight, curved or labyrinthic furrows, with more
or less clearly distinguishable centres.
The compound corallum of a polyp stock I'emains practically the same as in
solitary individuals, excepting that the conditions are more complicated when
the separation of the zooids is incomplete. Dendroid and massive colonies
frequently develop a common connective matrix or tissue (coenenchyma) which
unites the various corallites into a whole ; it is secreted by the common
colonial flesh, called coenosarc, which extends as a carpet between the polyps,
The coenenchyma is sometimes dense in structure (Oculinidae), or it may consist
of a vesicular or tubular tissue. The separate corallites are often also united
by means of the septa, which are produced over and beyond the thecae, and
fused with those of neighbouring individuals. In such cases the interseptal
loculi are almost always filled with strongly developed dissepiments. All
structures developed in the included space within the theca, with the exception
of the septa and columella, are designated collectively as endotheca ; those lying
without the theca as exotheca.
The Anthozoa are exclusively marine forms, and predominate in shallow
water. Many of the Adiniaria, Antipatharia and Madreporaria occur also at
greater depths, ranging from 50 to 300 and sometimes to over 3000 fathoms.
The so-called reef-corals inhabit depths usually not exceeding 45 metres, and
require a temperature of the water of 20° C, or higher. Hence, existing
coral-reefs are restricted to a zone extending about 30° on either side of the
equator ; they are distinguished according to form as fringing reefs, barrier
reefs and atolls. While the stony corals (Porites, Acrop)ora, Tnrhinaria,
Pocillopora, numerous " Astraeidae" and Fungidae) and the .Alcyonarians
(Heliopora) are the most important, they are not the only agents concerned in
the formation of reefs, as an active part is also played by the Hydromedusae
(Milleporidae), calcareous algae (Lithothamnium, Melohesia), mollusks, echino-
derms, bryozoans and worms. Of the ancient coral-reefs which have been
formed in nearly all of the great geological periods, those of the Cenozoic and
Mesozoic periods are composed in part of genera similar to those now living ;
while those of the Paleozoic represent genera and families that are now
principally extinct, and whose relation to living forms is often quite uncertain.
The Anthozoa are divided by Haeckel into three subclasses : Tetracoralla,
Hexacoralla and Alcyonaria or Odocoralla. Of these the two first-named groups
are by some authors collectively termed Zoantharia.
80 COELENTERATA— ANTHOZOA phylum ii
Subclass 1. TETRACORALLA Haeckel/
(Zoantharia Bugosa Milne Edwards ; PterocoralUa Freeh.)
Extinct, Paleozoic, simple or composite scleroderm,ic corals, with septa arranged
according to a tetrameral system, and either hilaterally or radially symmetrical ;
without coenenchyma, hut with usually strongly developed endothecal tissue in the form
of tabulae or dissepiments, and with well-marked, frequently wrinkled epithecal wall.
The Tetracoralla are especially characterised by having the septa, subse-
quent to the formation of the primaries, introduced along four lines rising
from the apex of the base of the corallum. The earlier stages of the Tetra-
coralla have recently been reinvestigated by Duerden, Carruthers and others.
Duerden concluded that the observations of Ludwig and Pourtales on the
primary hexamerism of these corals were correct. According to Carruthers,
in the developing young Tetracoralla the first stage of septal formation is for
a single septum to stretch entirely across the calice from wall to Avail. This
septum, which is called the axial septum, later breaks up to form the main
(cardinal) and the counter septum of the mature coral. In the next stage a
small septum appears on each side of the main septal end of the axial septum.
These two septa form the alar septa of the mature corallum. In the third
stage two other septa appear, one on each side of the counter septal end of the
axial system. After the formation of these six ^epta there is a distinct pause
in the formation of new septa and any irregularity in the dispos'ition of the
septa is corrected. Four of the six septa are called principal, and are con-
spicuous in the later septal arrangement ; these four are the main, counter,
and alar septa. Two of the first six septa, one on each side of the end of the
counter septum, are not so prominent in subsequent development.
There is a controversy as to whether the primary septa of the Tetracoralla
are four or six in number : Duerden and Carruthers holding the number to be
six, while Brown and Gordon contend that it is four. The four principal septa
are sometimes of equal proportions, when they may be either stouter and
longer than the others (Stauria), or thinner and shorter (Omphyma) ; or they
may be of unequal proportions. Of the two principal septa which lie in the
longitudinal axis of the corallum, one (called the main or cardinal septum) is
frequently situated in a depression or furrow known as t\iQ fossula (Fig. 100) ;
while the other or counter septum is either normally developed, or is more or
less reduced. Occasionally the counter septum is placed in a fossula, while
the cardinal septum is normally developed ; but the two laterally disposed or
alar septa are always equal in size. The remaining septa not infrequently
exhibit a well-marked radial arrangement, in which the longer and more
strongly developed usually alternate with the shorter and less strongly
developed. New septa, according to Kunth and Dybowski, are inserted in
the following order. First, a new septum is given off on either side of the
1 Tjiterature : Kunth, A., Beitriige zur Kenntniss fossiler Koralleii. Zeitschr. deutscli. geol.
Ges., 1869-70, vols, xxi., xxii. — Dyhowski, W. N., Monograpliie tier Zoantharia Rugosa, etc. Archiv
fiir Naturkunde Liv-, Est-, imd Kurlands, 1874, vol. v. — Roemer, F., Lethaea Palaeozoica, 1883,
pp. 324-416. — &chliHcr, Clem., Antliozoeu des rlieinischen Mittel-Devons. Aljluuidl. preuss. geol.
Landes-Aiistalt, 1889, vol. viii. — Brown, T., Studies ou the Morphology and Development of certain
Rugose Corals. Ann. N.Y. Acad. Sci., 1909, vol. xix. — Faurot, L., Affinites des Tetracoralliaires
et des Hexacoralliaires. Annales de Palcont., 1909, vol. iv.
SUBCLASS I
TETRACORALLA
81
cardinal septum (Fig. 100, h), and takes up a position parallel with the alar
septum. This leaves an intermediate space between the cardinal and the
newly formed septa, which becomes filled, however, by the repeated insertion
of new septa one above the other in the same manner as the first ; and hence
they diverge from the cardinal septum, as they grow upward, in a pinnate
fashion. Likewise the two counter quadrants lying between the alar and
counter septa become occupied by lamellae which are given off from the alar
septa, and gradually arrange themselves parallel with the counter septum.
The mode of growth in the Tctracoralla will be readily understood on inspect-
ing the surface of those specimens, the septa of which are visible on the
exterior, or where the wall is readily removed by corrosion or polishing. One
may then note three distinct lines extending from the calicinal margin to the
base ; these mark the cardinal and the two alar septa, from which the other
pinnately branching septa are directed obliquely upward (Fig. 101). The
order in which the septa are given
off in the four quadrants, according
to Kunth, is indicated by the
numerals in Fig. 100.
Many of the Tetracoralla multiply
only by sexual reproduction, and occur
only as single individuals ; asexual
reproduction takes place usually by
calicinal, more rarely by lateral gem-
mation, and results in dendroid or
massive colonies.
Dissepiments are generally abund-
antly developed between the septa,
which latter are compact, and the
upper edges of which are either
smooth or serrated. Sometimes the
dissepiments fill the whole interior
with a vesicular tissue, and the
central visceral cavity is frequently
entirely partitioned off by horizontal,
inclined or funnel-shaped tabulae. The Wall is usually composed of the
thickened and fused septal edges ; sometimes it is invested with epitheca
and furnished with vertical rugae or root-like processes. A true coenenchyma
is absent. In a few genera the calice is provided with a lid or operculum,
which may be composed of one (Calceola) or of several plates (Goniophyllum).
With the exception of a few genera the systematic position of which is
uncertain, all the typical Tetracoralla are confined to the Paleozoic rocks.
Fig. 100.
Menopli yll am tenuimnr-
ginatinn B. and H. Car-
boniferous Limestone ;
Tournay, Belgium. 2/j.
h, Cardinal septum ; g,
Counter septum ; s, Alar
septa.
Fig. 101.
Streptelasma profundum
(Owen). Ordovician ; Cin-
cinnati, Ohio. Natural
size.
Family 1. Oyathaxonidae Milne Edwards and Haime.
Turbinate or horn-shaped simple coralla. Septa with regular radial arrange-
ment. Tabulae and dissepiments absent. Silurian to Permian.
Cyathaxonia M-ich. (Fig. 102). Acutely pointed, conical. Cardinal septum
in fossula. Septa numerous, extending inward as far as the strongly developed
styliform and considerably elevated columella. Carboniferous limestone ;
Belgium and England.
VOL. I
G
82
COELENTERATA— ANTHOZOA
PHYLUM 11
Duncanella Nich. Corallum top-shaped. Septa nearly all of uniform
length and size, forming a spurious columella in centre of the deep calice,
exsert at the base. Silurian ; North America. D. horealis Nich,
Petraia Miinst. (Fig. 103). Turbinate or conical. Septa short, reaching
to the centre only at the base of the very deep calice. Columella absent.
Ordovician to Carboniferous.
Folycoelia King (Fig. 104). Horn-shaped. Calice very deep ; four prin-
cipal septa reach nearly to its centre, between which in each quadrant are
five shorter septa. Zechstein.
Kanophyllmn Dyb. Ordovician and Silurian.
Fio. 102.
Cyathaxonia
cornu Mich. Car-
boniferous Lime-
stone ; Tournay,
Belgium. Cor-
allum with
fractured theca,
showing open in-
ter.septal loculi.
2/i.
FiQ. 103.
Petraia radiata
Miinster. Devonian ;
Enkeberg, near
Brilon. i/j. o, Cor-
allum viewed from
the apex ; b, Trans-
verse section below
the middle.
Fig. 104.
Folycoelia •pro-
funda (Germ.).
Zechstein;
Gera. i/i (after
Roemer).
Fig. 105.
Palaeocyclns por^nta
(Linn.). Silurian ;
Gotland. a, Top
view of calice ; i!;,
Fig. 106.
Microcyclus dis-
cus Meek and
Worth. Hamil-
ton (Devonian) ;
North America,
i/j. a, Corallum
from below ;
h, from above
(after Nicholson).
Family 2. Palaeocyclidae Dybowski.
Coralla simple, discoidal or bowl-shaped. Septa mimerous, stout, approaching
radial symmetry in disposition. Tabulae and dissepiments wanting.
Palaeocyclus E. and H. (Fig, 105). Discoidal to depressed top-shaped,
Avith epitheca. Septa numerous, radially disposed, the larger ones reaching
to the centre. Silurian. Type, P. porpifa (Linn.).
Combophyllum, Baryphyllum E. and H. Devonian,
Hadrophyllum E, and H. Cushion-shaped, with epitheca. Calice with
three septal fossula, that of the cardinal septum being the largest. Devonian;
Eifel and North America,
Microcyclus Meek and Worth. (Fig. 106). Like the preceding, but with
only one septal fossula, Devonian ; North America,
Family 3. Zaphrentidae Milne Edwards and Haime.
Coralla simple, turbinate, conical or cylindrical; septa numerous, exhibiting
distinct bilateral symmetry in arrangement. Theca generally formed by fusion of
septal ends. Tabulae completely developed ; dissepiments not very abundant in inter-
septal locrdi.
Streptelasma Hall (Fig. 107). Turbinate, often curved. Septa numerous
SUBCLASS I
TETRACORALLA
83
(80-130), alternately long and short; the free edges of the longer septa are
twisted together in the centre to form a pseudo-columella. Tabulae few or
absent. Position of the cardinal septum is recognisable on the exterior by the
system of pinnately diverging costal ridges. Common in Ordovician and
Silurian. S. pro-
fundum (Owen),
the type species,
has often been
confused with *S'.
corniculum and
various species of
Zaphrentis.
Zaphrenfis Raf .
(Caninia Mich.
pars) (Figs. 108-
10). Simple, tur-
binate or sub-
cylindrical, fre-
quently elongated.
Calice deep, with
circular margin. Septa numerous, reaching to the centre ; cardinal septum in a
deep fossula. Tabulae numerous; somewhat irregular, and passing from side to
side of the visceral chamber ; dissepiments sparingly developed in outer zone
of corallum. 50 to 60 species known, ranging from Silurian to Carboniferous.
Maximum development in Carboniferous.
Amplexus Sow. Simple, sub-cylindrical or elongated turbinate. Calice
Fig. 107.
Streptdasma profuiulwm (Owen). Cincinnatian Group
(Ordovician); Cincinnati, Ohio. Vi- ^, Side view.
/;, Transverse section. C, Longitudinal section, (h.
Cardinal septum ; g, counter septum ; s, alar septum.)
Fig. 109.
"'■ Zaphrentis cornucopiae
Zaphrentis cornicula Mich. Calice enlarged.
Lesueur. Devonian lime- Carboniferous Limestone ;
stone ; Ohio. Tournay, Belgium.
Fig. 110.
Zaphrentis ennislcilleni Nich. Carboniferous Lime-
stone ; A, B, Transverse sections through respectively-
upper and lower portions of calice. C, A long and two
short septa united at the ends to form the wall. D,
Longitudinal section showing tabulae (after Nicholson).
shallow, usually with septal fossulae. Septa moderately numerous, short,
never produced to centre. Tabulae highly developed, horizontal. Ordovician
to Lower Carboniferous. Type, A. coralloides Sow.
Aulacophijllum E. and H. Turbinate. Septa numerous, extending to
84
COELENTERATA— ANTHOZOA
PHYLUM II
centre. Cardinal septum in deep fossnla ; adjacent septa pinnately developed.
Ordovician to Devonian.
Menophyllum E. and H. (Fig. 100). Turbinate. Cardinal septum in
largest of three fossulae. Lower Carboniferous limestone.
Lophophyllum E. and H. Carboniferous limestone. Anisophylliim E. and
H. Ordovician to Devonian. Pycnopliyllum Lindstr. Ordovician and Silurian.
Apasmophylluni Roem. Metriophyllum E. and H. Thamnophyllmn Penecke.
Devonian. Penfaphyllum de Koninck. Carboniferous.
Family 4. Cyathophyllidae Milne Edwards and Haime.
Simple or composite coralla. Septa numerous, radially arranged; the four
principal septa rarely distinguished by greater or smaller size. Tabulae and
vesicular tissue (dissepiments) abundant.
Cyathophyllum Goldf. (Figs. 111-13). Extremely variable in form,
sometimes simple, turbinate or sub-cylindrical ; sometimes giving rise to
bushy, fasciculate or astraeiform colonies, where reproduction takes place by
Fig. 111.
Cyathophyllum caespitosum .Goldf.
Devonian ; Gerolstein, Eifel. Natural
size.
Fig. 112.
Cyathophyllum hexagonum, Goldf. Devonian ; Gerol-
.stein, Eifel. Natural size.
calicinal or lateral gemmation. Septa very numerous, strictly radial in
arrangement, and often alternately long and short ; the longer septa extend-
ing to the centre. Visceral chamber filled with numerous imperfectly
developed tabulae ; vesicular dissepiments highly developed in peripheral
portion. Nearly 100 species known, ranging from Ordovician to the Lower
Carboniferous. Maximum development in Devonian.
Campophyllum E. and H. (Fig. 114). Like the preceding, but septa not
extending to the centre. Devonian and Carboniferous Limestone.
Heliophyllum Hall. Usually simple and turbinate, more rarely forming
dendroid colonies. Septa numerous, extending to the centre, and thickened
on their sides by conspicuous vertical ridges ("carinae"). Devonian.
Diphy2)hyllum Lonsd. (Fig. 115). Ordovician to Carboniferous. Pholido-
phyllum Lindstr. Ordovician and Silurian; Eridophyllum E. and H. Silurian
SUBCLASS I
TETRACORALLA
85
I
and Devonian. Grepidophyllwm Nich. Craspedophyllum Dybowski. Devonian.
Koninckophyllum Nich. Chonaxis E. and H. Carboniferous. ClisiophyUum
Dana. Silurian to Carboniferous.
' OmphymaUai. (Fig. 116). Corallum simple, conical or turbinate; theca
Fig. 113.
(Jyathcq^hyllum heteropliyllmn B. and H. Middle De-
vonian ; Gerolstein, Bifel. A,y Transverse ; i>', Longi-
tudinal section (after Nicholson).
Fig. 114.
CmniwphyUum, com-
pressum Ludw. Car-
boniferous Limestone ;
Hausdorf, Silesia. a,
Longitudinal ; h, Trans-
verse section.
Fig. 115.
Dipliyphyllum con-
dniiiim Lonsd. Car-
boniferous Lime-
stone ; Kamensk,
Ural.
with root-like processes. Septa numerous ; the four principal septa in shallow
fossulae. Surface marked with pinnately branching striae. Tabulae numerous.
Silurian.
Chomphylhim E. and H. Silurian and Devonian.
W
Fig. 110.
OmpUyma suhturhinata B. and H. Silurian limestone ;
Gotland, Sweden, a, Side view ; h, Calice from above.
Fig. 117.
Lithostrotioii
martini E. and H.
Lower Carbonifer-
ous ; Hausdorf,
Silesia. Sections
of individual
eorallite (after
Kunth).
PtychophyUum E. and H. Simple and turbinate, or composite. Each
stock is composed of funnel-shaped, invaginated layers, representing calicinal
buds, the marginal lips of which are more or less reflected outwards. Septa
numerous and strongly twisted in the centre to form a pseudo-columella ; their
86
COELENTERATA— ANTHOZOA
PHYLUM II
peripheral edges are thickened and are fused with one another so as to form a
wall. Silurian (P. jnitellatum Schlot. sp.) and Devonian.
Cydophylhim Duncan and Thorn. Simple, cylindro-conical. Septa numer-
ous, the longer ones forming a thick pseudo-columella with enclosed spongy
_ tissue.
Aalophyllwn E. and H. ; Aspidophyllum, Eho-
dophyllum iSTich. and Thorns., etc. Carboniferous,
LitJiostrotion Llwyd (Stylaxis M'Coy ; Petalaxis
E. and H.) (Fig. 117). Fasciculate or astraei-
form stocks composed of prismatic or cylindrical
corallites. Septa numerous, alternately long
and short. Styliform columella in the centre.
Abundant in Carboniferous limestone.
Fig. 118.
Lonsdaleia floriformis Lonsd. Car-
boniferons Limestone ; Kildare, Ire-
land, i/j. a, Two cylindrical corallites,
partially split open ; h, Two hexagonal
calices, seen from aljove.
Fig. 119.
PMlKpsastrea hennahi (Lonsdale). Devonian limestone ; Ebersdorf,
Silesia, a, Upper surface ; 1j, Transverse section. Natural size.
Lonsdaleia M'Coy (Fig. 118). Fasciculate or astraeiform, composite
coralla. Septa well developed ; columella large, composed of vertically rolled
lamellae. Central tabulate area bounded by an interior disscpimental wall,
between which and the theca vesicular endotheca is abundantly developed.
Common in Carboniferous rocks.
Strombodes Schweigg. Astraeiform stocks composed of small prismatic
corallites. Septa extremely numerous, very slender, extending to the centre.
Fio. 120.
Stauria astraelformis E. and H. Silurian ; Gotlaml, Sweden. A, Transverse section parallel to upper
surface. B, Enlarged transverse section of individual corallite. C, Several calices from above. Natural size
(after Nicholson).
Theca imperfectly developed. Visceral chamber filled with infundibuliform
tabulae and vesicular tissue. Silurian (S. typus M'Coy sp.) and Devonian.
Pachyphyllum, Spongophyllum E. and H. Silurian and Devonian.
Acervularia Schweigg. Astraeiform or bushy colonies. Septa stout and
SUBCLASS I
TETRACORALLA
87
numerous. An interior wall is present ; tabulae are developed in the central
area, while the peripheral zone is filled with vesicular tissue. Silurian {A.
ananas Linn, sp.) and Devonian,
Phillipsastrea d'Orbigny (Fig. 119). Astraeiform colonies, with indi-
vidual corallites united by confluent septa, Avhich are produced beyond the
theca, and obscure the same. Interseptal loculi filled with vesicular endotheca.
Devonian and Carboniferous. Type, P. hennahi (Lonsd.).
Stauria E. and H. (Fig. 120). Astraeiform or bushy composite coralla.
Septa well developed; the four principal septa characterised by larger size, and
forming a complete cross in the centre of each corallite. Silurian (Wenlock).
Colunmaria Goldf. (FavisteUa Hall). Astraeiform stocks, composed of
long, polygonal, thick-walled corallites. Septa radially arranged in two cycles,
alternately long and short, barely reaching the centre. Tabulae horizontal,
disposed at regular intervals apart, and stretching across the entire visceral
chamber. Dissepiments imperfectly developed or absent. Ordovician to
Devonian.
Hetcrophyllia M'Coy. Carboniferous, Batiershyia E. and H. Devonian.
Family 5. Cystiphyllidae IMilne Edwards and Haime.
Usually simple coralla. Septa very thin ; interseptal loculi filled with vesicular
endotheca or compact st ere oplasma. 2'abidae absent; central area of visceral chamber
either completely filled with vesi- a
cidar tissue or stereopl'asma, or
containing the same only in the
lower portions of chamber. Cal-
careous operculum sometimes
present.
Gysttphyllum, Lonsd. (Figs.
121, 122). Simj)le, very rarely
forming bushy colonies. Calice
deep; the entire visceral cham-
ber filled with vesicular tissue,
which, as a rule, wholly
obliterates the numerous radi-
ally directed sejjta. Silurian
and Devonian.
Strephodes M'Coy (Fig.
123). Usually simple coralla.
Septa well developed, alter-
nately long and short, some-
times forming a pseud o-
columella. Silurian to Carbo-
niferous.
Goniophyll'um E. and H.
(Fig. 124). Corallum simple, in the form of a four-sided pyramid, and
covered with thick epithecal tissue. Calice deep ; septa numerous, thick
and very short. Entire visceral chamber filled with vesicular and stereo-
plasmic endotheca. Operculum composed of four plates symmetrically
paired. Silurian.
Fig. 121.
Fio. 122.
Cystii)hyUiim cyKndricum
Lonsd. Silurian ; Iron Bridge,
CystiphyUuni vesicidosnm, Ensland. A, B, Transverse
Goldf. Devonian ; Eifel. and longitudinal sections (after
Natural size. Nicholson).
88
COELENTERATA— ANTHOZOA
PHYLUM II
Rhizo'phyllum Lindst. Corallum simple, pyramidal or hemispherical,
flattened on one side ; external surface corrugated, and sending off" hollow,
root -like epithecal processes. Calice marked with septal striae ; internal
structure consisting of vesicular tissue and stereoplasma. Operculum in form
of semicircular plate ; inner surface traversed by median ridge and fainter,
granulated, parallel elevations. Silurian.
Calceola Lam. (Fig. 125). Corallum simple, semi-turbinate, or slipper-shaped,
Fig. 123.
Strephodes mnrclusoni Lonsd.
Showing strongly developed
dissepiments and tabulae.
Pig. 124.
Goniophyllum pyramidale
(His.). Silurian ; Gotland.
A, Specimen with operculum.
B, Calice seen from above.
Natural size (after Lind-
striim).
Fin. 125.
Calceola sa.ndalina Lam.
Eifel. Natural
Devonian ;
size.
with one side flat and triangular. Calice very deep, extending nearly to apex,
and marked internally with fine septal striae. Cardinal septum placed in the
centre of the vaulted side, counter septum in middle of flattened side, and alar
septa at the angles. Internal structure composed of fine vesicular tissue and
stereoplasma. Operculum semicircular, very thick, under surface marked with
prominent median and fainter lateral septal ridges. C. sandalina Lam. Very
common in Middle Devonian of Europe, rare in Carboniferous Limestone of
Belgium.
Range and Distribution of the Tetracoralla.
The typical Tetracoralla are confined to the Paleozoic rocks. They are
unknown in the Cambrian, and make their first appearance in the Ordovician,
where they are sparsely represented in North America and in Europe. Here
the most abundant genus is Streptelasma, and next in order of importance are
Cyathophyllwn, Ptychophylhmi and Columnaria. The maximum development
falls in the Silurian, which contains the largest number of genera and species.
There are limestones found on the islands of Gotland and Dago (Esthonia), as
well as at Dudley, Shropshire, at Lockport, New York and other places in
North America, which are made up of ancient coral-reefs. The principal agents
concerned in the formation of these reefs were Cyathophyllnm, Heliopliyllum,
Omphyma, Ptychophyllnm, Stromhodes, Acenndaria, Stauria, Aulacophyllum, Cysti-
phyllum, etc., of the Tetracoralla, besides numerous Tabulata, Octocoralla,
SUBCLASS 11 HEXACORALLA 89
Bryozoa, and Echinoderms. The Tetracoralla are not less conspicuons in the
Devonian, especially in the Middle and Upper Devonian of the Eifel district,
Westphalia, Nassau, Harz, Boulogne, England, and North America. Particu-
larly abundant here are the genera CyatJiophyllum, Campophylhtm, Zaphrentis,
Cystiphyllu7n, Phillipsasfrea, Calceola, etc. Zaphrentis, Amplexus, Lithostrotion,
Lonsdaleia, CydophyUum, etc., predominate in the Carboniferous Limestone of
Belgium, England, Ireland, and North America ; while in the Zechstein the
solitary genus known is Polycoelia. On the other hand, the Permo-Carboni-
ferous rocks of the Salt Range in India and of the island of Timor contain the
genera Zaphrentis, AmplexAis, Clisiophyllum, and Lonsdaleia. According to Freeh,
the genera Gigantostylis, Pinacophyllum, and Coccophyllum, occurring in the Alpine
Trias, belong to the Tetracoralla ; and to this group also have been assigned
Holocystis E. and H., from the Cretaceous, and the recent genera Haplophyllum
Pourtales, and Guynia Duncan. A number of Paleozoic Tetracoralla, such as
Batter sbyia, Heterophyllia, and Stauria, are referred by Duncan and Nicholson to
the Hexacoralla {" Astraeidae").
Subclass 2. HEXACORALLA Haeckel.
(Zoantharia Blainville ; Hexadinia and Folyadinia Ehrenberg.)
Simple or composite polyps, with radial mesenteries arising in cycles of six, twelve,
or midtiples of six (more rarely pentameral, septameral or odameral) ; frequently with
calcareous corallum, but sometimes fleshy or with horny axis.
To the Hexacoralla belong the calcareous reef-building and deep-sea corals
[Madreporaria) of the present day, the fleshy sea-anemones (Adiniaria), and
those forms characterised by the secretion of a horny axis (Antipatharia). Of
these three orders, only the Madreporaria are known in a fossil state. These
forms are distinguished from the Tetracoralla by the hexameral system and
radial arrangement of mesenteries and septa ; and from the Octocoralla, in
addition to the above-named characters, by their simple tentacles.
According to Duerden, either before or shortly after extrusion of the
larva, the six primary pairs of mesenteries (protocnemes), constituting the first
cycle, make their appearance. The organs arise in bilateral pairs, in a
regular and well-defined order, Avhich is uniform for all the species yet
studied. The first two or three pairs arise around the oral extremity of the
larva, while the others first appear at varying distances down the wall. The
protocnemic sequence is represented by the Roman numerals in Fig. 126, and
agrees with that established for the greater number of actinians. The first
four pairs very early unite with the stomodaeum, but the fifth and sixth
pairs remain free or incomplete for a lengthened period, suggesting a diff"erent
phylogenetic significance from the others.
The six pairs of second cycle mesenteries (metacnemes) arise after fixation,
but in a manner altogether diff'erent from that followed by the first cycle.
They appear on the polypal wall in unilateral pairs or couples within the
six primary exocoeles, and in a succession which is from the dorsal to the
ventral side of the polyp, not the whole cycle at a time. For a long time,
as shown in Fig. 127, the six pairs present a difference in size, corresponding
with their dorso-ventral or antero-posterior order of appearance.
90
COELENTEEATA— ANTHOZOA
PHYLUM II
succession
The twelve pairs of third cycle mesenteries are found to develop in a
'which is altogether unexpected. They follow the same dorso-
ventral order as the second cycle pairs, but in two series. A primary series
of six pairs — one pair within each sextant — appears within the exocoele on
the dorsal aspect of each of the second cycle mesenteries, one pair following
upon another, and then another series of six pairs arises on the ventral
aspect of the second cycle mesenteries in the same order (Fig. 128). In the
later stages of development the regularity of the mesenterial succession is not
3E Ts:
re E
m
m
Fio. 126.
GrowUi stages of coral polyp in Mnrandni {" Manicina") areolata. Diagrammatic figures showing orfler of
appearance of the six primary pairs of mesenteries. In n only two i)airs of mesenteries are present, of which one
pair (i) is united with the stomodaeum, while the other (ii) is free ; in /) the second pair of mesenteries has become
complete, and a third pair(!ii) has appeared on the ventral border ; in c another pair(iv) is found within the dorsal
chamber ; in </ the first four pairs of mesenteries to arise have all become complete, and the fifth and sixth
pairs (v, vi) have appeared, but remain incomplete for a long period, the secondary mesenteries ap]jearing in
the meantime (cf. Fig. 127). The actual stages given are taken from Maeandra areolata, but a like sequence is
presented by other species whose development has been followed (after Duerden).
always maintained ;■ one region may be somewhat in advance of, or may lag
behind its normal development.
The sequence thus outlined in the briefest manner is sufficient to show
that the develoi^ment of the mesenteries in coral polyps is bilateral, and
takes place in stages from one extremity to the other. The radial symmetry,
characteristic of the adult polyp, is thus derived from primitively bilateral
organs, which appear in an antero-posterior succession. Moreover, each cycle
represents a separate period of development, as compared Avith the successive
growth in one direction of ordinary segmented animals.
The first two cycles of tentacles (prototentacles) generally arise a cycle at
a time, either simultaneously or one following the other. The later tentacles
SUBCLASS II
HEXACORALLA
91
are developed in an order in correlation with that of the mesenteries, some-
times entocoelic and exocoelic members appearing together. In the process
of growth the exocoelic members are always relegated to the outermost
cycles, in a manner first established by Lacaze-Duthiers for actinians ; only
the entocoelic tentacles are of any ordinary value. Siderastrea radians (Pallas)
is exceptional in that the exocoelic tentacles appear in advance of the
entocoelic.
B
Fig. 127.
Growth stages of larval polyps in Siderastrea radians. Three rlia,L,Taiiiiiiatir figures illustrating the manner
of appearance of the six mesenteries (A-C) constituting the second cycle. The mesenteries arise in unilateral
pairs within corresponding exocoelie chambers on each side of the polyp. At tirst («) a i)air api)ears within the
dorso-lateral exocoele on each side ; shortly after (h) a sinular pair arises within each middle exocoele ; then (c)
a pair within each ventro-lateral exocoele. For a long time the pairs retain a difference in size, corresponding
with their order of appearance (after Duerden).
The skeleton never appears until after fixation of the larva. It makes its
first appearance in the form of minute plates or granules, as an ectoplastic pro-
duct of the ectodermal cells (calicoblasts) of the base. A flat, circular, basal
plate is formed by the union of these, and may later become i:)roduced upward
at the edge as the epitheca, while from its inner or polypal surface the septa
begin to appear as vertical upgrowths formed within invaginations of the
basal disk of the polyp. The skeletal cup first formed is known as the
prototheca.
92
COELENTERATA— ANTHOZOA
PHYLUM II
Like the tentacles, the first two cycles of septa (protosepta) may appear
simultaneously, or the cycle of six entosepta may arise in advance of the
cycle of six exosepta. The order of appearance of the later cycles is not yet
thoroughly understood, the relative sizes in the mature corallum by no means
indicating the actual order of development. As in the case of the mesenteries,
the radial plan of the mature septa is derived from structures which appear
bilaterally, in a more or less definite dorso - ventral or antero - posterior
n.
IHz
Fig. 12S.
Tliree stages in the development of tlie twelve pairs of third-cycle mesenteries. All the six pairs of primary
mesenteries are now complete, and the second-cycle pairs are all equal, but free from the stomodaeum. In a a,
pair of third-cycle mesenteries (in) has appeared on each side, within the exocoele next the doi\sal directives ; in
h a corresponding pair occurs within tlie dorsal of the two exocoeles of all the six systems, the order being from
the dorsal to the ventral aspect ; in c another series of six pairs is beginning, situated within the ventral of the
two exocoeles in each system. Growth in tlie dorsal region is in advance of that in the ventral (after Duerden).
succession. Furthermore, as in the case of the tentacles, the exosepta remain
exosepta throughout the course of their development, always constituting the
outermost cycle. The entosepta beyond the primary six follow the same
succession of growth as the mesenteries, so that the t)rder assigned the
secondary and tertiary mesenteries in Fig. 129 will also hold for the septa.
Reproduction takes place either sexually, when separate individuals are pro-
duced ; or asexually, by means of lateral or basal gemmation ; or by fission.
In composite coralla, the individual corallites are sometimes united by a
SUBCLASS II HEXACORALLA 93
common coenenchyma. Endothecal structures are frequently present in tlie
form of synapticulae, dissepiments, and tabulae.
The order of stone corals or Madreporaria {Zoantharia sderodermata) was
divided by Milne Edwards and Haime into five suborders : Eugosa, Tabulata,
Tuh'ulosa, Perforata, and Aporosa. Of these, the Rugosa have been elevated by
Haeckel into a separate subclass under the name of Tetracoralla. The groups
Aporosa and Perforata are called Hexacoralla ; while the affinities of the
Fig. 129.
Diagram showing the order of appearance of all the mesenteries in a polyp having three cycles. The Roman
numerals represent the cycles to which the mesenteries belong, and the smaller Arabic numerals indicate the
order in which the mesentery appeared within its cycle. The regularity here indicated is constant for the
primary and secondary cycles, but departure may be encountered in the third cycle (after Duerden).
Tabulata (with which the Tuhulosa are now generally included) are still
unsatisfactorily determined. The group is certainly composed of a varied
assemblage of forms, some of which have been assigned to the Hexacoralla,
some to the Odocoralla, and some to the Hydrozoa and Bryozoa.
Order 1. MADREPORARIA Milne Edwards. ^
(Zoantharia sderodermata E. and H.)
Radially symmetrical sclerodermous corals with typically hexameral (rarely
pentameral, heptameral, or odameral) arrangement of septa.
1 Literature : Pratz, E. , Ueber die verwandtschaftliche Beziehungen einiger Korallengattimgen,
etc. Palaeoutogr. 1882, vol. xxix. — Freeh, F. , Die Korallenfauna derNordalpinen Trias. Palaeontogr.
1890, vol. xxxvii. — British Museum Cat. of Madreporarian Corals, vol. i. by George Brook, 1893,
vols, ii.-vi. by H. M. Bernard, 1896-1906. — Volz, W., Die Koralleu der Schichten von St.
Cassiau in Siid-Tirol. Palaeontogr. 1896, vol. xliii. Felix, J., Antliozoen der Gosauschichten
in den Ostalpen. Palaeontogr. 1903, vol. xlix. — Duerden, J. E., The Coral Siderastrea, etc.
Carnegie lust. Wash., 1903, Pub. No. 20.— Lang, W. D., Growth-Stages in the Coral Genus Para-
sniilia. Proc. Zool. Soc. London, 1909, pt. ii. — Parana, C. F., La Fauna coralligena del Cretaceo
dei Monti d' Ocre nell' Abruzzo. Mem. Com. Geol. Ital., 1909, vol. v. (See also ante, p. 74).
94
COELENTERATA— ANTHOZOA
PHYLUM II
Suborder 1. APOROSA Milne Edwards and Haime.
Septa and theca compact; inter septal loculi umally partitioned off hy dissepi-
ments or synapticulae, more rarely hy tahulae, seldom empty throughout. Theca
either independently secreted, or formed by fusion of the septal edges, or absent.
Family 1. Turbinolidae Milne Edwards and Haime.
Corallum simple, very seldom composite ; septa numerous, long, and with entire
margins. Interseptal locidi empty throughout. Columella usually, pali often present.
Theca complete.
The Turbinolidae begin in the Jurassic, and are especially abundant in the
Tertiary and at the present day. Sexual reproduction prevails,
although a few forms multiply by gemmation ; the buds, how-
ever, become separated from the parent animal at an early
period.
Turbinolia Lam. (Fig. 130). Coi-allum free, conical, with
circular calice. Septa produced beyond the theca. Styliform
Fig. 130.
Turbinolia bower-
hanki E. and H.
Eocene ; Highgate,
England. 6/j.
Fif!. 131.
CeratotrocJius dnodecimocostatus (Goldf.). Miocene ;
Baden, near Vienna. Natural size.
Fill. 132.
Flabellnm roissyannm B.
and H. Miocene ; Baden,
near Vienna. Natural size.
columella present. Tertiary and Eecent ; common in Calcaire Grossier of
the Paris Basin, and Eocene of England and southern United States.
Sphenotrochus E. and H. Free, cuneiform with elongated calice ; colum-
ella lamellar. Cretaceous to Eecent. Type, S. crispus (Lam.). Eocene to
Recent. Common in Calcaire Grossier of the Paris Basin, and in the Eocene
of the Gulf States.
Smilotrochus E. and H.; Stylotrochus From.; Onchotrochus Duncan. Cre-
taceous. Discotrochus E. and H. etc. Tertiary.
Ceratotrochus E. and H. (Fig. 131). Horn-shaped ; young forms attached
at the apex. Septa very numerous, produced above the theca ; columella
fasciculate. Cretaceous to Recent.
Flabellum Lesson (Fig. 132). Corallum wedge-shaped, compressed, free,
or attached. Septa numerous. Wall covered with epitheca, and sometimes
furnished with spinous processes. Tertiary and Recent.
Trochocyathus E. and H. (Fig. 133). Horn-shaped, with circular calice.
Septa stout ; columella papillous and trabecular, and surrounded by several
cycles of pali. Numerous species from Lias to Recent.
SUBCLASS II
HEXACORALLA
95
Thecocyathus E. and H. Depressed, conical, or discoidal, attached early in
life, later becoming free. Wall with thick epithecal investment. Calice
circular, septa numerous ; columella fasciculate, and sur-
rounded by several cycles of pali. Lias, Jurassic, Cre-
taceous, and Recent.
Faracyathus, Deltocyathus E. and H. (Fig. 134).
Tertiary and Recent. Discocyathus E. and H. Jurassic.
CoenocyatJms, Acanthocyathus, Bathycyathus E. and H., etc.
Tertiary and Recent.
Caryophyllia Lam. (Fig. 135). Turbinate, with broad
Fig. 133.
Trochocyathus conulus From. ^ Aptian ;
Haute Marne. a, Profile, natural size ; li,
Calice enlarged.
Fig. 13-i.
Deltocyathus italicus B. and H. Miocene ;
Fig. 135.
Caryophyllia cyathus
Sol. Recent. Longitudi
Porzteicli, Moravia, a, Profile, natural nal section, natural size
size ; h, Calice enlarged.
(after Milne Edwards).
base, attached. Calice, circular ; columella papillous, trabecular, and sur-
rounded by a single cycle of pali. Cretaceous to Recent.
Family 2. Oculinidae Milne Edwards and Haime.
Invariably composite corolla, increasing by lateral gemmation. Walls ofcorallites
thickened by a compact coenenchyma. Lower portion of visceral chamber narrowed or
filled up by deposition of stereoplasma. Septa moderately numerous ; hderseptal loculi
usually open to the base. Lias to Recent ; fossil forms not particularly numerous.
Oculina Lam. Corallites irregularly or spirally distributed over the smooth
surface of coenenchyma. Septa slightly projecting ; columella papillous,
surrounded by cycle of pali. Tertiary and Recent.
Agathelia Reuss. Like the preceding, but form-
ing tuberous or lobate colonies. Cretaceous and
Tertiary.
Synhelia E. and H. Cretaceous. Astrohelia E.
and H. Tertiary. Psammohelia, Euhelia E. and H.,
etc. Jurassic.
Haplohelia Reuss. Small, arborescent, with
corallites all disposed on one side of the branches.
Coenenchyma striated or granulated. Septa in
three cycles ; columella and pali present. Oligocene.
Enallhelia E. and H. (Fig. 136). Stock branch-
ing ; corallites disposed usually in alternating
sequence in two rows along the sides of branches.
Coenenchyma highly developed, striated, or granulated ; columella rudi
mentary. Jurassic. Tyj^e, E, Compressa (d'Orb.).
Fig. 136.
Enallhelia striata Quenst. Coral-
Rag ; Nattheim. a, Natural size ;
6, Calice enlarged.
96 COELENTEEATA— ANTHOZOA phylum ii
Family 3. Pocilloporidae Verrill.
Composite, branching, lohate, or massive colonies, with small cylindrical corallites,
united by compact coenenchyma. Septa few {Q-24:), sometimes rudimentary. Visceral
chamber partitioned off by horizontal tabulae.
Of the two Recent genera belonging to this family, Pocillopora and Seriato-
pora Lam., the former occurs also in the Miocene of the West Indies.
Family 4. Stylophoridae Milne Edwards and Haime.
Composite coralla, ivith corallites united by vesicular or compact coenenchyma.
Septa well developed ; a prominent, styli-
form central columella; inier septal loculi
empty throughout. Jurassic to Recent.
Stylophora Schweigg. (Fig. 137).
Stock branching, or depressed,
massive and tuberous. Calices
small, embedded in abundant,
spinous, coenenchyma. Septa well
Styloplwra suhretlculata Reuss. Miocene ; Grund, near developed, moderately numerOUS ;
Vienna a, Corallura, naturalsize; b, surface greatly columella stvliform. JuraSsic,
enlarged. . -^ '
Tertiary, and Recent.
Araeacis E. and H. Eocene. Stylohelia From. Jurassic ; Europe.
Family 5. Astraeidae i Milne Edwards and Haime.
Corallum composite, or more rarely simple. Theca formed by fusion of septal
edges. Septa numerous, usually well developed, upper edges toothed, serrated, or
lobular; visceral chamber partitioned off by more or less abundantly developed
dissepiments, more rarely by tabulae. Multip>lication by budding or fission. Corallites
of massive colonies visually reaching considerable altitude, and united loith one another
either directly by the walls or by means of septa, exothecally jyroduced (costal septa).
Very abundant from the Trias onwards, and by far the most protean family
of all the Hexacoralla. According to the serrated or entire character of the
free septal edges, Milne Edwards and Haime divided their Astraeidae into two
subfamilies — the Astraeinae and the Eusmiliinae, the latter of which has been
elevated by Verrill to family rank.
a. Simple coralla.
Montlivaltia Lamx. (Fig. 138). Cylindrical, conical, turbinate, or dis-
coidal, and either acutely pointed, or broadly expanded at the base. Septa
numerous, upper edges serrated. Columella absent ; epitheca thick, corrugated,
^ The family waxae' Astraeidae is not available for use among corals, as the generic name Astraea
was applied by Bolten in 1798 to mollusks now referred to Turbo and Xeno2)hora, three years
previous to its application, in 1801, by Lamarck to corals. It is known that the Astraeidae of
Milne Edwards and Haime does not represent a natural association of corals, and, therefore, must
be dismembered and divided into a number of families. Several subdivisions have already been
proposed, but the detailed investigation of all the constituent genera has not progressed far enough
to determine their natural affinities in all cases. In view of this condition it seems better to
continue temporarily the use of the term Astraeidae until all the corals included under it have been
thoroughly studied and their systematic affinities ascertained than to propose a substitute name
for one known to be invalid.
SUBCLASS II
HEXACOEALLA
97
Firi. 138.
Monti! vaUia riiryuiihyllata (Lanix.)-
Caen, Calvados. Natural size.
Great Oolite ;
readily becoming detached. Common in Triassic and Jurassic ; somewhat rare
in Cretaceous and Tertiary. The genus should probably be made to include
various species which have been referred to Epismilia From., and the so-called
OpjJdismilia Duncan.
/3. Simple corolla or composite colonies
multiplying Inj calicinal or marginal gem-
mation.
Stylopliyllum Keuss. Corallum simple,
either with or without calicinal or
marginal gemmation, or forming massive
colonies. vSepta stout, but only in-
feriorly complete, terminating above in
strong vertical spines. Dissepiments vesicular ; wall covered with epitheca.
Alpine Trias.
Stylophyllopsis Freeh. Simple or imperfectly branching. Septa terminating
near the centre in detached vertical spines. Alpine Trias.
y. Bushy colonies multiplying by lateral gemmation.
Cladocora Ehrbg. Corallum composed of long
' cylindrical branches, free on all sides. Calice circular ;
septa well developed ; columella papillous ; cycle of
pali present. Jurassic to Recent.
Sfylocora Reuss (Fig. 139). Branches cylindrical;
septa stout, those of the first cycle with columnar
PiQ i39_ thickenings or inner edges ; columella styliform.
styhcom e.ri.iis Reuss. Mio- Cretaceous and Mioceue.
c::;L^^fn!i^'S^. t: Plenrocora E. and H. Cretaceous. Goniocora E.
Calice enlarged (after Reuss). and H. TriaSsic and JuraSsic.
8. Composite coraUifes multiplying by basal gemmation ; buds arising from stolons
or basal expansions.
Bhizangia E. and H. (Fig. 140). Corallites united by short, sub-cylindrical
Rhisantjiamichelini Reuss. Middle
Cretaceous ; Gosau Valley, Austria.
Natural size (after Reuss).
Fio. 141.
Claikmgia conferta Reuss. Miocene ; Bischofs-
wart, Moravia, a, Corallum, natural size ; b,
Calice enlarged (after Reuss).
stolons. Calices shallow, circular; columella papillous. Cretaceous and Tertiary.
Latusastrea d'Orbigny. Corallites arising from common basal expansion,
short and strongly inclined to one side, so that the calices acquire a semi-
VOL. I H
98
COELENTEEATA— ANTHOZOA
PHYLUM II
circular contour and assume the form of protruded lips. Jurassic and
Cretaceous.
Astrangia, Cryptangia, Phyllangia, Gladangia (Fig. 141), Ulangia E. and H.,
etc. Tertiary and Eecent.
e. Massive coralla multiplying by lateral gemmation.
Orbicella Dana (Fig. 142). Cylindrical corallites united by exothecally
produced, confluent, costal septa. Columella spongy ; dissepiments numerous
between the septa both within and exterior to the theca. Jurassic to Eecent.
Plesiastraea From. Like the preceding, but with several pali in front of
all the cycles excepting the last. Tertiary and Recent.
Fig. 143.
Inastrea lielianthoides (Goldf.).
Coral-Rag ; Nattheim, Swabia.
Natural size.
Fig. 145.
Favin caryophylloides
From. Cnrai- Rag; Natt-
heim. Natural size.
Fig. 142.
OrhieeUa conoicka (RenaH.). Mio-
cene ; Bnzesfeld, near Vienna, a,
Corallum, natural size ; //, Calices
enlarged.
ps^fti^il
':'^m
Fig. 144.
Latomeandra ^eriata
Beck. Coral-Rag ; Natt-
lieiin. Natural size (after
Becker).
Fig. 146.
CalainophylUa siokesi E. and H.
Coral-Rag ; Steeple Ashton, England.
Natural size.
Isastrea E. and H. (Fig. 143). Corallites prismatic, closely crowded, and
with fused walls. Calices polygonal ; columella imperfect or absent. Trias
to Cretaceous.
Latomeandra d'Orb. (Fig. 144). Like the preceding, but with the calices
situated in short furrows. Trias to Cretaceous.
Stylastraea From. Lias ; Europe. Amphiastraea From. Upper Jurassic ;
Europe. Leptastrea, Solenastrea, Prionastrea, E. and H. etc. Tertiary and
Eecent.
(. Massive coralla vudtiplying by fission.
Favia Oken (Fig. 145). Corallum massive; calices oval or distorted, and
united by confluent costal septa ; columella spongy. Jurassic to Eecent.
SUBCLASS II
HEXACORALLA
99
Fig. 147.
Thecosmilia trichotnmri
Goniasfrea E. and H. Corallites prismatic, calices polygonal. Septa well
developed ; columella spongy ; pali in front of all cycles
excepting the last. Cretaceous to Recent.
ij. Branching coralla mnltiplying by fission.
Calamophi/llia Blainv. (jRJiahdophyllia E. and H.;
Lithodendron p. p. Mich.) (Fig. 146). Colony fasciculate
or bushy ; corallites very long, cylindrical. Wall
costate, without epitheca ; columella absent. Trias,
Jurassic and Tertiary. Especially common in Alpine
Trias. C. dathrata (Emmrich).
Thecosmilia E. and H. (Fig. 147). Colony bushy,
calices dividing by . fission, and more or less free.
Epitheca corrugated, readily wearing away ; columella
absent or rudimentary. Trias to Tertiary. Accord-
ing to Freeh identical with Calamophi/llia. Very (GoTd7.)7 "X^rai-iiag T Na'tt
° . rn . . , -r . heiiii. Natural size.
common m iriassic and Jurassic.
Baryphyllia From. Hymenophyllia E. and H., etc. Cretaceous.
0. Coralla with confluent calices increasing by fission.
Leptoria E. and H.'(Fig. 148). Corallum massive, composed of labyrinthic
rows of confluent corallites with fused walls. Septa closely crowded,
approaching parallelism ; columella lamellar. Jurassic to Tertiary.
Diploria E. and H. Like the preceding, but with corallites united by
produced costal septa instead
of directly by their walls.
Cretaceous to Recent.
AspidisciisYJdn\g(F\g. 149).
Corallum discoidal, circular or
elliptical, covered on lower side
with wrinkled epitheca. Cali-
cinal furrows radiating from the
centre outwards, and separated
from one another by sharply
crested ridges. In the centri-
fugally disposed corallites the
outermost septa are thickened,
and form by their union a banded margin. Cretaceous.
Stiboria Etall. Jurassic. Stelloria d'Orb. Cretaceous. Symphyllia E. and
H. Tertiary and Recent.
Fifi. 148.
Leptoria kotiiiicld Reuss. Upper
Cretaceous ; Gosau Valley. Natural
size.
Fio. 149.
Aspidisms cristatiis
Kiiuig. Middle Cre-
taceous ; Batna, Al-
geria. Natural size.
Family 6. Eusmiliidae Verrill.
Like the Astraeidae, except that upper septal edges are entire, not serrated.
a. Simple coralla.
Trochosmilia E. and H. (Fig. 150). Turbinate, base acutely pointed or
Septa numerous, extending to the centre. Without epitheca,
costae granulated. Columella absent, dissepiments 'Numerous. Cretaceous
and Tertiary.
encrusting
100
COELENTERATA— ANTHOZOA
PHYLUM II
Coelosmilia E. and H. (Fig. 151). Like the preceding, but with dissepi-
ments sparsely developed. Cretaceous and Recent.
Placosmilia E. and H. (Fig. 152). Cuneiform, base acutely pointed or
slightly pedunculate. Calice laterally compressed, elongated. Septa numerous ;
Fk;. 1.30.
Trochosmilia fiiyuiifera Haime. Turonian ; Bains-de-
Rennes, France, a, Profile ; b, Calice slightly enlarged
(after Fronientel).
Fir' 1 ^1^
Coelosmilia hixii E. '' ' "'
and H. White PlacosmUia ciineiformh E.
Chalk ; Liineburg, and H. Upper Cretaceous ;
Hanover. Natural St. Gilgen on Wolfgangsee,
size. Austria. Natural size.
dissepiments abundant ; columella foliaceous. Epitheca absent ; costae granu-
lated. Cretaceous.
Diplodenium Goldf. Calice laterally compressed, greatly elongated in
transverse direction, and bent downwards at the ends so as to become crescent-
shaped. Columella and epitheca absent. Costae dichotomously or tricho-
tomously furcate. U])per Cretaceous.
Axosmilia E. and H. Jurassic. Fhyllosmilia From. Cretaceous. Lopho-
smilia E. and H. Cretaceous and Recent.
/3. Coralla multiplying by lateral gemmation.
Placophyllia d'Orb. (Fig. 153). Buds originating on calicinal margin or
sides, and giving rise to bushy or massive colonies. Columella styliform
Jurassic.
Fi(!. 153.
Placophnllki diaiitlnts (Ooldf.). Coral-
Rag ; Naittheim. a, Corallum, natural
size ; b, Calice enlarged.
Stjilinadelnbt'clici E. and H. Coral-Rag ; Steeple
Ashton, England, n, Natural size ; b, Calices en-
larged.
Galaxea Oken. Bushy colonies with cylindrical corallites united by layers
of finely vesicular coenenchyma. Recent.
Stylina Lam. (Fig. 154). Massive colonies, with corallites united by
coalescent costae. Septa well developed, disposed in six, eight, or ten cycles.
Dissepiments numerous ; columella styliform. Multiplication by costal gemma-
tion. Profuse in Trias, Jurassic, and Cretaceous.
SUBCLASS ir
HEXACORALLA
101
Fig. 155.
Astrocoenia decaphylln E. aiul H. Upper Cretaceous ; Gosau
Valley, Austria, a, Corallum, natural size ; 6, Calices enlarged.
Flacocoenia d'Orb. ; Crijptocoenia E. and H. Jurassic and Cretaceous.
Cyathophora Mich. Massive colonies, with corallites united by costae.
Septa short, not reaching the centre ; columella absent. Visceral chamber
partitioned otf by horizontal
tabulae. Jurassic and Cre-
taceous.
Coccophyllum Eeuss. Massive
colonies, with corallites united
directly by their walls. Calices
polygonal, septa numerous. Col-
umella absent ; visceral cham-
ber tabulated. Alpine Trias.
Pinacophyllum Freeh. Tri-
assic.
Holocystis Lonsd. Massive colonies, with corallites united by costae. Four
of the septa larger or stouter than the rest. Tabulae in visceral chamber.
Cretaceous.
Astrocoenia E. and H. (Fig. 155). Massive colonies. Corallites polygonal,
united by their walls ; septa numerous, long. Columella styliform ; only
dissepiments present in visceral chamber. Trias to Tertiaiy.
Stephanocoenia E. and H. Like the preceding, but with columella
surrounded by cycle of pali. Trias to Recent.
Fhyllocoenia E. and H. {Confusastrea d'Orb. ; Adelastrea Reuss). Massive
colonies. Corallites round or oval, imperfectly united by costae. Septa
strongly developed, thickened in the middle between theca and the centre.
Columella rudimentary. Trias to Tertiary.
Convexasfrea d'Orb. Trias to Cre-
taceous. Columnastrea, Stylocoenia E.
Cretaceous and Tertiary.
and H., etc.
7-
Corolla multiplying by fission.
Fig. 156.
Plomphyllia calycidata Eeuss. Oligocene ; Monte
Carlotta, near Vicenza. Natural size.
Haplosmilia d'Orb. Bushy colonies.
Corallites usually with dichotomously
dividing crests. Calices circular or
elongated ; columella styliform ; theca
with ridge-like costae. Jurassic.
Plocophyllia Reuss (Fig. 156).
Branching, foliaceous, or massive
colonies. Corallites either becoming
free or grouped into detached rows.
Columella absent. Tertiary.
Barysmilia E. and H. Corallum massive, forming a thick stem, the apex
of which is covered with short buds. Calices oval, sometimes disposed in
series ; columella rudimentary. Cretaceous.
Stenosmilia From. Like the preceding, but with lamellar columella.
Cretaceous.
Fachygyra E. and H. Corallites arranged in winding rows, and united by
a broad mass of costal coenenchyma. Columella lamellar. Jurassic and
Cretaceous.
102
COELENTERATA— ANTHOZOA
PHYLUM II
Phjfogyra d'Orb. Jurassic and Cretaceous ; Europe.
Ehipidogyra E. and H. (Fig. 157). Corallum fan-shaped, often corrugated,
and with but a single calicular furrow. Columella himellar. Jurassic and
Cretaceous.
Fig. 157.
Rhipidogyra crussa From. Coral-Rag ; Gray, Haute-Saone. 1/2 natural size.
Suborder 2. FUNGIDA Duncan.
Solitary or colonial corals. Syna'pticulae in the interseptal and intercostal loculi.
Dissepiments present or absent. Septa lamellate and solid or slightly perforate, or
composed of a trahecular lattice-work with numerous perforations. Basal structures
perforate or imperforate.
Family 1. Fungiidae Dana.
Embryo after becoming attached forms a trophozooid, which gives rise to buds
(anthoblasts) ; these become detached, forming free individuals (anthocyathi). Adult
corallum, simple or colonial, depressed or mitroid in form. Septa of higher cycles
perforate, those of the lower perforate or solid. Synapticula, but no dissepiments
present. Wall usually perforate in young, free individuals, subsequently more or less
compact. No epitheca.
Fungia Lamarck ; Halomitra Dana ; Polyphyllia Quoy and Gaimard ;
Zoopilus Dana ; Cryptabacia E. and H. ; Lithactinia Lesson ; Herpetolitha
Escholtz. Recent. Fungia oc-
curs also in the post-Pliocene.
JRi
Family 2. Agariciidae Verrill.
Simple or colonial Fungids
with lamellar, usually imper-
forate, septa. Wall solid in
simple genera, basal wall solid
in colonies, walls between coral-
lites solid when developed. Dis-
sepiments present or absent.
Microseris From. (Fig.
158). Corallum simple, dis-
coidal, circular ; upper side
vaulted, lower flat and granu-
lated. Cretaceous.
Trochoseris'E. and H. Simple species, trochoid and fixed. Tertiary and Recent.
Cyathoseris Y.. and H. (Fig. 159). Corallum turbinate, attached. Young
Fig. 158.
Microseris liemisphaerica From. Greensand (Cenomanian) ; Le
Mans, Prance, a and 6, Upper and lower surfaces, enlarged ; c,
Profile, natural size.
SUBCLASS II
HEXACORALLA
103
corallites arising fro'm periphery by costal gemmation. Common outer wall
naked, striated. Cretaceous and Tertiary. »
Leptophyllia Reuss (Fig. 160). Corallum simple, conical or cylindro-conical,
with suj)erficial calice. Septa numerous, thin, regularly-toothed ; solid or only
¥ic.. 159.
Cyathoseris siibretjidans Reuss. Oligocene ; Monte Carlotta, near Vicenza, Italy.
a. Top view ; Ji, Side view, natural size.
I^eptophyllla sinuoxa
From. Neoconiian; St.
Dizier, Haute - Maine.
Natural size.
partially perforate. Thin dissepiments present. Thin epitheca present.
Thamnasteria Lesauv. (Thamnastraea auct., of which T. lamourouxi is the
type.) Jura. Lophoseris E. and H. ; Agaricia Lam. ; Siderastrea Blv., etc.
Tertiary and Recent.
Family 3. Anabaciidae Diuuan.
(Pseudoastraeinae and Pse'udoagaricinae Pratz ; Microsolenidae Gregory.)
Simple coralla, or composite, basally expanded or massive colonies. Septa
numerous, perforate, and composed of calcareous bodies (trabeculae) arranged in
vertical or fan-shaped rows (traheculate). Theca beticeen individual corallites absent,
but may be present on under side of corallites or on lower side of the common
stock. Interseptal loculi with synapticula and dissepiments. Abundant from Trias
to Cretaceous ; i^arer in Tertiary and Recent.
Anabacia d'Orb. Simple, free, discoidal, or lenticular coralla, with flat
base. Upper side vaulted, calice slit-like. Septa very numerous, thin, and
united by synapticulae. Theca absent. Jurassic ; Europe.
Genabacia E. and H. Like the preceding but composite, the central calice
being surrounded by a row of smaller calices. Jurassic ; Europe.
Micrabacia E. and H. Cretaceous ; Europe.
Omphalophyllia Laube. Simple, turbinate or sub-cylindrical, attached,
and covered with epitheca. Septa very numerous, upper edges granulated.
Calice shallow, columella styliform. Alpine Trias.
Cyclolites Lam. (Fig. 161). Simple, free, discoidal, upper side vaulted,
lower flat and covered with corrugated ejDitheca. Septa very thin, extending
to the centre, extremely numerous, composed of vertical rows of trabeculae,
and united by synapticulae and dissepiments. Very abundant in Cretaceous,
rare in Jurassic and Eocene.
Dimorpharaea From. (Fig. 162, A, B). Composite, laterally expanded and
pedunculate, or mushroom-shaped coralla. Common wall restricted to lower
104
COELENTEEATA— ANTHOZOA
PHYLUM II
side of corallum ; individual corallites without proper walls, but united by-
costal septa. Columella styliform or rudimentary. Septa well developed,
composed of fan-shaped rows of cylindrical trabeculae, and united by synapti-
culae and dissepiments. Very abundant from Trias to Oligocene.
Cyclolites undidata Lam.
Fk;. ir.i.
Upper Cretaceous ; Gosan Valley, Salzkammergnt. n, Side view ; h, Lower
surface ; r, Lateral aspect of septum, natural size.
Dimorphastrea d'Orb. Like the preceding, but with calices concentrically
arranged about a central individual. Trias to Tertiary.
Comoseris d'Orb. (Fig. 163). Like Dimorpharaeo, but with calices separated
into groups by ascending flexuous ridges. Jurassic and Tertiary.
Astraeomorpha Reuss. Coralla composite, tuberous, basally expanded, or
branching, and covered with corrugated epitheca. Corallites small, united by
short and stout costal septa ; columella styliform. Trias to Oligocene.
Fi(i. 102.
A, Dimorjiharam, Lateral surface of costal septum, enlarged
(8/1), showing trabecular constitution ; in., Line of junction of
two septa belonging to diHercnt corallites ; t, Trabeculae ;
]i, Trabecular lacunae (after Pratz). />', I)imurjili<iraca ai/ari-
cites (Goldluss). Upper Cretaceous ; Gosau, Salzkanimergut.
Portion of upper surface of corallum, natural size.
Fk;. 163.
Comoseris conferia Reuss. Oligocene ; Monte
Carlotta, near Vicenza. Twice enlarged.
Microsolena Lamx. Colony massive, polymorphous, mammiliform, conical,
with a broad base, nearly spherical, turbinate and pedunculate. Trias and
J urassic.
Suborder 3. PERFOEATA Milne Edwards and Haime.
Skeleton built up of small calcareous bodies (sclerites), between which are empty
Interstices of greater or lesser size. Theca formed by fusion of outer septal edges or
absent. Interseptal Icculi empty throughout or traversed by synaptiada or
dissepiments.
SUBCLASS II
HEXACORALLA
105
Family 1. Archaeocyathidae Walcott.^
Simple, turbinate, or sub-cylindrical coralla. Septa and theca porous; inner
septal edges united by perforated interior wall, which encloses a holloio central space.
Synapticula present in interseptal loculi.
All but one of the genera described up to the present time (Archaeocyathus
Bill., Ethmophylhmi Meek, Spirocyathus Hinde, Protopharetra Bornem., etc.)
occur in the Cambrian rocks of North America, Spain, Sardinia and Aus-
tralia. Atikokania Walcott is known from the Lower Huronian of Ontario.
They represent possibly a distinct order of the Madreporaria.
Family 2. Eupsammidae Milne Edwards and Haime.
Corallum simple or becoming composite by lateral gemmation. Septa very
numerous, sometimes united by synapticula, and frequently with their inner edges
fused together. Theca naked or covered with epitheca, and formed by thickening of
the septal edges. Silurian to Recent.
Calostylis Linds. Corallum simple, sub-cylindrical, or composite and
multiplying by lateral gemmation. Septa very numerous, of spongy con-
sistency, and either fused together or united by synapticulae.
'"^ Columella thick, spongy ; wall covered with epitheca. Silurian;
Gotland. ' This genus probably belongs to the Tetracoralla.
Haplaraea Milasch. Simple, cylindrical coralla, with broad
Fir.. 1(34.
Eupsammiix
t r 0 ch ifo nil is
(Pallas). Cal-
caire Gmssier ;
Chaussy, near
Paris. Natural
size.
Fi<!. 105.
BalanophijUla siniiata Reuss.
Oligocene , Waldbockelheiiii,
Prussia, a, Natural size ;
b, Number of septa enlarged.
Fig. 166.
StepTianophyUUi eleiians (Bronn). Pliocene ;
Stazzano, near Modena, Italy, a and h, Upper
and lower surfaces, enlarged ; r-, Profile, natural
size.
encrusting base. Septa numerous, extending to the centre, perforated
by large apertures, and sometimes fused together or united by synapticulae.
Dissepiments also present, but no columella. Jurassic and Cretaceous.
Eupsammia E. and H. (Fig. 164). Conical or turbinate, acutely pointed,
free. Septa very numerous, arranged in five cycles, those of the last cycle
stouter than the rest. Columella present or absent. Eocene to Recent.
- Balanophyllia Wood (Fig. 165). Simple, sub-cylindrical, attached by
the base. Columella spongy ; septa closely crowded, partly fused together.
Eocene to Recent.
Stephanophyllia Mich. (Fig. 166). Simple, discoidal; base horizontal, calice
1 Billings E., Palaeozoic Fossils of Canada, i., 1861-65.— TFa/co«, C. D., Bull. U.S. Geol.
Survey, No. 30, 1886. — Borneviann, J. G., Versteiiierungen des Canibrischeu Systems voii Sardinien.
1886. — Hinde, G. J., Quart. Journ. Geol. Soc, 1889, vol. xlv. — Lamhe, L. M., Revision of the
Genera and Sjiecies of Canadian Palaeozoic Corals. Geol. Surv. Canada, Contrib. to Canad. Palaeont.,
1899, vol. \\.— Taylor, W. T. G., The Archaeocyathinae. Mem. R. Soc. S. Aust., 1910, vol. ii.
106
COELENTERATA— ANTHOZOA
PHYLUM II
circular. Septa numerous ; the six principal septa extending to the centre,
the remainder with fused inner edges. Cretaceous and Tertiary.
Bendrophi/Uia Blv. (Fig. 167). Corallum
branching, increasing by lateral gemmation.
Calices oval ; septa numerous and slender, those
of the last cycle extending to the spongy
columella, and fused with the converging ends
of shorter septa of preceding
cycle. Tertiary and Recent.
Lohopsammia, Stereopsammia
Edw. and H. Eocene. Astroides
E. and H. (Fig. 97). Recent.
Family 3. Poritidae Dana.
Composite coralla composed of
porous sderenchyma. Corallites
small ; septa as a rule only moder-
Fi<:. 167. ately numerous, sometimes repre-
Dendrophyllla elegant Duncan. Oligocene ; Brockenhurst, seilted hy TOWS of tfabeculae Or
caliieTeniai^^?'""''"'' ""'"''"^ '''' ' '' ^'''"''■'''' '''''°" °' lajueUae. Tluca absent.
Subfamily A. Spongiomorphinae Freeh.
Corallum composed of thick trabeculae and strengthened by horizontal synapticulae.
Calices very imperfectly differentiated from coenenchyma, and loithout distinct septa.
Dissepiments usually sparsely developed.
Of the genera belonging to this subfamily, Spongiomorpha, Heptasfylis and
Stromal omorj)ha Freeh, are found in the Alpine Trias (Rhaetic and Zlambach
beds). These are all tuberous, composite coralla of extremely irregular form.
In Spongiomorpha and Heptastylis, six septa are indicated by somewhat regularly
disposed columns of trabeculae ; and in the latter form these are bound
together by synapticulae which are projected at equal altitudes, and form
perforated horizontal storeys. In
Stromatomorpha no radial arrange-
ment of the trabecular septa exists.
Falaeacis E. and H. (SpJienopo-
terium Meek and AVorth.), occurring
in the Lower Carboniferous limestone
of North America and Scotland, per-
haps also belongs here.
'>v
Subfamily B. Poritinae Milne Ed-
wards and Haime.
Sep)ta not very numerous, well developed.
Corallites united by their porous walls.
169).
Fig. 16S.
Adinacis de'jans Reuss.
Valley, Salzkammergut. a
h, Transverse section, enlarged ;
enlarged (after Eeuss).
Upper Cretaceous ; Gosan
Upper surface, natural size ;
Longitudinal section,
Litharaea E. and H. (Fi
Massive coralla. Calices sub-polygonal,
septa generally in three cycles ; columella spongy. Eocene and Miocene.
Rhodaraea E. and H. Massive coralla. Spurious walls of corallites thick ;
pali prominent. Miocene and Recent.
SUBCLASS II
HEXACORALLA
107
Porites Link (Fig. 170). Massive or branching coralla. Calices shallo-w,
polygonal ; septa irregularly reticulated, usuall}^ twelve in number ; columella
Fic. 160.
Litharaea websteri (Bowerb. ). Eocene
Bay, England, a, Coralluni, natural size ;
enlarged.
Bracklesham
h, Four calices
Fig. 170.
Pontes incrustans Reuss. Jliocene ; Mo-
ravia, a, Tranverse section ; b, Longi-
tudinal section. Both figures highly magni-
fied.
papillous, surrounded by a single cycle of pali, the latter five or six in
number, and not very distinct from the septal ends. Endotheca exists
sparingly, and may be dissepimental or tabulate, or may be mere stereoplasm.
Cretaceous to Recent. The genus 6 c
Porites is one of the most im-
portant of existing reef-builders.
Subfamily C.
Alveoporinae Verrill.
Septa composed of detached
trabeciilae, spines, or reticulated
lamellae: Theca perforate. Vis-
ceral chamber with perforate tabulae.
i'
Fig.
ITl.
a, Al veoponi spongiO!!a Vansi. Recent; Fiji Islands. Longi-
tudinal section of corallite showing perforate walls and tabulae;
h, Alveopora rudis Reuss. Nunimulitic limestone ; Oberburg,
Styria, i/i ; c, Calices, greatly enlarged. (Fig. a, after Dana;
li, after Ileuss.)
Alveopora Quoy and Gaim.
(Fig. 171). Massive coralla.
Calices small, polygonal. Septa
represented by detached spinous processes. Tabulae sparsely developed,
remotely situated. Tertiary and Recent.
Koninckia E. and H. Cretaceous ; Europe.
Family 4. Acroporidae Verrill.
Composite, branching, lobate, foliaceous, or massive coralla with corallites embedded
in a canaliculated arul reticulated coenenchyma. Septa (6-24) compact, somethnes
imperfectly developed. Two long septa often projected from opposite sides and meeting
in the centre.
The genus Acropora Oken {Madrepora auct., non Madrepora Linn., 1758)
(Fig. 172), is an important agent in the construction of existing coral reefs,
and builds Colonies sometimes of considerable size. It occurs sparsely in the
fossil state in Tertiary strata of various regions.
Actinacis d'Orb. (Fig. 168). Massive or branching coralla. Coenenchyma
abundant, gx'anulated ; septa stout, of nearly uniform proportions, columella
papillous ; pali in front of all the septa. Cretaceous and Tertiary.
108 COELENTERATA— ANTHOZOA phylum ii
Astreojwra Blv. Massive coralla. Coenenchyma porous and on upper
surface echinulate. Septa of dissimilar proportions; columella and pali
absent. Tertiary and Eecent.
Dendracis E. and H. ; CryjMxis Reuss. Tertiary.
Turbinaria Oken (Gemmipora Blv.). Corallum foliaceous. Coenenchyma
tolerably compact and finely echinulate. Septa of similar proportions:
columella spongy. Cretaceous to Recent.
Range and Distribution of the Hexacoralla.
The group Aporosa of the Hexacoralla begins as the Tetracoralla disappear,
and develop a great variety of forms in the Trias, from the Mesozoic onward
to the present day they have continued to play a leading part in the con-
struction of coral-reefs. Of the families constituting the Aporosa, the
" Astraeidae " is by all odds the most important and most protean, in com-
parison to which the Fungida, Stylo-
^ plioridae, Pocilloporidae, Oculinidae and
¥*|"^'s^'(f//'A-j Turbtnolidae fall into greatly subordinate
&''^l%Tff^t( ^'^^^^- The other families are all younger
, ^^,f^^ ;|/*'^ than the " Astraeidae," not beginning until
firw the Jurassic, the Pocilloporidae, indeed, not
-V until the Tertiary.
Fio. i7'j. The Enpsammidae and Poritidae of
Acroporaawiiuu(v>unca,n). oiigocene; Brocken- the Perforata occur Sporadically in the
hurst, England, a, Calices enlarged: b, Longi- „., . t r^ ^ -i i, M ,•*. ,% ,,^4-
tudinai section, greatly enlarged. Silurian and Carboniterous, While It IS not
until the Trias that the Anabraciidae and
Poritidae develop a large variety of forms ; from the Trias to the Tertiary,
however, these genera continue to be important reef-builders. The Enpsam-
midae attain their greatest development in the Tertiary and Recent, while the
Acroporidae belong almost exclusively to the present period.
Occasional isolated deep-sea forms are met with in most of the several
geological periods, but the usual mode of occurrence of the Hexacoralla is
associated in masses in coral limestones ; the limestones may be of very vari-
able thicknesses, but as a rule are interstratified between deposits of distinctly
littoral character. Ancient coral-reefs most nearly resemble modern fringing
or barrier reefs, but not atolls, the origin of which is clearly dependent upon
peculiar conditions.
The St. Cassian, Zlambach and Rhaetic beds of the Alpine Trias contain
large numbei's of reef-building Hexacoralla ; but the pure limestones and
dolomites of the Alps, as well as the Trias outside the Alpine region, are
frequently either almost or entirely destitute of coral remains.
In the Lias, coral-reefs have been found in England, Luxemburg and
Lorraine. Certain beds of the Dogger, usually of but meagre thickness, are
occasionally charged with corals, as in Swabia, the Rhine valley in Baden, the
Swiss Jura, Normandy and England. Coral limestones are abundantly
developed in the Upper Jurassic of the Jura Mountains in France and Switzer-
land, in Lorraine, Southern Baden, Swabia (Nattheim, Blaubeuern), Bavaria
(Kelheim), many places in France and England, as well as in the whole province
of the Alps, Carpathians, Cevennes and Apennines ; here the uppermost
SUBCLASS III
ALCYONARIA 109
horizon (Tithonian) is especially characterised by their development. Reef
corals are also greatly developed in the Cutch (Jurassic) series of India.
In the Lower Cretaceous (Neocomian) coral-reefs are found in France
(Haute -Marne and Yonne), Crimea and Mexico; while the Urgonian of
Switzerland and the Bavarian Alps is occasionally charged Avith corals. In the
Turonian and Senonian of the Alps (Gosau Beds), Pyrenees and the Provence,
numerous coral-reefs occur, usually accompanied by Ihidistae ; elsewhere, how-
ever, except in Holland (Maestricht) and Denmark (Faxoe), the Upper
Cretaceous contains but a limited number of reef-building Hexacoralla.
In the older Tertiary (Eocene and Oligocene) occurrences of coral-reefs are
known on the northern and southern flanks of the Alps and Pyrenees, in Arabia,
India, the West Indies, and in Georgia, Florida, Alabama, Mexico and Central
America ; outside these areas their distribution is mostly sporadic. In the
Miocene and Pliocene the true coral-reefs retreat more and more towards the
equator (Red Sea, -Java, Japan, Gulf of Mexico), while the Hexacoralla which
persist in geologic formations within the temperate zone (Vienna Basin, Italy,
Touraine) constitute .but an insignificant feature of the general fauna.
[The foret^oing sections on the Tetracoralla and HexacoraHa have been revised by Dr. T.
Wayland Vaughan, of the United States National Museum at Washington. It should be
observed that, in the present unsatisfactory state of our knowledge of these organisms, the
classification adopted in this work, although perhaps as good as any available, is tentative in
character. — Editor.]
Subclass 3. ALCYONARIA Milne Edwards.
(Octadinia Ehrenberg ; Odocoralla Haeckel).
Composite colonies, rarely simple polyps, the individuals provided with eight
mesenterial folds and eight broad, pinnately fringed, or plumose tentades, which form
a single cycle about the mouth.
Hard skeletal elements are very generally developed in the Alcyonaria, being
absent in comparatively few forms, and are remarkable for their manifold
variety ; they occur either detached in the ectoderm and mesoderm, or ai-e
closely packed together at the base to form a horny or calcareous axis (sdero-
basis), about which the polyps are distributed. Sometimes the calcareous
bodies {sderodermites) form compact tubes which are periodically partitioned
off' into storeys with the upward growth of the animal. Reproduction is
accomplished either sexually, or asexually by basal or lateral gemmation,
rarely by fission.
Only the calcareous parts are known in the fossil state, such as the solid
axes, detached skeletal elements, tubes and composite coralla ; the horny
structures are totally destroyed during fossilisation. The Alcyonaria make
their appearance in the Ordovician, but rarely occur in great abundance.
Family 1. Alcyonidae Milne Edwards and Haime.
Fixed, fleshy, lobate, or ramose polyp stocks {very rarely simple individuals), with
echinulate or spicular calcareous bodies (sclerodermites) occurring detached in the
soft parts.
Isolated sclerodermites readily escape observation, owing to their minute
no
COELENTERATA— ANTHOZOA
rHTLUM II
size and fragile constitution. They have been detected as yet only by Pocta ^
in the Upper Cretaceous strata near Laun, Bohemia.
n Family 2. Pennatulidae Milne Edwards and Hainie.
Fohjji stocks until base embedded in sand or mud, and icith horny
or calcareous sclerobase ; 2^ohjps dimorphic.
Slender, round or quadrate calcareous axes referable to the
Pennatulidae have been detected with certainty only in the
Trias [Prographidaria Freeh.), Cretaceous (Pavonaria Cuv. ;
Pennatulites and Palaeosceptron Cocchi ; Glyptosceptron Bohm),
and Tertiary (Graphularia E. and H.) (Fig. 173).
Fig. 17B.
Graphularia de-
sertorvm Zitt.
Numraulitic lime-
stone (Eocene) ;
Farafreh, Libyan
Desert, Africa, a,
Axis, natural size ;
b, Section of same ;
c, Sti'iatod .surface,
enlarged.
Family 3. Gorgonidae Milne Edwards and Haime.
Fixed, branching or fan- shaped colonies, with horny or calcareous
solid sclerobase, or tvith jointed axis composed of alternating horny
and calcareous segments.
All the genera possessing horny, flexible axes (Gorgonia,
Ehipidogorgia, etc.) are perishable. Detached remains referable
to Primnoa, Gorgonclla and Virgularia, the axes of which are
composed of both horny and calcareous layers, have been
described from the Tertiary. In the genus Isis the axis con-
sists of cylindrical calcareous segments alternating with horny
connecting joints. It is found fossil in the Tertiary, and has
been reported also from the Cretaceous. The genus Moltkia,
occurring in the Upper Cretaceous, has cylindrical joints which
are pitted with slight depressions indicating the position of
branches. In the red or gem coral (Corallium Linn.) the axis
is built up of spiniform sclerites, which are united by a fibro-
crystalline calcareous matrix impregnated with organic matter.
It occurs only rarely in the fossil state, but is known from
the Cretaceous and Tertiary.
Family 4. Tubiporidae Milne Edwards and Haime.
Cor alia composed of red-coloured parallel calcareous tubes connected
by horizontal plates.
The cylindrical tubes of the recent Organ-pipe Coral (Tubi-
fora) are composed of spiniform sclerites, which are united with one
another directly in such manner as to enclose small hollow spaces appearing
superficially as pores. The connecting horizontal plates or floors are tra-
versed by canals which communicate with the visceral chambers of the
tubes by means of numerous round openings. New corallites are budded
from their upper surfaces. Unknown in fossil state.
^ I'oita, Philipp, Sitzuiigsljer. Akad. Wiss. Wien, 1885, vol. .xcii.
SUBCLASS III
ALC YON ARIA
111
Family 5. Helioporidae Moseley.^
Calcareous corolla, composed of two series of tuUform corallites ; the larger tubes
{antopores) are embedded in a strongly developed coenenclujma made up of smaller
tubes {siphonopores). Both autopores and siphonopores are closely tabulate; the
autopores are provided with ridge-like pseudosepta, which, however, do not correspond
numerically with the tentacles.
The affinities of the Helioporidae with the Alcyonaria were first pointed out
by Moseley. The larger polyps inhabit the autopores, and are furnished with
eight mesenterial folds and a crown of eight tentacles ; while the smaller
polyps, which are without either tentacles or sexual organs, are lodged in the
siphonopores. The skeleton is composed of calcareous trabeculae, the same as
in the Hexacoralla, from whose centres of calcification radial fibres extend
outwards in caespitose fashion. The siphonopores multiply by intermural
gemmation, while the autopores
are formed by the coalescence
and fusion of a number of the
siphonopores. JS^'o:^;^^^^
Heliopora Blainv. {Fig. 174, fe^-^^V
Corallum massive or
ramose; autopores with 12-25
slightly developed pseudosepta,
and embedded in a coenen-
chyma made up of smaller f,o. 174.
the latter are
tabulate than
Heliopora iMTtsi-hl (Renss). Upper Cretaceous; St. Gilgen on
Wolfgangsee, Salzkammergut. ,4, Corallum, natural size. i>, Por-
tion of surface, enlarged. <', Poh/tremacis blainvUleana Reus.s.
Cretaceous to upper Cretaceous ; Gosau, Salzkammergut. Vertical section,
enlarged.
siphonopores :
more closely
the autopores.
Recent,
Polytremacis d'Orb. (Fig. 174, C). Like Heliopora, but pseudosepta much
more strongly developed, sometimes reaching nearly to the centre. Cretaceous.
Octotremacis Gregory (Polysoleiiia Eeuss non Ehrenb.). Miocene; Java.
Family 6. Heliolitidae Lindstrom.-
Corallum. massive, more rarely ramose, varying from spheroidal to Jiahellate,
composed of tubular or vesicular coenenchyma enclosing corallites in the form of large
cylindrical and numeroiis smaller angular cells ; both the macro- and microcorallites
with tabulae. Usually tivelve septa present in the large cylindrical cells, but these
are often r%idimentary. No mural pores; basal epitheca present. Silurian and
Devonian.
The genera assigned to this family exhibit in their general appearance,
finer structure and manner of multiplication, considerable resemblance to
Heliopora, with which they were associated by Moseley, Nicholson, Bourne,
^ Moseley, II. N., The Structure and Relations of Heliopora eaerulea. Philos. Traus. Roj^al
Society, 1877, vol. clxvi. — Bourne, G. C, On the Structure and Affinities of Heliopra caernlea.
Ibid., 1895, vol. clxxxvi. pt. 1.
'^ Lindstrbm, G., Remarks on the Heliolitidae. K. Svensk. Vetensk. Akad. Handl. , 1899,
vol. xxxii. — Kiar, J., Die Koralleufauna der Etage 5 des norwegischen Sihirsystems. Palaeontogr.
1899, vol. xlvi. — Idem, Revision der mittelsilurischen Heliolitiden, etc. Videnskabs-Selskabets
Skrift. I. Classe, No. 10, 1903.
112
COELENTERATA— ANTHOZOA
PHYLUM II
Gregory and others. Here, as in HeUopora, the autopores are formed by
coalescence of numerous siphonopores in the coenenchyma. On the other hand
the corallites in the Heliolitidae have well-developed walls of compact homo-
geneous matter, and as a rule also twelve strong septa are present, sometimes
reaching nearly to the centre of the cylindrical chambers. On account of
these differences the family has been separated from HeUopora, and some
authors have proposed to associate them with certain Hexacoralla, or with
the problematical Tabulata.
Heliolites Dana {SfeUiporellaWenzel; Nicholsonia Kiar) (Fig. 175). Corallum
massive, nodnlar or ramose. Autopores with twelve more or less strongly
developed pseudosepta, though occasionally represented by rows of spinules,
and frequently with central columella. Siphonopores without septa, and
multiplying by fission or intermural gemmation. Abundant from Ordovician
to Devonian.
Plasmopora E. and H. (Diploepora Quenst.). Like Heliolites, but having
walls of the siphonopores incomplete, and tabulae of contiguous tubes fused
together so as to form a vesicular tissue. Ordovician to Devonian.
Fill. 175.
Heliolites }iorosa GoWfnss. Devonian; Eifel. .4, Corallum, natural size. 7j, Portion of outer sir. face,
enlarged. C, Longitudinal section, enlarged.
Protaraea E. and H. (Stylaraea E. and H., nan Seebach). Low incrusting
corallites, with relatively little coenenchyma. Tabulae present in the autopores.
According to Kiar, this form and Cocr.oseris Eichwald are closely related, and
perhaps identical. Ordovician and Silurian ; Scandinavia and North America.
Cosmiolithes Lindstr. Corallites thin, lamelliform. Coenenchymal pores
thick-walled, not all of the same size, with concave or obliquely directed
tabulae. Autopores with well - developed septa. Silurian ; C. ornatus
Lindstr.
Plasmoporella, Palaeoporites and TrorMscolifhus Kiiir. Silurian ; Scandinavia.
Acantholithus, Pycnolithus Lindstr. Related genera having the same distri-
bution.
Appendix to the Anthozoa.
Suborder. TABULATA Milne Edwards and Haime. '
Invariably composite coralla composed of tuhiform or prismatic corallites. JFalls
thick, independently calcified, compact or perforated by connecting mural pores. Sep)ta
^ Literature: Lindstrom, G., Affinities of the Antliozoii Tabulata. Ann. Mag. Nat. Hist., 1876,
ser. 4, vol. xviii. — Xicholxoii, H. A., On the Structure anil Affinities of the Tabulate Corals of the
Palaeozoic Period. London, 1879. — ■Roeincr, F., Lethaea Palaeozoica, i., 1883, p. 416. — WuMgen,
SUBCLASS III TABULATA— FAVOSITIDAE 113
hat slightly developed {usually six or twelve), sometimes represented merely by vertical
ridges or rows of spines, and sometimes entirely absent. Visceral chamber partitioned
off' into successive storys by tabulae. Synapticxdae and dissepiments warding.
To the Tabulata were originally assigned by Milne Edwards and Haime
all corals having numerous tabulae and I'udimentary septa. Later researches
have shown, however, that some of these forms (Focilloporidae) belong to the
Aporosa, others (Helioporidae) to the Alcyonaria, and still others (Millepora) to
the Hydrozoa. The majority of the typical Tabulata (Favositidae, Syringoporidae,
Halysitidae) exhibit close relationships to the Hexacoralla ; but since they are
for the most part now extinct and are largely confined to the Paleozoic rocks,
the determination of their systematic position is a matter of much difficulty.
The ontogeny of the corallites in the Tabulata shows that the development of
mural pores is homologous with the process of gemmation. Keproduction
sometimes takes place by fission, but generally by means of buds from the
edges of the calices at various stages during the growth of the parent corallites.
Buds ai-e given off early in Aulopora, producing basal corallites only ;
periodically in Romingeria, producing verticils of corallites ; periodically and
on one side in Halysites, producing linear series of adjacent corallites ; and
very frequently in Favosifes, etc., producing compact coralla with numerous
mural pores representing aborted buds.
Family 1. Favositidae Milne Edwards and Haime.
Massive or branching corcdla. Corallites uniformly prismatic, tall and united by
their walls, ivhich are perforated by large-sized pores. Septa very short, usually
represented by but faintly projecting ridges or rows of spines, but seldom completely
absent. Tabulae numerous, situated at regular intervals, complete and horizontal,
more rarely oblique or irregularly vesicular (" cystoid").
The Favositidae are distinguished from the Poritidae, with which Verrill
associates them, by their thick solid walls, which are perforated by round,
sometimes tubiform mural pores. The corallites are usually polygonal in
contour, and their walls exhibit in transverse sections a dark, or sometimes
light-coloured median line, with thickenings of stereoplasma on either side
(Fig. 176, 6'). The family is exclusively Paleozoic, and plays an important
part in the formation of Silurian, Devonian and Carboniferous coralline
limestones.
Favosites Lam. (Calamopora Goldf.) (Fig. 176). Corallum massive, more
rarely branching. Corallites prismatic, polygonal, generally hexagonal.
Mural pores distributed at considerable intervals. Septa very faintly
developed, represented by longitudinal ridges or rows of spines, or occasion-
ally obsolete. Tabulae numerous. Ordovician to Carboniferous ; very
abundant in Silurian and Devonian.
ir., and We7itzet, J., The Salt Range Fossils. Palaeontol. Indica, 1887.— Beecher, C. E. , The
Development of a Palaeozoic Poriferous Coral.— Symmetrical Cell Development in the Favositidae.
Trans. Conn. Acad., 1891, vol. viii.- — Wentzel, J., Ziir Keuntuiss der Zoantliaria tabulata.
Denkschr. Akad. Wien, 1895, vol. \\\\.-~Sardeson, F. W., tjber die Beziehungen der fossilen
Tahulaten zu den Alcyonarieu. Neues Jahrb. Mineral., 1896, Supplem. vol. x. — Weissennel, W.,
Siud die Tabulaten Vorliiufer der Alcyonarien ? Zeitsehr. deutsch. geol. Ges., 1898, vol. 1. —
Vinassa de Regny, P. E., Trias-Tabulaten, etc. Res. d. wissensch. Erforsch. des Balaton-Sees,
vol. i. pt. 1. Budapesth, 1901.
VOL. I I
114
COELENTERATA— ANTHOZOA
PHYLUM II
Columnopora Nich. (Calapoecia Billings). Like the preceding, but with
numerous, short, well-marked septa. Mural pores large, disposed in vertical
rows between the septa. Ordovician.
>f
J}
t*. — .fp- A
^
s^
^SSIf'^^ss?
1 — ^8ll^==^
^^B
^^^^s
^=
*SM-
Fig. 17tl.
Favosites polymorpha (Goldf.). Devonian; Eifel. A, Corallum, natural size. B, Corallites enlarged, two
of them broken open and showing tabulae. C and D, Transverse and longitudinal sections showing spinitbrni
septa and mural pores 0*). (C and D after Nicholson.)
Emmonsia E. and H. Ordovician to Carboniferous. Nydopora Nich.
Ordovician (Trenton). SyriiigoUtes Hinde. Silurian (Niagara).
^ 2j Pachypora Lind. (Fig. 177). Corallum branch-
ing, composed of prismatic, polygonal corallites,
the walls of which are so thickened towards their
mouths by layers of stereoplasma that the calices
appear to have circular contours. Septa very
minute ; mural pores scanty, but often of large size.
Abundant in Silurian and Devonian.
Trachypora E. and H. Dendroid with cylindrical
stems. Corallites polygonal ; walls so thickened by
layers of stereoplasma that the calices become round
„ ll.^ f ''^'^'h find greatly contracted, and appear to be superficially
Middle Devonian; Eifel. A, ., , nx i r ^ ■ ^ i
Transverse section. B, Longi- Widely Separated. Mural pores few and irregularly
Mura\''pot^e?(X^- N^d^^^^^^ ''' distributed. Septa represented by rows of spines.
Tabulae at remote intervals. Common in Devonian.
Striatopora Hall (Fig. 178). Like the preceding, but with tubes con-
tracted by stereoplasma at a greater depth, so as to give the calices a
funnel-shaped appearance. Silurian and Devonian.
Alveolites Lam. (Fig. 179). Corallum massive or
branching, composed of small, contiguous, compressed,
thin-walled corallites, with obliquely opening triangular
or semilunar calices. Septa very faint, represented
merely by ridges or rows of spinules, sometimes but
a single row present. Mural pores of large size, ir-
regularly distributed. Very common in Silurian and
Devonian.
Cladopora Hall ; Coenites Eichw. Silurian and Devonian.
Fleurodidyum Goldf. (Fig. 180). Corallum depressed, discoidal, circular
Fi(i. 177.
Pachypnra nirliolsoni
Fig. 178.
Striatopora flejiiosa Hall.
Silurian (Niagara) ; New
York.
SUBCLASS III
TABULATA— FAVOSITIDAE
115
or elliptical in contour, lower surface covered with concentrically striated
epitheca, and frequently a foreign vermiform body occupying the centre of the
base. Corallites small, j^olygonal, contracted inferiorly so as to become
funnel-shaped. Septa I'epresented by faint marginal ridges, or obsolete.
Fig. IT'.i.
A, Alreolites auborhicvlaris Lam. Middle Devonian ; Gerolstein, Eifel.
Natural size, /.'and (\ Alveolites lahecliei B. and H. Silurian (Weiilock) ;
Ironbridge, England. Tangential and vertical sections, lo/j (after Nicholson).
Pig. 180.
rieuroilictyuin prohlematicmn
Goldf. Lower Devonian ; Co-
blenz. Natural size. Vermiform
foreign body in the centre.
Walls pierced by irregularly distributed mural pores ; tabulae sparse.
Devonian. P. probleniaticum Goldfuss, is rather abundant in the Lower
Devonian " Spirifera sandstone " of the Eifel, but is known only in the form
of casts. In these the walls of the corallites are represented by narrow
fissures which are bridged across by transverse rods, while the visceral chamber
is filled up with sandstone. F. sfylopora Eaton, from the Hamilton Group of
North America, is a closely related species and also possesses the vermiform
body'.
Fig. 181.
Mifhelinia favnxn de Kon. Carboniferous Limestone ; Tournay, Belgium. A, Corallum from above.
Lower surface with radiciform epithecal processes. (.', Vertical section (after Gaudry).
P',
Michelinia de Kon. (Fig. 181). Discoidal or hemispherical coralla, often
of considerable size, and covered on the under surface with concentrically
striated ej^itheca, which frequently develops hollow radiciform processes.
Corallites polygonal, rather large. Septa represented by numerous longi-
116
COELENTEEATA— ANTHOZOA
PHYLUM II
tudiual striae or ridges ; mural pores irregularly distributed ; tabulae very
uumerous, oblique or curved, incompletely developed, and usually filling
the visceral chamber with loose vesicular tissue. Devonian and Carboniferous.
M. favosa de Kon., extraordinarily profuse in the Lower Carboniferous Lime-
stone of Belgium.
Family 2. Auloporidae Nicholson (Tuhulosa Milne Edwards and Haime).
Creeping, branching or reticulated tuhula-r coralla, composed of cylindrical, leaker
or trumpet-shaped corallites, with thick, imperforate, wrinkled walls. Septa repre-
sented by faint marginal striae ; tabulae moderately numerous
or wanting. Reproduction by basal or lateral gemmation.
Ordovician to Carboniferous.
Aulopora Goldf. (Fig. 182). All the corallites of the
prostrate corallum are attached by the whole of the lower
surface to some foreign object {Alveolites, other corals, or
mollusks). Tabulae more or less curved ; reproduction by
basal gemmation. Ordovician to Carboniferous.
Cladochonus M'Coy {Pyrgia E. and H.). Corallum
branching, attached only at isolated points, and composed
of funnel-shaped corallites without tabulae and septa.
Reproduction by lateral gemmation. Carboniferous.
B.omingeria Nich. {Quenstedtia Rom.). Spreading,
semi-erect, bushy coralla, only basally attached, and with
, , , . cylindrical corallites increasing by lateral gemmation.
Goldf. Devonian ; Geroi- Tabulae moderately numerous, horizontal. fSilurian and
stein, Eifel. Natural size -px
(after Goldfuss). JJeVOniaU.
Fig. 182.
Family 3. Syringoporidae Milne Edwards and Haime,
•
Fasciculate coralla composed of cylindrical corallites, united at intervals along the
sides by hollow connecting processes or by horizontal expansions. Walls thick,
wrinkled; septa faintly developed, represented by delicate
ridges or longitudinal rows of spinules ; tabulae numerously
developed, usually irregularly funnel-shaped. Reproduction
by basal gemmation or by buds arising from the connecting
processes and horizontal expansions. Ordovician to Car-
boniferous ; maximum in Devonian and Carboniferous.
Syringopora Goldf. (Fig. 183). Fasciculate coralla,
often attaining considerable size, and composed of
cylindrical, thin-walled, somewhat flexuose corallites ;
the latter communicate by means of hollow, cylindrical,
connecting processes. Septa rudimentary ; tabulae
funnel-shaped. Corallum commencing with prostrate c^tnSfs^lJ^s^onfi
basal zooids similar to Aulopora. Numerous species Regnitzicsaii, Fichteigebnge.
P d-i • J i^ 1 •(• Natural size.
ranging from Silurian to Carboniferous.
Chonostegites E. and H. Corallum massive ; cylindrical corallites connected
by horizontal, hollow, laminar expansions into which the endothecal tissues are
directly continued ; tabulae oblique, cystoid. Devonian.
Fig. 184.
H(d USUI'S ratenularia
SUBCLASS III TABULATA— CHAETETIDAE 117
Thecostegites E. and H. Corallum encrusting ; corallites short, cylindrical,
and connected by thick horizontal plates. Tabulae approximately horizontal ;
septa twelve in number, represented by marginal ridges. Devonian.
Family 4. Halysitidae Milne Edwards and Hainie.
Chain corals.
Corallum composed of long, cylindrical, laterally compressed
corallites, which are joined to one another only along the more
restricted edges, and form free, vertical, intersecting and anas-
tomosing laminae. Wall thick, covered on free sides by wrinkled
epitheca ; tabulae numerous, horizontal or concave ; septa repre-
sented by vertical ridges or rows of spines, in cycles of twelve,
sometimes entirely absent. Increase by stolonal gemmation.
The unique genus Holy sites Fischer (Catenipora Lam.)
(Fig. 184), comprises two groups of species; those in
Avhich the corallum is composed throughout of coral-
lites of equal size (H. escharoides Lam. sp.), and others in
which any two of the larger coi-allites are separated by
the intervention of a sjngle smaller, closely tabulate tube
(H. catenularia Linn, sp.) Ordovician and Silurian ; maxi- (T.kui.). sihman ; Got
. ,1 ri'i • laiul. Natural size.
mum in the Snunan.
Family 5. Chaetetidae Milne Edwards and Haime.
Massive corolla, composed of fine, subequal, tubiform corallites, contiguous on all
sides. Calices rather irregular in shape, one diameter slightly greater than the other.
Walls thoroughly amalgamated, common to adjacent corallites, imperforate, apparently
composed of closely arranged, ankylosed vertical columns, which terminate at the
surface in hollow prominences. Septa absent, but one or two tooth-like projections
often observable in sections. Tabulae horizontal, remote or abundant.
The forms belonging to this family are extinct, and occur chiefly in the
Ordovician, Silurian, Devonian and Carboniferous systems ; but a few are
also found sporadically in the Trias, Jura and Cretaceous. They are largely
concerned in the formation of Paleozoic coral reefs, especially during the
Carboniferous. Milne Edwards and Haime regarded them as Anthozoans,
Eominger and Lindstrom as Bryozoans, while Dybowski emphasised their
affinities with the Favositidae. By Nicholson they were assigned to the Octo-
coralla, for the reason that the corallites frequently exhibit a dimorphous
character the same as in Heliolites and Heliopora, besides agreeing in their
microscopic structure with Heliolites ; while in addition they possess well-
developed tabulae and imperforate walls. Many genera and species formerly
included under this family are now assigned to the Bryozoa.
Chaetctes Fischer (Figs. 184rt, 1845). Corallites long, thin-walled, prismatic,
polygonal, all of one kind, and multiplying by fission. Uncompleted fission
of the tubes often indicated in section by tooth-like projection extending
into the visceral chamber. Walls structureless, without dark median line ;
tabulae complete, remote. Very abundant in Lower Carboniferous ; found
118
COELENTERATA— HYDROZOA
PHYLUM II
also in Lias and Upper Jurassic. C. radians Fisch., is an important rock-
builder in the Russian Lower Car-
boniferous, especially near Moscow.
Dahlia E. and H. Silurian. Tetra-
dium Dana. Ordovician and early Sil-
urian. Pseudochaetetes Haug. Upper
Jurassic; Europe. P. polijjyor us (Qnenst.).
Fu:. 184ti.
Chaetetes septosus Fleni. Lower Car-
boniferous ; England. A, Transverse
section parallel to upper surface. B,
Vertical section both enlarged ; ji, Pro-
jecting spines representing uncompleted
fission (after Nicliolson).
Fig. 1846.
Chaetetes radians Fischer. Lower Carbon-
iferous ; Moscow, Russia. Portion of longi-
tudinally fractured corallum, natural size.
Geological Range of the Tabulata.
With but few exceptions the Tabulata are restricted to Paleozoic for-
mations, and from the Ordovician to the Carboniferous systems inclusive
occur in considerable profusion, being associated with the Tetracoralla and
certain Hydrozoa (Stromatoporoids) in the building of large coral reefs. Of
the various families constituting this group, the systematic position of which is
uncertain, the Halysitidae are limited to the Ordovician and Silurian, and the
remainder, including the genus Chaetetes Fischer, are represented continuously
from the Ordovician to the Carboniferous. In the Middle Cambrian shales
of British Columbia, Walcott has recently discovered a remarkably well-
preserved actinian, named Mackenzia, which appears to belong to the family
Edwardsiidae, and to be closely related to the genus Edwardsia.
Class 2. HYDROZOA Huxley. Hydroids and Medusae.^
Sessile or free-swimming polyps or polyp stocks, without oesophageal tube, and with
simple gastrovascular cavity not divided into radial pouches.
The Hydrozoans are organisms which rarely secrete hard parts, and hence
are ill-adapted for preservation in the fossil state. The ramifying polyp stocks
are usually inferior in size to those of the Anthozoa, and possess always a
simpler structure ; dimorphism or polymorphism is, however, exhibited by the
different individuals, some of which perform solely vegetative, and others only
reproductive or protective functions. Of great interest is the prevailing alterna-
tion of generations, in which process fixed polyp stocks give rise to a generation
of free-swimming Medusae, the eggs of which develop in turn into polyps.
' Huxley, T. If., Tlic Oceanic Hydrozoa. London, l^^^. — Agassiz, A., North American Aca-
lephae. 111. Cat. Miiscuni Conip. Zool. Cambridge ii., 1865. — Hincks, T., Natural Historj' of the
British Hydroid Zoophytes. London, 1868. — Clans, C.,, Uutcrsuchungen iiber die Organisation, etc.,
der Medusen. Leijizic, 1883.
CLASS II
HYDROMEDUSAE
119
The Hyrlrozoa are all aquatic, and with few exceptions are inhabitants of
the sea. They are commonly divided into the two following sub-classes : —
Hydromedusae and Acalephae.
Subclass 1. HYDROMEDUSAE Vogt.
Sessile or free-swimming, usually branching colonies, with dimorphic, nutritive and
reproductive polyps ; the latter frequently become liberated in the form of small, free-
sivimming Medusae, with non-lobate umbrellas composed of a hyaline, gelatinous
substance.
Six orders of Hydromedusae are recognised : Hydrariae, HydrocoralJinae,
Tubulariae, Campanulariae, Trachymedusae and Siphonopihorae. Of these only
the Hydrocorallinae, Tuhulariae and Campanulariae secrete calcareous or
chitinous structures capable of preservation in the fossil state.
M^m
c~:
Order 2. HYDROCORALLINAE Moseley.i
Naked polyps secreting at the base a dense calcareous skeleton, traversed at intervals
by two series of vertical tubes, info which the dimorphic zooids can be retracted.
The Hydrocorallinae comprise the two Recent groups Milleporidae and Stylas-
teridae, which were universally regarded as true corals until Louis Agassiz and
Moseley proved their relation-
ship to the Hydrozoa.
Millepora Linn. (Fig. 185).
Massive, foliately expanded,
encrusting or branching pol}--
paria (coenosteum), often attain-
ing considerable size. Upper
surface punctured by round
openings of the larger tubes
(gasfrop>ores), between which
are the mouths of numerous
smaller tubes (dacfylopores).
The skeleton is composed of „.„ , ,. t. . , „ ,. .
-.J. . Millepora vodosa Bsp. Recent. A, Upper surtaee of coeno-
a network OI anastomosing stpum, showing gastropores, A", and dactylopores c, 40/j. b,
1 -orvi fil-ir-oo +vairovoorl Ktt- Vertical section, k, gastropores with tabulae, < ; c, Vermiform
CalCaieOUS nores, iraverseci Oy canals communicating with dactylopores, so/j (after Stelnmann).
a system of tortuous canals.
The gastropores lodge the larger, nutritive polyps, and the dactylopores the
smaller, food-procuring zooids ; the latter have no mouths, but are provided
with short, clavate tentacles on their sides, and their tubes communicate with
the vermiform canals. Zooidal tubes tabulate, but nonseptate. The genus
is an important reef-builder of the present day, but occurs only sparsely in
the fossil state. Earliest known forms appear in the Eocene.
1 Literature : Alhnan, J. G,, Monograph of the Gyninoblastic or Tuhuhiriau Hydroids. Ray
Society, 187l-72._ — Moseley, H. N., Philosophical Transactions Royal Society, vol. 167, 1878. —
Steininaiin, (?., Uber fossile Hydrozoeu aus der Familie der Coryniden. Palaeontographica, vol.
XXV., 1877.^ — Idem, Uber triasische Hydrozoen vom ostlichen Balkan. Sitzber. Akad. Wiss.
Wien, math. -phys. Classe, vol. cii., 1893. — Canavari, M., Idrozoi Titoniani appartenanti alia Famiglia
delle Ellipsactinidi. Mem. Comitato Geol. vol. iv., 1893. — Vinassa de Regny, 0. E., Studii sulle
Idractinie fossili. Mem, Accad. dei Lincei, 1899, ser. 6, vol. iii.
Fig. 185.
120
COELENTERATA— HYDROZOA
PHYLUM II
Sfi/Iaster Gray. Branching polyparia composed of a netAvork of fibrons,
rose-coloured coenenchyma, in which are situated calicular depressions that are
provided with pseudosepta and columellae, and communicate with the zooid
tubes and vermiform canals. Eecent, and occurring sparsely in the Tertiary.
V../-o'VvA/\Aiy\A
O y . ,
^ V 0 W.-^ J_^5Jw Qjiuiyr/q
Order 3. TUBULARIAE Allman.
Foli/p stocks which are either naked or covered with chitinous outer layer {jieriderm).
Both the polypoid nutritive zooids, and also the medusoid reproductive animals are
without cwp-shaped hydrothecae surrounding the polyp head. A chitinous or calcareous
skeleton (hydrophyton) is frequently secreted at the base.
Hydractinia v. Bened. (Fig. 186). Hydrophyton in the form of encrusting,
chitinous, rarely calcareous expansion, frequently investing gastropod shells.
The crust consists of successive, slightly separated, horizontal laminae, which
are supported by num-
erous vertical rods or
columns {radial pillars).
The surface is covered
with projecting hollow
spines and tubercles,
and is also traversed
by shallow, branching
grooves (astrorhizae).
Interlaminar spaces
communicating with
the surface by means
of rounded tubes.
Tertiary and Eecent.
Ellipsactinia Steinm.
Hydi'ophyton irregu-
larly ellipsoidal, com-
posed of thick, con-
centric, slightly separ-
ated, calcareous lam-
ellae, which are united
by sparsely distributed
vertical columns.
Lamellae are formed by the anastomosis of exceedingly delicate calcareous
fibres, punctured by numerous fine radial tubes, and furnished on both sides
with pits, tubercles and branching furrows. Upper Jurassic (Tithonian) ;
Alps, Carpathians and Apennines.
Sphaeractinia Steinm. Like the preceding, but composed of thin, widely
separated lamellae, which, are supported by numerous radial pillars. Centre
frequently occupied by a foreign body. Upper Jurassic (Tithonian).
Loftusia Brady (Fig. 187). Ellipsoidal or fusiform bodies, composed of
thin, concentric or s})i rally rolled calcareous lamellae. Literlaminar spaces
wide, intersected by numerous radial pillars, and often secondarily filled with
calcareous mud. Eocene ; Persia.
Farkeria Carp. Globular or walnut- shaped organisms with nodulated
Flo. 186.
A, HydrnctiniaechinataF]em. Recent; North Sea. Portion of commensal
colony.'greatly enlarged ; hy, Polyps (liydranths) ; !/o, Generative buds (gono-
phores) ; liph, Hydrophyton adherent to shell of Buccinium unihitum, and
showing reticulated structure in vertical section. 7>, Ihidractlnia caJcarea
Cart. Vertical section of liyiirophyton, greatly enlarged (after Carter); a.
Primary basal lamella ; '), InterUiniinar space ; c, Second lamella ; d. Radial
pillars between the lamellae ; c, /, Tubercles and spines projecting on upper
surface. C, Hydractinia plioraciKi AUm. Pliocene ; Asti, Italy. Hydro-
phyton encrusting on Nasm shell (natural size). D, Portion of magnified
surface of the latter, showing branching grooves and wart-like tubercles.
CLASS II
TUBULARIAE
121
exterior, and composed of rather thick, concentric, calcareous lamellae. Inter-
laminar spaces divided into chamberlets by stout radial pillars, which usually
extend continuously through a number of lamellae. Both lamellae and pillars
consist of minutely tabulated tissue, the tubules of which are radial in arrange-
ment. Centre frequently occupied by a foreign body. Cambridge Greensand
(Cenomanian).
The genera ParJceria and Loftusia were originally described as agglutinated
Foraminifera ; they are, however, manifestly very closely allied to Ellvpsactinia
and Sphaer actinia.
Porosphaera Steinm. (Fig. 188). Globular masses of the size of peas or
hazel-nuts frequently growing around some foreign body, and composed of
anastomosing calcareous fibres which are penetrated by
numerous radial tubules ; the latter open on the surface
in the form of large pores, around which radial or stel-
late furrows (astrorhizae) are sometimes grouped. Upper
Cretaceous.
A B
1S7.
Fig. 188.
Poros2}haera (jlohidaris
(Pliill.). Upper Cretace-
ous ; Rligeu. .-1, Skeleton,
natural size ; /, Cavity
originally occupied by
foreign body. B, Trans-
verse section showing
Loftusia j^erKiiu Brady. Eocene ; Persia. A, Specimen cut open to show general radial tubes of gastro-
structure, natural size (after Brady). B, Section showingitwo lamellae and inter- pores, "/i (after Stein-
laminar tilling, greatly enlarged. niann).
Sfolicz'karia Duncan. Trias ; Karakoram and Balkan Mountains.
Cycloporidium, EJiizoporidium Parona. Ci-etaceous. Foradinia and Cydac-
tinia (Kerunia Mayer-Eymar) Vinassa. Tertiary.
Heterastridium Reuss (Syringosphaeria Duncan). Includes spheroidal, nodular
bodies of considerable size, composed of slender, anastomosing, and more or
less distinctly radial calcareous fibres. Skeleton comparatively dense, but
perforated by two series of zooidal tubes appearing superficially as pores. The
apertures of the larger tubes are round, those of the smaller stellate, and are
surrounded by radial furrows. Alpine Trias.
Appendix to the Hydrocorallinae and Tubulariae.
Stromatoporoidea Nicholson and Murie.'
Closely allied to the Hydrocorallinae and Hydractinia are the extinct Stromaio-
poroidea, which combine in many respects the characters pertaining to both of
1 Bargatzki, A., Die Stromatoporen des rlieinischen Devons. Bonn, 1881. — Nicholson, H. A.,
Monograph of the British Stromatoporoids. Palaeont. Soc. 1886-92.— 6?i:r<2/, G. 11., Revision of
the Sponges and- Coelenterates of the Lower Helderberg Group of New York. 14th Ann. Rept. N.Y.
State GeoL, 1894. — Toniquist, A., Uber mesozoisclie Stromatoporiden. Sitzber. preuss. Akad.
Wiss., 1901, vol. xlvii. — Yabe, 11. , On a Mesozoic Stromatopora. Journ. Geol. Soc. Tokj'O, 1903,
vol. X. — Deningev, K., Einige neue Tabulaten nnd Hydrozoen aus niesozoischen Ablagerungen.
Neues Jahrb. f. Mineral, i., 1906.— Bofhpletz, A., Uber Algen nnd Hydrozoen im Silur von
122
COELENTERATA— HYDROZOA
PHYLUM II
the above-named groixps, but whose exact position in the zoological system
remains as yet uncertain. During the Paleozoic era, to which they are con-
fined, the Stromatoporoids were important geological agents, whole beds of
limestone being often essentially constituted of their remains. In the Mesozoic
era they are replaced by very closely allied forms of Hydmctinia, which in all
probability represent their immediate descendants.
The Stromatoporoids secrete hemispherical, globular, nodular or hori-
zontally expanded skeletons, which are sometimes encrusting, sometimes
attached by a short basal peduncle, and are covered on the under side with
concentrically wrinkled epitheca, while the apertures for the emission of the
polyps are situated on the upper surface. The general tissue of the coenosteum
is composed of numerous, concentric, undulating, calcareous layers or laminae,
which are separated by narrower or wider interlaminar spaces, but are at the
same time connected by numerous vertical rods {radial pillars). The pillars
as well as the laminae are traversed, as a rule, by minute, irregularly directed
^ canaliculi. In some
genera the coenosteum
is provided with verti-
cal tabulate tubes,
which most probably
served for the recep-
tion of the polyps, as
in the genus Millepora ;
but in many instances
they are wanting. The
surfaces of the laminae
typically exhibit pores
and small tubercles,
and frequently also
shallow stellate furrows
(astrorhizae), which radiate outwards from numerous centres. Sometimes the
laminae consist merely of a loose network of horizontal calcareous fibres.
Groldfuss at first held the Stromatoporoids occurring so profusely in the
Eifel for corals (Blillepora), and subsequently for sponge-like zoophytes ; while
von Rosen considered them as horny sponges that had become secondarily
calcified. Sandberger and F. Roemer assigned them to the Bryozoans ;
Dawson to the Foraminifera ; Sollas to the siliceous sponges (Hexadinellida) ;
and Salter to the calcareous sponges, whose example Nicholson also followed.
Lindstrom, Carter and Steinmann subsequently pointed out their relations
to Hijdracfinia and Millepora ; and Nicholson and Murie came finally to
regard them as a group of extinct Hydrozoans allied to Hydradinia on the
one hand (Actinostromidae), and Millepora on the other (Stromatoporidae
and Idiosti'omidae).
Adinostroma Nich. (Fig. 189). Skeleton having vertical or radial pillars
disposed at tolerably regular intervals, and extending continuously through all
Gotland uiid Osel. K. Svensk. Vetensk. Ak.id. Handl., 1908, vol. x\ui. ^Giirich, (?., Les Spongio-
stromides du Vise daiisle Province de Namur. Mem. Miis. Ro}'. d'Hist. Nat. Belg. , 1906, vol. iii.
— Idem, Neues Jahrb. f. Mineral., 1907, i. — Parana, C. F., La Fauna coralligena del Cretaceo del
Monti d' Ocre nell' Abruzzo Aquilano. Mem. Comni. Geol. Ital., 1909, vol. v. —Parks, W.iA., The
Stromatoporoids of the Gnel])h Formation in Ontario ; the Niagara ; tlie Silurian of America ; the
Ordovitian. Univ. of Toronto Studies, Nos. 4-7, 1907-1910.
Fig. 1S9.
Actinostrnma interfextum Nich. Silurian (Wenlock) ; Shropshire. A,
Tangential section showing radial pillars and reticulated structure of con-
centric laminae. 7i, Vertical section, showing formation of laminae from
processes given off horizontally hy radial pillars, I2yj (after Nicholson).
CLASS II
STROMATOPOROIDEA
123
or at leas't a considerable number of laminae ; in vertical sections, accordingly,
exhibiting a quadrate meshwork. The laminae consist of an anastomosing
network of calcareous fibres, generally having a porous structure; their surfaces
are covered with projecting granules or tubercles, which represent the free
upper ends of the vertical pillars. Kare in the Silurian, but very abundant
, ■ ■ ~~^^r^f^y^~^p^
Fig. 190.
Strom(ttopora tubercvlata Nich. Devonian
(Corniferons limestone) ; Jarvis, Ontario,
Natural .size (after NicholsonV
Fio. 101.
Oniniopora %ilacenta Phill. Devonian; Torquay,
Devonshire. .4, Tangential .section, natural size.
K, The same, highly ma^'uified ; n, Vertical " Cauno-
pora tube " ; h, Canal partially cut into ; c, Calcare-
ous fibres traversed by delicate ramifying canaliculi.
C, Vortical section, highly magnified.
in Devonian of the Eifel, England and North America. A. clathratum Nich,
(^ = Stromafopora concentrica p. p., Goldf.).
Clathrodidijon Nich. Like the preceding, but wnth radial pillars extending
only between the upper and lower surfaces of successive laminae. Character-
istic of Silurian ; rare in Devonian.
Stromatopora G;o\Ai. emend. Nich. (Pa%s^?-o??ifl Nich. and Murie) (Fig. 190).
Radial pillars uniting with the thick concentric strata or latilaminae to form a
finely reticulated tissue, in Avhich tabulate zooidal
tubes are sparsely distributed. Plentiful in Devon-
ian ; less common in Silurian.
Caunopora Lonsdale (Fig. 191), and Diapora
Bargat., are Stromatoporoids which are indis-
tinguishable from other genera except by the
presence of numerous definitely walled tubes pene-
trating the coenosteum at closer or remoter in-
tervals. The tubes are often thick-walled, are
furnished with horizontal or funnel-shaped tabulae, Hcr?)!n!>)stro7Hosp.ind. Devonian;
1 • n •,! L ^ • • „ Torquay, Devonshire, a, Hori-
and occasionally with septal spines; in many cases zontai "lamina composed of two
they evidently represent the corallites of Anlopora f-terillin'I'XmL^fet-'rRLiiai
and Si/ringopora colonies, which have become en- piiiar traversed by axiai canai.
veloped, but have continued to live coramensally
within the tissues of the Stromatoporoid. In other cases, however, the tubes
appear to have been formed by true Stromatoporoid polyps. Devonian.
Hermato stroma Nich. (Fig. 192). Massive or foliaceous skeletons, composed
of thick parallel latilaminae, connected by vertical pillars ; pillars often running
continuously through several concentric laminae. Both pillars and laminae
exhibit a dark median line Avhen view^ed in cross-section, indicating either the
presence of axial canals or composition out of two lamellae. Devonian.
Fio. 192.
124 COELENTERATA— HYDROZOA phylum ii
Idiostroma Winch. Coenosteum cylindrical or fasciculate, traversed by
axial, tabulate zooidal tubes, which give off secondary lateral tubes. General
tissue reticulated, similar to Stromatopora. Devonian.
Labechia E. and H. Ordovician and Silurian ; North America and Europe.
Stylodidyon, Sfromafoporella and Syringostroma Nich. ; Amphipora Schulze ;
Stachyodes Bargat. Devonian of Europe and North America.
A number of genera are described by Waagen and Wentzel from the
Permo-Carboniferous rocks of Farther India, such as Carterina, Disjectopora,
Circopora, etc. Probably in the same neighbourhood should be placed several
peculiar encrusting marine forms from the Carboniferous of Belgium, described
by Glirich under the names of Aphrostroma, Spongiostroma, Chondrostroma,
Malacostroma, etc. The first-named of these occurs also in the Silurian of
Gotland, and was associated by Giirich with the Foraminifera.
Order 4. CAMPANULARIAE Allman.
(Leptomedusae, Calypioblastea Allman ; Thecaphora Hincks).
Delicate, branching, plant-like, sessile colonies, with chitinous periderm, enveloping
the base, pieduncle, and also the cup -like receptacles {Jiydrothecae) which enclose the
individual polyps. The proliferous zooids are developed within urn-shaped capsules
(gonothecae) of comparaiively large size, and sometimes become separated off as free-
swimming velate Medusae.
Recent Campanularians, such as are comprised by the families Sertularidae,
Plumularidae and Campanularidae possess durable hard parts, but nevertheless
their remains have not as yet been found in the fossil state, with the exception
of a few forms from Pleistocene deposits.
Range and Distribution of the Hydromedusae.
Of those members of this group in which the preservation of structural
parts is at all possible, the Hydrocorallinae have been recognised with
certainty as early as the Upper Cretaceous. During the Tertiary they
became more widely distributed, and at the present day are important reef-
builders.
During the Upper Jura, and notably in Tithonian beds of the Mediter-
ranean region, certain genera of the Hydractinidae {Ellipsactinia, Sphaeractinia)
are abundantly represented. Contrariwise, other Tubularians, such as the
Triassic Ileterastridium, and Farkeria and Porosphaera from the Cretaceous of
central I^urope, occur only sparsely.
The extinct organisms known as Stromatoporoids were extremely
important rock-builders during the Paleozoic, much of the limestone of the
Silurian and Devonian systems resulting from the destruction of the reefs
built by these fossils. Their massive stocks sometimes attain gigantic size.
Stromatoporoid remains are profusely distributed in Ordovician and Silurian
rocks of North America, England and Russia, also in the Middle Devonian of
the Eifel and Ardennes, and in equivalent strata of Nassau, Devonshire, the
Urals, Spain, etc. Except for a few rare survivors, the group does not
continue beyond the Paleozoic era.
CLASS II
GEAPTOLITOIDEA 125
Appendix to the Hydromedusae.
Class or Subclass. GRAPTOLITOIDEA Lapworth.^
(Ehabdophom Allman . )
Under the term of Graptolitoidea are included organisms which have been
considered by various authors as plant remains, horny sponges, Pennatulidae,
Cephalopods and Bryozoans. Portlock, in 1843, first pointed out their
analogy with the Sertularians and Plumularians ; and his inferences as to
their genetic relationship were afterwards confirmed by the painstaking
researches of Allman, Hall, Hopkinson, Lapworth, Nicholson, and others.
More recently, however, their kinship has been denied by Neumayr and
Wiman, who, on account of the bilateral symmetry of the sicula and thecae,
claim that Graptolites cannot be included within any of the now existing
classes of organisms.
Graptolites are generally found in an imperfect state of preservation, lying
flattened in the same plane upon the slaty laminae in which they are embedded,
and associated in large numbers. More rarely they occur in limestone, when
the interna] cavities are filled with calcareous matter, and the original form
accurately preserved. Such specimens have been successfully etched out and
investigated under the microscope by Holm and Wiman.
The general skeletal tissue (periderm) was obviously flexible, and composed of
1 Literature : Hall, J., Palaeontology of New York, vols, i., iii., 1847, 1859. — Graptolites of
the Quebec Group. Canad. Organic Remains, dec. ii. Geol. Surv. Canad. , 1865.— Introduction to
the study of Graptolites. 20th Ann. Rept. N.Y. State Cab. Nat. Hist., 1868.— Barrcmde, J., Grapto-
lites de Boheme. Prague, 1850. — Sitess E., Uber bohniische Graptolitheu. Haidiuger's Naturw.
Abhandl. , 1851, vol. iv. — Scharenberg, W., Ueber Graptolitheu. Breslau, 1851. — Geinitz, H. £.,
Die Versteinerungen der Grauwackenforinatiou in Sachsen. Leipzic, 1852. — Die Graptolitheu des
mineral. Museums in Dresden, 1890. — lilchter, B., Tliiiringische Graptolitheu. Zeitschr. Deutsch.
Geol. Ges., vols, v., xviii., xxiii., 1853, '66, 71. — Nicholson, II. A., Monograph of the British
Graptolitidae, 1872. — Lcqjworth, C, Notes on the British Graptolites. Geol. Mag., vols, x., xiii.,
1873, '76. Also various articles in Quart. Journ. Geol. Soc, 1875, '78, '81, and Ann. Mag. Nat.
Hist., 1879, '80.— On the Graptolites of County Down. Ann. Rep. Belfast Nat. Field Club, 1877,
vol. i., pt. iv. — Tnllberg, S. A., On Species of Didymograptus. Geol. For. Stockholm Forh., 1880,
vol. v. — Spencer, J. IF., Graptolites of the Upper Silurian System. Bull. Mus. Univ. Missouri, 1884.
— Tornqiiist, S. L., Observations on Graptolites. Acta Univ. Lund, 1890-92, vols, xxvii.-xxix.—
Holm, G., Skandinaviens Graptoliter. Svensk. Vetensk. Akad. Forh., 1881, vol. xxxviii. — Gotland's
Graptoliter. Bihang Svensk. Vetensk. Akad. Handl. 1890, vol. xvi. — Barrois, C, Memoire sur la
distriliution des gi-aptolites en France. Aunales Soc. Geol. Nord, 1892, vol. xx. — Wiman, C, tjber
Monograptus und Diplograptidae. Bull. Geol. Inst. Upsala, 1893, vol. i. (English translation in
Journ. Geol., 1893, vol. ii.). — Tornquist, S. L., Observations on the Structure of some Dipriouidae.
Fisiogr. SiiUsk. Handl., 1893, '97, vols, iv., viii. — Researches into the Graptolites of the Scanian and
Vestrogothian Phyllo-Tetragraptus Beds. Lunds Univ. Arsskrift, 1901, vol. xxvii. — Perner, J.,
Etudes sur les graptolites de Boheme. Prague, 1894-99. — Holm, G., Om Didymograptus, Tetra-
graptus och Phyllograptus. Geol. For. Forh., 1895, vol. xvii. No. 164. — Ruedemann, R., Synopsis of
tlie Mode of Growth and Development of the Genus Diplograptus. Amer. Journ. Sci. (3), 1895, vol.
xlix. ; Also in Ann. Rept. N.Y. State Geol. 1894, and Amer. Nat., 1897, vol. xxxii. — Graptolites of
New York, N.Y. State Museum. Memoirs vii. 1904, and xi., IQOS.—Gurlei/, R. R., North American
Graptolites. Journ. Geol., 1896, vol. iv. — Wiman, C, tJber die Graptolithen, Bull. Geol. Inst.
Upsala, 1895, vol. ii. ; also Nat. Sci., 1896, vol. ix., and Bull. Geol. Inst. Upsala, 1897, No. 6. 1900,
No. lO.—Elles, G. L., and Wood, E. M. R., Monograph of British Graptolites, ed. by C.
Lapworth. Palaeontogr. Soc, 1901 to date. — IlaU,T. S., Note on the Distribution of the Graptolithidae
in the Rocks of Castlemaine. Rept. Austral. Assn. Adv. Sci., 1894 ; also Proc. Roy. Soc. Victoria
1892, '97, '98, '99 ; Geol. Mag., 1899, vol. vi.—Roemer, F., and Freeh, F., Lethaea Palaeozoica, 1897,
vol. i. — Bassler, R. S., Dendroid Graptolites of the Niagarau Dolomites at Hamilton, Ontario.
Bull. Smithson. Inst., No. 65, 1909. — Westergard, A. H., Studier ofver Dictyograptusskittern. Med.
fr. Lunds Geol. Fait Klub. Ser. B, No. 4, 1909.
126 COELENTERATA— HYDEOZOA phylum ii
smooth or finely striated chitine ; usually it has the form of a dense continuous
membrane, but in the lietiolitidae it is attenuated and supported by a latticed
network of chitinous threads. It is usually preserved as a thin bitumino-
carbonaceous film, which, however, is often infiltrated with pyrites, and is not
infrequently replaced by a glistening greenish-white silicate (Giimbelite).
The compound organism or rhabdosome {'^ polvpari/ ") of the Graptolites is
usually linear, more rarely petaloid in form, undivided or branching, and is
either straight, bent, or in exceptional instances spirally enrolled. These
rhabdosomes, each of which originates from a sicula (see below) may again be
united into colonies of a higher order (synrhabdosome). Cup-shaped rhabdo-
thecae, which are usually obliquely set and more or less overlapping, are borne
on one or on both sides of the polypary, and are united by a common
coenosarcal canal enclosed in the periderm. The polypary is in later forms
strengthened by a peculiar chitinous axis (virgula, solid axis), which in the
Monograptidae runs in a groove lying outside the coenosark on the dorsal side
of the organism {i.e. on the side opposite to the theciferous margin). But in
the biserial Graptolites the virgula is either enclosed between the laminae of
a central or sub-central septum, which is formed by the coalescence of the
flattened dorsal walls {Diprionidae) ; or it is double and the two virgula (see
text Fig. 209) are placed on opposite sides of the coenosark, and are united with
the peridermal network (Retiolitidae).
Springing from the common canal, is a series of tlucae (cellules, denticles), Avhich
are disposed in longitudinal rows along either one (Fig. 193), two (Fig. 194)
or four sides of the polypary. They usually have the form of elongated,
cylindrical, rectangular or conical sacs; their walls are in most cases applied
to those of their neighbours above and below, although occasionally they
spring out quite isolated from one another. Each theca opens directly into
the common canal, and is furnished distally with an external aperture, the
form and size of which vary extremely in different species. In some forms it
is circular or quadrate or introverted or introtorted ; in others it is contracted.
Not infrequently the outer lip is ornamented with one or two slender spines,
which often subdivide and inosculate with one another. The form of the
thecae and apertures has been employed by Lapworth to define families and
subfamilies.
The polypary in most Graptolites is furnished at its proximal end with a
minute, triangular or dagger-shaped, originally conical, body called the sicula
(Fig. 195), which represents the original embryonic skeleton and is suspended
from an originally tubular filament, the 7iema ov neiaacaulus (Fig. 196). In the
wall of the sicula is formed, in the later Graptolites, an axis or rod, the
virgula, which extends through the rhabdosome. Ehabdothecae are then
budded either uuiserially along one side, or in alternate sequence along both of
the lateral margins of the sicula, originating from one theca near the major end
of the sicula. They grow either laterally away from the sicula (Axonolipa) or
along the nemacaulus (Axonophora). The sicula itself ceases to grow, as a
rule, after the first thecae are budded, and sometimes it becomes obsolete or
absorbed. Sometimes the rhabdosome remains undivided, sometimes it forms
branches, which may diverge at various angles ; in other cases two or four
uniserial polyparies may be placed back to back with their dorsal walls
coalescing, thus giving rise to di- or tetra-serial colonies. In the latter types
the coenosarc is commonly divided by one or two median septa.
CLASS II
GEAPTOLITOIDEA
127
Graptolites commonly occur in argillaceous schists, more rarely in limestone
formations, of the Upper Cambrian, Ordovician and Silurian systems. They
seem to have swarmed in the muddier portions of the sea, and floated either
attached to sea-weeds, etc., or as free-swimming colonies ; or, in rarer instances,
remained stationary with the sicula or a root embedded in the mud, or attached
to foreign bodies. They are divided into two orders : Dendroidea Nicholson
{CladoplLora Hopkinson), and Graptoloidea Lapworth, or Graptolites proper. The
•f^r^-agSr
^A C
-tl,
f
/ /
/
'"^.
'%
'-Tit
^
CtK
Fig. 193.
A, C, Monograptus priodon
(Broun). Silurian (Etage E) ;
Prague. A, Khabdosoma,
natmal size. B, Longitudinal
section, enlarged. (', Dorsal
aspect, enlarged. D, Mono-
graptus bohem icna Barr. Same
locality, a, Virguki ; c, Com-
mon canal ; th, Thecae ; x,
External aperture (after
Barrande).
Fig. 194.
n, c, Climacograptus typicalis
Hall. Ordovician (Trenton
limestone) ; Cincinnati, Ohio.
a. Vertical section, enlarged,
showing central virgula ; b,
Individual of the natural size ;
c, Cross-section, enlarged ; il, e,
Diplograptus palmeut: Barr.
Silurian ; Prague. Khabdo-
soma of the natural size and
several times enlarged (after
Barrande) ; /, Dijilograptni-
/oUmvui! Murch. Ordovician
(Llandeilo Group) ; Scotland,
natural size (after Lapworth).
SI
Fig. 195.
a, Munograpttns gregarias Lapw. Sil-
urian ; Dobbs, Linn, Scotland. Proxiiual
end showing sicula, enlarged ; /;, Dhit/-
inogmjitus punnatulug Hall. Ordovician
(Quebec Group) ; Point Levis, Canada.
Pro.vimal cud showing sicula, enlarged
(after Lapworth).
Fig. 196.
Dictyonema cavernosum Wiman. Or-
dovician ; Gotland. Proximal end of
rhabdosome with adhesion disk (,r), large
nourishing individual {z), and small
budding individual or gonangium (z{).
3/j (after Wiman).
latter are again divided into two suborders : AxonoUpa Freeh, redefined by
Ruedemann, without axis or virgula; and Axonophora Freeh, limited by
Ruedemann, with an axis.
Order 1. DENDROIDEA Nicholson.
Family. Dendrograptidae Eoemer.
This family, which includes all dendroid forms, is represented during the
older Paleozoic by the genera Dendrocjmpius, Dictyonema, Desmograpius, Callo-
128
COELENTERATA— HYDROZOA
PHYLUM II
graptus and Ptilograptns. Their polyparies are finely branching and plant-like
in appearance, sometimes furnished with a strong foot-stalk, in other cases
terminating acutely at the base. The original substance was undoubtedly
chitinous. In well-preserved specimens are seen on one or occasionally on
both sides of the branchlets numerous small cellules or thecae, in which
evidently the zooids were seated. These thecae have been shown by Wiman
to be of threefold character, some of them having lodged nourishing, others
budding and others sexual individuals or goiiangia. Very often the branches
of the dendroid rhabdosome are united by numerous delicate processes or
dissepiments.
Dendrograptus Hall. Rhabdosome consisting of a strong main stem and a
broad, spreading, shrublike, variously ramifying frond. Thecae commonly
i
Fio. 197.
Dldyonemii fldheUi forme (Eichw.). Upper Cambrian; Rensselaer County, N.Y.
neina, x -Vi- i', Mature rhabdosome with adhesion stem, x i/i (after Ruedeniann).
A, Sicula with very long
obscure, but sometimes distinct and angular, or they may occur as round or
elliptic pits or pustules. Cambrian to Silurian.
Ftilograptus Hall. Rhabdosome with branches giving off" branchlets
alternately on opposite sides, the general habit being suggestive of Recent
hydrozoans. Ordovician and Silurian ; eastern North America.
Dirfyonona Hall {Didyograptus Hopkinson) (Figs. 196, 197). Rhabdosomes
forming funnel or fan-shaped fronds, composed of numerous bifurcating
branches arising from an acute base, and united at intervals by fine dissepi-
ments. Thecae with complicated appendages, their branches supporting three
kinds of individuals, nourishing, budding and sexual. Cambrian to Car-
boniferous ; especially abundant in Ordovician of Norway, but usually com-
pressed into a basket-like network.
Desmograptus Hopkin. Dift'ers from the preceding in the flexuous char-
acter of the branches, which coalesce at intervals ; dissepiments chiefly in
lower part of the frond. Ordovician to Devonian ; Europe and North
America.
CLASS II
H YDEOZO A— GRAPTOLITOIDE A
129
Order 2. GRAPTOLOIDEA Lapworth.
Suborder A. AXONOLIPA Freeh (emend. Eueclemann).
Family 1. Dichograptidae Lapworth.
Uniserial Graptolitoidea tvith bilateral rhabdosome ; branches dichotorhous ; thecae
simple, sub-cylindrical.
Dicliograptus Salter (Fig. 198). Ehabdosome consisting of eight simple
Via. mo.
Tetragraptus hryonoides Hall.
Ordovician ; Point Levi.s, Canada
(after Hall).
Pig. 200
Didymograptus pennatulus Hall.
Ordovician ; Point Levis, Canada
(after Hall).
fi m
Fig. 19S.
Dichograptus octohrachiatus Hall. Ordovician (Quebec
Group) ; Point Levis, Canada (after Hall).
Fig. 201.
Didymograp-
tus murchisoni
(Beck). Middle
Ordovician
(L 1 a n d e i 1 o
Group) ; Wales.
Fig. 202.
Phyllograptus fypus Hall.
Ordovician (Quebec Group) ;
Point Levi.s, Canada, a, Several
polyparies of the natural size ;
h, Ideal cross-section, enlarged
(after Hall).
uniserial branches which are produced by rejDeated dichotomy, and their bases
often enveloped in a central corneous disk. Ordovician.
Tetragraptus Salter (Fig. 199). Rhabdosome consisting of four uniserial
branches which are produced by twice repeated dichotomous division.
Ordovician.
Didymograptus M'Coy (Figs. 195, b; 200; 201). Rhabdosome consisting of
two symmetrical branches diverging from a small jDrimary cell (sicula) at
various angles. Thecae obliquely directed, having the form of flattened
rectangular prisms, and in contact with one another throughout. Ordovician.
Phyllograptus Hall (Fig. 202). Rhabdosome leaf-like, composed of four
VOL. I K
130
COELENTERATA
PHYLUM II
uiiiserial rows of prismatic thecae coalescing along the whole length of their
dorsal margins ; the entire structure resembling Tetragrcqitus with the four
branches grown together, each two back to back and forming a cross in
transverse section. Ordovician.
Family 2. Leptograptidae Lapworth.
Uniserial, Jlexuous, bilateral rhabdosomes, with simple or compound lateral
branches; thecae with a slightly sigmoid curvature,
apertures inclined, somewhat introverted.
Leptograptus Lapworth. Rhabdosome consist-
ing of two long, filiform, bilaterally symmetrical
branches. Ordovician.
Nemagraptus Emmons (Coenograptus Hall) (Fig.
203). Two primary branches originating from the
Fif; 2(13. centre of a triangular sicula, more or less flexed,
Cocnmjraptus nrnriUs Hall. Ordo- and giving off simple branches from the convex
vician; Point Levis, Canada (after gide at approximately regular intervals. Ordovician.
Family 3. Dicellograptidae Lapworth.
Uniserial or uni-biserial Graptoloidea. Thecae tubxdar, with conspicuous
sigmoid ventral curvature. Apertures situated in excavations and frequently intro-
verted a,nd introtorted.
ig
Dicellograptus Hopk. Rhabdosome bilaterally symmetrical, consistin
two uniserial branches diverging from the sicula at angles ex-
ceeding 180 degrees. Ordovician.
Dicranograptus Hall (Fig. 204). Rhabdosome Y-shaped, com- ^ ||
posed of two symmetrically developed bi'anches which are
coalescent in the proximal and free in the distal portion of
of
their length.
Ordovician.
Fig. 204.
Dicranograptus
ramn.sns Hall.
Ordovician
(Hud.son River);
New York (after
Hall).
Suborder B. AXONOPHOEA Freeh (emend. Ruedemann).
Family 1. Diplograptidae Lapworth.
Biserial Graptolitoidea with rectilinear rhabdosomes.
Climacograptus Hall (Fig. 205, a, c). Rhabdosome bilaterally
symmetrical. Thecae tubular, ventral walls sigmoidally curved,
apertural margin horizontal, situated within a well-defined ex-
cavation. Ordovician and Silurian.
Diplograplus M'Coy (Figs. 205, d-f ; 206). Rhabdosome bilaterally sym-
metrical, rectangular, concavo-convex or tabular in section. Thecae mostly
sub-prismatic, ventral walls inclined and straight. Subgenera : Orthograptus
and Glyptograptus Lapworth ; Mesograptus Elles and Wood ; Petalograptus
Suess ; Cephalograpt'us Hopkinson. Ordovician and Silurian.
Family 2. Glossograptidae Lapworth.
Biserial Graptoloidea with straight rhabdosomes, test attenuated, with framework
of strengthening fibres. Thecae of Diplograptid type, provided ivith spurs and other
processes which often form an external lacework.
Glossograptus Emmons (Figs. 207, 208). Rhabdosome having Ungulate
CLASS II HYDROZOA— GRArTOLITOIDEA 131
outline and rounded extremities, ornamented with two rows of isolated spurs ;
Pig. 205.
o, c, Climacograptustypicalin Hall. Orfloviciaii (Tieii
ton limestone) ; Cincinnati, Ohio ; a, Vertical section
sliowinj; common axis In the centre, enlarged ; h, I'oly
pary of the natural size ; c. Cross-section, enlarged
(I, e, IHjiIoijraptus palmeus Barr. Silm-ian ; Prague ; d.
Folypary of the natural size; e, Polypary enlarged
/, DiiihxjraptHS foliacens Murch. Silurian (LlaiKleilo
Group) ; Scotland. Natural size.
Fifi. 20i;.
DiplograplusfoHaceiis Hall.'Utica shale (Ordovician);
Dolgeville, New York. Synrlial)dosonie showing
central organs and primary disk (hi) with funicidus
(/), to which the rhabdosomes (c) are attached by a
slender nemacaulus («). Gonangia (;/) with young
siculae (s) are also present, x % (after Ruedemann).
Glossographhs quadrimucronatus Hall var. approxinatus
Rued. Utica shale (Ordovician); Dolgeville, New York.
Syurliabdosome. x i/i (after Ruedemann).
Fio. :iOS.
Glossograptus qnadnmucronatus (Hall)
var. approximates Rued. Utica shale
(Ordovician) ; Dolgeville, New York.
Young .synrhabdosome showing central
disk and siculae. xS/i (after Ruedemann).
each theca with two long spines. Ordovician. Eetiographts Hall ; Lasiograptus
Lapworth. Ordovician.
132
COELENTERATA
PHYLUM II
Family 3. Retiolitidae Lapworth.
Biserial Graptolitoidea with straight rhahdosomes, the latter characterised hy a
network of delicate chitinous tracery (reticula) which forms the outward covering of
the walls of the thecae.
Retiolites Barr. (Fig. 209). Ehabdosome with periderm attenuated and
supported on a meshwork of fibres. Thecae arranged biserially, their apertures
A B opening outward. Two virgulae attached to
opposite sides, in the median plane. Ordovician
and Silurian. Subgenera : Gladiograptus Hop-
kinson and Lapworth ; Gothograptus Freeh.
Family 4. Dimorphograptidae Lapworth.
Uni-biserial Graptolitoidea, in which the proximal
portion is uniserial, bearing thecae of the general
Monograptus type ; the distal portion is biserial ivith
thecae of the Diplograptid type.
Dimorphograptiis Lapworth. Silurian.
Family 5. Monograptidae Lapworth.
Uniserial Graptolitoidea, with simple or compound,
straight or convex rhabdosome and thecae of varied
form.
Monograptus Geinitz [Monoprion Barrande ;
Pomatograptus and Pristiograptus Jaekel) (Figs.
193, 210). Rhabdosomes with only a single
row of thecae, which are in contact, usually
overlapping, their apertures entire or contracted,
often directed downward. Form of the rhab-
dosome may be straight, curved or sometimes
spirally coiled. Silurian and Devonian.
1). Rhabdosome simple, spirally coiled ; common
parts of thecae more or less linear and widely
Silurian. The zonal distribution of species in
been worked out in detail by Eisel.
Variously branching Monograptidae. Silurian.
Fio. 209.
Betiolites geinitzianus Barr. Silurian.
A, Specimen from siliceous schists of
Feaguerolles, Calvados ; natural size.
B, C, Polyparies from Motala, Sweden.
75, Cross-section. C, Lower end, en-
larged ; calcareous matter dissolved
out by acid, v, Zigzag-shaped virgula ;
v', Uod-lil<e virgula ; th, Conjoined
walls of hydrothecae ; s', Crossbars
connecting the virgulae ; o. Apertures
(after Holm).
Bastrites Barr. (Fig. 21
canal very narrow ; distal
se})arated from one another
Thuringia and Saxony has
Cyrtograptxis Carruthers
Range and. Distribution of Graptolites.
Graptolites are excellent index fossils of the older Paleozoic rocks, owing
to their limited vertical range, and wide geographical distribution. The
simpler forms, such as are derived by a succession of budding from a primary
sicula (Axonolipa), are especially characteristic of the uppermost Cambrian
and lower half of the Ordovician rocks. The group as a whole becomes extinct
at the close of the Silurian, except for a few stragglers in the Devonian and
Carboniferous. The occurrence of these organisms in rocks of the same age
in all parts of the world is explained by the fact that while some forms were
SUBCLASS II
HYDROZOA— ACALEPHAE
133
probably attached to seaweeds, as often in modern hydroids, others were free-
floating or planktonic creatures.
Remains of Graptolites are profusely distributed in the siliceous schists
and alum slates of the Fichtelgebirge, Thuringia, Saxony and Bohemia.
They are plentiful also in the Harz, in Poland, Silesia, the Baltic Provinces
and the Ural district ; and again in Scandinavia, Cumberland, Wales, the
north of England, Scotland and Ireland, as well as in Normandy, Brittany,
Spain, Portugal, Sardinia and Carinthia. In America they are found ex-
a h r quisitely preserved in Newfoundland,
Canada, New York, Virginia, Alabama,
Ohio, Wisconsin, Iowa and Arkansas. They
Fig. 210.
rt, Monograptus nilsxoni Ban\ Silurian (Alum
Schists) ; Gnifenwertli, nearSchleitz, Germany;
'(, Monograptiis colonus Barr. Silurian; Kliots-
tield, Scotland, showing sicula (after Lap-
worth); c, Monoiji'aplns turricnlatns Barr. Sil-
urian ; Prague (after Barrande). All figures
natural size.
Pig. 211.
Eastritcs linnaei Barr. Silurian ; Zekko-
witz, near Prague (after Barrande).
are known also in South America (Bolivia), and Australia, and are not un-
common in the drift which covers the plains of Northern Germany.
According to Lapworth, Graptolites are distributed vertically throughout
six different horizons ; the first of these coincides with the Upper Cambrian,
the three following with the Ordovician, and the two uppermost with the
Silurian. The Monoprionidae are especially characteristic of the two Silurian
horizons.
[The discussion of the group GraptoUtoidea in the present work has been revised by Dr.
Rudolf Ruedeniann, of tl'ie New York State Geological Survey, at AUiany, New York.—
Editor.]
Subclass 2. ACALEPHAE Cuvier. Scyphomedusae.^
(Discophora Huxley).
Free-swimming, discoidal or bell-shaped Medusae, with downwardly directed mouth,
with g astro-vascular pouches and numerous radial canals, and having, as a ride, the
margin of the umbrella lobed. Cambrian to Recent.
The Acalephs or Lobed Jelly-fishes, though frequently of considerable
size, are entirely without hard parts, and therefore are unfitted for preservation
1 Literature : Huxley, T., Memoir on the Anatomy and Affinities of the Medusae. Phil. Trans.,
1849. — Kner, R., Ueber eine Meduse in Feuerstein. Sitzungsber. Akad. Wiss. Wien, 1865, vol. lii. —
Haeckel, E., Ueber fossile Medusen. Zeitschr. fiir wissenschaft. Zool., 1865 and 1870, vols, xv., xvii.
Neues Jahrb. fiir Mineral., 1866. Jenaische Zeitschr., 1874, vol. viii. System der Medusen, i. and
ii., Jena, 1880-81.— A'a^/tors^, A. G., Om Aftryek af Medusor, etc. K. Svenska Vetensk. Akad.
134
COELENTERATA
PHYLUM II
in the fossil state. Nevertheless, under exceptionally favourable conditions,
as, for instance, in the Upper Jurassic Lithographic Stone of Bavaria, and in
the Middle Cambrian shales of British Columbia, impressions of these delicate
organisms are sometimes preserved, which admit of precise determination.
The best preserved and at the same time the most abundant species is
Pihizostomites admirandus Haeckel, belonging to the Acraspedote family of
Rhizostomidae (Fig. 212). Impressions also occur in flinty concretions of the
Upper Cretaceous, which are most nearly referable to the Medusae. Of a
more questionable nature are the organisms occurring in the Cambrian
sandstone of Lugnaes, Sweden, described by Thorrell under the name of
Fio. 212.
Rhizo/ttomites admirandus Ilaeck. Lithographic stone ; Eichstiidt, Bavaria. 1/7 natural .size.
(Missing parts restored in outline.)
Spatangopsis, but assigned by Nathorst to the Acalephs. In the same strata
also are found those peculiar fucoidal structures known as Eophyton, which are
commonly supposed to be of vegetable origin. Nathorst has brought forward
evidence, however, to show that these may really have been produced by the
trails of Jelly-fishes, Here also should be noticed the forms described by
Nathorst as Iledusifes, from the Lower Cambrian of Sweden, and regarded by
this author as casts of the gastric cavity of Jelly-fishes.
In 1898 a valuable monograph on fossil Medusae was contributed by
Walcott, and in 1911 our knowledge of these organisms was increased in
important respects by the same author, as a result of his studies of remarkably
well-preserved specimens from the Cambrian of British Columbia.
Han (11., 1881, vol. xix. — Ammon, L. v., Ueber jurassische Medusen. Abhandl. Bay. Akad. 1883,
vol. xvii. — Brandt, A., Ueber Ibssile Meduseu. Mom. Acad. Imp. St-Petersb., 1871, 7th ser.,
vol. xvi. — Po/difj, II., Altperniisclie Medusen. Festschrift zum 70teii Geburtstage R. Leuekarts,
l9,92.--]Valrott, a />., Fossil Medusae. U. S. Geol. Surv. Monogr., xxx., 1898.— /(?c?», Middle
Cambrian ilolotlnirians and Medusae. Smitbsou. Misc. Coll., 1911, vol. lix. No. 3. — Mayer,
A. O., Tlie Medusae of the World, i.-iii. Carnegie lust. Wash., Pub. No. 119, 1911.
Phylum III. VERMES. Worms.^
Bilaterally symmetrical animals with unsegmented or uniformly segmented, and
usually elongated bodies having a distinct body cavity. Segmented lateral appendages
wanting. A dermal muscular system and paired excretory
canals (water-vascidar system) present.
Of all the larger divisions of the animal kingdom, none
is so poorly adapted for preservation in the fossil state as
the Worms, whose bodies are as a rule entirely destitute
of hard parts.
All Worms are bilaterally symmetrical, and dorsal and
ventral surfaces are cle&vly difterentiated. The unsegmented
Worms (Vermes proper) have either flat or cylindrical bodies,
and are accordingly distinguished as Platyhelminthes or
Flat Worms, and Nemathelminthes or Round Worms. But
with the exception of the Cambrian genus Amiskwia (Fig.
213), supposed to be allied to the Recent Sagltta, and a few
rare parasitic forms discovered in Carboniferous insects, or
in Tertiary insects enclosed in amber, neither of these classes
is represented in the fossil state.
The segmented Worms, or Annelida, are characterised
by a division of the body into metameres, which, although
primitively alike, do not always remain homonomous.
They have a brain, a circumoesophageal ring, a ventral chain
of ganglia, and a vascular system. The body is more or less elongated, and
^ Literature : Pander, C. H., Monographle der fo.ssileu Fisclie des silurisehen Systems des
russisch-baltischen Gouvernemeuts, 1851. — Elders, K, Die Borsteiivviirmer (Annelida Chaetopoda).
Leipzic, 1864-68. — -Idem, Uber tbssile Wiirmer aus dem lithographischen Scliiefer in Bayern.
Palaeontogr. , 1868, vol. xvii. — Qlaparede,, 7^'. , Recherches siir la structure des Annelidas sedentaires,
1873. — Newberry, J. S., Palaeontology of Ohio, vol. ii. part 2, 1875. — Hinde, G. J., On Couodonts
from the Chazy and Cincinnati Groups ; and on Annelid Jaws from the Cambro-Silurian, Silurian,
and Devonian Formations in Canada, and from the Lower Carboniferous in Scotland. Quar. Journ.
Geol. See, 1879, vol. x.xxv. — Ulrich, E. 0., Journ. Cincinnati Soc. Nat. Hist., 1879, vol. i. —
Hinde, G. J., On Annelid Jaws from the Wenlock and Ludlow Formations of the West of
England. Quar. Journ. Geol. Soc, 1880, vol. xxxvi. — Ethcridge, R.,jun., British Carboniferous
Tubicolar Annelida. Geol. Mag., 1880, vol. vii. — Nathorst, A. G., On the Tracks of some
Invertebrate Animals and their Palaeontological Significance. K. Svensk. Vetensk. Akad. Handl.,
1881-86, vols, xviii., xxi. — Hinde, G. J., On Annelid Remains from the Silurian Strata of the Isle of
Gotland. Bihang till K. Svensk. Vetensk. Akad. Handl., 1882, vol. \ii.—ZMel, K. A., and
Rohon, J. v., Ueber Conodonten. Sitzber. Bay. Akad. Wiss., 1886, vol. xvi. — Clarke, J. M.,
Annelid Teeth from the Lower Portion of the Hamilton Group, New York. Sixth Annual Report,
N.Y. State Geologist, 1886. — Rorereto, G., Studi monografici sugli Annelidi fossili. Palaeont. Ital.,
1904, vol. x.~Walcott, C. £»., Middle Cambrian Annelids. Smithson. Misc. Coll., 1911, vol. Ivii.No. 5.
135
Pig. 213.
Amiskwia saijitti-
forniis Walcott. Mid-
dle Cambrian; British
Columbia. Flattened
specimen, x -/i (after
Walcott).
136
VERMES
PHYLUM III
sometimes flattened, sometimes cyliiulrical. According as the internal
segments correspond exactly with the external, or as each internal segment
corresponds to a definite number (3, 4 or 5) of the external rings, two
classes, Chaetopoda and Hirudinea, are distinguished. A further difl^'erence is
to be noticed in the locomotive organs, the Chaetopoda having bristle-bearing,
unjointed appendages {parapodia) on each ring of the body ; and the Hirudinea
having a terminal sucker. The latter group includes only the Leeches, which
are not known with certainty in the fossil state. Fossil representatives of the
third class, the Gephyrea, Annelids with the body devoid of any appearance
of segmentation in the adult condition, are known ; but of the fourth and last
class Archiannelida, the most primitive of all living Annelids, no fossil remains
have been found.
Class 1. CHAETOPODA. (Earthworms, Annelids, etc.)
It is only with the subclass of marine worms (Polychaeta) that the
paleontologist is concerned since the earthworms and their allies (Oligochaeta)
are wholly unknown as fossils. The marine Chaetopoda are divisible into
three orders, the Miskoa, the Tubicola or Sedentary Worms, and the Nereid
or Errant Annelids.
Order 1. MISKOA Walcott.
Polychaeta with similar segments and parapodia throughout the length of the body ;
retractile proboscis ; straight enteric canal. Body not distinctly specialised into
sections.
This order is founded upon a remarkable series of Annelids discovered by
Fid. '214.
Wiivaxia corrngatn Wiilcott. Middle
Cainbriaii ; British (Joliiinbia. Crushed
specimen sho\viii<^ disiilacea s]>iiu's and
scales, X l/i (after Walcott).
Figs. 215 and 21G.
Cambrian Polychaeta from British Columbia (after
Walcott). Canadiu spinosa and A ii^hcaia pcdunculata
Walcott, both x -Vi-
Walcott in the Middle Cambrian of British Columbia and described by him in
1911. The order is represented by four families, namely Miskoidae and
Aysheaidae, with the genera iMiskoia and Aysheaia respectively ; Canadidae
including Canadia and SelkirJcia ; and the Wiwaxidae with the three genera
CLASS I CHAETOPODA 137
TFiwaxia, Pollingeria and JForthenella. Typical examples of these Annelids are
shown in Figs. 214-16. Protoscolex and EotropJionia Ulrich, from the Eden
•• ' ■.:"">it:.^;-<-'V;'^
It ■ < ' r'^Z
HnH
p^l
^rapK^^Mg^i^-^
■^^^^
l^^M»«i
^■.'*t;oAJ^^^M
1
Fig. 217.
Gephyrean Annelid, Pikrda gmcUcni' Walcott. Middle Cambrian ; British Columbia, x 2/j (from Walcott).
shale of the Ohio Valley, are probably Ordovician representatives of this
order.
Order 2. TUBICOLA. (Sedentaria.)
Poh/chaetous Annelids ivith indistinctly separated head, and short, usually non-
protrusihle proboscis, without jaws. Parapodia short, and never used for swimming.
Inhabiting more or less firm tubes, which they construct, and subsisting ypo7i vegetable
matter.
The Tubicolous Annelids invest themselves with a protective tube of more
or less irregular form, to which they are not organically attached, and within
which they can move freely. Sometimes the tubes are free^ but more com-
monly they are attached to foreign objects, either by the apex or by one side,
and may occur either singly or in clusters. The tubes frequently consist of
concentric layers of lime -carbonate, with vesicular cavities between the
lamellae, or the latter may be traversed by fine tubuli. In other cases the
tubes are composed of agglutinated grains of sand and other foreign particles ;
or they may be membranaceous or leathery. The materials for constructing
the tubes are procured by the tentacles or branchial filaments of the head,
and arc cemented together by a glutinous secretion from large glands. Fossil
worm-tubes are by no means of infrequent occurrence, and are known from
the Ordovician onwards. Only a few of the more common examples can be
mentioned here.
Serpula Linn. (Fig. 218). Under this head are included the majority of
fossil Tubicolous Annelids. They build firm, irregularly contorted, sometimes
spirally enrolled, free or adherent calcareous tubes, which are frequently
clustered together in large numbers. Beginning in the Silurian, they are
sparsely represented in the Paleozoic era ; but from the Jura onward, numer-
ous forms occur, the usual condition being attached upon other fossils.
Notably in the Lower Cretaceous their gregarious masses form beds of con-
siderable thickness (Serpulitenkalk of Brunswick, and Serpulitensand of
Bannewitz, near Dresden). S. spirulaea Lam. (Fig. 218, H) is an abundant
and characteristic Eocene species. Eecent Serpulas have a world - wide
distribution.
138 VERMES phylum hi
Terehella Cuv. (Fig. 218, /). Cylindrical, elongate, more or' less bent
Firi. 218.
A, Scrpula Hmo,r Goldf. Middle Jnia; Franconia. /.', C, S. ijimlialU Scliloth. Upper Cretaceous: Baiiiie-
witz, near Dresden. D, t'!. roiivohUa, Qo\dt Middle Jura ; Stuilen, WurteniberK. E, S. socialis Goldf. Middle
Jura ; Lahr, Baden. F, Same, enlarged. G, S. septemsulcata Eeich. Upper Cretaceous ; Bannewitz. //, S.
(lt<ittilnriaT)efr.)sjiirularaha,m. Eocene; Monte Berici, near Vicenza. /, Te rrhrUa. lapUloides Mimster. Upper
Jura ; Streitberg, Franconia.
tubes, composed of cemented grains of sand, fish-debris, or other adventitious
particles. Lias to Recent.
Spirorhis Daudin (3Iicroconchus Murch.)
(Fig. 219). Minute, snail-like or spirally
enrolled calcareous tubes, cemented by the
flattened under side. The spiral may be
either dextral or sinistral, and is usually
ornamented externally Avith concentric striae
or annulatious, sometimes with tubercles or
spines. Abundant in the Paleozoic forma-
tions from the Ordovician onward, and also
at the present day ; somewhat less common
in the Mesozoic and Cenozoic eras. Recent
species usually adherent on seaweeds.
Fin. 21'.».
Spirorhis mnphalodef: (Goldfuss). Tubes
seated U|)()n a BrachioiJod shell (Schnchcrti'.lla
niiihrncnlniii). Devonian ; (iernlstcin, Eifel.
The following genera are commonly
regarded as Annelids, but their systematic position is doubtful :
CLASS I
CHAETOPODA
139
Serpulites Murch. Very long, smooth, compressed, and somewhat bent
calcareous tubes, the layers admixed with organic substance. Ordovician and
Silurian.
Cormdites Schloth. Thick-walled, trumpet-shaped tubes, Serpula-like at the
lower end, and sometimes attaining a length of three or four inches. Exterior
annulated, and covered with very fine longitudinal striae. Some authors
regard the tubes as Pteropod shells. Ordovician to Devonian.
Ortonia Nich. Small, conical, slightly flexuous, thick-walled calcareous
tubes, cemented by the whole of one surface to some foreign body. Sides of
the tube ringed with imbricating annulations, the free ujDper surface apparently
cellular in structure. Ordovician to Carboni-
ferous.
Conchicolites Nich. Conical, slightly bent,
thin-walled tubes, growing together in clusters,
and attached by the small lower ends to
orthoceratite or Brachiopod shells. Tubes
made up of numerous short rings, each of
which partially overlaps the subjacent one.
Ordovician.
The peculiar group Myzostomidae, which
are external parasites on Recent Crinoids, are
thought to be related to the Chaetopoda.
Graft' has shown that they also infested the
column segments of Jurassic Crinoids.
Order 3. ERRANTIA. (Nereidae).
Free- swimming, predaceoiis Polycliaeta, with
well-marked head. Proboscis capable of protrusion,
and armed with papillae or poiverfid jaws. Para-
podia rmich more developed than in the Tubicola,
beset with setae, and serving for locomotion.
Undoubted remains of Errant Worms have
long been known from the Lithographic Stone
(Upper Jura) of Bavaria, and include the
trails, calcified jaws and excrements of num-
erous species. The principal genus from this
horizon is Eunicites Ehlers (Geophilus Germar)
(Fig. 220), perfect impressions of which are
also found in the Upper Eocene limestone of
Monte Bolca, Italy. Archarenicola Horwood
is known from the English Rhaetic.
Under the designation of Lumbricaria
Mlinster [Lumbricites Schlotheim) (Fig. 221)
are included a variety of obscure remains from the Lithographic Stone,
which may be best regarded as the excrements of Annelids. They occur
as irregularly contorted bands or stinngs, sometimes in the form of very
long labyrinthic coils.
Of peculiar interest are the minute detached jaws and denticulated plates
Pig. 220.
Eunicites avitus Ehlers.
Stone ; Eichstadt, Bavaria
Lithographic
Natural size.
140
VERMES
FHTLUM III
described by Hinde in the Ordovician, Silurian, Devonian and Carboniferous
rocks of the United States, Canada, Great Britain and Sweden (Island of Got-
land). These are very small, black, highly lustrous bodies, extremely variable
in form (Fig. 222), and mainly
composed of chitinous material
which is unaffected by acid. They
exhibit a striking resemblance to
the jaws of recent Annelids, and
probably represent a large number
of genera.
Of less certain derivation are
the microscopic teeth first described
by Pander under the name of
" Conodonts " (Fig. 223), which
occur detached in the Cambrian
(Blue Clay underlying the Ungulite
Grit) of St. Petersburg, and are
also very abundant in beds of
Ordovician, Silurian and Car-
boniferous age in Russia, Great
Britain, the United States and
Canada. They are usually translucent, lustrous or corneous, and are composed
Fig. 221.
Lumhricaria colon Miinst. Lithograi)hic Stone
hofen, Bavaria. Natural size.
Solen-
B
D
Fk;. 222.
Paleozoic Annelid-jaws. A, Lnmhriconereiteshasalis Hinde. Silurian ; Dundas, Ontario, lo/j. B, Oenonitcf:
rostrahis Hinde. Toronto, i^/j. (', Etinicites varimis Grinnell. Toronto. B/j. X), Araheliltes scutellutus
Hinde. Ordovician ; Toronto. I'Vi-
of carbonate and phosphate of lime. They exhibit verj^ great variety in form.
By Pander and others these fossils have been regarded as fish-teeth. Zittel
Fio. 223.
Conodonts, greatly enlarged. A, B, J'altudus truncatiis Pander (after Pander). C, Prioniodus elcgans Pander.
Cambrian ; St. Peter.sburg. D, Polygnathus duhiua Hinde. Devonian ; North Evans, New York. 20/j.
and Rohon, however, consider that they are Annelid jaws, but their tiue
position cannot yet be said to have been positively determined.
CLASS II
GEPHYREA
141
Class 2. GEPHYREA.
Marine Annelida tvitlwut parapodia and typically devoid of any trace of
segmentation in the adult condition.
The Cambrian genera referred to this class by Walcott differ in certain
respects from the Recent members, but with our available information the
position here assigned them
seems most advisable. Two
families, (1) Ottoidae, with the
genera Ottoia and Banffia, and
(2) Pikaidae, including Pikaia
(Fig. 217) and Oesia, all from
the Middle Cambrian of British
Columbia, are recognised.
A quantity of supposed
worm-borings, trails, impres-
sions and other obscure remains
have been described from the
older Paleozoic formations.
The burrows have the form
of straight or tortuous tunnels,
and are sometimes hollow,
but more commonly have been
filled up by solid matrix. Various names have been applied to them,
such as ScolifJms, Arenicola, Histioderma, Planolites, Diplocraterion, Spirocolex,
Scolecoderma etc., but they are obviously incapable of precise determination.
Arthrophycus Hall, originally described as a plant, Daedalus (including Vexillum
Roualt) and Taonurus Fisher-
Fio. 224.
Nereltes ccmbrensis M'Leay. Cambrian ; Llampeter, Wales.
Natural size.
Ooster {Spifophjton Hall), have
in recent years been interpreted
as worm burrows.
Similarly, the serpentine or
vermiform impressions known as
--a Nereites, consisting usually of a
' ' number of windings, and often of
profuse occurrence in various
Paleozoic formations, were until
(|uite recently regarded as worm-
trails, or markings made by
Fucoids. These also have re-
ceived numerous appellations,
such as Nereites (Fig. 224), Ne-
mertites, Myrianites, Nemapodia,
Crossopodia (Fig. 225), Phyllodo-
Ordovician ; citss, Naites, etc. Nathorst, how-
ever, has brought forward ex-
perimental evidence to prove that the majority of these markings have been
produced by the movements of Crustaceans, Annelids and Gastropods. A like
origin may reasonably be ascribed to the extraordinarily abundant and variable
Fic. 225.
Crossopodm {Crossochorda) scotica M'Coy.
Bagnoles, Norniandy.
142 VEEMES phylum hi
vermiform structures known as " Hieroglyphics," which occur in the Flysch,
Carpathian Sandstone, and in the marine facies of the Cretaceous and Jurassic
formations. The trails known as Climactichnites Logan,^ from the Potsdam
sandstone (Cambrian) of New York and Wisconsin, are of uncertain origin,
but may be those of some large crustacean. Other peculiar markings have
been interpreted by B. B. Woodward {Proc. Malacol. Soc, London, 1906, vol,
vii.) as the feeding-tracks of Gastropods.
^ These tracks, known as Olimactichnites, were first described by Logan {Oan. Nat. and Geol.,
1860, vol. V.) and later recorded by Hall (N.Y. State Miis. 42nd Report, 1889) from Port Henry.
Essex connty, N.Y., and by Woodworth (N.Y. State Mus. Bull. 69, 1903) from the town of
Mooers, Clinton county, N.Y. In the latter locality they assume gigantic proportions, being 6 inches
wide and 15 or more feet long, terminating in an oval impression 16 inches long.
Various explanations have been suggested for these tracks. Besides having been referred to
trilobites, burrowing crustaceans, plants, gastropods and annelids, they have been compared with
those of the horseshoe crab, first by Dawson and recently again by Hitchcock and Patten. Sir
William Dawson {Can. Nat. and Cfeol., 1862, vol. vii.), who studied Limulus on the seashore,
pointed out that when the animal creeps on quicksand, or on sand just covered with water, it uses
its ordinary wallcing legs and produces a track strikiugly like that described as Protichnites from
tile Potsdam saiidstone ; but in shallow water just covering the body, it uses its abdominal gill-plates
and produces a ladder-like track the exact counterpart of Climactichnites except that in the track of
Livmlus the lateral and median lines are furrows instead of ridges. Patten {Science, 1908, vol. viii.
p. 382) " described the inovements of a modern Limulus in advancing uj) a sandy beach with the tide,
and the action of the abdominal gill-plates making rhythmic ridges in the sand. He compared
these with the tracks of Climactichnites, which he ascril)ed to forms related to the eurypterids rather
than the trilobites. Tlie tracks showed a beginning in a hollow in the sand and where continued
on the specimen to the further end there became fainter, as if the animal rose fi'om the bottom.
This would correspond with the habit of the Limulus, which remains buried on recession of the tide
and upon its first return crawls and then swims away. Beside one track were seen two symmetric-
ally placed impressions attributed to the longer arms of a Eurypteroid form."
In favour of this view is the fact that Struhops is a Cambrian Eurypterid that would appear
competent to produce such tracks ; contrariwise, however, Woodworth has suggested that the trail
was made by a mollusk, and that the sedentary impression is the end of the trail instead of its
beginning. Tlie direction of the obliquely transverse marks of Climactichnites is always toward
the oval impressions, and comparison with those of the Limulus tracks (Dawson, figs. 1-3, and also
fig. 157 in Cambridge Nat. Hist. vol. iv.) would indicate that the animal, if an Eurypterid, moved
toward the sedentary impression and not away from it. The most recent discussion of the nature
of these and other j)roblematical markings is to be found in a paper by Walcott (Smithson. Alisc.
Coll., 1912, vol. Ivii., no. 9), where it is suggested that the Climactichnites trails may have been
formed liy a large segmented Annelid like Pollingcria. Sjiecimens of the latter are known from
the Cambrian which have a length of 13 cm. and width of 7 cm.
Phylum IV. ECHINODERMATA
The Echinoderms are animals with primarily a radial (usually pentamerous)
and secondarily more or less bilateral symmetry, which were formerly included
with the Coelenterates under the general category of Radiata ; but were
recognised by Leuckart as the representatives of a distinct animal type.
Recently it has been suggested by two authors, working independently, one
from a study of comparative embryology (Patten), and the other from
evidence furnished by the adult anatomy (A. H. Clark), that the Echinoderms
are derived from acraniate crustacean ancestors, through the Cirripedia.
Echinoderms possess a well -developed, usually pentamerous dermal
skeleton, which is composed of calcareous plates, or of minute, isolated,
calcareous bodies embedded in the integument, and sometimes also in the
walls of many of the internal organs. The exoskeleton may be immovable,
or more or less movable, but is very frequently provided with movable
appendages (spines, pedicellariae, etc.). The arrangement of both the
skeletal parts and the principal organs is so generally pentamerous, that
five may be regarded as the fundamental numeral pervading the phylum of
Echinoderms.
Apart from this constitutional difference, Echinoderms are distinguished
from Coelenterates by the presence of a true digestive canal, a distinct
body-cavity, a vascular system, and a water-vascular apparatus ; by a more
perfectly developed nervous system ; and, except in certain Starfishes, by an
exclusively sexual mode of reproduction.
The skeleton of Echinoderms is primarily composed of a series of plates
which are situated in the integument, and are covered with living dermal
tissue during life of the individual. Although lying near the surface, the
plates are strictly internal in position, and are capable of growth or resorption
throughout life. Besides skeletal plates, other hard parts may occur, such as
spines, pedicellariae, the jaws or so-called " Aristotle's lantern " of Echini, and
spicules of the kind found in the tube-feet and some of the internal organs.
Certain Crinoids also show a series of calcified convolutions supporting the
digestive tube. The calcification of the internal organs is sometimes sufficient
to form solid skeletal parts. The plates and other skeletal parts of Echino-
derms are composed of open cribriform tissue (Figs. 226, 227), which in the
cleaned test of Recent specimens is highly porous. During fossilisation the
interstices are commonly infiltrated with lime carbonate, so that the whole
structure is transformed into calcite, exhibiting unmistakable rhombohedral
cleavage. Each plate, joint and spine of a sea-urchin, star-fish or crinoid
143
144
ECHINODEEMATA
PHYLUM IV
behaves miiieralogically and optically like a single calcite crystal. The plates
forming the main skeleton of an Echinoderm may be few or numerous, and
may be polygonal with vertical sides forming a solid skeleton, or they may
be rounded, scale-like or imbricating, forming a more or less flexible test ; or
again they may be reduced to minute, dissociated bodies embedded in the
integument and forming a partial dermal skeleton, as in certain Holothurians.
All the Echinoderms are marine, and only a very few of them occur in
even very slightly freshened water. In the system proposed by Haeckel
Fig. 226.
(i, Magnified cross-section of an
Echinoid spine ; Fiji Islands. /), Mag-
nified section of coronal plate of a
Recent Sea - urchin {Sphaercchinus) ;
plane of section jjarallel to surface.
Fif!. 227.
Pentitcrinus suhtcres Goldf. Upper Jura ; Keichen-
bach, Wurtemberg. a, Vertical section of stem-joint in
plane indicated in c, IS/j. b, Transverse section of
same, IS/j. c, Joint-face, d, Series of columnals
(natural size).
seven classes are recognised, of which the first three, namely, Cystidians,
Blastoids and Crinoids, are grouped together as a distinct subphylum called
Felmatozoa. Corresponding to this are two other subphyla, Astero::oa and
Echinozoa, the former including the classes of Asteroids and Ophiuroids,
and the latter comprising the classes of Echinoids and Holothurians,
Subphylum A. Pelmatozoa Leuckart.
The Pelmatozoa are Echinoderms, nearly all of which, during the whole or
at least the early portion of their existence, are fixed by a jointed, flexible
stalk, or are attached by the dorsal or aboral surface of the body. The prin-
cipal viscera are enclosed in a bursiform, cup-shaped or spherical test (calyx),
which is composed of a system of calcareous plates. On the upper surface of
the test are placed both the mouth and anus, as well as the ambulacral or
food grooves conducting to the mouth. In some forms, however, the calyx is
so reduced as to form merely a small horizontal platform upon which rest the
viscera, usually protected by a covering of secondary dermal ^^lates. As a
CLASS I CYSTOIDEA 145
rule, jointed flexible arms spring from the distal ends of the ambulacral
grooves around the margin of the calyx ; but sometimes, as in Blastoids, arms
are wanting, the ambulacral areas being extended down the sides of the calyx,
and beset on both sides with pinnules. The inferior (dorsal, aboi-al) portion
of the calyx is composed of a single or double series of basal plates, which
rest either directly upon the stalk, or upon a centrodorsal representing a
single greatly enlarged columnal, or they may be grouped about a central
apical plate or centrale. Sometimes these plates are so small as to be invisible
externally, so that the calyx appears to be composed of radials only.
The Pelmatozoa comprise three classes : Cystoidea, Blastoidea and Crinoidea.
Of these, the first two are wholly extinct, being confined to the Paleozoic
rocks ; all three are found well developed in the Ordovician, and doubtless
originated in pre-Cambrian time from unknown ancestral forms. The Cystids
are the oldest, substantially ending with the Silurian, though feebly repre-
sented in the Devonian and Carboniferous. The Blastoids culminated in the
Lower Carboniferous and ended in the Permian. The Crinoids also cul-
minated in the Carboniferous, but continued to survive, nevertheless, and are
represented in existing seas by numerous genera and species, the dominant
type being the unstalked forms, or Comatulids.
Class 1. CYSTOIDEA Leopold von Buch.i
Extinct, pedunculate, or more rarely siemless Pelmatozoa, with calyx composed
of more or less irregularly arranged plates. Food brought to the mouth by a system
of ciliated grooves, either between the calyx plates, over them, or along jnvrcsses from
the calyx {arms, brachioles, etc.), or subtegminal. Anus usually on the oral half of
the calyx. Calyx plates often perforate. Brachial processes usually imperfectly
developed, sometimes absent.
The calyx is globose, bursiform, ovate or ellipsoidal in form, more rarely
cylindrical or discoidal, and is composed of quadrangular, pentagonal, hexa-
gonal or polygonal plates, which are united by close suture. The plates
vary in number from thirteen to several hundreds, and only exceptionally
1 Literature: Volhoiih, A. von, Ueber die Ecliinoeucriueti. Bull. Acad. Imp. Sci. St-Pt'tersb.,
1842, vol. X. — Volborth, A. von, Ueber die russischen Sphaeroniten. Verhandl. Mineral. Gesell.
St. Petersb., 1845-46. — Buck, L. von, Ueber Cystideen. Abhandl. Akad. Wiss. Berlin, 1844
(1845). Translated in Quart. Journ. Geol. Soc. London, 1845, vol. ii. — Forbes, E., On the
Cystidea of the Silurian Rocks of the British Islands. Mem. Geol. Survey Great Brit., 1848,
vol. ii. part '2. — Midler, /.,' Ueber den Bau der Echinodermen. Abhandl. Akad. Wiss. Berlin,
1853.— ^aZZ, /., Palaeontology of New York, vol. ii., 1852, and vol. iii., 1859.— Billings, E., On
the Cystidea of the Lower Silurian Rocks of Canada (Figures and Descriptions of Canadian Organic
Remains, Decade III.), 1858. — Hall, J., Descriptions of some new Fossils from the Niagara Group.
20th Ann. Rept. N.Y. State Cabinet of Nat. Hist., 1867. — Billings, E., Notes on the Structure of
Crinoidea, Cystidea, and Blastoidea. Amer. Journ. Sci. (2nd ser.), 1869, vol. xlviii., and 1870,
vol. xlix. — Volborth, A. von, Ueber Achradocystites und Cystoblastus. Mem. Acad. Imp. Sci. St-
Petersb., 1870, vol. xvi. — Schmidt, F., Ueber Baltisch-Silurische Petrefacten. Mem. Acad. Imp.
Sci. St-Petersb., 1874, vol. xxi. — Barrande, ./., Systeme Silurieu du Centre de la Boheme, vol. vii.
Cystidees, li^T .—Carpenter, P. H., On the Morphology of the Cystidea. Journ. Linn. Soc, 1891,
vol. xxiv. — [lae.ckel, E., Die Amphorideen und Cystoideen, etc. Festschr. fiir Gegenbaur, No. 1,
1896. — Jacket, 0., Stammesgeschichte der Pelmatozoen, Thecoidea und Cystoidea, 1899. — Jaekel,
0., tjber Carpoideen. Zeitschr. Deutsch. Geol. Gesell., 1900, vol. Hi. — Bather, F. A., Treatise
on Zoology (Lankester), part 3, Echinoderma, 1900. — Schuchert, C, Siluric and Devonic Cystidea.
Smithson. Misc. Coll., 1904, vol. xlvii. part 2.— Bather, F. A., Ordovician Cystidea from Burma.
Mem. Geol. Surv. India, 1906, n. s. vol. ii. — Kirk, E., Structure and relationships of certain
Eleutherozoic Pelmatozoa. Proc. U.S. Nat. Mus., 1911, vol. xli. No. 1846.
VOL. I L
146 ECHINODERMATA— PELMATOZOA phylum iv
exhibit a regular an-angement. Sharp demarcations between the actinal and
abactinal systems of plates, and between radial and interradial areas, rarely
exist ; the plates of the sides of the calyx pass insensibly intp those of the
ventral surface, and are disposed in regular cycles only in a few instances.
The base, however, is composed of a distinct ring of plates, and is usually
recognisable by the presence of an articular surface for the attachment of a
stem, or by being directly adherent to some foreign object.
The mouth is indicated by a central or subcentral aperture on the upper
surface, or at the end opposite to that which is attached to the column or
stem. It is sometimes covered by five small plates corresponding to the
orals of Crinoids, and from it radiate from two to five simple or branching
ambulacral grooves. The second opening on the ventral surface is situated
eccentrically, and is frequently closed by a valvular pyramid, consisting usually
of five or more triangular plates ; or the covering may consist of a variable
number of smaller pieces. This aperture, which was regarded by L. von
Buch, Volborth, Forbes and Hall as a genital opening, is now generally con-
ceded to represent the anus. A third smaller opening, situated between the
mouth and the anus, is present in a few forms only. The functions of this
latter orifice are not well understood, but it is commonly regarded as the
ovarian aperture, or genital pore (Fig. 228). Yet another small, slit-like opening,
situated in the vicinity of the mouth, was detected by Barrande in the genus
Aristocystites ; but its functions are altogether unknown.
The ambulacral grooves, or food-grooves, which are present in most
Cystideans, are usually simple, although sometimes distally branching, and
are frequently roofed over by alternately arranged covering pieces. In a few
forms (Caryocrinus, Cryptocrinus, etc.) the grooves are wholly absent. The
genera Aristocystites, Pyrocystites and Calix are without exposed ambulacral
grooves ; but they have instead, as Barrande discovered, a peculiar system of
five or six covered passages on the inner surface of the calyx plates, which
converge towards the mouth, and are distally more or less branching (Fig.
229). These structures, the so-called " hydropho7-es palmces," were homologised
by Barrande with the hydrospires of Blastoids ; but as Neumayr has pointed
out, they are probably the equivalent of subtegminal food-grooves in Crinoids.
The calyx or thecal plates exhibit most remarkable structural peculiarities.
As a rule they are more or less extensively perforated by pores or fissures ;
although in some forms (Cryptocrinus, Malocystites, Ateleocystites, etc.) they
appear to be imperforate, and are composed of a homogeneous calcareous
layer of greater or less thickness, the same as in Cricoids. But in Aristo-
cystites, Calix, Proteocystites, Glyptosphaerites, Echinosphaerites, etc., the plates
are uniformly covered both externally and internally with a very thin,
generally smooth, calcareous membrane, which may be perforate or imperforate.
The central layer is of variable thickness, and is traversed by numerous
canals (Figs. 229, 230) which extend from the inner to the outer surface,
sometimes rectiliuearly {Aristocystites, Calix, etc.) ; sometimes in slightly
sinuous lines ; and in rare instances they divide dichotomously. The canals
terminate on either surface in small round apertures or pores, which are
arranged either singly or in pairs, and may or may not penetrate the outer
calcareous membrane. The pores are commonly situated either on a tubercular
elevation, or in a slight superficial depression.
But still more frequent than the canals are the so-called ptore-rliomhs (Fig.
CLASS I
CYSTOIDEA
147
231) which occur indifterently in types possessing numerous or but few
calycine plates. The pores are arranged so as to form lozenge-shaped or
rhombic figures, in such manner that one half of each rhomb belongs to one
plate, and the other half to its contiguous neighbour ; while the line of suture
between the plates forms either the longer or the shorter diagonal of the
rhomb. The pores of opposite sides of the rhomb are united by perfectly closed,
straight ducts, which pass horizontally through the middle layer and across
the line of suture between the two plates, thus producing a transversely
striated appearance. Occasionally the connecting tubes appear on the outer
surface as elevated striate rhombs ; but as a rule they are concealed by the
above-mentioned covering layer, and are only visible in weathered or abraded
speeimens. The pores of the rhombs also communicate with short canals
Fio. 229.
Aristocystites. Canals
perforating the median
layer of plate.
Fig. 230.
a, Aristocystites. Inner surfaoeof two
calyx plates showing simple pores ;
b, Ghjptosphaerites. Outer surface of
calyx plate showing double pores.
Fig. 228.
Glyptos2^haerites leuchtenhergi Volborth.
Calyx showing ambulacral grooves, plated
month-opening, large laterally situated anus,
and small ovarian aperture between mouth
and anus.
Fig. 2.S1.
Pore-rhombs of (a) Echinospluierites, and (h) Caryocrinus,
enlarged. The left half of Fig. a is abraded, so that the
connecting-tubes appear as open grooves.
passing vertically through the plates, the ends of which are either covered
over by the outer calcareous layer, or appear on both surfaces as fine indepen-
dent pores. A pair of oppositely situated pores of the latter description
may sometimes receive as many as two or three fine canals, while in other
genera they are entirely wanting.
The pore-rhombs are sometimes present upon nearly all plates of the calyx,
but in other cases they are only developed on a certain number or on all of
the plates forming the side-walls of the calyx, being absent from its upper
surface. In still other instances (Pleurocystites, Callocystites, Fig. 232), the
pore-rhombs are greatly reduced in number, and occur in the form known as
pectinated rhombs or pedino-rhomhs. The component halves of the latter
stand on contiguous plates the same as the ordinary pore-rhombs, but are
always separated externally by an interval ; frequently the two parts are of
different form or size, and sometimes one of them may become obsolescent.
As regards the functions of these canals and pores (the " hydrospires " of
148
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Pig. 232.
CaHor!jHitef!Jew''tti Hall. Silurian (Niagara Group); Lockport, New-
York. A, Caly-^c from cme .side (natural .size). B, Ambulacral grooves
and three pectinated rhombs (/■/(), enlarged ; o, Mouth ; (t?i, Anus ; g,
Genital pore (after Hall).
Billings), the anatomy of existing Crinoids furnishes us with no positive con-
clusions. They have been compared with the pores which are present in the
tegmen of the latter, and the rather plausible suggestion has been offered that
they served to admit water into the body-cavity, and thus performed
respiratory functions. At all events, they could not have served for the pro-
trusion of tube-feet, since
they are frequently covered
over by an outer calcareous
membrane, which effectu-
ally shuts off communica-
tion with the exterior.
The arms or brachioles
in the Cystideans are as
a I'ule feebly developed,
and are sometimes either
entirely wanting, or re-
duced in number (2, 3, 6,
9-13). The pentamerous
symmetry, so generally
characteristic of Echino-
derms, pervades neither the arrangement of the calyx plates nor the number
and disposition of the arms. The latter are invariably simple, are either
uniserial or biserial, and exhibit a ventral groove protected by covering plates.
In some genera the arms attain considerable thickness, but in others they
are very diminutive, and seem to have closer affinities with pinnules than
with the arms of Crinoids. In the Callocystidae and Agelacrinidae, as well as in
the Canadian genera, Amygdalocijstites and Malocystites, the arms are either
recumbent with their dorsal side facing the calyx, or they are prostrate and
incorporated into the calyx. The ventral side, in these cases, is directed out-
wardly, and the ambulacral furrow is bordered on either side by a row of
alternating, jointed pinnules, which are
attached by small articular facets running
parallel with the groove.
The stem, as a rule, is greatly abbrevi-
ated, and is frequently obsolete. Some-
times the calyx is attached by the entire
lower surface (Agelacrimis) ; or in other
cases by means of a tubular process
(Echinosphaerites). Only in rare instances
does the stem appear to have served for
attachment, since it generally tapers dis-
tally to a point, and is invariably destitute
of cirri. The stem sometimes resembles that of the Crinoids, in being composed
of a number of short, prismatic or cylindrical joints ; these are pierced by a
wide canal, and are either united by horizontal, striated, articular surfaces, or
they overstride one another like the draw-tubes of a spy-glass. In other cases
the up})er part, and occasionally, indeed, the entire stem, is composed of vertical
rows of alternating plates. These plates, as a rule (Dendroq/stites), enclose
a large central s})ace, which may be regarded as a prolongation of the Itody-
cavity.
a, Aristorysfites. Suhtegminal ambulacral
grooves ; b, Same of Pyrovi/stitet:. Enlarged (after
Barrande).
CLASS I CYSTOIDEA 149
The Cystideans constitute the oldest and least specialised group of the
Pelmatozoa. Appearing first in the Cambrian, they develop a great variety of
forms in the Ordovician and Silurian, but become extinct before the close of
the Carboniferous. While their own ancestry is obscure, it is highly probable
that from them have descended both the Crinoids and Blastoids. If, on the
one hand, the families of Aristocystidae, Sphaeronitidae and Echinosphaeritidae
differ radically from Crinoids in respect to their numeroiisly and irregularly
plated calyx, or as regards the feeble development or even total absence of
their arms ; nevertheless, the Cryptocrinidae and the imperfectly preserved
Cambrian genus. Lichenoides, evince a striking similarity, especially as concerns
the more or less regular arrangement of the calyx plates, and a certain
approach to radiation. On the other hand, forms like Porocrinus and Cleiocrinus,
along with strong pentamerous symmetry and regular arrangement of plates
which seem to ally them with the Crinoids, have also, in the presence of
pectino-rhombs and calycine pores, characters by which they might with equal
propriety be assigned to the Cystids.
If we can explain the derivation of Crinoids from Cystideans on the
supposition that the calyx plates of the latter gradually took on a more
definite arrangement, while the loss of pores and pore-rhombs was counter-
balanced by a stronger development of the arms and the stem ; so, too, it is
possible to derive Blastoids from the same source. Although hydrospires
are clearly wanting in "the Cystids, nevertheless, other characters, such as the
recumbent attitude of the arms upon the sides of the calyx, or their insertion
in grooves on the ventral surface, predicate an intimate relationship with
the Blastoids. Probably the most notable similarities are presented by the
peculiarly modified families, Callocystidae and Agelacrinidae. Various attempts
have been made to affirm a connection between Agelacrinus and the Asteroidea,
and between Alesites and certain of the Silurian Echinoidea (Echinocystites) ;
but such hypotheses are scarcely warranted, since they proceed from an over-
valuation of purely external resemblances, which in nowise prove genetic
relationship.
The Cystids were first recognised as a distinct division of Echinoderms by
Leopold von Buch in 1844, but their more detailed classification long remained
in an unsatisfactory condition, and is still involved in considerable difficulty.
This is largely owing to the comparative scarcity of material and its
frequently imperfect preservation, affording insufficient knowledge of the
exact structure in many forms. The classification of Johannes Miiller was
based primarily upon the structure of the calyx plates, according to which
two main groups were recognised, EhomUfera and Diploporita. To these
Roemer afterwards added a third, Aporita, and other divisions were made by
Barrande, Neumayr and Steinmann. In later years the Cystids have been
treated extensively by Haeckel, Bather, and Jaekel, who have proposed
classifications based upon phylogenetic principles. While in some general
features these are in substantial agreement they differ considerably in
details. The arrangement adopted by Bather, with some of the modifica-
tions introduced in the later editions of Zittel's Grundzilge, is in the main
here followed.
150
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Fig. 234.
Aristocystites boheinicut;] Barr. Ordovician (,Dd-i) ; Zahorzan,
Bohemia, a, Side view ; h, Sumniit aspect (after Banande). ^^
Order 1. AMPHORIDEA Haeckel (pars).
No radial symmetry in food grooves or calyx plates. .
Family 1. Aristocystidae Neiimayr.
Calyx composed of mmierous plates without regular arrangement. No extension
of food-grooves or brachial processes. Stein undeveloped,
or very short. Cambi'ian to Silurian.
Pilocystites, Lapillocystites and Acanthocystites Bar-
rande. Cambrian ; Bohemia, These are obscure genera.
Aristocystites Barr. (Fig. 234). Calyx bursiform
or ovate ; ventral surface with four apertures ; stem-
less. Ordovician ; Bohemia.
& Deutocystites Barr. Ven-
tral surface with three aper-
tures. Calix Rouault {Cra-
terina Barr.). Conical, trun-
cate. Baculocystites Barr.
Ordovician ; Bohemia.
Megacystifes Hall (Holocystis
S. A. killer). Elongate,
cylindrical or sub-cylindrical ;
short - stemmed or stemless,
with subcentral mouth. Silur-
ian ; North America, Gotland.
? Lodanella Kayser. Devonian ; Germany. Said to be a sponge.
Family 2. Anomalocystidae Meek.
Calyx oval, more or less compressed, with dissimilarly plated broad sides
either imperforate or loith simple pores ; pore-rhombs absent.
Food-grooves extended in one or more processes. Stem short,
tapering, of polymeric columnals. Cambrian to Silurian.
Trochocystites Barr. (Trigonocystis Haeckel). Calyx
strongly compressed. Plates of the right and left sides
large, those of both the anterior and posterior small,
polygonal. All plates perforate, but without pore-
rhombs. Ventral surface with three apertures. Stem
composed of several vertical rows of plates. Cambrian ;
Bohemia, Spain, Northern France.
Mitrocystites Barr (Fig. 235). Like the preceding,
except that one side of the calyx is composed of toler-
ably large, and the other of small plates. Ordovician ;
Bohemia.
Mitrocystella, Bhipidocystis Jaekel. Ordovician ;
Bohemia.
Anomalocystites Hall (Atdeocystites Bill. ; Platycystis
S. A. Miller ; Enopleura Weth.). Calyx plates smaller and more numerous
on the convex side than on the concave. Anus situated very low down on
Plates
Fig. 235.
Mitrocystites mitra Barr.
Ordovician ; Wosek, Bohemia.
Supposed right side (after
Jaekel).
CLASS I
CYSTOIDEA
151
the convex side. Arms feeble, filiform. Ordovician and Silurian ; North
America, England, Bohemia.
Balanocystites Barr. Ordovician ; Bohemia.
Belemnocystis Miller and Gurley. Ordovician ; North America.
Flacocysfites de Koninck (Fig. 236). Silurian; England.
Dendrocystites Barrande. Ordovician ; Bohemia. Cigara Barrande. Cam-
brian ; Bohemia. Syringocrinus Billings. Trenton Group ; Canada.
Eocystites Billings. Cambrian ; Canada.
Protocystis Hicks. Cambrian ; England.
Ceratocystis Jaekel. Cambrian ; Bohemia.
Pig. 23(5.
Placocystites forhesianus de Kon. Silurian ; Dudley,
England. A, Concave aspect, showing brachioles (hr)
and proximal stem joints. B, Convex aspect, h, basals ;
■HI, marginals ; v, ventrals (after Jaekel).
Fia. 237.
Amygdcdocystites florealis Bill. Tren-
ton Group; Canada. 1, from side; 2,
single plate enlarged ; 3, portion of
food - groove enlarged. Br, dotted
outline of some brachioles ; Br', facet
for attachment of same (after Bather).
Family 3. Malocystidae Bather.
Calyx plates numerous and indefinitely arranged. Radial folds of stereom
strongly marked, but no definite pore-rhombs or pectinated rhombs. Brachioles borne
on processes either free or recumbent on the calyx. Stem uniserial.
Malocystis Billings. Calyx globular. Ordovician ; Canada. Canadocystis
Jaekel. Same horizon.
Sigmacystis Hudson. Ambulacra 8-shaped. Ordovician ; Canada.
Amygdalocystiies Billings (Fig. 237). Calyx flattened and elongate. Two
unbranched ambulacra, fringed with brachioles, pass from a subcentral mouth
over the calyx. Ordovician ; Canada.
Comarocystites Billings. Ordovician ; Canada. Achradocystites Volborth.
Ordovician ; Eussia.
Order 2. RHOMBIFERA Zittel (emend. Bather).
Radial symmetry affects food-grooves, and sometimes calyx plates. Food-grooves
borne on jointed processes (brachioles). Calyx plates more or less folded, and provided
with rhombs.
152
ECHINODEEMATA— PELMATOZOA
PHYLUM IV
Family 1. Echinosphaeritidae Neumayr.
Calyx globular or hursiform, adherent or with short stem, and composed of
numerous, irregularly arranged plates, all of which are furnished with pore-rhombs.
Amhdacral grooves short, unbranched; arms two to five, free, hiserial, rarely preserved.
Stem, when present, composed of several vertical series of alternately arranged plates.
Ordovician and Silurian.
Fig. l'38.
Echinosphaerites aurantium (Hising). Ordovician (Vaginatenlolk) ; Pulkowa, Russia, a, Summit view of
calyx; ft, Calyx seen from the anal side; <■, Month, arms, and covered anibulacral gi-ooves ; d, Calyx plates
enlarged, showing pore-rhombs (cf. Fig. 231).
Echinosphaerites Wahlenb. (Crystallocystis, Citrocystis, Trinemacystis Haeckel)
(Fig. 238). Globose, non-pedunculate. Mouth central, ambulacral grooves
short. Anal opening protected by a valvular pyramid ; arms unknown.
Very abundant in the Ordovician of Russia and Scandinavia.
E. aurantium (Hising).
Arachnocystites Neumayi-. Like the preceding, except
that it has strong arms, usually three in number, which
sometimes attain a length of 10 cm. Stem tapering dis-
tally to a point. Ordovician ; Bohemia. A. infaustus
(Ban-.).
Caryocystites v. Buch (Amorphocystis Jaekel) (Fig. 239).
Calyx plates relatively large. Pore-rhombs on external
surface elevated, prominent. • Stem wanting. Ordovician ;
Russia, Scandinavia, England. C. granatum Wahlenb.
Palaeocystites Billings. Calyx ovate or pyriform ; plates
numerous, and poriferous at the margins. Ordovician; Canada.
Orocystites Barr. Ordovician ; Bohemia. Heliocrinus Eichwald. Ordo-
Stichocystis Jaekel. Ordovician ; Europe.
Fig. ■23d.
Caryocvstiteti grana-
/um (Wahlb.) Ordovi-
cian ; Oelan<i. Plates
of the natural size
showing elevated
pore-rhombs.
vician ; Russia.
Family 2. Caryocrinidae Bernard.
Calyx composed of a moderate number of plates exhibiting a more or less definite
arrangement in cycles. Certain or all of the side plates with pore-rhombs ; those of
the ventral surface imperforate. Food-grooves primitively three, branching, and
leading to free arms in varying number. Stem constantly present, occasionally long.
Ordovician and Silurian.
Hemicosmites v. Buch (Hexalacystis Haeckel), Calyx composed of four
basal plates, two zones containing six and nine lateral plates respectively, and
a circlet of six plates forming the ventral surface. The latter carries three
of which are situated small articular
short ambulacral grooves, at the ends
CLASS I
CYSTOIDEA
153
facets for the attachment of arms. Pore-rhombs present on all of the side
plates. Ordovician ; Russia. H. pyriformis v. Buch.
Caryocrinus Say {Stribalocystis S. A. Miller ; Enneacystis Haeckel) (Fig.
240). Calyx hexamerous, with dicyclic base. Infrabasals four, unequal;
followed by a second row (basals)
of six jDlates, alternating with the
plates of the first and third cycles.
The latter ring consists of eight
plates, six of which, according to
Carpenter, represent the radial s,
and two (the interscapulars of
Hall) the interradials. Ventral
surface formed of six or more
small pieces. All plates of the
cup furnished with pore-rhombs ;
the summit plates imperforate.
Mouth and ambulacral groove
subtegminal. Anus protected
by valvular pyramid, and situated
on the outer margin of the ventral
surface. Here also ai'e placed
the arms, which are six to thirteen
in number, and relatively feeble. Stem long, composed of cylindrical
segments. Ordovician ; Scandinavia. Silurian ; New York and Tennessee.
Heterocystites Hall. Silurian ; New York. Corylocrinus, Juglandbcrinus
von Koenen. Upper Ordovician ; France.
Fig. 240.
C'aryocrinus ornatus Say. Silurian ; Lockport, New York.
II, Calyx from one side, with two arms attaclied ; ft, Summit,
natural size ; c, Inner and outer surfaces of calyx plate of the
second circlet, with pore-rhombs.
Family 3. Oallocystidae Bernard.
Calyx composed of large plates arranged in three to five cycles, and exhibiting
three to fim pectinated rhombs, the component halves of which stand on contiguous plates,
and are separated by an interval. Mouth forming the centre of radi-
ation for two to five brachioliferous food-grooves which are protected
by covering pieces, and either rejwse upon the calyx, or are sunk below
the surface in grooves. Stem well developed, tapering distally to a
point. Ordovician and Silurian.
Subfamily A. Callocystinae Jaekel.
Pseudocrinites Pearce (Fig. 241). Calyx ovate,
two- to four-sided, and composed of four cycles
of polygonal plates. Anus closed by valvular
pyramid, and occupying a lateral position. Pore-
rhombs three in number; one placed above the
base, the remaining two to the right and left of
the anus. Arms two to four, recumbent upon the
calyx, extending to the base, and beset with biserial
jointed pinules. Stem robust. Silurian ; England.
Callocystites Hall {Anthocystis Haeckel) (Fig. 242).
Calyx olive-shaped, the oral end being more attenuated and obtusely pointed,
Fig. 241.
Pseiodocrinites quadnfaseiatus
Pearce. Silurian ; Tividale, Eng-
land. A, Calyx from one side.
B, Summit, sliowing mouth (»i),
anus (o), and tliree "of the arms.
The fourth arm (.);), broken away,
exposing flattened surl'ace of calyx.
154
ECHINODERMATA— PELMATOZOA
PHYLUM IV
the base flat or truncated ; plates twenty-five iii number. Arms sometimes
bifurcating. Silurian ; North America.
Apiocystites Forbes. Calyx regularly oval, elongate or slightly compressed,
and composed of nineteen plates. Silurian ; England, Sweden and North
America.
HaUicystis Jaekel. Like the preceding, except in having five deltoid
plates instead of one. Silurian.
Lepocrinites Conrad (Lepocrinus or Lepadocrimis Hall ; Staurocystis Haeckel).
Silurian ; New York and Tennessee.
Lepadocystis Carp. {Meekocystis Jaekel). Ordovician ; North America.
Sphaerocystites Hall ; Coelocystis, Jaekelocystis, Tetracystis and Trimerocystis
Schuchert. Silurian ; North America.
Strobilocystiies White. Devonian ; North America. Hyhocystiies Wetherby
Silurian ; North America.
A B
Fig. 242.
Callocystites jeiiHti Hall. Sil-
urian (Niagara Grouj)) ; Lock-
port, New York. Calyx seen
from one side (natural size), a,
anus ; hr, braclnoles, p, pectino-
rhombs. x J (after Jaekel).
Pig. 243.
I'leurocystUesJUitextiis Billings. Ordovician ; OttaAva,
Canada. A, Calyx from the anterior side. /!, Same
from the anal side ; A, anal area ; a, anus ; h, basals ;
br, braclnoles ; g, genital aperture ; I ^-'^, laterals ; m,
madrei)orite. x J (after Jaekel).
Subfamily B. Glyptocystinae Jaekel.
Pleurocystites Billings (Fig. 243), Convex side with large plates arranged
in cycles ; flattened side covered with very minute plates. Three isolated
pore-rhombs borne on the convex side. Arms two in number, robust. Stem
round, tapering distally to a point. Ordovician ; Canada.
Glyptocystites Billings. Ordovician ; Canada and Russia.
Cheirocrmus Eichwald ; Cystohlastus Volborth. Ordovician ; Russia.
Homocysiites Barrande. Ordovician and Silurian ; Bohemia.
Subfamily G. Echinoencrininae Jaekel.
Echinoencrinus v. Meyer (Sycocysfites v. Buch and Gonocrinites Eichw.) (Fig.
244, A). Calyx composed of four basal plates, and three cycles containing five
plates each. All calycine plates ornamented with costae or ridges radiating
CLASS I
CYSTOIDEA
155
B
outward from the centre. Ventral surface with short ambulacral grooves, and
articular facets for the attachment of three small arms. Anus removed to a
lateral position between the first and
second circlet of side plates. Three
pore-rhombs present ; of these, two are
situated above the base on the side
opposite the anus, and the third above
and slightly to the right of the anus.
Stem round, short, tapering distally
to a point, and composed of hollow
segments inserted one within the other
like the draw - tubes of a spy-glass.
Ordovician ; Kussia.
Scoliocystis, Erinocystis (Fig. 244, B)
and Glaphyrocystis Jaekel. Ordovician ;
Russia.
Prunocystis Forbes.
Schizocystis Jaekel. Silurian ; England.
Pig. 244.
A, Echinoencrinus senckenhergi v. Meyer. B,
Erinocystis volhorthi Jaekel. a, anus ; '), basals ; I,
laterals ; p, pectino-rlionibs. x | (after Jaekel).
Order 3. DIPLOPORITA Zittel (emend. Bather).
Radial symmetry affects food-grooves, and to some extent the calyx plates connected
thereivith. Food-grooves extended over the calyx plates themselves, and prolonged to
hrachioles which line the calyx grooves. Pectinated rhombs and pore-rhombs not
developed ; but calyx plates may be folded, and diplopores always present.
B
Family 1. Sphaeronitidae Neumayr.
Calyx globular or cylindrical, short-stemmed or stemless, and composed of
numerous irregularly arranged plates with pores united in pairs. Ambulacral
grooves either open or protected by
covering plates, and either short and
simple, or elongated and branching,
not extending from the mouth beyond
the adoral circlet of plates. Arms
as a rule exceedingly small and
primitive. Ordovician and Sil-
urian.
Sphaeronites Rising. (Pomo-
cystis Haeckel) (Fig. 245), Glo-
bose, stemless. Five short ambu-
lacral grooves radiating from the
mouth towards the arm bases.
Ordovician (Vaginatenkalk) ;
Russia, Sweden and England.
>S'. pomum Gyll.
Eucystis Angelin. Ordovician ; Sweden.
Trematocystis, Palmocystis, Archegocystis and Codiacystis Jaekel. Ordovician ;
Bohemia.
Allocystites S. A. Miller. Silurian ; North America.
Pig. 245.
Sphaeronites globulus Angelin. Ordovician, Sweden. A,
Tlieca, lateral aspect. B, Oral aspect, enlarged, an, anus ;
hr, facets for attachment of brachioles ; g, genital aperture ;
0, mouth ; x, base for fixation.
156
ECHINODERMATA— PELMATOZOA
PHYLUM IV
ProteoGijstites Barrande. Lower Devonian ; Bohemia. Carpocydis CEhlert.
Lower Devonian ; France.
Family 2. Glyptosphaeridae Bather.
Food-grooves extend over the calyx loell beyond the adoral circlet, and irregularly
transgress the sutures between the plates. Diplopores diffuse.
Glyptosphaerites Miill. (Fig. 228). Differs from Sphaeronites in having
long, branching, ambnlacral grooves, and a short, well-developed stem. Arms
recumbent and grooves beset with small plates. Ordovician ; Russia and
Sweden.
Fungocystiies Barrande. Clavate. Ordovician ; Bohemia.
Family 3. Protocrinidae Bather.
Food-grooves extend over the calyx almost to the adoral pole, and are regularly
bordered by alternating plates on which are the brachiole-facets. Diplopores diffuse,
or conff,ned to the adambulacrals.
Protocrinites Eichw. (Fig. 246). Nearly hemispherical, non-pedunculate.
Ambulacral grooves long and branching ; arms un-
known. Ordovician ; Russia and Bohemia.
Proteroblastus Jaekel {Dactylocystis) (Fig. 247).
Ordovician ; Russia.
Fui. 24t).
Fig. 247.
Proteroblastus schmidti Jaekel.
Ordovician ; Estlionia ; amh, food-
]'rotoi:rinites ovifonnis Ei('hwald. Ordovician; Pulkowa, Russia. grooves; hr, brachioles ; lamh,
a, Calyx viewed from abo\e, ; b, Same from below showing basal inter-anibulacrals ; o, mouth (after
l)late in the centre (after Volbortli). Jaekel).
Mesocystis Bather (3Iesites Hoffmann ; Agelacrinus Schmidt). Ordovician ;
Russia.
Family 4. Gomphocystidae Bather.
Ambuloxra in five main grooves curving around the calyx, and not prolonged to
the brachioles.
Goniphocystites Hall. Calyx flattened above, greatly elongate below, com-
posed of many irregular plates, pierced by diplopores. Covering plates often
developed, and grooves sunk below the thecal surface. Silurian ; North
America and Clotland.
Pyrocystites Barrande. Ordovician ; Bohemia.
CLASS I
CYSTOIDEA
157
Order 4. APORITA Zittel (emend.).
Radial symmetry affects food-grooves and calyx plates. Food-grooves home on
processes around the oral centre. No folds, rhombs or diplopores.
This division is admittedly artificial and ill-defined, being chiefly a
receptacle for genera whose relations are imperfectly understood, or whose
systematic position is doubtful.
Family 1. Cryptocrinidae Zittel.
Calyx composed of three rings of very finely perforate or imperforate, someivhat
regularly arranged plates. Mouth central, snrroimded by articidar facets for the
attachment of small arms. Anus eccentric; stem round and
slender. Ordovician to (?) Permian.
Cryptocrinus v. Buch (Fig. 248). Base composed of
three plates, and surmounted by two zones, each con-
taining five plates of unequal sizes. Mouth and anus
enclosed within a ring of smaller pieces. Ordovician ;
St. Petersburg. C. cerasus v. Buch.
Lysocystites Miller {Echinocystites Hall non Wyv.
Thomson, Scolocystis Gregory). Silurian (Niagara
Group) ; North America.
Hypocrinus Beyrich. This
genus, described as a Cystid,
from the Permian in the island
of Timor, and Coenocystis Girty,
from the same formation in
western America, are probably
Crinoids.
Fig. 249.
Macrocystella marlae Call.
A, from side X 1/1 . B-D, por-
tion of a brachiole, XiS/1,
from side, dorsal and ven-
tral surfaces. B, single plate
enlarged (after Bather).
Fig. 248.
Family 2. Macrocystellidae
Bather.
Calyx consisting of three or four
circlets of plates, displaying more Cryptocrinus cemsnsv Buch.
■' -^ .' -^ "^ "^ Ordovician ; Pulkowa, Russia.
or less pentamerism. JSO pores or a, l, c, Calyx from one side,
,7 ry \ • from abo\'e, and from below
rhombs. Oam brian. („at. size); m, Mouth ; «, Anus.
Macrocystella Calloway.
(Mimocystites Barr.) (Fig. 249). Three ranges of five plates each, followed
by a fourth of the same number bearing bifurcating brachioles. Radiating
folds strongly marked, dividing surface into triangles. No rhomb structure
visible. Stem rapidly tapering. Pentamerous symmetry is well marked,
and the form might be characterised as a tri-cyclic Crinoid. Cambrian ;
England.
Lichenoides Barr. (Lichenocystis Haeckel). Cambrian ; Bohemia and
Bavaria. Aethocystis S. A. Miller. Silurian ; Indiana.
Family 3. Tiaracrinidae Bather (emend.).
Calyx composed of not more than two circlets of plates : three (basals) in the first,
and four (radials) in the second ; followed by a range of short plates resembling
158 ECHINODERMATA— PELMATOZOA phylum iv
brachials surrounding the periphery of the tegmeii, either in an almost conti7iuous
ring, or in groups where the interoral sutures meet the radials. Whether there are
further brachials in succession is unknown. Stem with a small axial canal.
Silurian and Devonian. Kelations doubtful, may be monocyclic Crinoids.
Zophocrinus S. A. Miller, has arm plates in clusters of about three. Surface
smooth. Silurian ; North America.
Tiaracrinus Schviltze {Staurosoma Barrande). Arm plates eight or ten to
each radius, forming a rather continuous ring. Surface strongly marked with
folds crossing the sutures, which seem to be accompanied by pores. Devonian ;
Eifel, France, Bohemia.
Order 5. EDRIOASTEROIDEA Billings.
(Syn. : I7iymc?ea Chapman, 1860 ; Agelacrinoidea^. K.M.\\\q\\ 1877-1883;
Cystasteroidea ^iQmvadiMn, 1888; Bernard, 1893; Thecoidea J aekel, 1895).
The eminent Canadian paleontologist, E. Billings, as early as 1854, called
attention to the great difference between the forms now grouped under this
name and the typical Cystideans, and in 1858 suggested that they should be
arranged as a suborder to be called Edrioasteridae. Subsequent authors have
generally agreed to this in principle, but not as to the relative rank which the
group should have. Bather, regarding it as a class, assigns it equal rank with
the Cystids, Crinoids and Blastoids. Jaekel recognises it as one of three
orders into which he divides the Cystidea (sensu L. von Buch), and this pro-
cedure is in principle here adopted, without, however, denying that it may be
entitled to the higher rank. Bather's definition and general characterization
of the group is substantially as follows :
Pelmatozoa in which the theca is composed of an indefinite number of irregular
plates, some of which are variously differentiated in different genera ; with no subvective
skeletal appendages, but with central mouth, from which there radiate through the theca
five unbranched ambulacra, composed of a double series of alternating plates (covering-
plates), sometimes supported by an outer series of larger alternating plates {side-plates
or flooring -plates). Fores between [not through) the ambulacral elements, or between
them and the thecal plates, permitted the passage of extensions from the perradial
water-vessels. Anus in posterior interradius on oral surface, closed by valvular
pyramid. Hydropore {usually, if not always, present) between mouth and anus.
This would represent primitively, as Bather explains, a form with flexible
sack-like calyx, composed of numerous irregular, polygonal plates deposited
in the integument ; having a mouth in the centre of the upper surface, and
being attached by some indefinite portion of the lower surface. The struc-
ture of the ambulacra would remove it far from the earlier Amphoridea,
among Cystids, from which group it may have been derived.
Upon this primitive ancestral form the following characters were, to a
greater or less degree, impressed : a sessile habit ; the consequent assumption
of a circular, flattened form ; the differentiation of the upper and under
surfaces ; the development of marginals or concentric frame-plates ; and the
tendency to increase the food-gathering surface by spiral coiling of the ambu-
lacra. According to the varying extent of these modifications, the order is
divisible into three families : Agelacrinidae, Cyathocystidae, Edrioasteridae.
The Edrioasteroidea have a somewhat greater geological range than the
CLASS I
CYSTOIDEA
159
majority of Cystids, extending from the Cambrian to the Lower Carboniferous.
Two genera, Agelacrimis and Edrioaster, are fairly abundant in certain localities
of North America, but the others are rare.
Family 1. Agelacrinidae Hall.
Calyx composed mostly of thin plates, flexible, attached temporarily or per-
manently by the greater part of the aboral surface ; ambidacra confined to the oral
surface. Cambrian to Carboniferous.
Agelacrinus Vanuxem (Fig. 250). Calyx in the form of a depressed or
convex disk, stemless, and attached by the entire under surface ; composed of
numerous, small, polygonal, usually imbricating
plates, which are perforated by fine, usually
conjugate pores. Mouth surrounded by four
oral plates ; radiating from this are five small,
more or less curved food-grooves, which are
embedded in the disk, and are protected by a
double row of covering plates. Ordovician ;
North America, Rhineland and Bohemia. Rare
in Silurian and Devonian.
Stromatocystis Pompeckj. Cambrian; Bohemia.
Cystaster Hall [Thecocystis Jaekel). Streptaster
Hall. Ordovician ; Ohio.
Hemicystites Hall. Ordovician and Silurian ;
North America and Bohemia.
Haplocystis Roemer. Devonian ; Rhineland.
Lepidodiscus Meek and "Worthen. Devonian to Carboniferous ; North
America. Discocystis Gregory, Carboniferous ; North America.
Pig. 200.
Agelacrinus cincinnatiensis Roemer.
Ordovician ; Cincinnati, Ohio. Indi-
vidual of the natural size adherent to
test oi Baflnesquina alteniata (Conrad).
Family 2. Oyathocystidae Bather.
Calyx composed on the oral surface of five deltoids surrounded by marginals, but
beloiv of a fused solid mass of stereom, with irregular longitudinal sutures ; ambu-
lacra confined to oral surface ; permanently attached by the aboral surface, as by an
encrusting roof. Ordovician.
Cyathocystis Schmidt. Ordovician ; Esthonia.
Family 3. Edrioasteridae Bather.
Calyx flexible, composed of thin plates; attached, if at all, by a small central
portion of the aboral surface ; ambulacra pass on to the aboral surface. Ordovician
to Devonian.
Edrioaster Billings (Aesiocystis Miller and Gurley) (Fig. 251). Ordovician ;
Canada and Kentucky.
Dinocystis Bather. Devonian ; Belgium.
1 Cyclocystoides Billings and Salter. Ordovician ; North America and Great
Britain. Probably a Cystid, but not sufficiently known to be assigned to any
particular family.
160
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Family 4. Steganoblastidae Bather.
Calyx rigid, composed of plates relatively larger and thicker than in other
families of this group, including elements comparable to the radials and basals of
Blastoidea. Ambulacra descend into the radials. A short stem present. Ordovician.
Sfeganoblastus Whiteaves {originally desci'ibed as Astrocystites, name pre-
occupied). In all the prominent external characters resembling a Blastoid,
but careful study of the type specimens by Bather has shown the ambulacra
to have essentially the same structure as ,in Edrioaster, and that brachioles are
absent. Ordovician ; Canada.
am
P arpt vg Q^
Fifi. 251.
Edrioaster higshyi Bill. Ordovician ; Ottawa, Canada. 1, Oral surface with covering plates (auih) on two
of the grooves, and side- or floonng-i)lates (ad) on the others, x 1/1. 2, Vertical section of same, 1/1. 3, Sec-
tion across an ambulacrum, enlarged. Ad, flooring-plates; (i-mi'i, covering-plates ; an, anus; i.a, interanibu-
lacrals ; M, madreporite ; m, membrane with imbricating plates, thrown into live lobes (?) ; /, frame of stouter
plates ; 'ps, subtegminal peristome ; j/, pores ; v(j, ventral groove (after Bather).
The following generic names have been incorrectly applied to Cystids :
Probably a Camerate Crinoid.
{Loholithus BaiT.). Inflated or bullions root of the Caiiiei
Ascocystites Barrande
Caiimrocrinus Hall.
Crinoid, Scyphocrinus.
Cardiocystis Barraude. Indeterminable.
Qrinocystis Hall. Probably a Camerate Crinoid.
Oyclocrinus Eiehwald {Pasceolus Billings). Not an Echinoderin.
Dictyocrinas Conrad. A Receptaculite.
Hyponomc Loven. The ejected disk of a Coniatulid.
Lichenocrimis Hall. The terminal stem-plate or root of some Pelmatozoan
Neocystites Barrande. Probably the root of a Pelmatozoan.
Porocrinus Billings. An Inadunate Crinoid.
ate
Range and Distribution of the Cystoidea.
The Cystideans, a wholly extinct class, are the oldest known members of
the Pelmatozoa. They are represented in the Cambrian by a number of poorly
preserved foi'ms, whose affinities are in many cases doubtful {Protocystites,
Macrocystella, Eocystites, Lichenoides, Trodiocystites). They attain their maximum
development in the Ordovician and Silurian, whereupon they suddenly diminish
in numbers, and probably disappear in the early Carboniferous. Of the 250
species that have been described, scarcely a dozen are found in strata above
the Silurian.
CLASS II , BLASTOIDEA 161
Although a few forms {Echinosphaerifes, Aristocystites, Caryocystites) appear
in considerable abundance in certain formations, and are locally profuse in
some beds, the majority are of comparatively rare occurrence. The brachioles
are only exceptionally preserved, owing to their fragile constitution, and the
stem is also usually lost.
Cystideans are found most plentifully in the Ordovician rocks of St.
Petersburg, Russia, and in the Silurian localities of Oeland, Gotland, Sweden,
Wales and Bohemia (Etage D). The Bohemian specimens are usually pre-
served in the form of casts and moulds, and are contained in siliceous or
argillaceous slates. The Chazy and Trenton limestones of Canada, New York,
Ohio and Indiana also yield a large variety of forms.
Excellently preserved specimens of Pseudocrinites, Apiocystifes, Echinoen-
crinus and Anovialocystites are obtained from the Silurian limestones of Dudley
and Tividale, England ; and similar forms (Lepadocrinus, Callocystites, Caryo-
crinus) are found in the Silurian (Niagara Group) of North America. Only
scanty remains are known from the Devonian, and from the Lower Carboni-
ferous but a single genus, Lejndodiscus.
Two genera have been described from the Permian, Hypocrinus Beyrich,
and Ooenocystis Girty ; but their systematic position is doubtful, and until more
is known of their structure they may be left out of consideration.
Class 2. BLASTOIDEA Say.i
Extinct, short-stemmed, or stemless Pelmatozoa with a rigid calyx resembling a
floioer-hud in shape, with pentamerous symmetry predominant {occasionally modified
by atrophy), usually composed of thirteen principal plates. Food-grooves lying in
lanceolate or linear areas {ambidacra or pseudamlndacra) which radiate from a
central peristome between fire interradiol deltoid plates and are not crossed by sutures
between calyx plates ; they bear at their lateral margins pinnule-like appendages, and
from their inner floor hang lamellar tubes known as hydrospires. Grooves and peri-
stome protected by small, movable covering plates.
The ccdyx is clavate, pyriform, ovate or globose, frequently pentangular
at its upper face, and composed of plates which are firmly united among
themselves. The plates of the abactinal system are arranged in three suc-
cessive cycles, represented by the basals, radials and interradials or deltoids.
The plates of the actinal system comprise the summit plates and the ambulacra.
The basals consist of two plates of equal size, and a third smaller one,
which is directed invariably toward the right anterior interradius. Eesting
upon the basals are five V-shaped, usually equal radials (commonly known
1 Literature: ,Srt?/, T'., Observations on some Species of Zooiiliytes, etc. Anier. Joiirii. Sci. , 1820,
vol. ii. — Say, T., On two Genera and several Species of Crinoids. Journ. Acail. Nat. Sci. Pliilad.,
1825, vol. iv. (Also in Zool. Journ., 1825, vol. ii.) — Roemer, F., Monographic der fossilen
Crinoidenfamilie der Blastoideen. Troschel's Archiv fiir Naturgescli. , 1851, Jahrg. xvii., vol. i. —
Rofe, J., Notes on Ecliinodermata. Geo!. Mag., Dec. 1, 1865, vol. ii.— Billings, E., Notes on the
Structure of Crinoidea, Cystoidea, and Blastoidea. Amer. Journ. Sci. 2nd ser., 1869-70, vols,
xlviii.-l. — Etheridge, R., and Carpenter, P. II., Catalogue of the Blastoidea in the Geological
Department of the British Museum, 1886. [Complete bihliogi-aphy, pp. 303-310.] — Bather, F. A.,
Genera and Species of Blastoidea, with a list of specimens in the British Museum, 1899. [Complete
index of names with references to literature.] — Batlier, F. A., Treatise on Zoology (Lankester).
Part III., Echinoderma, 1900. — Hambach, G., Revision of the Blastoidea. Trans. Acad. Sci.
St. Louis, 1903, vol. xiii. — Hudson, G. H., Pelmatozoa from Chazy Limestone. New York State
Museum Bull. No. 107, 1907.
VOL. I M
162
ECHINODERMATA— PELMATOZOA
PHYLUM IV
as "forked plates"), whose superior margins are more or less deeply incised by
the radial si7iuses. The term sinus is applied to the open space between the
two prongs or limbs of the plate (Fig. 252).
Succeeding and alternating with the radials,
and resting upon their limbs, are five interradial
or deltoid plates, which vary excessively in size ;
they are considered to be homologous with the
oral plates of the Crinoids. In some species they
occupy a large part of the sides of the calyx, and
in others they are confined to the upper face.
In Nihcleocrinus and certain species of Orhitremites,
the deltoids extend down so far into the calyx as
to constitute more than half, or nearly the whole
of its sides, while the radials are so short as to
Fig. 252. l^e almost invisible in a side view. Only a part
Pmtremites godoni (DQh\). Analysis of the deltoids is exposecl to view, their sides
of calyx, h, Basals ; r, Radials; ir, , . • i i -ii n i • i i
interradiais or deltoids. being provided With Hanges which are covered
by the outer ends of the ambulacra. The name
dejtoid has reference to the exposed part of the plates, which in most forms
is triangular or rhomboidal in outline.
The radial sinuses between the limbs of the radials and the superjacent
deltoids are filled by the ambnlacral fields or amlmlacra {" pseudambulacra" of
Eoemer), The ambulacra vary in form from petaloid to narrow lanceolate or
linear, and extend from the summit of the calyx to the distal ends or lips of
the radial sinuses. The open space in which the ambulacra meet, the so-called
" summit- ojJening " or peristome, is pentangular, and central in position. Ordin-
arily this space is open, but in well-preserved specimens it is covered
by a greater or less number of minute calcareous pieces (Fig. 253); these
a D
Fio. 253.
A, OrhUremites iKirwoodi (O. and S.). Upper face of perfect specimen, with month and anus (a) closed by
plates. Spiracles {sp) separate. B, (h-dithocrinua stellljhrmis (O. and S.). Upper face with closed peristome and
exposed anus. Spiracles slit-like. (', rcnttvniitett siih-ntus Koem. Central niouth-oiieninj; surrounded by live
spiracles, the ]:)ostorior one confluent with the anus. /), Cryftnhldntiis- mclo ((). and S.). Upper face with
central mouth-openini;, larj^e anus, and eiL?ht spiracles (after Carpenter). All specimens from Burlington
Group ; Iowa.
may be either regularly or irregularly arranged, but leave at each angle of
the summit-opening a small passage-way, by means of which the ambulacra
communicate with the peristome. The mouth is invariably subtegminal.
The summit structure is rarely observed. The small plates which cover
the peristome are merely extensions of the ambnlacral covering plates variously
modified in shape. In Nucleocrinus, Orophocrinus and Schizohlasf us sayi, the
central space is occupied by five asymmetrical plates, formerly called orals,
surrounded by smaller ones toward the grooves. In Orhitremites norwoodi and
CLASS II
BLASTOIDEA
163
Cri/ptohlastus melo the plates are all small and irregularly arranged. In the
genus Fentremifes the covering plates are modified in a singularly different
way : toward the centre they become increasingly elongate and spine-like,
surrounding not only the central opening, but also the spiracles and anal
aperture, with a fringe of tapering spines, which meet over the summit in a
tuft-like stellate pyramid, with salient angles interradial.
The summit in most Blastoids is surrounded by a cycle of five pairs of
openings ; and between the two posterior ones there is usually interposed
a single additional aperture. The former were regarded by Roemer as con-
nected with the genital system, and were called by him '^ovarian apertnres" ;
but they are now known as the spiracles. The other opening which pierces
the upper end of the posterior deltoid is the anus.
The form and arrangement of the spiracles is extremely variable ; they
-may be round or slit-like ; they may consist of ten separate openings, or those
of the same pair may be con-
fluent with one another. The
members of the posterior pair
may be fused Avith each other
and with the anus, in which
case the fifth or posterior
spiracle is considerably larger
than the others. Orhitremites,
Penfreniites, Pentremitidea, etc.
(Fig. 254, A), are examples of
the latter case ; Orhitremites
having five circular orifices
with tube - like projections,
while in Pentremites and Pent-
remitidea the four smaller
spiracles are divided into two
.1
Fig. 204.
A, Pentremites (loclnnl (Defr.). Lower Carboniferou.s ; Alabama.
Upper face with ambulacral fields in various states of iHeservatioii.
a, Ambulacrum after the removal of lancet- and side-plates ; hydro-
spires exposed ; h, Lancet-plate with upper surface denuded by
weathering ; c, Perfectly preserved lancet-plate bordered by side-
1. 1 ii- i. -1 plates ; '/., The same, but with transverse markings of lancet-plate
compartments by tne terminal obliterated ; e, Ambulacrum covered with pinnules (after Roemer).
B, Phacnoschisnia acutiini (Svvby.) Lower Carboniferous ; Lancashire.
Upper face, enlarged ; a, Ambulacrum after removal of the lancet-
and side-plates ; hydrospire slits {hi/) cutting through radials and
deltoids ; h, c, Ambulacra in which lancet-plates (?) only are pre-
served : d, e, Ambulacra intact ; lancet-plate concealed by side-plates
(after Etheridge and Carpenter).
median ridge of the deltoids.
The posterior spiracle in the
two latter genera is divided
by a duplicate ridge into three
compartments ; of these the middle one enters the inner cavity, and the two
outer ones communicate with the hydrospires by means of the hydrospire
canal. In Troostocrinus, SchizoUastus and Cnjptohlastus (Fig. 253, D) the
posterior spiracles are confluent with the anus, while those of the four regular
sides are separated. Nudeocrinus, Mesohlastiis and Acentrotremites have ten
separate spiracles, and a large, distinct anal aperture. The typical Codasteridae
(Codasfer and Phaenoschisma), in which the hydrospires are exposed externally,
have no spiracles and no hydrospire canal. OropJiocrinus (Fig. 253, B) has
ten elongate clefts extending along the sides of the ambulacra ; but these are
in reality the unclosed portions of the radial sinuses, and correspond to the
open hydrospire canals of Pentremites, which are apparent upon the removal of
the side-plates.
The ambulacra are usually depressed below the general level of the calyx,
but are sometimes raised above it, or they may be placed in the same plane
with it. They vary in form from narrow linear to broad petaloid, and are
164
ECHINODERMATA— PELMATOZOA
PHYLUM IV
opening
,Plc.. 255.
A, Pentremites iiyriformis Ba,y. Portion
of an ambulacrum, exhibiting the lancet-
considerably complicated in structure (Fig. 255). The centre of each ambu-
lacrum is occupied by the lancet-plate, a long, narrow piece, pointed at both
ends, which extends to the full length of the fields. Its proximal end is
inserted between the deltoids, and takes part in the lip around the summit-
The upper surface of the plate is excavated along the median line,
and forms an open, well-defined groove, which
conducts to the mouth, and in all probability
represents the food-groove. The interior of the
plate is traversed by an axial canal, which com-
municates by means of the ambulacral opening
with an oral ring belonging to the water-vascular
system. In a number of forms (Pentremites,
Orophocrinus) there is to be seen a second,
smaller, and extremely thin plate underlying,
the median portion of the first ; this is called
the under lancet-plate.
The lancet-plate rarely occupies the full
width of the ambulacral field, and the spaces
between its lateral edges and the sides of the
radial sinus are either wholly or partially
i)iate (I) ; median food-groove of the same covcred bv a row of Small, horizontally elongated
(rt) ; side-plates (s) ; outer side-plates («) ; i , /a 7 j » j; -r> \ t D ^
and marginal pores (p), 5/1, (after E. and sule-plates {" pore-puites ot Koemer). in rent-
0. B, Ambulacrum of Nucleocrinus. -i rt i ■ i ii u;
Lettering as in ^ (after Roemer). remites, Oropkocnnus, and Other genera, an addi-
tional series of still smaller pieces, called the
outer side-plates ("supplementary pore-plaies" of Koemer), are placed between
the side-plates and the walls of the radial sinus. Pentremites and Cryptoschisma
have the entire upper surface of the lancet-plate exposed to view, and the
side-plates are situated alongside of it in the
same plane. But in other forms the lancet-plate
is wholly, or to a very large extent, concealed by
the side-plates (Fig. 255, B), so that as a rule
only a small space along the food-groove is visible.
The sutures between the side-plates are indicated
by shallow, horizontal furrows, which are con-
tinued as superficial grooves over both halves of
the lancet-plate as far as the median ambulacral
groove. These crenulations, it should be noted,
are frequently efi"aced in weathered specimens
(Fig. 255, A and B). Small, pit-like depressions,
or small tubercles, which are observable on the
side-plates, indicate the places where the append- m;;^-^;""^ °LSrS''and"S^t.;
ages or pinnules were formerly attached. These are perfectly preserved pinnules (after Meek
o J . and Wortlien).
only exceptionally found intact, but when pre-
served they completely conceal the ambulacral fields, and extend upward above
the summit of the calyx (Fig. 256). They differ considerably in length, even
among species belonging to the same genus. They are jointed structures like
miniature arms, uniserial as far as observed, but with ossicles sometimes
wedge-shaped and interlocking to some extent from opposite sides, thus
simulating a biserial arrangement. Whether they performed the function of
discharging the ova, like the pinnules of Crinoids, can only be conjectured.
CLASS II
BLASTOIDEA
165
The crenulations, or file-like markings across the ambulacra in Pentremites
above noted, are not mere surface ornamentation ; but the ridges constitute
the sides, and the depressions the floor, of a series of small ducts leading from
the pinnules, and forming lateral branches of the main ambulacral groove
into which they discharge. These lateral ducts, as well as the main median
groove of the ambulacrum, are, in well-preserved specimens, roofed over
throughout the entire field by very minute alternating covering plates extend-
ing all the way to the pinnules, and probably continuing along their ventral
side. In this respect the structure of th^ ambulacral area has not been
generally understood, and not heretofore correctly described. The arrange-
ment of the side ducts, their discharge by a distinct curvature into the main
groove, and their connection with the pinnules, leave no doubt that they
were the closed food-grooves serving to conduct nutriment from the pinnules
on toward the mouth.
In most Blastoids the side-plates, or the outer side-plates when such are
present, are pierced by marginal pores (or hydrospire pores), which communicate
with the hydrospires. The pores are situated at the extreme outer margins
of the plates, at the end of the lateral ridges, and
alternate in position with the sockets of the pinnules.
They are present in all forms having the hydrospires
concealed within the calyx ; but are absent in the
Codasteridae, in which the hydrospires are wholly or
in part exposed on the outer surface.
The hydrospires (Figs. 257, 258) are bundles of
flattened, lamellar tubes, extending underneath the
lancet- and side-plates, in a direction parallel with
the boundaries of the ambulacral fields. They begin
at the lower end of the ambulacra, and terminate in
the hydrospire canals, of which the spiracles form the
adoral apertures. When the spiracles are confluent, PentremitcssuieatusSay. Lower
the canals of adjacent groups of hydrospires enter the ^e"^°Sr Lf 'clS\t ''.bout
same opening. The hydrospires are suspended in the Vs pe height of the ambulacral
. -^ j.% 1 ,1 n j-.ii 1 -^ fields, xli/2- /iy, Hydrospires;
majority oi lorms along the walls oi the body-cavity i, Lancet-piate ; p, Pore-piates;
(Pentremites, Fig. 257), being attached either to the '"- ^•■^^iais.
outer margins of the under lancet-plate or to a separate piece known as the
hydrospire plate (Orhitreniites, Mesohlastvs and Cryptoblastus). Pentremites has
Fig. 257.
A
'^^^TKc/
Fig. 25S.
Transverse sections through the ambulacral fields, showing various forms of hydrospires. A, Orbitremites
derhi/ennif:. B, Orbit remites nonuoodi. C, Metablastus lineatus. DjOrophocrlnus verus. All sections enlarged
(after Etheridge and Carpenter).
from four to nine hydrospires in each group ; Orbitremites two, or exceptionally
one ; Troostocrimis and Mesohlastiis generally three, and Orophocrinus from five
to seven (Fig. 258, A-D). In PhaenoscUsma and Codaster (Fig. 260) the tubes
166 ECHINODERMATA— PELMATOZOA phylum iv
open externally by slits piercing the radials and deltoids and running parallel
with the ambulacra.
The functions of the hydrospires can only be surmised, but they are sup-
posed to have served for respiration : they correspond doubtless to the pec-
tinated rhombs and calycine pores of the Cystideans and to the respiratory
pores of some Crinoids. It is probable that water was admitted to the
hydrospire sacs through the marginal pores, and was discharged through the
spiracles. Koemer and Forbes have suggested that the hydrospires may
also have performed reproductive functions. Ludwig has called attention to
the resemblance between the genital bursae of Ophiuroids and the slit-like
spiracles in Orophocrinus ; his theory is that the hydrospires served both for
purposes of respiration and for the discharge of genital products, a view
which was also shared by Carpenter.
The stem in Blastoids is preserved only in exceedingly rare instances. It
is round, provided with a small axial canal, and composed of short joints,
which apparently multiplied in a similar manner to that in the Crinoids. In
Orophocrinus and Pentremites it has been traced for a length of 15 cm. without
reaching the end; and in the latter.form it has occasionally been found with a
few, comparatively heavy cirri. A few genera, like Eleutherocrinus, are stemless.
It has frequently been claimed, owing to the superficial resemblance of
their ambulacral areas, that the Blastoids and Echinoids are mutually related ;
but such presumptions are founded upon a total misconception of the value
of external characters. The construction of the calyx, the presence of pin-
nules, and the stemmed condition, are features which identify them unmis-
takably as Pelmatozoa ; and their nearest relatives under this group are the
Cystideans. The j^arallelism between the ambulacral fields of the one class
and the recumbent arms, apparently soldered on to the calyx of the other, is
self-evident. The hydrospires of Blastoids correspond to the pore-rhombs of
Cystideans, as has already been remarked ; and the position of the mouth and
anus is the same in both types. The Blastoids constitute a peculiar, but, on
the whole, a very well-defined group, which is now regarded as of equal rank
with the Crinoids and Cystids.
The earlier forms occurring in the Ordovician are primitive, representing
transitions from ancestors of Cystid type, and having the characters of the
two groups intermingled in varying degrees. In one genus, Asterohlastus, the
presence of diplopores and lack of hydrospires are correlated with the presence
of the Blastoid ambulacrum together with its bordering pinnules, and more
strongly developed basals and radials. In another. Blast oidocrinus, the diplo-
pores are replaced by hydrospires, thus further strengthening a line of
development which becomes thoroughly established in the Silurian with the
genus Troostocrinus.
Several genera are represented in the Devonian, both of Europe and
America. But the climacteric of Blastoid development takes place in the
Lower Carboniferous of North America ; some of the beds of the Kaskaskia
Group are densely charged with their remains, which, as a rule, are excellently
preserved. They occur sparsely in the Upper Carboniferous and Permian of
western America and the island of Timor, but above this horizon no traces of
Blastoids have as yet been discovered. Nineteen genei-a, comprising upward
of 120 species were recognised by Etheridge and Carpenter in their mono-
graph of 188G, and a few have been added since.
CLASS II
BLASTOIDEA
16^
' The last-named authors subdivided the Blastoids into Begulares and
Irregulares, an arrangement representing incidental variation rather than any-
broad morphological differentiation. That presented by Bather in Part III.
of Lankester's Zoology, 1899, appears to be more logical, and is followed in
principle here. By separating the typical Blastoids, in which the character-
istic calyx plates have become fixed at a small and definite number, from the
earlier forms which have not attained that structure, two main divisions may
be recognised, viz. : Protohlastoidea and EuUastoidea. Hudson, whose admirable
studies upon Blastoidocrinus have thoroughly elucidated that hitherto obscure
type, has suggested a third, ParaUastoidea, to express the differences shown by
his researches between it. and the other Ordovician forms. As the general
division is a somewhat arbitrary one at best, it is thought that these differences
are sufficiently emphasised by the family diagnosis.
Order 1. PROTOBLASTOIDBA Bather (emend.)
Calyx plates numerous, not limited to a definite number.
Family 1. Asteroblastidae.
Blastoidea with calyx plates indefinitely arranged above basals and radials, and
having, along with pentamerous ambulacra
and marginal brachiole^s, diplopores and
pore-plate, but no hydrospires. Ordovician.
JsteroblastusEichw. (Fig. 259). Calyx
gemmiform, pentagonal, pedunculate, and
composed of numerous rigidly united
plates which are perforated by conjugate
pores. Upper surface marked by five
large petaloid or stellate areas which
are occupied by alternating plates, and
bordered by sockets for the attachment of brachioles. Ordovician ; Russia.
Fig. 250.
Asterohlastus stellatus Eichwald. Ordovician ;
Pulkowa, Russia. Natural size (after Schmidt).
Family 2. Blastoidocrinidae Bather (emend.).
Calyx plates more definitely arranged in four circlets, without diplopores or pore-
plate, but with hydrospires present. Ordovician.
Blastoidocrinus Billings (emend. Hudson). Calyx pentagonal, composed of
four circlets of principal plates, viz. : (1) basals (number unknown); (2)
radials with angular distal face, followed by (3) two large plates called bi-
brachials, with numerous interbrachials in each interradius ; and (4) very
large triangular deltoids, with hydrospire-slits at their lower margins
Adambulacrals, heavy covering plates, and some additional plates in the oral
portion. Ambulacra large, bordered with numerous brachioles or pinnides.
Base invaginate, with strong column occupying the concavity. Ordovician
(Chazy Group) ; Canada and New York.
Order 2. EUBLASTOIDEA Bather.
Calyx plates limited to a definite number of about thirteen. Hydrospires always
present.
168
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Family 1. Oodasteridae Etheridge and Carpenter.
Base usually well developed, and sometimes very long. Amhulaera without
marginal pores. Hydrospire -folds coming to the surface of the radial sinus.
Hydrospire-slits either wholly exposed, piercing the calyx plates along the sides of
the radial sinuses, or restricted j^ortions of them remain open as spiracles, while
the remaining parts are concealed by the amhulaera. Devonian and Lower
Carboniferous.
Codaster M'Coy (Codonaster Eoemer ; Heteroschisma Wachsm.) (Fig. 260).
Calyx inverted, conical or pyramidal. Upper face broad, truncate or gently
convex ; section, as a rule, distinctly pentagonal. Basals forming a conical or
triangular cup, usually deep. Eadials large, their limbs bent inward horizon-
tally, to assist in forming the truncated upper face of the calyx, and never
deeply excavated by the sinuses. Deltoids wholly confined to the upper face,
as are also the ambulacra. The latter are petaloid, or narrow and linear ;
lancet-plate, as a rule, deeply excavated for the side-plates. Spiracles absent,
Fi(i. 200.
Codaster aeutus M'Coy. Lower Carbonifer-
ous ; Derbyshire. A, Side-view of calyx. B,
Base. (', Venlral aspect, enlarged (after
Roemer).
Fig. 261.
Oroplwcrimis steUiformis (O. and S.). Lower
Carboniferous ; Burlington, Iowa. A, Calyx and
base of the natural size. 1!, Ventral surface en-
larged (after Meek and Worthen).
hydrospires pendent, arranged in eight groups, two in each of the four
regular interrays, but wanting in the anal one. The tubes open externally
by a variable number of elongated slits, which are sei:)arated by intervening
ridges ; one or more of them may be partially concealed by the overlapping
side-plates. Anus large, ovate or rhombic, and piercing the posterior deltoid.
Ornament consisting of fine lines arranged parallel to the margins of the
plates. Silurian to Lower Carboniferous ; Europe and North America.
Fhaenoschisma E. and C. (Fig. 254, 11). Calyx resembling that of Codaster
in general form, but with ten groups of hydrospires instead of eight. Radials
bear each three more or less distinct folds diverging from the lip ; sinuses
wide and deep, generally with stee}) sides. Deltoids small, confined to the
truncated upper face of the calyx. Lancet-plates in all but one species
(P. caryophyllatum) concealed by the side-plates ; outer side-plates very small.
Spiracles rarely present. Hydrospires pendent, and opening externally by a
series of elongate slits with intervening ridges, distributed in sub-parallel
order on the sloping sides of all the radial sinuses. The slits are only
partially covered by the ambulacral plates, and are sometimes visible for their
entire length. Lower Devonian ; Spain. Lower Carboniferous ; Europe and
North America.
CLASS II
BLASTOIDEA
169
Onjptoschisvia E. and C. Calyx elongated, with a broad, .flat, truncated
upper face. Radial sinuses wide and open, their sloping sides pierced by
hydrospire slits, which are completely concealed by broad, petaloid ambulacra.
Spiracles small, single or more rarely double ; in the latter case the posterior
pair are confluent with the anus. Rej^resented by the solitary species C.
schuUzi d'Archiac and de Vern. Lower Devonian ; Spain.
Ofopliocrinus v. Seebach (Dimorphocrinus d'Orb. ; Codonitcs M. and W.),
(Figs. 258 D, 261). Calyx balloon-shaped to truncate ob-pyramidal, with
more or less concave upper face. Section distinctly pentagonal or stellate.
Ambulacra narrow, linear to sub-petaloid. Deltoids generally visible in side-
view, the posterior one wider than the others. Spiracles ten, varying from
wide clefts along the sides of the ambulacra to narrow slits at their upper
ends ; the posterior pair separate from the anus. Hydrospire-slits almost
completely concealed, being concentrated at the bottom of the radial sinuses.
Stem round, composed of short, nearly equal joints. Pinnules extending to
nearly twice the height of the calyx, of uniform thickness throughout, and
composed of sharply cuneate pieces interlocking from opposite sides ; ventral
furrow wide, and covered by small pieces. Lower Carboniferous ; Britain,
Belgium and North America (Kinderhook and Burlington Groups).
Family 2. Pentremitidae d'Orbigny.
Base usually convex', and often much elongated. Spiracles five, but sometimes more
or less completely divided by a median septum, and bounded proximally by the upper-
most side-plates. Lancet-plate either entirely visible or partially covered by side-plates
which extend to the margins of the ambulacra.
Hydrospires concentrated at the lowest part of the
radial sinus. Devonian and Lower Carbon-
iferous.
Fentremites Say (Figs. 254-7, 262-3).
Calyx usually ovate or pyriform, with elon-
gate, sub-truncate base. Ambulacra broad,
sub-petaloid. Lancet-plate wholly exposed,
and resting below on an under lancet-plate.
Side-plates and outer side-plates numerous,
the former abutting against the edges of the
lancet-plates. Hydrospires three to nine ;
spiracles single, or occasionally double ; the
two of the posterior side confluent with the
anus, and forming with it a single large
orifice. Oral centre surmounted by numerous
spines, placed closely against one another so
as to form a pyramid, which comjoletely covers
the summit and the greater portion of the Lower carbon- Roemer. Lower Carbon-
1 Ti . , '', 1 , • ,1 T iferotis ; 111. iferous ; 111.; A, Summit
spiracles, liixcessively aoundant in the Lower (Nat. size). aspect, b, base.
Carboniferous of North America (Burlington
to St. Louis and Kaskaskia Groups), but not identified in Europe. P. godoni
Defrance, and P. pyriformis Say, are the most familiar species.
Pentremitidea d'Orb. Calyx clavate-pyramidal, with elongate, usually
conical base, and truncate or convex ujjper face. Ambulacra narrow, short ;
Fig. 202.
Fentremites
qodoni Defr.
Fio. 263.
Fentremites siilratus
170
ECHINODERMATA— PELMATOZOA
PHYLUM IV
lancet-plate more or less completely concealed by side-plates. Deltoids very
small, generally confined to the upper face of the calyx, and seldom visible in
a side-view. Spiracles and hydrospires as in the preceding. Lower and
Middle Devonian ; Eifel, Ardennes, Spain, Great Britain and North America
(Hamilton Group of Indiana, Michigan, Canada). P. pailletti de Vern.; P.
eifelianuS Roemer ; /-'. davatus Schultze.
Family 3. Troostoblastidae Etheridge and Carpenter.
Calyx elongate. Ambulacra narrow, linear, deeply impressed, descending out-
ward from the summit.' Deltoids confined to the narrow upper end, rarely visible
A externally, except the posterior one in Troostocrinus. Lancet-
plate entirely concealed by side-plates. Spiracles distinct, repre-
sented by lineal slits at the sides of the deltoid ridge, and
bounded by deltoids and lancet-plates, but not by side-plates.
Silurian to Lower Carboniferous.
Troostocrinus Shum. {Clavaeblastus Hambach) (Fig.
264). Calyx narrow, elongate, somewhat fusiform, with
contracted, subtruncate, or slightly convex upper face.
Ambulacra short. The four anterior deltoids overlapped
by the radial limbs ; the posterior one much larger than
the rest, and appearing externally. Posterior spiracles
confluent with the anus. Silurian (Niagara Group) ;
North America.
Metaldastus E. and C. (Fig. 258, C). Like the preced-
ing, but all the deltoids equal, and the two posterior
spiracles not confluent with the anus. Spiracle slits ten
in number ; hydrospires four to each side of an am-
bulacrum. Devonian to Lower Carboniferous (Keokuk
Group) ; Europe and North America.
Tricoelocrinus M. and W. (Saccoblastus Hambach). Calyx
(TrooS'''t"^^^^^^^^ pyramidal, broadest below and narrowing upwards ; when
nessee.^,caiyx from anal geen from abovc Or below strougly pentagonal in outline,
side. B, Summit aspect. . ii
<?, Deltoid ; ir, Deltoid of owmg to the projecting and carinated character of the
anal side (after E. and C). j- i -rv i^ • i n i i
radiais. Deltoids small ; ambulacra
long, and extremely narrow. Spiracles ten, distinct ; anus
large. Hydrospires small, enclosed within the substance of
the forked plates. Lower Carboniferous (Warsaw Group) ;
North America.
Family 4. Eleutherocrinidae Bather.
Elongate, stemless, asymmetrical, with four narrow ambulacra ; , ,^""'- "!''''•
J..,, 7 7 7,7 7-7 7 TT" 7 • J J'Jeutlierocmins msse-
Jijth ambulacrum shortened and widened. Hydrospires not con- dayi{Shnm.o.m\\'a.na.).
J 1 1 T\ • Lower Devonian ; Ky.
centrated. Devonian. ventrai surface, -J/,
Eleutherocrinus Shumard and Yandell (Fig. 265). '
Devonian (Hamilton Group) ; Indiana, Kentucky, New York and Canada.
Family 5. Nucleocrinidae Bather.
Calyx usually globular or ovoidal, with flattened or concave base, and linear
ambulacra extending the whole length of the calyx. Spiracles distinctly double, and
an^-sp
Pig. 264.
Troostocrinus reinivardti
CLASS II
BLASTOIDEA
171
chiefly formed by the apposition of notches in the lancet-plate and deltoids.
and Carboniferous.
Devonian
Nucleocrinus Conrad {Elaeacrinus Eoeiuer ; Olivanites Troost) (Fig. 266)
Basals small, inconspicuous, sometimes hidden within the columnar cavity
Eadials small, with very short limbs. Deltoids
greatly enlarged and elongated, forming over
two-thirds of the entire calyx ; the posterior one
wider than the others, and divided by a large
anal-plate. Lancet-plate exceedingly long and
narrow, partly exposed. Side-plates numerous ;
hydrospires two on each side of the ambulacra.
Summit covered by comparatively large orals,
asymmetrically arranged and forming a flattened
disk which completely closes the peristome.
Devonian (Onondaga and Hamilton Groups) ;
Indiana, Michigan, New York.
Schizohlastus E. and C. {Crihroblastus Ham-
bach). Calyx resembling that of Orbitremites in
form. Basals almost always confined to the
lower face of the calyx ; deltoids of variable
size, but always visible in a side-view. Hydro- Devonian ;Coiunibus, ex (after Roemer).
. f 1 , , c^ . , A, Side-view of calyx. />, Base. C,
spires one to tour to each a,mbulacrum. Spiracles Ventral surface, i), same enlarged.
small, slit-like, placed between the lancet-plates
and deltoid ridges ; the posterior pair sometimes confluent with the anus.
Lower Carboniferous ; Ireland and North America (Kinderhook to Keokuk
Groups) ; Permian, Timor.
Fio. 266.
Nucleocrinus rerneu Hi {Troost). Lower
Family 6. Orbitremitidae Bather.
Calyx globidar or ovoidal, with flattened or concave base, and long linear
ambulacra. Spiracles five, piercing the deltoids, or ten, grooving their lateral edges.
Lower Carboniferous.
Orbitremites Austin (Granatocrinus Hall ex Troost MS. ; Cidaroblastus and
Globoblastus Hambach) (Figs. 253 A, 258 A). Calyx ovate to globose. Lower
face from slightly concave to deeply funnel-shaped ; interradial areas more or
less depressed. Basals small, generally concealed in the central columnar
cavity. Radials very variable in size, often long, and invariably turned in
below to assist in forming the base. Deltoids also variable ; usually unequally
rhombic, but sometimes triangular ; the anal deltoid frequently differing from
the others. Ambulacra nearly parallel-sided, always impressed within the
sinuses at their proximal ends. Lancet-plates narrow, not filling the sinuses,
and more or less exposed throughout two-thirds of the ambulacra. Side-plates
transversely elongated ; outer side-plates generally well developed. Hydro-
spires pendent, usually but two or three folds on each side of an ambulacrum ;
the inner one forming a well-defined hydrospire-plate. Spiracles five, piercing
the apices of the deltoids. Posterior spiracle larger, including the anus.
Summit closed by minute pieces which rarely exhibit any definite arrange-
ment. Lower Carboniferous ; England and North America (Burlington
Group), (?) Australia.
172 ECHINODERMATA— PELMATOZOA phylum iv
Cryptoblastus E. and C. Calyx sub-globose, with a flattened or slightly
hollowed base. Basals and deltoids small. Lancet-plate separated from the
radials by a hydrospire-plate, which does not extend above the radio-deltoid
suture ; but above this line the lancet-plate meets the deltoids without leaving
any hydrospire-pores. Spiracles round, distinctly double at four of the sides,
but those of the posterior side confluent with each other and with the anus.
Summit covered by numerous, irregularly arranged small pieces. Lower
Carboniferous (Burlington Group) ; North America.
HeteroUasfus E. and C. Resembling the preceding in form and proportion
of its component parts. The proximal ends of the deltoids produced in short
spine-like processes, at the base of which minute lateral openings, one to each
deltoid, are visible. These openings lead into gutter-like channels excavated
in the substance of the plates for the reception of the proximal ends of the
two hydrospire- canals. Radial sinuses wide, their edges sloping gently
downwards to the slightly petaloid ambulacra. Lower Carboniferous ;
England and (?) North America.
Mesoblastus E. and C. Calyx ovoid to globose, with concave to protuberant
base. Radials long, deltoids small, short, unequally rhombic. Ambulacra
very narrow, extending to the base. Spiracles, as a rule, distinctly double,
but sometimes incompletely divided. Lancet-plate entirely, or for the most
part, concealed by side-plates. Lower Carboniferous ; Belgium, England,
(?) North America and Australia.
Acentrotremites E. and C. Calyx elliptical, with broad pentagonal lower
face. Radials large, taking up three-fourths of the height of the calyx.
Deltoids unequally rhombic, each notched by two spiracles at the ends of the
radio-deltoid suture. Anal opening situated close to the summit in the
posterior deltoid. Ambulacral edges of the deltoids without hydrospire-pores.
Lower Carboniferous ; England.
Carpenteroblastus and Lophohlastus Rowley. Lower Carboniferous (Kinder-
hook and Burlington Groups) ; North America.
(?) Ny7iiphaeoblastus von Peetz. Lower Carboniferous ; Russia.
Family 7. Pentephyllidae Bather.
Calyx stemless and suh-pentagonal ; radials, asymmetrical. Ambulacra linear,
extending down to the base ; one shorter than the rest. Carboniferous.
Pentephyllum Haughton. Carboniferous ; Ireland.
Family 8. Zygocrinidae Bather.
Stemless. Calyx depressed, asymmetrical, quadrilobate. Four ambulacra
between the lobes, accompanied by a single hydrospire on either side ; fifth ambulacrum
shortened and widened.
Zygocrinus Bronn {Astrocrinus Austin, non Conrad nee Miinster). Lower
Carboniferous • Great Britain.
[The text lor tlie group Blastoidea in the present work has been revised by Mr. Frank
Sjjringer, of Las Vegas, New Mexico, and Washington, D.C. — Editor.]
CLASS III CRINOIDEA 173
Class 3. CRINOIDEA Miller. Sea-lilies. '
(Brachiata Bronn ; Adinoidea F. Roemer.)
Usually long-stalked, more rarely non-pedunculate and sessile, frequently free-
swimming Pclmatozoa, with calyx composed of regularly arranged plates, and provided
with iveU-developed movable arms.
The Crinoid organism, consists of three principal elements — calyx, arms
and stalk. The calyx and arms together are sometimes spoken of as the
crown, as contrasted with the column (also called stem or stalk).
1. The Cahjx. — The calyx has usually the form of a cup-shaped, bowl-
shaped, or globular capsule, within which the more important organs are
enclosed. Its lower (dorsal or abactinal) surface commonly I'ests upon a
column (Fig. 267); but in some forms it is attached directly by the base,
and in rare instances it is free. The superior (ventral or actinal) surface is
either membranous or plated ; it carries the mouth and ambulacral grooves,
and hence is homologous with the under side of a star-fish or sea-urchin. As
a rule, only the inferior and lateral portions {dorsal cup) of the calyx are
visible, owing to the concealment of the summit by the arms. The cup
is constituted of two or more circlets of plates, which are uniformly oriented
with reference to the ambulacral organs.
a. By the base is understood the one or two circlets of plates intervening
between the topmost joint of the column and the first cycle of radially situated
1 Literature : Miller, J. S., A Natural History of the Crinoidea or lily-shaped Animals, 1821. —
Mailer, J., Ueber den Ban des Pentacrinus caput-viedusae. Abhandl. Akad. Wiss. Berlin, 1841.
— de Koninck, L. Q., et le Hon. H., Recherches siir les crinoides du terrain carbonifcre de la Bel-
gique. Brussels, 1854. (Very extensive bibliography.)— iJcyric/!-, E., Die Criuoideen des Muschel-
kalks. Abhandl. Akad. Wiss. Berlin, 1857. — Schultze, L., Monographie der Echinodermen des
Eifler Kalks. Denkschrift Akad. Wiss., 1867, vol. xx\i.—Shumarcl, B. F., Catalogue of Palaeozoic
Echinodermata of North America. Trans. St. Louis Acad. Sci., 1868, vol. ii. (Very complete
bibliography.) — Carpenter, W. B., On the Structure, Physiology, and Development of Antedon
rosaceus. Philos. Trans., 1876, vol. clvi. — Wachsmuth, C, and Springer, F., Revision of the Palaeo-
crinoidea. l.-lll. Proc. Acad. Nat. Sci. Philad., 1879-86. — Idem, Discovery of the Ventral Struc-
ture of Taxocrinus and Haplocrinus, ibid., 188S.— Idem, The Perisomic Plates of Crinoids, ibid., 1890.
■ — Idem, The Crinoidea Camerata of North America. Mem. Mus. Comp. Zool.,1897, vols, xx., xxi.
— Loriol, P. de, Paleontologie Fran9aise. Crinoides Jurassiques, I. -II., 1882-89. — JS'eiimayr, M.,
Die Stiimme des Tierreichs, 1889. — Agassiz,A., Calamocrinus Diomedae. Memoirs Museum Comp.
Zool. 1892, vol. xvii. — Bather, F. A., British Fossil Crinoids. Ann. and Mag. Nat. Hist., 1890-92,
ser. 6, vols, v.-ix. — Ide7)i, The Crinoidea of Gotland. K. Svenska Vetensk. Akad. Handlingar,
1893, vol. XXV. — Idem, A Treatise ou Zoology (Lankester) pt. iii., Echinoderma, 1900. — Jacket,
0., Criuoiden Deutschlands. Pal. Abhandl. Jena, neue Folge, 1895, vol. iii. — Springer, F., Uiuta-
crinus, its structure and relations. Mem. Mus. Comp. Zool., 1901, vol. xxv.. No. 1. — Idem, Cleio-
crinus. Mem. Mus. Comp. Zool., 1905, vol. xxv., No. 2. — Idem, Discovery of the disk of
Ouychocrinns. Journ. Geol., 1906, vol. xiv. — Idem, A Trenton Echinoderm Fauna. Geol. Surv.
Canada, 1911, Memoir No. 15, P. — Idem, New American Fossil Crinoids. Mem. Mus. Comp. Zool.,
1911, vol. XXV., No. 3. — Idem,, The Crinoidea Flexibilia. (Mouogiaph in preparation.) — Cliad-
ivick, H. €., Antedon. Liverpool Marine Biol. Coram., 1907, Mem. 15.- — Clark, A. II., Variou.« im-
portant papers on recent and fossil Crinoids in Proc. U.S. Nat. Mus., 1908-11, vols, .xxxiv. -xl. —
Idem, On a collection of Crinoids from the Zoological Museum of Copenhagen. Vidensk, Medd.
fra den Naturhist. Forening i. K0benhavn, 1909. — The probable origin of the Crinoidal nervous
system. Amer. Nat. 1910, vol. xliv. — Remarks on the nervous system and symmetry of the
Crinoids. Journ. Wash. Acad. Sci., 1911, vol. i. — The Recent Crinoids of Australia. Memoir 4,
Australian Museum, Sydney, N.S.W., 1911.— The Crinoids of tlie Indian Ocean. Memoir of the
Indian Museum, Calcutta. (In press.) — The Existing Crinoids. Special Bulletin, U.S. National
Museum. (In press.) — Wood, E., A critical summary of Troost's unpublished manuscript on the
Crinoids of Tennessee. Bull. U.S. Nat. Mus., 1909, No. 64. — Kirk, E., Structure and relationships
of certain Eleutherozoic Pelmatozoa. Proc. U.S. Nat. Mus., 1911, vol. xli.
174
ECHINODERMATA— PELMATOZOA
PHYLUM IV
plates at the base of the ambulacra or arms. When the base is monocyclic
(Fig. 268) the position of the proximal ring of plates is interradial ; but when
Fig. 267.
Eusinroorinus spir-
alis Aug. Stalked
Crinoid with dioyclic
base and anal inter-
radius, a, Anals ; b,
Basals; ib, Infrabasals;
?■, Radials. (Right and
left sides reversed,
after Angelin.)
Fio. 268.
Cactocriniis jwoboscidialis (Hall). Projec-
tion of calyx showing the three basals (b),
5x3 simple radials (r), four paired interrays
(ir), and a fifth unpaired anal interray (a).
Fio. 269.
Parliylocrinus mnltiplcx
(Traut). Calyx with dioy-
clic base, radials, costals,
and distichals.
dicyclic it is radial, and the upper ring corresponds with the basals of mono-
cyclic forms (Fig. 269).
In the nomenclature of P. Herbert Carpenter, the upper series of plates in
the dicyclic base are properly termed basals, and the lower series infrabasals
(^iinderbasals). The basals as thus defined are equivalent to the " parabasals "
in the older nomenclature of Johannes Midler,
and to the " subradials " of de Koninck and
other authors.
Both basals and infrabasals are primarily five
in number ; but owing to the supposed morpho-
logical (rarely if ever actual physical) fusion of
two or more of the plates, the number of basals
in the monocyclic forms may be reduced to four,
three, two, or even to a single undivided plate ;
and that of infrabasals in the dicyclic to three.
During the ontogenetic development of the Recent
Antedon, a more or less complete resorption of the
basals has been observed, which ultimately results
in their passage from the dorsal to the ventral
side of the so-called chambered organ, where they
are again rebuilt, becoming a curious plate-like structure known as the
rosette ; and the same probably also was true for certain Mesozoic genera
(Eugeniacrimis, Phyllocrinus). In many of the non-pedunculate Crinoids
{Uintacrinus, Marsupites, Fig. 270) an additional plate known as the centrale
rests against the infrabasals, and probably represents an undeveloped stalk.
The basals are united with one another and with the overlying radials by
Fir,. 270.
Mitrsupites testiulinaris (Schloth.).
Diagi'ani of calyx, cd, Centrale ; tj,
Infrabasals ; /), Basals ; r, Radials.
I
CLASS III CRINOIDEA 175
very numerous short fibres of connective tissue, which may become more or
less calcified ; this forms an immovable union of the type known as a close
suture, in which the plates are immovably held together by fibrous con-
nective tissue. Though usually smooth, the joint faces are sometimes
striated, which striations are visible externally as incised lines.
b. Succeeding the base is a cycle of five (rarely four, six, or ten) plates,
which, on account of their position with reference to the rays, are called
radials. The radials form the sides (more rarely the floor) of the calyx
in nearly all Mesozoic and Recent Crinoids, and give origin directly to
the arms, which may become free immediately above the radials, or may be
incorporated for some distance in the calyx, either by means of supplementary
plates, or by lateral union among themselves.
The upper boundary of the calyx is diff"erently demarcated by diff'erent
authors. Many assign all the plates above the first cycle of plates in each
ray to the arms, even when they are immovably united with one another at
the sides ; while, according to Schultze and others, the arms begin invariably
at the point where they first became movable, i.e. above the first articular
facet. The latter course is open to serious objections, inasmuch as strictly
homologous parts receive different appellations in different groups.
Carpenter, Wachsmuth and Springer, and Bather restrict the term " radial "
to the lowermost circlet of radially situated plates, and consider the succeed-
ing cycles as far as and including the first axiliary plate as brachials (dis-
tinguished as first, second, and third costals, distichals, and palmars ; or as
first, second and third primibrachs (IBr), secundibrachs (IIBr), and terti-
brachs (IIIBr) respectively), in all cases, whether the plates are free or
fixed.
In most Paleozoic Crinoids one or more interradial ylafes are intercalated
between two of the rays, and in line with the anal aperture; these are called
the anal plates or anals. If a plane be passed thfough the latter and through
the radial situated directly opposite, the calyx will be divided into two
symmetrical halves : the parts lying to the right or left when viewed from the
posterior or anal side are so designated ; while the anterior side is that oppo-
site the anal interray. Interradial plates, however, are not confined to the
anal interray, but are frequently developed also between the other rays, when
the calyx is correspondingly expanded. If several cycles of radials and
brachials are present, an equal number of interradials may be developed, and
are distinguished in like manner as interradials and distichal interradials of
various orders. The anal interray is frequently characterised by the peculiar
number, size and position of the anal plates.
c. The superior side of the calyx is known as the tegmen cal/jcis. The
covering may be in the form of a coriaceous skin, in which large numbers of
thin calcareous ossicles are embedded (Figs. 271, 272), or of a plated disk
rising from the base of the arms. It fi^equently exhibits a more or less
central, externally visible mouth-opening, and a usually eccentric interradial
anal aperture. The mouth opens into an oesophagus and thence into the ex-
panded visceral mass, which fills the greater portion of the inner cavity. The
intestinal canal is directed downwards at first, and after making usually one
complete circle, more rarely after numerous windings, discharges into the
anal opening. In certain fossil Crinoids (Actinocrinidae) the digestive appara-
tus is represented by an extremely thin-walled, finely perforated, convoluted
176
ECHINODERMATA— PELMATOZOA
PHYLUM IV
calcified body, which occupied the vertical axis of the body cavity, and was
contracted into a narrow tube toward the base (Fig. 280).
In all of the Recent Crinoids (excepting in certain species belonging to the
family Coraasteridae where they may be quite absent from the arms arising from
one, two, or even three of the posterior rays) each arm, and each pinnule
which it bears, carries on its ventral surface an open ambulacral fui'row lined
with ciliated epithelium. At the base of the arms these ambulacral furrows
unite and form five large furrows, which, traversing the tegmen, converge at
the central mouth, or, as in the Comasteridae, lead to a horse-shoe shaped
furrow just within the border of the tegmen in the centre of which is the
mouth. Just below the floor of these furrows runs a nerve band (absent from
ungrooved arms), and under this the genital rachis (especially developed in
ungrooved arras), and the canals of the water and blood vascular systems ;
below these, deeply buried within the substance of the calcareous plates, lies
the large nerve cord of the dorsal nervous system. All but the last of these,
which leads to a central nervous mass in the dorsal apex of the calyx, run to
a in
Fig. 271.
..
Isocrimia asteriu (Linn.). Ventral
disk, protected by very thin peri-
somic ])lates, witli central nioutli (»),
exposed ambulacra, and eccentric
anus {A).
.aJL
Fig. 272.
Hyocrinus hethelianuf: (Wyv. Tliom.). Re-
cent. Ventral disk, enlarged, o. Orals ; p,
Mouth (iieristome) ; s, Covering plates ; c,
Dorsal canals of the anus ; am, Ambulacra!
furrows of the arms ; an, Anus (after Wy ville
Thomson).
ring-like structures surrounding the oesophagus. The circumoesophageal ring
canal of the water vascular system is in communication with the body cavity,
which in turn communicates with the exterior by means of very numerous
(five only in Rhizocrinus) interradial perforations. The margins of the
ambulacral grooves are bordered with a series of small lajipets, and at the
base of each of these is a group of three tentacles ; these tentacles, which are
absent from ungrooved arms, are connected with the canal of the water
vascular system ; they also secrete a more or less poisonous fluid which serves
to paralyze the small organisms which serve as food.
In all Recent Crinoids five (occasionally four) open ambulacral furrows
lined with epithelium conduct from the mouth to the tips of the arms,
remaining either simple or subdividing as often as there are arms. Under-
neath the floor of the grooves runs an ambulacral vessel filled with water ;
and accompanying this are the blood and vascular canals and a nervous cord.
Distensible tentacles pass out from alternate sides of the ambulacra, and the
latter unite to form a circumoral ring canal. From the ring canal five short
open tubes {stone or water canals) extend downwards into the body cavity and
supply the ambulacral system with water.
CLASS in
CRINOIDEA
177
In certain of the Recent stalked genera, as in Hyocrinus (Fig. 272), in
the young of all the Recent species, and in a large number of fossil Crinoids,
a triangular oral plate is situated at each of the five angles of the mouth-open-
ing. The apices of the orals are directed towards one another, and between
them run the ambulacra. Oral plates are extremely variable in size ; and
although well-developed in the larvae of the Comatulids and in the young of
many of the stalked species, they become wholly resorbed before maturity.
In a number of Paleozoic Crinoids (Fig. 275) the summit is entirely or in
large part composed of five oral plates which may be either laterally in
contact or separated by furrows. More frequently, however, the orals occupy
only the angles of the mouth-opening, the remaining area between the
ambulacral furrows being covered with more or less regularly arranged
infer amhulacral plates (Fig. 272). In most of the Paleozoic Camerata, and in all
the Recent species, the anus is placed at the upper end of a tube known as the
Fig. 273.
Lecythoerinus eifelianus
Mtiller. Crinoid with elon-
gated anal tube (after
Schultze).
Fig. 274.
Dorycrlniis quinquelobus (Hall).
Specimen showing plates of tlie teg-
men and eccentric anus.
C'occocrinus rosaceus
Roem. Devonian ;
Eifel. Calyx with ven-
tral pavement, x -/i
(after Schultze).
anal tuhe or proboscis. In the Fistulata, however, the anal opening is situated
along the anterior side of the ventral sac, or between the sac and the mouth.
Of the interambulacral plates a greater or smaller number (in Calamocrinus
all in the vicinity of the mouth) are perforated by pores for the admission
of water into the body .cavity. Pores evidently performing a respiratory
function occur in some of the Fistulata ; but these, instead of piercing the
body of the plates, enter only their outer angles. Other Fistulata have a
madreporite.
The ambulacra are frequently lined along their sides by more or less
rounded covering plates which are capable of being folded down over them
so as to serve as a protection ; these covering plates are, at least in the
Recent forms, perisomic plates developed in the marginal ambulacral lappets ;
they may occur alone, as in the genera Bhizocrimis, Nemaster, etc., but they are
usually separated from the pinnulars or brachials by a second series of squarish
or oblong plates known as the side plates. Both series of plates occur every-
where along the ambulacral grooves, but they become irregular and ill-defined
on the disk. In the Paleozoic Taxocrinus (Fig. 276), the covering pieces are
VOL. I N
178
ECHINODEEMATA— PELMATOZOA
PHYLUM IV
arranged in alternate rows, with side-j^ieces adjoining them. The latter plates
occur also in most of the Inadunata and Flexibilia, but are rarely represented
in the Camerata. The mouth may be exposed or closed ; either being
surrounded by five oral plates (I'axocrinus, Fig. 276), or the posterior oral may
be pushed in between the four others, so as to conceal the mouth ; the latter
is then said to be subtegminal (Fig. 277).
A very remarkable modification of the ventral disk occurs in the Paleozoic
Camerata. Here the usually very numerous plates attain considerable thickness,
and fit into one another like the stones of an arch to form an extremely rigid,
more or less convex vault, which is sometimes surmounted by an equally rigid
plated proboscis. At the apex of the dome five large-sized plates are often
distinguishable, of which that lying in the anal interradius commonly differs
from the rest in form and size, and ajopears to be wedged in amongst the others.
These five plates are identified by Wachsmuth and Springer as orals. The
remainder of the tegminal plates are distinguished according to their position as
ambulacrals and interambulacrals ; in most of the Batocrinidae the ambulacrals
Pig. 276.
Taxocrinus intenned-
ius W. and Sp. Ventral
disk (after Wachsmutli
and Springer).
Platycrinus ItalU Slium. Projection
of ventral disk. «, Ambulacrals ; ia, In-
terambulacral areas ; ia', Anal inter-
radius ; e, Covering pieces of the ambu-
lacrals : i, Interradials ; p, Interior
and lateral orals ; o, Posterior (anally
situated) oral ; x, Plates of the anal
interambulaeral area (after W. and Sp.).
Fig. 278.
Hexacrinus elongatus Goldf.
with tegmen. a, Profile ; /),
from above.
Calyx
Viewed
are not arranged in alternate rows (Fig. 279), but frequently consist of
large single plates of one or more orders, which are separated from one
another by the continuous interposition of supplementary pieces. In other
groups, notably the Platycrinidae, the ambulacrals are generally arranged in
two rows of rather large plates, which, however, lose their original character
to some extent. The interambulacrals usually meet with the interbrachials.
The tegmen of the Camerata, as a rule, is composed of large convex or nodose
plates, for the identification of which considerable experience is required.
Most of the Paleozoic Crinoids have but a single opening in the tegmen,
which is interradial in jiosition, or sometimes central, and represents the anus.
With the exception of the Flexibilia the mouth is subtegminal, and the food
grooves are rigidly closed. In many cases the covering pieces are pushed
inward, and the ambulacra follow the inner floor of the tegmen, forming a
skeleton of ramifying tubes ; these are conducted along open galleries from
the mouth to the arm-openings (Fig. 280, A).
2. The Arms (Brachia). — The arms of the Crinoid body form the immediate
prolongation of the radials. The plates of the arms are termed hrachials, and
CLASS III
CRINOIDEA
no
are arranged either in single or double alternating rows ; and hence are spoken
of as uniserial (Fig. 281, A), or as biserial (Fig. 281, J5). The plates of the
uniserial arms may be either rectangular or cuneiform, the major ends being
directed alternately to the right and left. In biserial arms the smaller ends
of the plates meet midway, so as to form a zigzag suture. The arms invariably
B
Fig. 279.
AgaricQcrinus americaitus
Roeni. Ventral disk, r, Uni-
serial ambulacrals ; i, Inter-
ambulacrals ; o, Anally sitn-
ated oral ; -p, Anterior and
lateral orals ; x, Posterior in-
terambulacrals (after Wacli-
sniuth and Springer).
..a
Fio. 280.
CactocrUius jrrohoscidialis (Hall). A, Plates of tegmen partially
removed in order to show the covered ambulacral passages (o)
leading from the arms to the moutli. /;, Plated npper surface
of ambulacral galleries. C, Natural cast of ventral disk with
impressions of calyx ambulacra («) leading to tlu; mouth (u) ;
an. Anus.
begin uniserially, the biserial structure being gradually introduced in an upward
direction. They either remain simple, or branch in various ways ; the plates
upon which a bifurcation takes place are called axUlaries.
In the Camerata, the more highly organised Inadunata, and in all Recent
Pig. 281.
A, Carpocrinus comtus Aug., showing uni-
serial arms. B, Callicrhius costatvs Hising.,
with biserial arms (after Angelin).
Fig. 282.
Plated ambulacral furrows of the
arras, a, h, Cyathocrinus ramosus
Ang., showing covering pieces ;
c, Gissocriims arthriticus Hising.,
with covering pieces. All figures
enlarged.
Crinoids, the arms are furnished with pinnules, which are given off alternately
from opposite sides, usually one to each arm-plate, more rarely on alternate,
or on every third arm-plate ; sometimes they are partially or entirely absent
from the lower portion of the arms. The pinnules are jointed a^jpendages,
which at least basally repeat the general structure of the arms, and in living
180 ECHINODERMATA— PELMATOZOA phylum iv
Crinoids lodge the functional portion of the genital organs. When two or
more arm-joints, meet transversely by a rigid suture, and only the upper one is
pinnule-bearing, those joints form a syzrjgy, whether their apposed faces are
striated, dotted or smooth. The lower joint bearing no pinnule is called the
hypozygal joint, the upper one the episygal ; and the two together constitute
physiologically but a single segment, as is shown by the unaltered alterna-
tion of the pinnules.
The ciliated ambulacral furrows of the arms enter by the arm-openings
into the tegmen, and all converge to the mouth. Food-particles, consisting
chiefly of diatoms, infusorians and microscopic crustaceans, are propelled along
the furrows and into the body by the action of the cilia.
In all Recent and in numerous fossil Crinoids the brachials and pinnulars
are perforated by a single, or in some cases by a duplicate, canal (central canal)
containing the dorsal nerve cords, which give off four delicate branches
within each segment. The dorsal canal extends also into the radials and
basals, perforating the plates when they are thick, and running in a shallow
groove on the inside when thin. So far as has been observed, the axial
canals begin uniformly in the basals, where they divide dichotomously ; but
in the radials the branches generally reunite to form the so-called ring canal
(Fig. 329).
3. The Column. — The stem or column attains in some forms (Pentacrinus) a
length of a number of metres ; but in others it is much abbreviated, or
even atrophied, so that the calyx is either directly adherent by the base
(Cyathidium, Holopus), or is destitirte of all means of attachment (Agassizocrinns,
Uintacrinus, Marsupites, the Comatulids). The stem is composed of usually
short segments, having either circular, elliptical or angular (especially penta-
gonal) cross-sections, and being sometimes of uniform and sometimes of variable
proportions. Lateral appendages, called cirri, are present in numerous forms,
being given oft' either singly or in whorls at regular intervals along the
periphery. The larger and all cirrus-bearing segments are called nodals, and
those interposed between them the internodals. The distal end of the stalk
may taper gradually to an apex, in which vicinity fine radicular cirri are
commonly developed, or it may be thickened at the extremity so as to form a
bulbous or branching root, or a heavy, solid, terminal stem plate, or dorso-
central. Growth is accomplished by the insertion of new joints at the
proximal end of the stem, either just beneath the calyx, or both here and
between the earlier formed joints, the earlier segments becoming at the same
time gradually enlarged. The last-formed joints are commonly of smaller
size than those situated more remotely from the calyx.
Like the brachials and pinnulars, all the joints of the stem and cirri are
pierced by a (usually central) longitudinal canal which is circular, oval or
pentagonal in cross - section, and communicates with the peculiar dorsal
chambered organ which in the Comatulids is situated within the centrodorsal,
and in the stalked forms within the calyx just above the summit of the
stem. The outer walls of the chambered organ are composed of nervous
tissue, and form the central organ of the dorsal nervous system which
innervates all the dorsal structures ; within the chambered organ is divided
by partitions into five sections, and is continued ventrally as a thick tube
of uncertain function, known as the central plexus, to near the inner surface
of the disk, where it ends blindly.
CLASS III CRINOIDEA 181
All of the calcareous elements of which the dorsal skeletal system is com-
posed are developed within a uniform organic base ; with the growth of the
plates this within them becomes a diffuse network, and between them forms
a mass of strong connecting fibrils which bind the plates together.
In the so-called sutures between the calyx plates, in the intercolumnar
articulations in many of the older types (Encriiius, etc.), in the syzygies between
the brachials in many forms, and just below the cirrus-bearing joints in the
stems of the Pentacrinites, these fibrils are all of uniform length and uniformly
disti'ibuted over the joint face ; but usually there is a differentiation of the
fibrils by which they become more or less segregated into radial groups, as in
the stems of Pentacrinites ; or they become elongated and differentiated into two
comparatively dense masses separated by a strong fulcral ridge, and assume a
more or less contractile function as in the stems of such genera as Bhizocrinus
and Platycriniis, in the cirri of the Pentacrinites and Comatulids, and in the
pinnules beyond the second joint in many forms. Between the brachials they
are usually differentiated into two distinct types, one of which, occupying the
entire dorsal half of the joint face (the dorsal ligament) is comparable to one
of the two masses in the type just described ; while the other, occupying two
more or less triangular areas, one on either side of the central canal and just
ventral to the transverse ridge by which they are separated from the preced-
ing (the interarticular ligaments), is much more dense, and serves to bind the
brachials tightly together.
In addition to these ligamentous connections there are, between the
brachials, two muscular bundles situated on the ventral border of the joint
face, distal (ventral) to the interarticular ligament masses. Whereas the
ligament bundles are developed directly from the original uniform body
investment in which the calcareous elements are formed, the muscular bundles
have an entirely separate origin.
In certain of the older forms the proximal segments of the column
occasionally exhibit simple vertical clefts, which indicate an original quin-
quipartite composition. These divisions always occur alternately with those
of the basals in monocyclic, and with those of the infrabasals in dicyclic
forms. The entire crinoid stem is probably the homologue of a single apical
calyx plate, which has been reduplicated by a curious process of serial repeti-
tion common among the Echinoderms.
Ontogeny. — Although we are as yet acquainted with the life-history of but
thi'ee species, all belonging to the genus Antedon, and although the life-
history of but two of these {A. mediterranea and A. adriatica) is well under-
stood, the phenomena of their development are of such significance as
to shed most valuable light upon many conditions observed in fossil
Crinoids.
The eggs, extruded from the ovaries and hanging in little groups from the
genital pinnules, are fertilized externally, and the early metamorphosis of the
larva takes place within the egg membrane. At the time of the rupture of
the egg membrane and its consequent escape the embryo (a gastrula) is elongate-
oval in form, bilaterally symmetrical, bearing an anterior tuft of cilia and
encircled by five ciliated bands, resembling somewhat the larvae of certain
annelids. Internally there are to be seen the rudiments of five oral plates,
five basals, three (A. mediterranea) or five {A. adriatica) infrabasals, and about
eleven columnars ; the orals, basals, and infrabasals are arranged in horseshoe-
182
ECHINODERMATA— PELMATOZOA
PHYLUM IV
shaped bands, and the columnars are also horseshoe-shaped, not having as yet
formed complete rings.
After a free-swimming existence of a few hours the embryo attaches itself
by means of the so-called adhesive pit, a slight depression on the antero- ventral
face, the cilia disappear, and profound changes take place which result in a
rearrangement of the internal organs.
The five orals now form a pyramid over the superior (ventral) portion of
the animal, while the five basals form a similar, but inverted, pyramid, in the
wall of the proximal (dorsal) portion of the calyx ; between the apex of the
latter and the top of the column are the three or five infrabasals. The column
consists of about eleven cylindrical joints, each composed of the original central
annulus from which numerous longitudinal parallel calcareous rods are
developed, and is terminated distally, and attached, by a lobate terminal stem
plate. The larva is now said to have reached the " Cystid stage."
In the five diamond-shaped spaces which occur between the divisions of
the orals and basals the radials appear, and, increasing rapidly in size, intrude
upon the orals ; at the same time a sixth plate (the anal)
makes its appearance in the zone of the radials, but it gradu-
ally moves upward with the orals into the ventral disk. A
row of elongate cylindrical segments, bifurcating on the
second, is given off from each radial, and grows very rapidly
by the addition of new plates at its distal end. The column
ceases adding new segments, and the last one to be formed,
just beneath the calyx, increases in size and fuses with the
infrabasals to form the rudiment of the centrodorsal. The
larva is now said to have reached the " Pentacrinoid stage."
Simultaneously with the development of the arms and
column a resorption of the orals and the anal sets in, while
the basals begin to undergo a curious metamorphosis by
which they are transformed into a lobate ten-rayed plate
which is wholly internal, lying just above the chambered
organ. Finally the button-shaped centrodorsal, which is now
beset with numerous cirri, detaches itself from the remainder
of the stalk, and the animal becomes free.
The ontogeny of the Antedon (Fig. 283) reveals the fact
that the infrabasals, basals, orals and stem represent the
most primitive skeletal structures while the radials and
brachials are formed at a subsequent period. Similar
evidence is afii'orded by numerous fossil Crinoids, in which
the basals and column are very strongly developed, while
dorsal (alter Wyviiie the radials are mostly of inferior size, and the arms either
Thomson). "^ ^
rudimentary or absent.^
Habitat. — The existing Crinoids inhabit depths ranging from between tide
marks to 2900 fathoms, both extremes being occupied by unstalked forms
^ [Some of the Paleozoic Flexibilica are almost identical, iu fact, with the pedunculate stages of
Antedon. Wachsmuth and Springer, from their observations on the orientation of the stem and its
canal in fossil monocyclic and dicyclic Crinoids, were led to infer the presence of infrabasals in the
nepioiiic (or larval) stages of many forms previously supposed to be without them. This predic-
tion was abundantly confirmed by Mr. Bury 's discovery of nuuute infrabasals in the larva of A ntedon.
See especially II. Bury, Early Stages in the Development of Antedon rosaceus. Philos. Trans.,
1889, vol. clxxix.]
Fig. 283.
Larva of Antedon
rosaceus Linck. h, Ba-
sals ; r, Radials ;
o, Orals : cd, CentrO'
CLASS III
CRINOIDEA 183
(Coraatulids), the range foi^ the stalked species being from 5 to 2325
fathoms. The great majority of the existing types are littoral and sublittoral,
only a few descending into the abysses. A very large number of species,
many genera, and several families are confined to the East Indian region, while
all the species and genera occurring outside of that region have close relatives
within it. Most forms are highly gregarious, occurring in great numbers
together, these masses being often composed, in the East Indies, of twenty or
more different species, but a few appear to be more solitary in habit. As a
rule the Recent forms are very local, and, though they may be found in certain
very restricted areas in large numbers, and may have a very wide geographical
range, it is comparatively seldom that one meets with them.
Fossil Crinoids also appear to have been gregarious in habit, and their
remains are frequently found commingled with those of reef-building corals
in Paleozoic strata. Owing to the extremely delicate constitution of many of
the skeletal parts, and the looseness with which the plates and segments are
united, the Crinoid organism is by no means favourably adapted for preserva-
tion in the fossil state. Perfect crowns are of comparatively rare occurrence,
calices more frequent ; but, on the other hand, detached joints of the stem
and arms are often very abundant, and form beds of considerable thickness.
Crinoidal limestones of greater or lesser extent are met with in numerous
formations from the Ordovician to the Jura ; those of the Carboniferous and
Muschelkalk (Trochiteiikalk) being especially characteristic.
Classification. — The first attempt to construct a classification of the
Crinoids was that of J. S. Miller in 1821. Four groups differing in the form
and mode of vmion of the calyx plates were distinguished by Miller as
follows : C. articulata, semiarfiadata, inarticulafa and coadunata. The classi-
fication of Johannes Miiller, in 1841, was based iipon a number of differential
characters, such as the articular or close suture of the radials, the thick-
ness of the calyx plates, the mobility of the arms, and the plated or
coriaceovis character of the ventral disk. Two principal groups were
recognised : Articulata and Tesselata ; while a third (Costata) was constructed
for the reception of the unique genus Saccocoma. T. and T. Austin and
F. Roemer adopted the untenable divisions of Stalked and Unstalked
Crinoids.
The importance of Wachsmuth and Springer's investigations on the
structure of the calyx, especially of the tegmen, and on the orientation of
the stem and its canals in monocyclic and dicyclic forms, cannot be over-
estimated. Two groups were proposed in their classification of 1879 :
Palaeocrinoidea and Stomatocrinoiclea ( = Neocrinoidea, Carpenter) ; groups which
correspond in the main with the Tesselata and Articulata of Johannes Miiller.
This classification was subsequently abandoned, and a new one suggested for
it in 1888, afterwards more fully defined in their monograph on the North
American Crinoidea Camerata in 1897, in which three principal grand
divisions, or orders, were recognised, which were believed to include sub-
stantially all Crinoids, fossil and recent, viz.: Camerata, Inadunata and
Articulata.
Jaekel in 1894 proposed two orders, Cladocrinoidea and Pentacrinoidea,
the former containing only the Camerata (W. and Sp.), and the latter all the
rest. Bather in 1898 divided the Crinoids according to the composition of
the base into two subclasses, Monocyclica and DicijcUca, recognising for the
1 84 ECHINODERMATA— PELMATOZOA phylum iv
most part, as subordinate to them, the orders proposed by Wachsmuth and
Springer. The divisions established by Wachsmnth and Springer have been
adopted as the basis of the following systematic arrangement, substituting,
however, for their Articulata the preferable name Flexibilia, proposed by von
Zittel in 1895, and now adopted by Springer in his forthcoming monograph
of that group ; also retaining the name Articulata in the sense of Miller and
Miiller for a fourth division, including the Eecent and most of the Mesozoic
Crinoids.
Within the last few years, also, the terminology has been amended in
several important resj^ects ; and conformably to the usage of the leading
English and American authorities, certain of these changes have been adopted
in the present edition. An explanatory note on the use of terms is therefore
given at this place, in order to facilitate reference, and to exhibit the corre-
spondence between the older terminology and the new.
The only abbreviations employed in the text are the following : —
IB = Infrabasal. Br = Brachial.
i?= Basal. /i?r= Primibracli or costal.
i2^=Radianal. //5r = Secuiidibracli or disticlial.
a; = First or special anal. •ii?r=Iuterbracliial.
^ = Radial. .4m& = Ainbulacrals.
In addition to these the following are used in the figures, but are printed
in small letters : —
^= Calyx. 0 = Orals.
A = Arras. IH = Interradials.
St = Stcm. Z)isi =:Disticlials.
Explanation of Terms.
Crow7i = Criuoid minus the stem.
Oahjx = Crinoid skeleton minus the stem and free arms.
Dorsal ctq) = AW parts of the calyx below the origin of the free arms.
Tegme7i = Th.a,t part of the calyx lying above the origin of the free arms, and embracing
the disk ambulacra, the mouth, and the aniis. Includes the terms ventral disk, vault,
dome, swmmit, etc.
^«se = That part of the dorsal cup lying next to the column. It may be composed of one
ring of plates (monocyclic), or of two rings (dicyclic), which are distinguished as basals and
infrahasals. The basals adjoin the radials and alternate with them, being interradial in
position. The infrahasals, when ju'esent, form the proximal ring, and are radially disposed.
Radials = T\ie circlet formed by the first plate in each of the rays; or, the radially
situated circlet of plates above the basals, and this ring only. In some of the earlier Crinoids
one or more of the radials appear as if transversely bisected, due to the presence of a
radiaiial or inferradials.
Brachials = AW plates beyond the radials in radial succession. They are called fixed
brachials so far as tliey take part in the calyx ; /ree brachials or nrm-platfs when they do
not. The brachials forming the first circlet above the radials, whether free or fixed, are
called primihrachs or costals ; those of the second order secundihrachs or distichals ; those of
the third order tertihrachs or palmars; and so on for succeeding orders of brachials, to which
formerly the name post-palmars was applied.
Interradials = AW plates occupying the spaces between the rays proper, whether they
belong to the dorsal cup or the ventral disk. Those of the dorsal cup, which are inter-
posed between the brachials, are distinguisluid as intcrhrachials, and those of the tegmen,
which lie between the ambulacra, as interamlulacrals.
Eadianal = A plate disturbing the bilateral symmetry of the cup, located primitively
directly below the right posterior radial, and in later genera obliquely to the. left of it.
yi7trtZs = Interradials of the posterior side, forming the base of the anal structures. The
special or first anal plate (now usually designated x), when present, invariably rests upon
the truncated upper face of the posterior basal and between the radials. Higher anal plates
CLASS III
CRINOIDEA 185
may be present, even when the special anal is wanting ; they arc interposed between the
interbrachials, following the median line of the posterior area.
Orals = T\ie five large interradial plates which surround the mouth or cover it. They are
said to be symmctriccd when of nearly the same size and form ; asymmetrical when the
posterior plate is pushed in between, or is larger than, the other four.
Ambi(,lac7-als = The rows of small plates in the tegmen which are radially situated. They
consist of adamhulacrals or side-pieces, and the covering -iilates (Sauvipldttehen). The former,
when present, constitute the outer, the latter the inner rows of plates. The covering i)lates
form a roof over the food-grooves ; they are generally represented by two alternating rows
of small plates, more or less regular in their arrangement, which are movable upon the arms
and jnnnules, but upon the disk only in those Crinoids in which the mouth is exposed.
The orientation is based upon the natural position of the Crinoid, with the arms upper-
most, and viewing the specimen from the anal side. The anal interradius will then be
posterior, the radius opposite to it anterior, while the right and left sides of it correspond
with right and left of the observer.
Primary Divisions of the Crinoidea.
I.
Crinoids in which the lower brachials take part more or less in the dorsal cup.
All plates of the calyx united by close suture. Mouth and food-grooves closed. —
Order 1. Came rata.
II.
Crinoids in which the lower luachials are incorporated into the calyx either by
lateral union with each other, or by means of a skin studded with calcareous particles.
All plates from the radials up movable. Mouth aird food-grooves exposed. Arms
non-pinnulate. The top stem joint often fused with the infraljasals, and not always
the youngest joint of the stem. — Order 2. Flexibilia of Zittel { = Articulata of W.
and Sp. non Miller and Miiller).
III.
Crinoids in wliich the brachials are free above the radials. Plates of calyx united
by close suture. Mouth sub-tegminal. — Order 3. Inadunata.
IV.
Crinoids in which the mode of union of radials with the plates they liear is by
complete muscular articulation, and in which are combined the following additional
characters : open mouth and food grooves ; dorsal canals perforating radial and arm
plates ; uniserial arms only ; pinnules ; the general presence of a modified columnal,
or proximale ; the general absence of bilateral, and presence of pentamerous symmetry,
modified only by loss or addition of rays and not by anal structures. Brachials either
free, or more or less incorporated. — Order 4. Articulata.
The first three of these divisions are represented in the Ordovician. The Camerata
were the most specialised, and the first to disappear, being confined to the Paleozoic,
and becoming extinct in the Lower Coal Measures. The Flexibilia were similarly
limited. The Artic^data range from the Mesozoic to the present time. The Inadunate
type, representing the most generalised structure of the Crinoids, is in its most
essential feature, though variously modified, carried forward with the Articulata, and
thus has an unbroken range from the earliest Ordovician to the present.
Order 1. CAMERATA Wachsmuth and Springer.
{Sphaeroiclocrinacea Neumay r. )
Crinoidea in which the lower brachials take part in the dorsal cup. All plates of
the calyx united by close sutures, and immovable. Mouth and food-grooves completely
186 ECHINODERMATA— PELMATOZOA phylum iv
covered ; the covering pieces of the latter frequently incorporated in the tegmen. Anal
opening eccentric or subcentral, frequently situated at the end of a proboscis-like anal
tube. Arms uniserial or biserial, and jnnnulate. Ordovician to Carboniferous.
In some of the earlier (Ordovician) forms, as in the Reteocrinidae and
Batocrinidae, there is considerable flexibility in the tegmen, which is com-
posed of innumerable small plates ; but the mouth and food grooves in all
these are perfectly subtegminal, thus distinguishing them from the Flexibilia,
some of which, in respect to flexibility of the tegmen, they superficially
resemble.
Family 1. Cleiocrinidae.
Dicyclic. Brachials to height of several orders incorporated in calyx by lateral
union, those of different rays in contact except at the anal side. Calyx plates furnished
with pore-rhombs crossing the sutures as in some Cystoidea. Arms jnnnulate. Tegmen
of small undifferentiated plates. Mouth subtegminal. Ordovician.
C/eiocrwrns Billings (emend.). Calyx large, pliant; plates joined by loose
sutures, crossed by pore-rhombs. IBB five, invisible exteriorly. Basals and
radials not in typical succession, but alternating with each other in a
horizontal ring of ten plates surrounding the IBB and projecting downward
over the column like a collar. No iBr except at the anal side ; anals in
vertical series, resting on the truncate posterior basal, and extending high up
between the rays, Rays and their divisions up to the free arms contiguous
and interlocking ; brachials bifurcating several times in the calyx, giving off '
fixed pinnules, which are incorporated by lateral imion with adjacent brachials
and become free between the arm bases. Arms small, uniserial and
unbranched. Column obtusely pentagonal, or nearly round. Lowest
Ordovician (Chazy and Trenton) ; Canada and the United States.
Tills genus has the flexible calyx and loose sutures of the Flexibilia, but its pinnulate
arms and subtegminal mouth place it in closer relation with early Camerata, such as
Eeteocrinus. Its calycine pore-rhombs proclaim its not distant derivation from the Cystitis.
In the remarkable disposition of the basal and radial plates, in horizontal alternation instead
of vertical succession, touching the infrabasals by their exterior surface instead of the distal
edge, this form differs from all known Pelmatozoa. These intermediate and peculiar
features accord with its very early age.
Family 2. Reteocrinidae. Waclismutli and Springer (emend.).
Dicyclic. The lower plates of the rays more or less coiapletely separated from
those of other rays, and from the primary interradials, by irregular supplementary
pieces, without definite arrangement. Anal interradius divided by a vertical row
of cons])icuous plates. Ordovician.
Beteocrinus Billings (em. W. and Sp.). Dicyclic. IBB five, variable. EB
and fixed brachials folded into a strong median ridge, which follows the
bifurcations and passes insensibly into the arms. A similar ridge of anal
plates divides the posterior interradius, extending to the anal opening.
Radials separated all around. Arms usually branching; uniserial, or with
interlocking cuneate ossicles. Interbrachial areas filled with innumerable
minute pieces forming an apparently pliant integument continuous with the
tegmen. Column round or pentagonal. Ordovician (Trenton to Cincinnatian) ;
North America.
CLASS III
CRINOIDEA
187
<]QQ
Family 3. Dimerocrinidae Batlier. {Glyptocrinidae Zittel jpars ; Glyptasteridae
Angeliu ; Thysanocrinidae W. and Sp.)
Dkydic. Lower brachials and interbraehials forming an important paii of the
dorsal cup ; interbraehials well defined. Eadials in contact except at the posterior
side, where they are separated by an anal plate. Ordovician to Devonian.
Ptychocrinus W. and Sp. IBB five. Arms uniserial, simple, or branching
once. Radial and brachial plates marked by well-defined median ridge.
First anal plate usually succeeded by three plates in second range ; iBr few.
Anus without a tube. Ordovician; America.
Orthocrinus Jaekel. Arms stout and uniserial. Devonian ; Germany.
Dimerocrinus Phillips. (Thysanocrinus and Glyptaster Hall ; Eucrinus Ang.)
(Fig. 284). IBB five. Arms biserial, simple or branching. First anal plate
followed by three in second
range ; iBr in several ranges.
Anus without a tube. Silurian
to Devonian ; North America,
England, Gotland.
Cyphocrinus S. A. Miller
(Hyptiocrinus W. and Sp.). Calyx
constructed as in Dimerocrinus,
but low and wide, with arms
pendent and tegmen plates spini-
ferous. Silurian; North America.
Gazacrinus S. A. Miller (Idio-
crinus W. and Sp.). iBr limited
to a single large plate in each
interradius, that of posterior side
following an anal. Silurian ;
North America.
Lampterocrinus Eoemer. Calyx
like that of Dimerocrinus, but
asymmetrical from bulging at
anal side, and with anus at end of a tube. Anal plate followed by three
IBB, large. Rays produced into five tubular extensions, bearing biserial,
pinnuliferous arms on each side. Silurian ; North America.
Siphonocrinus S. A. Miller. Similar to preceding, but IBB small, calyx
larger and more asymmetric, from subtegminal recurving of the rectum.
Silurian : North America.
?^§,QR
o
c#3
~o
Dimerocrinus.
Fig. 284.
Analysis of calyx (after W. and Sp.).
Family 4. Rhodocrinidae Eoemer.
Dicyclic. Lower brachials and interbraehials forming an important part of the
dorsal cup. Badials separated all around by an interradial plate folloived by well-
defined, definitely arranged interbraehials. Infrabasals five. Anal area slightly,
and often not at all, different from those of other interrays. Ordovician to Lower
Carboniferous.
Bhaphanocrinus W. and Sp. {Coelocrinus Salter). Calyx obovate. Arms
188
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Bhodocrinus.
Fiii. 2«S.
Analysis of calyx (after W.
aud Sp.)-
uiiiserial ; from ten to twenty, and branching further. Otherwise simihir to
Archaeocrinus. Ordovician ; North America and England.
Archaeocrinus W. and Sp. Calyx obovate to hemispherical ; base usually
concave or invaginate. IBB small. Brachials to at least second order in-
corporated in the calyx. Arms biserial, usually ten at their origin and
branching beyond. Anal interradius
slightly distinguished by an additional
plate in second range ; iBr numerous.
Anus without a tube. Ordovician ; Canada
and Kentucky.
Diabolocrinus W. and Sp. Calyx de-
pressed globose. Anus at end of a tube.
First regular interbrachial frequently
surrounded by supplementary plates.
Ordovician ; Tennessee.
Deocrinus and Hercocrinus Hudson.
Ordovician ; Canada.
Bhodocrimis J. S. Miller (Acanthocrinus
Roemer) (Fig. 285). Calyx globose,
usually small and delicate, with concave
base, and constricted at the tegmen.
Arms becoming free at the distichals, and
branching ; biserial, either directly from
the calyx up, or only from the last bi-
furcation. Anal side frequently, but not always, distinct from the regular
interbrachial areas, by interposition of an extra plate in the second range.
Devonian to Lower Carbon-
iferous (Keokuk Gr.); North
America, England, Belgium,
Germany.
Gilbertsocrimis Phillips
(Goniasteroidocrinus Lyon and
Cass.; Ollacrinus Cumberland
nomen nudum). Calyx below
the arm-regions like that of
Bhodocrinus, but usually
larger, expanding at the
tegmen instead of constrict-
ing, and distinguished especi-
ally by large tubular ap-
pendages extending outward
and downward from the
margin of the tegmen, and
overhanging the arm bases.
These appendages are formed
of rows of cylindrical plates,
pierced to their full length
by a central canal ; they are
primarily ten in number, in some species free, and in some fused by their
outer margins to those of adjacent rays. Arms small, delicate, biserial, given
Fin. 286.
Uhipldocrinus crenatua (Goklf.). Uevouian ; Gerolstein, Eifel.
A, Perfect crown, of the natural size (after Schnltze). 7i, Tegmen,
with eccentric anus. C, Interior view of the base, showing the five
ll'Ji, two of Uie basals and one radial. /), Column. A', Face of stem-
joint.
CLASS in CRINOIDEA 189
off in clusters beneath the appendages. Anus subcentral, directly through
the tegmen. Devonian to Lower Carboniferous (Keokuk Gr.) ; North
America, Great Britain and Belgium.
Lyriocrinus Hall {Marsupiocrinus Hall, non Blv. nee Phill.). Calyx depressed
hemispherical, with base rather truncate ; tegmen almost flat, composed of
numerous small, irregular plates. Plates of dorsal cup usually smooth or
granular. Arms ten, strong, unbranched, biserial. Interbrachials few, incor-
porating brachials to only part of the second order. Anal side usually not
distinct ; anus eccentric, at the end of a small tube. Fii'st interradials some-
times touch basals. Silurian ; North America and England.
Thylacocrinus Q^^hlert. Eesembling Lyriocrinus, but calyx more elongate,
and iBr profusely developed ; anal side slightly distinct. Arms twenty or
more, biserial, and not branching in the free state. Devonian ; France,
Germany and North America.
Anthemocrinus W. and Sp. Has one costal and few iBr. Arms biserial,
branching. Silurian ; Gotland.
Bhipidocrinus Zittel {ex Beyrich MS.) (Fig. 286). Calyx similar to that of
Lyriocrinus. Plates highly ornamented. Rays produced into two long, heavy,
uniserial trunks, giving off biserial, pinnuliferous ramules alternately on either
side. Middle Devonian ; Eifel, Germany.
Diamenocrinus Qi^hlert. Arms uniserial, repeatedly branching. Devonian ;
France and Germany. '
Lahuseniocrinus Tschern. ; Conclylocrinus Eichw. Devonian ; Ural.
Ophiocrinus Salter (non Charlesworth, nee Semper nee Angelin). Devonian ;
South Africa.
Family 5. Melocrinidae Zittel (emend. W. and Sp.).
Monoeticlic. Lower brachials, with well-defined interbrachials between them,
forming part of dorsal cup. Badials in contact all around. Ordovician to
Devonian.
Glyptocrinus Hall (Canistrocrinus W. and Sp., Pyenocrinus S. A. Miller).
(Fig. 287.) Basals five. Dorsal cup obconical to subglobose, ornamented
with radiating sti'iae passing from plate to plate • the eleva-
tions following the rays pronounced, and forming well-defined
rounded ridges, which meet imperceptibly with the free arm-
plates. Interbrachials very numerous, and enclosing supple-
mentary anals on the posterior side, which sometimes form a
continuous series. There are also numerous interdistichals,
and frequently interpalmars, which form conspicuous depres-
sions between the arm -plates. Tegmen low, composed of
minute irregular pieces ; anus eccentric. Arms uniserial, ten
to twenty, branching in the free state, long and slender.
Column round, or exceptionally pentangular. Ordovician ; ^^^ .,g^
rsorth America. Glyptocrinus deca-
Schizocrinus Hall. Ordovician (Trenton Group) : New dactyius uaiLVwer
^ r/ -J Ordovician (Ciiicin-
York. natian) ; Cincinnati,
Stelidiocrinus Ang. (Harmoerinus Aug.). Basals four. *^"°'
Form of dorsal cup as in Glyptocrinus, but interbrachials fewer and much
larger, and plates generally without ornamentation. Plates of the tegmen
190
ECHINODERMATA— PELMATOZOA
PHYLUM IV
also comparatively large. Arms uniserial, sometimes interlocking. Silurian ;
Europe and North America.
PeriglyptocrimLS W. . and Sp. Basals five. Arms biserial, dichotomous.
Ordovician (Trenton Gr.) ; Canada and Kentucky.
Scyphocrinus Zenker. Basals four. Arms uniserial, dichotomising fre-
quently. Calyx very large and elongate. Symmetry of dorsal cup slightly
disturbed by anals which are interposed between the interbrachials. Brachials
to lower part of the third order incorporated in the calyx, the upper ones free.
Interbrachials very numerous. Stem attached to a large, hollow spheroid,
strengthened by internal septa, regarded as a float by Hall ( = Camarocrinus),
as a Cystid by Barrande ( = Lobolithus). Silurian and Devonian ; Europe and
North America.
Mariacrinus Hall (ZenJcericrinus Waag. and Jahn). Basals four. Arms
uniserial, branching once or twice. In general aspect, construction of calyx,
and surface ornament, resembling Glyptocrinus. Silurian ; America, Europe.
Melocrimis Goldf. (Ctenocrimis Bronn, Astrocrinus Conrad, Turbinocrinus
Troost, Casfanocriims Roemer, Clonocrinus ([Ehlert, Promeloerinus Jaekel).
(Figs. 288, 289). Basals four; interbrachials numerous; those of the posterior
interray enclosing one or more
supplementary anals. Anal aper-
ture eccentric, rarely extended in
a small tube. Rays produced into
two main uniserial rami, giving off
biserial, pinnule-bearing arms at
short intervals to the outside of
Fig. 2S8.
Melocrinn.i typns (Bronn). Devonian (Spiriferen-Sandstein) ;
Daun, Eifel. B, Basals. C, Mould of stem-joints (the so-
called " Schraubensteine ").
Pig. 289.
Mclocrinus. Analysis of calyx (after W.
and til).).
the bifurcation ; the rami may be separate (Silurian species), or more or
less fused by their inner margins (Devonian species). Column round. Silurian
and Devonian ; Gotland, England, Germany and North America.
Cytocrinus Roemer. Like Melocrimis, but with arms borne on a single main
radial trunk from each ray. Silurian ; America.
Clonocrinus Qucnstedt. (nov. (Ehlert ; Corymhocrinus Aug. ; Polypeltes Aug.).
Basals four, hidden by column. Arms dichotomous, biserial both above and
CLASS III
CRINOIDEA
191
below the bifurcations. Base concave, forming an inverted cup. Dorsal cup
strictly pentamerous ; no anal plate. Interbrachials large, not enclosing any
anal plates. Silurian ; England, Gotland and North America.
Tribliocrinus Geinitz {Spyridiocriniis G^hlert). Lower Devonian ; Germany
and France.
Technocrinus Hall. Like Melocrimis, but having ten strong, simple, biserial
arms, which do not bifurcate in the free state. Interbrachials not enclosing
supplementary anals. Devonian (Oriskany) ; Maryland.
Macrostylocrimis Hall. Basals three, unequal. Anal interradius much
wider than the others ; its first row consisting usually of three plates, while
that in the four other interrays consists of a single inter-
brachial. Arms ten, simple and biserial. Silurian ; North
America.
Patelliocrinus Ang. (Fig. 290). Basals three, unequal.
Arms biserial or of cuneate uniserial brachials. No anal
plates. Dorsal cup elongate. Silurian ; Gotland, North
America.
AUocrimis W. and Sp. Basals three, unequal. Arms
uniserial. No anal plates. Dorsal cup depressed. Inter-
brachials few. Silurian ; North America.
Briarocrinus Angelin. Silurian ; Gotland.
Centriocrinus Bather (pro Cenirocrimis W. and Sp., non
Austin, tiec Worthen). Basals fused. Dorsal cup depressed.
No anals. Arms unknown. Devonian ; North America. p„. 290.
Dolatocrinus Lyon (Cacabocrinus Hall). Dorsal cup per- pateiuocrinus upto-
fectly pentamerous, cup -shaped or saucer-shaped. Base urfan • ^^G^otianll."
usually concave. Basals primitively three, but completely ^'^'''^J?J. '''^'' ^^^^""^
anchylosed in the adult. Costals two ; iBr few, the first
ones extremely large. Tegmen comparatively flat, and composed of rather
large plates, of which the orals form the summit. Eespiratory pores be-
tween arm bases frequently present. Anns at the end of a short tube.
Arms little known, sometimes branching and biserial. Column with
numerous projecting rings and buttresses. Devonian ; North America.
Stereocrinus Barris. Like the preceding, but the anchylosis of the BB
incomplete, and with only one costal. Devonian (Hamilton Group) ; North
America.
Hadrocrinus Lyon (Coroiiocrinus Hall ex Troost). Dorsal cuj) extremely
large, with concave base ; basals closely anchylosed. Brachials to the fourth
or fifth order incorporated in the cup. Interbrachials numerous and large ;
no distinct anal plate in lower ranges. Tegmen composed of innumerable
small plates. Devonian (Onondaga) ; Falls of the Ohio, near Louisville,
Kentucky.
The type described under this genus lias not hitherto been well understood. It falls into
two subdivisions, dittering more strongly than ,Stercocri7ius and Dolatocrinus ; one (R. discus)
having few very heavy arms, and one costal ; the other {H. 2}ienissi')iius) witli numerous very
slender arms, and two costals.
Oalyptocrinidae
Angelin.
Family 6.
Monocyclic. Lower brachials and interbrachials forming an important part of
the dorsal cup, which above the base, is perfectly pentamerous. Plates of the calyx
192
ECHINODERMATA— PELMATOZOA
PHYLUM IV
usually limited to a definite number. Eadiah in contact all around. Arms resting
in compartments formed by partitions attached to the tegmen. Silurian and
Devonian.
Emalyptocrinus Goldf. {Hypanthocrinus Phill.) (Figs.
291, 292). Calyx with a deep concavity at the lower end,
the B forming the bottom, and the B the sides of an
inverted cup. Supplementary pieces of the calyx con-
sisting of 1 X 2 interbrachials, and one iuterdistichal ; the
latter of the same form as the interbrachials, and nearly
as large as the two upper ones combined. Tegmen
elongate, its upper part extended to form a tube. It is
composed of five ranges of plates, of which the two
middle ones are the least regular in their arrangement,
and the upper one closes the centre. Attached to the
outer walls of the tegmen, and extending to its top, are
ten partitions supported by the interbrachials and inter-
distichals, which form deep, vertical compartments for
the reception of two arms each. Arms twenty, biserial ;
composed of very narrow pieces. Column round. Sil-
urian ; Gotland, England (Wenlock Limestone), and
Fig. 291.
Eucalyptocrinus regu-
/ftW.9 (Hising.). Silurian; ,^ ,, . • /^r- n \ a • i
Gotland. Crown with JNorth America (JNiagara Group). A single species occurs
arms removed from one • i.-i t^ • j; , i ttit i
ray in order to show the m the Devouiau ot the Eifel.
re^'ose "' ''''"'"^' ^'"^ CalUcrirMS Ang. (Fig. 293). Calyx flask - shaped ;
concavity at the base deeper and wider than in the
preceding, sometimes involving not only the radials, but parts of the
ui : ri i2 : iri
dist. (list.
Pig. 292.
Eucalyptocrinus rosaceus (fidldt). Devonian; Gerolstein, Eifel. ^/Perfect crown. B, Diai^ranimatic longi-
tudinal section of the calyx (h, Basals ; ri, Radials ; r'-, First costals ; y, Lower, and S, npper piece of the wini;-
like processes), f', Tegmen. /), Dorsal cup (/■', Radials ; r-, First costals ; (/■, Inlerradials ; (((st., Distichals ;
int. (liKt., Interbrachials; 7-, Palmars) (after L. Schultz(^).
costals as well. Partitions for the rece])tion of the arms much shorter, ex-
tondinc; to less than half the heiiiht of the arras. Otherwise similar to
CLASS III
CRINOIDEA
193
Encahjpfocrinns, and sharing the same distribution in the Silurian ; not known
in the Devonian.
- 1 B C
Fk;. 293.
CcMici-inus coslatus (Hising.). Siluiian ; Gotluiul. A, Crown. B, Calyx showing the construction of the
tegrnen. C, Inner or ventral aspect of the base. £», Outer or dorsal aspect of the .same. Natural size (after
Angelin).
Chicagocrinws Weller. Like CalUcrinus, but the primibrachs (costals)
reduced to a single diminutive plate in each ray. Silurian ; North America
(Chicago area).
Family 7. Batocrinidae Wachsmiith and Si^ringer.
Monocyclic. The lower brachials forming an important jiart of the dorsal cup.
Radials in contact except at the posterior side, where they are separated by a hepta-
gonal anal plate, followed by three plates in
the second range. Base hexagonal. Rays ry
usually branching by equal bifurcations. c'ycy
Tegmen composed of numerous small, un- Ol^^'^ ^^
differentiated plates. Ordovician to Lower
Carboniferous.
Subfamily A. Periechocrininae.
o^o
O«^0a^
RlCb
Tanaocrinus W. and Sp. Interbrachials OvV'rs^ A>\ v^/ ^^l}/7n
lerous, indefinitely arranged in de- cTyo r^ '^ V^ y 0 Or^
;sed areas passing gradually into the cT^ ^ cC^^ 0^ Q^
numer
pressed areas passing gradually into the
tegmen, leaving brachials in ridges con
tinning to the free arms ; posterior area
divided by median ridge of anal plates
resembling brachials. Arms uniserial
with ossicles more or less cuneate, tend-
ing to interlock distally ; branching be-
yond the calyx. Calyx elongate. Basals
five. Column round, or sub-pentagonal.
Fig. 294.
Batocrinus sp. Lower Carboniferous. Analysis
of calyx ; b, Basals ; E, Radials ; ihr, Interbr.achials ;
SX, supplementary anal ; X, Special anal plate
(after W. and Sp.).
Ordovician (Cincinnatian) ; Ohio.
Xenocrinus^ S. A. Miller. Basals four.
Arms not branching.
Column
^ Better specimeus obtained since the preijaration of Wachsmuth and Springer's Monograph
show clearly not only that the interbrachials in this genus are definite plates with close sutures, but
VOL. I O
194
ECHINODERMATA— PELMATOZOA
PHYLUM IV
quadrangular. Structure otherwise substantially as in the preceding.
Ordovician (Cincinnatian) ; Ohio.
Compsocrinus S. A. Miller. Basals four. Arms simple or branching.
Basals and radials more evenly rounded and less excavate laterally, but other-
wise differing little from Xenocriims. Ordovician (Cincinnatian) ; Ohio.
Acacocrinus W. and Sp. Interbrachials few, definitely arranged, not in
strongly depressed areas, and brachials and anals not in prominent ridges.
First primibrach (costal) quadrangular. Arms uniserial, slender, unbranched,
with cuneate ossicles tending to interlock at the tips. Calyx rather low and
rotund. Basals three. Silurian ; Indiana and Kentucky.
Carpocri7ius Miiller (PJwenicocrinus Austin ; Ahracrimis d'Orb. ; Habro-
crinus, Pionocrimis, Lepiocrinus Ang.) (Fig. 295). Calyx as in the preceding.
Arms simple, heavy,
usually not exceeding
ten, with very short,
wide ossicles, slightly
cuneiform, the longer
face bearing two pin-
nules, the shorter but
one. Silurian; Gotland,
England.
Desmidocrinus
(Fig. 296). Like the
preceding but with arms
fifteen to twenty, ossi-
cles longer and quad-
rangular, bearing one
pinnule to each side.
Silurian ; Gotland and
Ang.
Flo. 296.
Pio. 295.
a, CarpocrinU'S comtits (Aug.). Siluinan ; (!ot-
land. Crown viewed from the anal side, natural
size. 6, //. or»a<!ts (Aug.). Tegnien showing cover-
ing pieces of the ambulacra (after Angelin).
Desmidocrinus
heterodactyhis (Ang.).
Silnrian ; Gotland.
Natural size (after
Angelin).
England.
Abacocrinus Ang.
(Carolicrinus Waag. and Jahn). Basals four. Calyx rotund. Interbrachials
rather numerous, definitely arranged, not in depressed areas ; brachials and
anals not in prominent ridges. First primibrach hexagonal. Arms branch-
ing, biserial from the calyx up. Silurian ; Gotland.
Macarocr'mns Jaekel. Devonian ; Germany.
Periechocrinus Austin {Geocrinus d'Orb.; Pyxidocrinus Miiller; Trochocriuus
Portlock ; Pradocrinus de Verneuil). Basals three. Calyx elongate, expanding
to arm bases ; plates thin and long, usually with narrow median ridges along
the brachial series, which bifurcate two or three times within the calyx, lead-
ing to twenty-five or thirty arms, which are biserial beyond the calyx and do
not branch after becoming free. First primibrach (costal) hexagonal. Inter-
brachials numerous, definitely arranged. Silurian ; England and Gotland.
Saccocrinus Hall. Like the preceding, but the arms branch from about
twenty openings after becoming free, and are biserial both below and above the
bifurcations. Silurian to Lower Carboniferous (Upper Burlington) ; North
America and (?) Gotland.
that they do not pa.ss down to the basals in either species. This leaves no character to separate it
from the Batocriuirlae, and the present reviser agrees with Batlier in placing it with Tanaocrinus
and Gompsocrittns as the primitive forms of that family.
CLASS III CRINOIDEA 195
(?) Bei/rirJiocrinus Waag. and Jahii. Silurian ; Bohemia.
Gennaeacrinns W. and Sp. Basals three. Calyx low and broad, strongly
lobed at the arm bases ; plates thin and highly ornamented. First primibrach
hexagonal ; iBr rather numerous. Arm openings twenty-five or more ; arms
unknown. Devonian ; Indiana and New York.
Megistocrinus Owen and Shum. {Tylocrinus Wood). Basals three. Calyx
usually large, hemispheric, with greatest height below the arm bases ; usually
but little lobed ; plates heavy, smooth or ornamented. Interbrachials
numerous ; first primibrach hexagonal. Arms sixteen to twenty, branching
in the free state, biserial above and below the bifurcations. Devonian to
Lower Carboniferous (Upper Burlington) ; North America.
Subfamily B. Barrandeocrininae.
Tegmen narrow and rigid. Arms permanently directed downward enclosing the
calyx.
A highly specialised type, represented by a single genus, which, though having a similar
calyx, differs so strongly in habitus from those of the next section that it is better kept
separate.
Barrandeocrinus Angelin (Cylicocrinus S. A. Miller). Basals three. Calyx
rather elongate, with tegmen nearly flat. Interbrachials few, definitely
arranged. Arms ten, heavy, biserial, directed downward over the calyx, with
pinnules opening outward. Silurian ; Gotland and North America.
Subfamily C. Batocrininae.
Tegmen broad, toell differentiated ; plates large and heavy, forming a rigid roof.
Arms not branching beyond the calyx ; biserial. Respiratory pores frequently present.
First primibrach (costal) usually quadrangular. Basals three in all known genera.
Devonian to Lower Carboniferous.
This section flourishes amid a remarkable local development of Crinoid life especially
characteristic of the Mississippian area of the United States. The founa is enormously prolific
in numbers and variety in the Burlington and Keokuk limestones of the Mississippi Valley, but
almost entirely wanting in the Lower Carboniferous of Great Britain and Belgium, and of
other parts of the United States. Only a few straggling species come from the Devonian.
§ 1. Anus at the end of a tube.
a. Interbrachials few, separated from tegmen by arch of brachials.
Batocrimis Casseday. Calyx biturbinate. Arms short, equidistant. Anal
tube very long, central, extending beyond arms. Kinderhook to St. Louis
Group ; North America.
Eretmocrinus Lyon and Cass. Like Batocrimis, but arms paddle-shaped,
and anal tube short, eccentric, tending to curve. Devonian to Keokuk
Group ; North America.
Alloprosallocrinus Lyon and Cass. Calyx conical ; dorsal cup almost flat,
greatest height above the arm bases. First primibrach usually wanting.
Approaching Agaricocrinus in shape. Anal tube sub-central ; arms unknown.
Keokuk limestone ; North America.
p. Interbrachials few, usually separated from the tegmen except at anal side.
Macrocrinus W. and Sp. Calyx elongate, biturbinate to subovoid. Anal
196
ECHINODEEMATA— PELMATOZOA
PHYLUJI IV
tube rather lai'ge, extending beyond arms. Arms twelve to sixteen. Upper
Burlington and Keokuk Gr. ; America.
Dizygocrinus W. and Sp. Calyx rotundate. Anal tube rather small,
usually not extending beyond the arms. Arms single or double, from twelve
to twenty openings. Upper Burlington to St. Louis Group ; America.
Eutrochocrinus W. and Sp. Calyx wheel-shaped. Anal tube long. Arms
short, either single or double from twenty openings. Upper Burlington and
Keokuk Group ; America,
y. Interlrachials few, sometimes connected with tegmen all around.
Uperocrijiii'S Meek and Worthen (Lobocrinus W. and Sp., Hyperocrimis
Bather) (Fig. 297). Calyx pyriform. Anal tube large
and often spiniferous. Arms short, single, often arranged
in groups, openings directed upward. Upper Burlington
and Keokuk ; America.
§ 2. Anus ivithout a tube, directly through tegmen.
Interbrachials few, usually not connecting with tegmen except
at anal side.
Aorocrinus W. and Sp. Calyx small, elongate to ro-
tund or biturbinate. Arms
rather strong, onefrom each
opening, cylindrical. Teg-
men plates not spiniferous.
Devonian to Burlington ;
Europe and America.
Coelocrinus M. land W.
{Sphaerocrinus M. and W.
non Roemer). Similar to
preceding genus, but with
concave base. Burlington
Group ; America.
Dorycrinus Roemer (Fig.
var. im<ermerfiM.s(M. and W.). Lower Ayb). OalyX Small tO hxrge;
Carboniferous ; Burlington, Iowa. „„„<.„,„• i ^ -.i
Calyx viewed from the anal side. pOSteriOr Oral aloue, Or With
Natural size (after Meek and Wor- primary radial plates of
tegmen, spiniferous. Arms
rather small, usually two from each opening. Devonian to Keokuk ; America.
Agaricocrinus Hall (ex Troost). Calyx small to large, hemispherical, with
dorsal side usually flat or concave, and greatest height above the arm bases.
First primibrach sometimes hexagonal. Arms ten to sixteen, very heavy,
directed outwards. Burlington to Keokuk ; America.
Fig. 297.
Pig. 2'.)S.
Dorycrinus quiwiuelohus (Hall)
Uperonrinus 'pyrlforinis
(Shumard). Lower Carbon-
iferous ; Burlington, Iowa.
Nat. size (after Meek and
Worthen).
Family 8. Actinocrinidae.
Monocyclic. Loiver brachials, with well-defined interbrachials between them,
forming an important part of the dorsal cup. Radials in contact except at the anal
side, where they are separated by a hexagonal anal plate, followed by two plates in the
second range. Basals three, forming a hexagon. Arms biserial in all known genera.
Rays usually branching by alternate bifurcations. Lower Carboniferous. Kinder-
hook to Keokuk.
CLASS III CRINOIDEA 197
This feniily represents another line of profuse crinoidal development characteristic of the
Mississippian area in the United States, parallel to that of the later Batocrinidae. It may be
considered as a direct branch from that family, but sharply and consistently distinguished
from it by the fact that the anal plate is followed by two plates instead of three. It was
short lived, being restricted to the lower part of the Lower Carboniferous, where it culminated
in large and striking forms, not found outside of the Mississippi Valley. Only two of its genera
are certainly known to occur in the approximately equivalent formation of Europe.
§ 1 . Tegmen composed of well differentiated plates, with anus at the end of a tube,
a. Interbrachials connecting with the tegmen.
Amphoracrinus Austin. Calyx lobed, the largest part above the arm zone ;
rays widely separated. Interbrachials few. First primibrachs usually quad-
rangular, sometimes hexagonal. Arms stout, either simple or branching,
biserial below and above the bifurcations. Anal tube short, eccentric. Oral
plates often strongly spiniferous. Anal plate exceptionally followed by three
plates in the second range. Lower Carboniferous ; AYaverly to Lower Bur-
lington Group in the United States, and lower part of the Mountain Lime-
stone in Britain.
This genus is a transition form from the Batocrinidae, in which the Actinocrinoid structure
of the anal side has not become constant. In some species the middle plate of the second row
has not been entirely eliminated, but occasionally appears in diminished size, and scarcely
touching the anal plate. This is consistent with its geological position as one of the earliest
of its family, and one of the first to disappear.
Actinocrinus Miller {Amphora Cumb. ; Phillipsocrimis M'Coy; Blairocrinus
S. A. Miller) (Fig. 299, D). Calyx lobed, rays widely separated ; largest part
below arm zone. Interbrachials numerous. First primibrachs usually
hexagonal. Rays within the calyx bifurcating alternately from every second
or third plate above the first. Arms either simple from the calyx, or
branching, and biserial below as well as above the bifurcations. Anal tube
long, central. Lower Carboniferous; Lower Burlington to Keokuk, in the
United States, and Mountain Limestone of Britain and Belgium.
Stegamcrinus M. and W. {Samp)so)iocriiius M. and G.). Calyx similar to that
of Actinocrinus, but relatively lower, and having the rays produced into one
(♦S*. sculptus) or two (S. pentagonus) tubular extensions giving off pinnulate arms
alternately at the sides. Anal tube small. Lower Carboniferous (Lower and
Upper Burlington) ; North America.
p. Interhrachials not connecting with tegmen.
Cactocrinus W. and Sp. (Fig. 299, A, B). Calyx not lobed. Arms usually
strong, twenty to forty, unbranched, about equidistant, given off in a more or
less continuous ring, and directed upward ; bifurcations beyond the costals
from every successive brachial. Anal tube long, central. Lower Carboni-
ferous (Kinderhook to Lower Burlington) ; North America, (? ) Belgium.
Teliocrinus W. and Sp. Similar to the last, but arms more slender and
numerous, usually sixty or more, their lower portions directed outward, and
forming a broad continuous rim. Lower Carboniferous (Upper Burlington) ;
North America.
§ 2. Tegmen of undifferentiated plates. Anus directly through the tegmen, without
a tube.
Physetocrinus W. and Sp. (Fig. 299, C). Interbrachials connecting with
tegmen. Calyx rotund, lobed, with arms in groups, stout ; tegmen rounded
198
ECHINODERMATA— PELMATOZOA
PHYLUM IV
and elevated ; anus eccentric. All bifurcations beyond costals given oft' from
every alternate brachial. Lower Carboniferous (Lower and Upper Burlington) ;
North America.
Strotocrirms M. and W. Interbrachials not connecting with tegmen.
an
D
m^
cfol)
%f
CoD
/-CM
6f
BE
Fro. 290.
A, Ccictocrinus proboscidiali'' (Hall). Lower Carboniferous ; Burlington, Iowa. Calyx with fractureil
tegmen, showing the subtegniinal ambulacral skeleton, and the convoluted digestive organ. B, Enlarged
portion of the anibulacral skeleton. C, Natural cast of tegmen of Phy.ictocrinii.-<, with impressions of food-
grooves (rt), conducting fi'om the arms to the mouth (o) ; an, Anus. D, Diagram of Actmorriuus (after W.
and Sp.).
Calyx not lobed ; rays bifurcating on alternate brachials from distichals up,
and extended into a broad, flanging rim, as in Teliocrimis, but more
pronounced. Arms very numerous and slender. Tegmen low, sometimes flat
or concave, composed of innumerable small pieces ; anus eccentric. Lower
Carboniferous (Upper Burlington) ; North America.
Family 9. Platycrinidae Roemer.
Monocyclic. Brachials and interbrachials usually hd slightly represented in the
dorsal cup : the lower brachials taking more or less the form of arm plates, but being
strongly connected, either tvith the solid tegmen by modified covering plates and strong
interambidacrals, or with the cup hy large interbrachials which are usually more or
less interambulacral in position, lladials in contact all around, there being no
special anal plate. Basals forming a pentagon ; three, unequal, and frequently
anchylosed. Silurian to Carboniferous.
CLASS HI
CRINOIDEA
199
§ 1. Rays with ttoo or more primibrachs (cosfals).
Coccocrinus Joh. Miiller. The simplest form of the Camerata, the calyx
consisting only of three basals, five radials, 2x5 costals, five interbrachials and
five orals. Calyx small, rotund ; basals and radials forming almost the entire
dorsal cup. Tegmen almost completely occupied by five large, triangular,
symmetrical orals, forming a pyramid. Anal opening in the interradio-
oral suture. Arms delicate, branching once, uniserial with cuneate joints.
Column round. Silurian ; North America. Devonian ; Eifel.
Oulicocrinus Joh. Miiller. Transitional between Coccocrinus and Platycrinus ;
generally similar to the former. Orals asymmetrical. Arms heavy, biserial.
Column round. Middle Devonian ; Eifel.
Hapalocrinus Jaekel em. Bather {Jgriocrimis, Thallocrinus and Clematocrinus
Jaekel). Orals small ; interambulacra visible. Arms uniserial, Avith cuneate
joints ; branching once or twice. Column round, with strong cirri. Silurian ;
England, Australia, North America. Devonian ; Germany.
Corclijlocrinus Angelin. Tegmen composed of numerous plates. Arms
uniserial, or slightly interlocking. Column round, with long cirri. Silurian ;
Gotland. Devonian ; North America.
§ 2. Bays with only one primibrach (costal). Orals occupying but a small part of
the tegmen, asymmetrical ; ambulacral plates well defined.
Marsipocrinus Bather (pro Marsupiocrinus Phill., non Blv.'). (Syn. Cypellocrinus
vel Cupellaecrimis Shumard, ex Troost, non Steininger.) Brachials to axillary
distichal usually incorporated in cup. Arms biserial, ten or twenty. Column
round. Axial canal large. Silurian ; England, Gotland, North America.
.^.'T>
Fig. 300.
Platycrinus subsjnnosus (Hall),
ous ; Burlington Group, Iowa,
cup, omitting anal inturray. h,
I, Costals ; ir, Interbrachials
and Springer).
Lower Carbonifer-
Analysis of dorsal
Basals ; R, radials ;
(after Wachsmuth
Fig. 301.
Platycrinus tnijintidactylus
(Austin). Lower Carbonifer-
ous ; Tournay. Belgium (re-
stored, after de Koninck).
Platycrinus Miller (Centrocrinus, Pleurocrinus Austin; Edwardsocrinns d'Orb.)
(Figs. 300, 301). Calyx rotund. Eadials large with crescent-shaped facets.
First interbrachials at the level of the arm bases ; consisting of three plates
horizontally arranged, usually partly interambulacral, but sometimes succeeded
by one or more ranges incorporating the distichals ; plates of anal interradius
usually more numerous than those of the other sides. Orals usually large,
asymmetrical, occupying but a small part of the tegmen. Ambulacra rigid,
200
ECHINODERMATA— PELMATOZOA
PHYLUM IV
and incorporated into the tegmeri. Anus either eccentric, or at the end of a
thick, usually short tube. Arms branching once to three times, uniserial in
the lower parts, but becoming biserial distally. Column elliptical and twisted ;
the axes of the uj^per and lower surfaces of the individual segments being at
a slight angle with one another; central canal very minute; strong cirri
toward distal end. Eare in Devonian ; abundant in Lower Carboniferous of
England, Belgium and North America (Hamilton to St. Louis Groups).
Brahmacrinus Sollas. Like Platycriims, but radials relatively smaller, and
lower brachials larger, and incorporated in dorsal cup to the height of the
second distichals. Lower Carboniferous ; England.
Eudadocrinus M, and W. Calyx like Flatycrimis, but with rays produced
into one or two main rami, roofed with rigid covering plates, forming tubular
extensions of the calyx, giving off at alternate sides biserial, pinnuliferous
arms. An extreme development of the family type, but not the latest in
time. Lower Carboniferous (Kinderhook to Keokuk) ; North America.
Family 10. Hexacrinidae Waclismuth and Springer.
Monocyclic. Eadials in contact excejyt at the posterior side, where they are
separated by an anal plate. Basals three, or two, forming a hexagon. Structure
otherwise as in the Platycrinidae. Devonian to Lower Carboniferous.
§ L Basals three.
Hexacrinus Austin (Fig. 302). Costals two, united by syzygy, or one.
Rays usually in two main trunks, bearing iiniserial pinnulate arms on one or
Fig. 302.
Hexacrinus elongatus (Goldf.). DRVouian ; Pelm, Eifel. a, Calyx seen from one side ; h, Aspect of summit ;
c, Analysis of calyx and arms ; d, e, Column of //. sxtinosus (Miill.) (after L. Schultze).
both sides at intervals. Tegmen as in Plafycrimis. Column round, with small
axial opening. Devonian. Represented by numerous species in England,
Belgium, and the Eifel, but by only a few in North America.
Arthracantha Williams (Histricrinus Hinde). Calyx as in Hexacrinus, but
the plates covered with movable spines borne on tubercles. Arms dichotomous,
biserial. Stem circular. Devonian ; New York and Canada.
CLASS III
CEINOIDEA
201
§ 2. Basals two.
Dlchocrimis Miinster (Cotyledonocrinus Lyon and Cass.). Costals two,
usually united by syzygy, as are also the first two brachials of each order,
giving the appearance of a single plate. Arms biserial, branching once to
three times ; occasionally pendent. Stem round. Lower Carboniferous ;
Belgium, Great Britain, North America (Kinderhook to Kaskaskia).
Campfocrinus W. and Sp. Like Dkhocrimis except in the stem, which is
concavo-convex in section, as in Herpetocrinus, tending to coil around the crown.
Lower Carboniferous (Burlington to St. Louis) ; North America.
Talarocrinus W. and Sp. Costal one, small, trigonal, sometimes hidden
by the distichals. Calyx plates massive ; anal resembling anterior radial in
form and size. Column round. Lower Carboniferous (St. Louis to Kaskaskia) ;
North America.
Fterotocrinus Lyon and Cass. (Asterocrinus Lyon non Miinster). A re-
markable modification of Talarocriims. Brachials up to third order incorporated
into dorsal cup. Anal plate much smaller than the radials. The axillary
first ambidacral produced into large wing-like processes, stretched out from
the tegmen. Lower Car-
boniferous (Kaskaskia) ;
North America.
Family 11. Acrocrinidae
WaclisniLith and Springer.
Monocyclic. Basals separ-
ated from radials hy a large
belt of accessory pieces. Badials
in contact except at the posterior
side, where they are separated
hy an anal plate. Structure
otherwise as in the Hexa-
crinidae. Lower Carboni-
ferous.
O
r>
o o^^o o
(Fi^
forming
'^ g8'o<& ^
Acrocrinus Yandell
303). Basals two,
a hexagon. Calyx as \n
Dichocrimis with intercala-
tion of several circlets (up
to twenty) of supplementary
plates, those immediately
above the basals being the
smallest and latest formed.
Costals small, trigonal. Arms two to four to the ray, biserial, either erect
or pendent. Column round. Lower Carboniferous. The last survivor of
the Camerata (Burlington to Coal Measures), and known chiefly in North
America but reported recently from England.
Fio. 303.
Acrocrinus sp. Lower CaibonifurouS. Ij, Basals; E, Radials ;
I, Costals ; x, Special anal plate. All the others are supplement-
ary plates (after W. and Sp.).
202 ECHINODERMATA— PELMATOZOA phylum iv
Order 2. FLEXIBILIA Zittel.
( = Articulata W. and Sp. non Miiller).
Crinoidea in which the lower brachials are incorporated in the dorsal cup, either
by lateral union, by interbrachials, or by a finely plated shin, but never rigidly.
Tegmen flexible, with ambulacra well defined, roofed with movable covering plates ;
mouth supra-tegminal and open. Arms non-pinnulate, with a wide and shallow
ventral groove. Base dicyclic ; infrabasals three, unequal, rarely undivided, some-
times greatly reduced or atrophied ; often fused ivith top columnal. liadials and
brachials united by modified muscular articulation, usually without transverse ridge,
accompanied by loose suture between other plates, producing a flexible calyx admitting
motion between apposed faces of the plates. Orals small, posterior one much the
largest, with the food grooves passing between them to the mouth ; they are more or
less surrounded by perisome, which often passes down between the rays. Stem round ;
proximal columnals usually very short, frequently wider than the others and forming a
conical expansion next to the calyx. Ordovician to Carboniferous.
The calyx and arm plates in this group are usually thick and relatively short,
with a muscular or loose ligamentous articulation, which admits of much mobility
upon one another. The combination of massiveness with flexibility is a strong
distinctive character. The union between brachials is frequently marked exteriorly
by arcuate sutures, produced by a downward projection of the outer proximal edge of
the plates into a corresponding depression on the distal edge of those preceding ; this
extends but little below the surface, the sutures beneath being perfectly straight. By
contraction in fossilising the projecting processes are frequently fractured, giving rise
to an erroneous appearance of "patelloid plates."
Owing to the fact that in most of the genera the rays are more or less continuous
from the radials up, with no well-defined zone of demarcation between calyx and
arms, there is a general similarity of type \\'hich renders the subdivisions less apparent
than in the Camerata. The most prominent modification of the general type relates
to the structure of the posterior interradius, upon Avhich two well-defined divisions
may be recognised : (1) the strong anal side, in which the anal plates, when present,
are partly or wholly incorporated in the calyx wall ; (2) the weak anal side, in which
the anal plates are sejiarated from adjacent brachials at one or both sides by a pliant
integument, and tend to form a flexible series supporting the anal tube, which is
a mere extrusion of the pliant perisome of the tegmen. The second of these
structures is analogous to that in the larval stage of the living Crinoids, is the most
generalised, and was the most persistent — appearing in the Ordovician, and ending
with the culmination of this group in the Kaskaskia, or possibly Coal Measures. The
first is more specialised, and ranges from the Silurian to the Warsaw. Within it modifi-
cations in the size and position of the infrabasals, and in the general habitus, aft'ord
ground for family divisions, which shade into one another to some extent.
Among the genera of each family there may be observed a migration of the
radianal, from a primitive position directly underneath the right posterior radial (as
if the radial were transversely bisected) in the older formations (Ordovician and some
Silurian), to an oblique position to the lower left of the radial (some Silurian and
Devonian), and then to complete elimination in the Carboniferous. Modifications m
the numljer of primibrachs, by increase from two to three or more, were also to some
extent coincident with these changes. The structure of the base remains remarkably
constant, the proximal circlet consisting of three unequal infrabasals, which are
exceptionally fused to an undivided disk, and in certain genera tend to disajjpear by
resoi'])tion.
CLASS III CRINOIDEA 203
A. Anal plates, when iwesent, partly or wholly incorporated in the
calyx.
Suborder 1. SAGENOCRINOIDEA.
Family 1. Lecanocrinidae Springer.
Infrabasals ahutting on dorsal side of basals, more or less erect, and taking
part in the calyx wall. Crown usually small, short, rotund, with arms ahutting,
frequently interloching, and closely infolding at the distal ends. Silurian to Lower
Carboniferous.
a. Rays in contact except at the posterior side, where anal x separates radials, touching
posterior basal. No iBr in other areas.
Lecanocrinus Hall {Cyrtidocrinus Ang.) (Fig. 304). Arms dichotomons,
flat, interlocking. BA rhombic, obliquely below r.post.E. Anal x alone.
IBr two (exceptionally one). Silurian to Devon-
ian; North America, Gotland, England.
Mespilocrinus Koninck and Lehon. No BA.
Anal X alone, or followed by a triangular plate.
Arms dichotomous, usually rounded, with dex-
trose twist. IBr two. Lower Carboniferous
(Kinderhook to Upper Burlington) ; Belgium,
England and Mississippian area. North America.
h. Rays above radials partly or wholly separated all Fjq 3Q4
around, by iB7' or perisome. Anal x usually between pos- ^ , . , .„. . , r.-i ■ .
',;',. ' . , , , ,. ,,^ , . \ Lecanocnmis htlliHfjsi 2\.ng. Silurian;
tenor radials, touching basal (exception, Nipterocrmus). Gotland. Crown, seen from the anal
side, figme re\'ersed (after Angelin).
Homalocrinus Ang. Lifrabasals very large,
enveloping basals, and sometimes radials. Arms heterotomous, with ten
main trunks, bearing ramules. Rays abutting above interbrachials, peri-
some not exposed interradially. Anal x, and large iBr in other areas,
followed by others. BA under r.post.R. between BB. IBr two. Silurian ;
Gotland, England.
Calpiocrinus Ang. Like the preceding, but the rays have twenty main
trunks bearing ramules, and there is no BA. Silurian ; Gotland.
These two genera are remarkably specialised in the enormous overgrowth
of the infrabasals, which envelop, and sometimes entirely conceal, both basals
and radials, a fact which has made them heretofore generally misunderstood.
Cholocrinus Springer. IBB not enveloping BB. Arms heterotomous,
with ten main trunks bearing irregularly branching ramules. Rays not
abutting, divergent, not closely infolding; no regular iBr, areas filled with
perisome. Anal x followed by perisome. BA rhombic, obliquely below
r.post.R. IBr two. Rays unequally developed, the two antero-lateral ones
being dwarfed. Type, Forhesiocrinus ohesus Ang. Silurian ; Gotland.
Anisocrinus Ang. Arms dichotomous. Rays abutting above iBr, perisome
not exposed. Anal x alone, or with others following ; iBr few, one large,
alone, or followed by others. BA more or less under r.post.R, above line
of BB. IBr two. Silurian ; Gotland, and North America (Western Niagara).
Fycnosaccus Ang. (Oncocrinus Bather). Arms dichotomous. Rays not
abutting ; no regular iBr, areas wide, filled with perisome. Radial facets
much less than the width of B. Anal x alone, followed by perisome. BA
204 ECHINODERMATA— PELMATOZOA phylum iv
rhombic, obliquely below r.post.R. IBr one to four. Silurian ; Gotland,
Enghuid, and North America (Niagara of Avestern area and of New York).
Niptevocrinns Wachsmuth, in Meek and AVorthen. Similar to Fycnosaccns,
but without RA or anal x, and with infrabasals fused to one. The last
survivor of this family. Lower Burlington to Keokuk ; Mississippian area,
North America.
Family 2. Sagenocrinidae Springer.
Infrabasals abutting on dorsal side of basals, low and flat, taking little part in
calyx wall. Croivn usually large, elongate, expanding above the radials. Hays
above radials partly or wholly separated all aroicnd. Silurian to Lower
Carboniferous.
Temnocrinus Springer. Arms dichotomous. Anals and iBr only in lower
part of interradial areas ; anals more than one abreast. BA in form of B
under 'r.post.R. Anal x separating BR and touching post.B. IBr two.
Type, Taxocrinus tuberculatus Miller. Silurian ; England, (?) North America.
Meristocrinus Springer. Similar to Temnocrinus, but with anal x followed
by other plates in series, and IBr three. Type, Taxocrinus loveni Angelin.
Silurian ; Gotland.
Sagenocrinus Austin. Arms dichotomous. Anal and iBr areas filled with
solid plates. RA obliquely below r.post.R, usually between BB, and not
touching r.ant.R. IBr two. Silurian ; England, Gotland, and North
America (Western Niagara).
Lithocrinus W. and Sp. (Forbesiocrinus Aug. non Kon.). No RA. Arms
heterotomous, with ten main trunks bearing branching ramules. iBr well
developed in lower part of areas. IBr two. Type, Forbesiocrinus divaricafus
Ang. Silurian ; Gotland.
Forbesiocrinus Koninck and Lehon. No RA. Arms dichotomous. iBr
usually numerous, filling the areas with solid plates. IBr three, except in
F. agassizi, which has two. The culmination of this family. Lower Carboni-
ferous (Lower Burlington to Warsaw) ; Belgium. Also Mississippian area,
North America.
Family 3. Ichthyocrinidae Waclismutli and Springer (restr.),
Infrabasals wholly within the ring of basals, concealed by the column,
sometimes disappearing by resorption. Crown usually elongate,
expanding above radials, but often infolding distnlly. Arms
usually closely abutting or interlocking. Silurian to Lower
Carboniferous.
a. Rays in contact except between posterior radials when separated
by anal a-.
Ichthyocrinns Conrad (Fig. 305). Arms dichotomous,
closely interlocking, and infolding. RA in form of /.' under
icUhywrinn^ inens r.post.R. No anal, posterior basal not differentiated. IBr
crown? 'siiuria'".KNia two. Silurian; Gotland, England and North America (New
Irani (Jroiiii); Luck- \t ^ i -itt i ■\t „ \
port, New York (after York and Western Niag;i,ra area).
"=!")■ Clidochirus Ang. Similar to Ichthyocrinus, but with
posterior basal difi"erentiated, supporting anal x alone, or followed by others.
CLASS III CRINOIDEA 205
Silurian ; Gotland. Silurian to Devonian (Niagara, Manlius, Helderbergian) ;
North America.
Metichthyocrimis Springer. No BA. No anal ; posterior basal not differ-
entiated. Crown rotund. Arms dichotomous, interlocking and infolding.
IBr two. Type, Iclithyocr. tiaracformis Hall ex Troost MS. Lower Carbon-
iferous (Kinderhook to Lower Burlington) ; Mississippian area ; North
America.
b. Rays above radials partly or wholly separated all around ; posterior radials separated
by anal x wlien present.
Euryocrinus Phillips. No BA. Arms dichotomous. Anal x followed by
others in a single series. iBr few, usually in single series. IBr three. Lower
Carboniferous ; England. Devonian to Lower Burlington ; North America.
Amphicrinus Springer. Similar to Euryocrinus, but with iBr numerous, in
more than one series, and primibrachs two. Lower Carboniferous ; Scotland.
Dadylocrinus Quenst. (Dimerocrinus Pacht non Phillips). No BA. Crown
elongate, expanding from BB up. Arms heterotomous, with twenty main
trunks bearing ramules. iBr few or absent. Anal x followed by others in
more than one series, suturally connected at the sides. IBr two. Devonian^
Russia, Belgium.
Synerocrinus Jaekel (Forhesiocrinus Trautschold non de Kon.). Similar to
Dadylocrinus, but with anal x followed by others in series tending to form a
tube (transition toward Taxocrinidae). Crown more rotund in young
individuals. Lower Carboniferous ; Bergkalk near Moscow, Russia.
Wachsmuthicrinus Springer. Similar to Dactylocrinus, but with no anal
plate, posterior basal not differentiated. The last survivor of this family in
America. Type, Forhesiocrinus thiemei Hall. Lower Carboniferous, Kinder-
hook to Upper Burlington ; Mississippian area ; North America.
B. All anal plates separated by perisome from adjacent brachials at one or both
sides, tending to form a tubular series, from posterior basal up.
Suborder 2. TAXOCRINOIDEA.
Family 4. Taxocrinidae Bather emend. Springer.
Infrabasals usually abutting on dorsal side of basals, but low, talcing little part
in the calyx wall. Croton usiially elongate, with arms divergent, and not abutting
above interbrachial areas. Interbrachials present all around, Ordovician to Lower
Carboniferous.
Protaxocrinus Springer {Taxocrinus Ang. pars ; Lecanocrinus Billings). Arms
dichotomous. BA in form of B, below r.post.R. iBr few. IBr two. Type,
Taxocrinus ovalis Ang. Ordovician to Silurian ; Gotland, Canada and the
United States. The geologically earliest known genus of the Flexibilia.
Gnorimocrinus W. and Sp. (Taxocrinus Ang. pars). BA rhombic, obliquely
below r.post.R. iBr few. IBr two (or three). Type, Taxocrinus expansus
Ang. Silurian ; Gotland and North America, western Niagara, area. (?)
Devonian ; Belgium.
Eutaxocrinus Springer. No BA. iBr variable. IBr two. Type, Taxo-
crinus affinis Miiller. Silurian and Devonian to basal part of Lower Carboni-
ferous (Kinderhook) ; Gotland, Germany, North America.
206
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Fia.
Taxocrinns
306.
interinndius
W. and Sp., showing
tegnien, with ambulacra,
iirais and ojhmi moutli be-
tween them (after Wachs-
muth and Springer).
Taxocrmus Phillips (Isocriims Phill., «o?i von Meyer; Cladocrinus Austin non
Ang. ; Euryalecrimis Austin). (Figs. 306, 307.) Like Eutaxocrimi^ but with
primibrachs three. De-
vonian to summit of
Lower Carboniferous ;
England, Belgium and
North America.
P a r ichthy 0 crinii s
Springer. No RA. iBr
few. IBr three. Rays
closely abutting above
iBr; arms interlocking
and infolding distally.
Has the habitus of
Ichihyocrimis, but with
the tube-like anal series of the Taxocrinidae
well developed. Lower Carboniferous ;
Upper Burlington and Keokuk ; (?) Coal
Measures ; Mississippian area, North Amer-
ica. Type, Ichthyocrinus noUlis (W. and Sp.).
Onychocrinus Lyon and Cass. (Oligocrinus
Springer). Arms heterotomous. Rays
widely divergent, produced into ten large,
rounded main trunks, bearing ramules. No
Bj4. iBr few or numerous. IBr three to
six, or more. Lower Carboniferous (Lower
Burlington to Kaskaskia) ; Mississippian
area. North America.
This is the culmination and most ex-
travagant development of the Taxocrinoid
type. AYith the exception of an imperfectly known species, probably of
this family, from the Lower Coal Measures, this and a depauperate species
of Taxocrinus are the last survivors of the Flexihilia.
Fig. 307.
Taxocr hills aAhtti White Perfect crown.
Lower Carboniferous ; Crawfordsville, Ind.
Usually known in collections as T. meclci, or
T. inultibrachiatus (F. Springer, original).
Incertae sedis.
Edriocrinus Hall. Superficially resembles Holopus, and its position is
doubtful. Has bi'oad branching arms, with shallow ventral groove, short
bi'achials, and no pinnules. No stem ; basals fused into a rounded conical
mass, attached by a flattened surface when young, free in the adult. Radials
five, with anal plate in same range. Lower Devonian (Heldei'bergian,
Oriskany) ; New York, Maryland, Tennessee.
Caleidocrinus Waagen and Jahn. Probably an Inadunate Crinoid, with
anal side not differentiated in dorsal cup. Silurian ; Bohemia.
Bhopalocrinus W. and Sp. Founded on a unique specimen described as
Taxocrinus gracilis Schultze, but does not belong to this group. It has a
strongly plated anal tube reaching to height of the arms, and might be
described as a dicyclic Synbathocrinoid, with some interbrachial plates.
Middle Devonian ; Eifel.
CLASS III
CEINOIDEA
207
Order 3. INADUNATA Wachsmuth and Springer.
Orinoidea in which the arms are free above the radials ; dorsal cnp liinited to
radials, basals, infrahasals when present, and anal plates; no interradials or inter-
hrachials except at the posterior {anal) side, and brachials never normally incorporated
in the cnp. All plates of the cnp united by close suture. Mouth snb-tegminal.
Suborder 1. LARVIFORMIA Wachsmuth and Springer.
{Haplocrinacea Neumayr ; Larvata Jaekel pars).
Monocyclic (except Cupressocrinus). Calyx consisting only of basals {tvith or
tvithoid infrabasals), radials, and orals, without anal plates, and usually without
visible ambulacra. All plates immovably united by close suture. Arms non-
pinnulate, simple and uniserial (exception, the doubtful Stephanocrinus). Silurian
to Carboniferous.
The simplest form of the Crinoidea ; containing only plates found in the larval or very
young stage of existing types, without any supplementary plates whatever except sucli as
may belong to an arm-like anal tube. They are usually small, one genus, AUagccrinus,
almost microscopic. Similar minute forms may yet be found in the pre-Silurian formations,
from which their absence thus far has been urged as an objection to the validity of the group,
considered as a phylogenetic representative of the larval stage. It must be admitted that its
limits are not very well defined, but the typical form is Haplocrinus.
Family 1, Stephanocrinidae Wachsmuth and Springer.
Monocyclic. Calyx cup-shaped, composed of three elongate basals, five radials,
and five orals, with ambulacra. Radials deeply forked ; the prongs formed by the
margins of two contiguous radials extending upward between the arms, in spinelike
processes. First costals semilunate and resting within a horseshoe -like concavity near
the outer end of radial incisions. Tegmen consisting of the orals, surrounding a
central space, which is roofed over by five greatly modified ambidacrals in form of
a flattened pyramid of triangrdar plates ; with anchylosed covering plates extending
outward to the arm bases. Anal aperture between posterior oral and interradial
process. Arms with one short hiserial trunk to
the ray, giving off slender biserial, non-pinnidate
side arms from the outer shoidder of each brachial.
Ordovician and Silurian.
Stephanocrinus Conrad (Bhombifera Barr.)
(Fig. 308). This unique genus is an inter-
mediate form, variously considered by different
authors as a Blastoid, a Cystid, or a Crinoid.
The presence of branching biserial arms, as
pointed out by Wachsmuth and Springer,
■■•, . ■',. .,, n • -J li.i,T_ urian ; Lockport, New York, o, Side view
makes it unquestionably a UrinOld, altnOUgn of calyx, natural size ; b, summit aspect,
not normal for the present group, in which it ^SbrUrawaylaft^erHa?^ °' ""
is placed on account of its simple and primitive
type of calyx. The forked radials, resemblance of the orals to the deltoids,
and the orientation of the small basal in the right anterior position instead
of the left anterior as in other Crinoids with three basals, are all characters
which indicate a close relationship to the Blastoids. Ordovician ; Bohemia.
Silurian ; North America.
Fig. soy.
litKjilianocrinns angidatns Conrad. Sil-
208
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Family 2. Pisocrinidae
Aiigeliii.
Monocyclic. Basals three to Jive ; radials five, very unequal, the right posterior
and right anterior compound, left posterior and anterior usually
muck the largest. Arms simple, uniserial and composed of long,
cylindrical joints. Silurian and Devonian.
risorrimis de Kon. {Fig. 309, A). Calyx small, globose.
B five, unequal, forming a triangle. Only the large an-
terior, and the left posterior radial resting upon the
basals ; one large plate, the radianal, serves as inferradial
for both right posterior and right anterior radials, and
also meets the basals. Anal or first tube-plate above line
of radials, followed by a tube. Articular facets of the
radials impressed between vertical partitions formed by
the lateral margins of the plates. Tegmen I'arely pre-
served, but as observed by Wachsmuth and Springer in
P. pilula, consisting of five large symmetrical orals, above
which rises a narrow anal tube. Arms long, and com-
posed of extremely elongate, cylindrical ossicles. Silurian ;
Gotland, Dudley, England and North America (Niagara
Group).
Triacrinus Miinst. (Fig. 309, B). Dift'ers from the pre-
ceding in having but three B. Wachsmuth and Springer
have shown, however, that some of the Eifel specimens
occasionally have five B, thus leading to the inference that
Fig. 309. the two fomis are identical. Middle Devonian ; Eifel.
Calycanthocrinus Follmann. B three. Additional small
arm-bearing plates introduced between the radials. Lower
Devonian ; Germany.
and Slocum. Calyx elongate,
shallow, concave, filling a greater
A , Pisocrinus flcujeJlifer
Ang. Silurian ; Gotland.
a, Perfect specimen, r.
posterior view ; li, Calyx
seen from r. ant. side ; c,
From below, i/i (after
Angelin). B, Triacrinus
alius Mtill. Devonian ;
Gerolstein, Eifel. a,
Calyx seen from r. post,
side ~
Hypsocrinus Springer
B five. Arm facets wide
part of radial margin.
R. ant. radial has in-
ferradial distinct from radianal. Middle
Devonian ; North America.
Family 3. Haplocrinidae Roemer.
Monocyclic. Calyx small, pyriform to
globose. Basals five. Three of the radials
compound, the others, left posterior and an-
terior, simple, and much the largest. Orals
large, triangular to pentagonal, laterally in
contact. Arms five. Devonian.
Haplocrinus Steining. (Fig. 310).
Arm facets narrow, indented upon distal
face of radials. Arms small, simple,
uniserial, resting within deep grooves formed along the sides of the orals
Orals large, pentagonal, and laterally in contact; the posterior one inter
Fig. 310.
Haplorrinns mespilifonnis Goldf. Devonian ;
Gerolstein, Eifel. c, Calyx seen from one side:
/), Seen from aliove ; c, Seen from below ; il, Analysis
of calyx ; b, Basals ; x, the three nnsynimetrical
plates situated between basals and radials ; r,
Iladials ; hr, First arm-ossicle ; o. Orals (antmior
side to the right).
CLASS III CRINOIDEA 209
locking with the others, and pierced by a small anal opening. Mouth
subtegminal ; column composed of thin joints. Not uncommon in the
Middle Devonian of the Eifel and Nassau ; sparse in the Upper Devonian of
North America.
Family 4. Allagecrinidae Etlieridge and Carpenter.
Monocyclic. Calyx very small, sometimes almost microscopic. Basalsfive, radials
five, of irregular form and size. Some of the radials axillary and supporting two
arms ; others truncate and supporting hut one arm ; their articular facets provided
with transverse ridges and large muscle plates. Lower Carboniferous.
Allagecrinus E. and C. B completely anchylosed in the adult, and the
suture lines between the orals also disappearing with age. Stem largest next
to the calyx, rapidly tapering downward. Carboniferous (Kinderhook to
Coal Measures) ; Great Britain and North America.
Family 5. Synbathocrinidae Waclismuth and Springer.
Monocyclic. Calyx small, howl-shaped, composed of three unequal or of five equal
hasals, and five nearly equal radials. Tegmen formed hy five small, astjmmetrical
orals ; hetween these and the posterior radials arises a long anal tube, follotuing an
anal, or first tube-plate', resting on the shoulders of the posterior radials. Entire
upper edges of the radials bevelled off so as to form straight articular facets, which
are furnished with well-developed transverse ridges. Arms five, simple ; column
round. Devonian and Carboniferous.
Phimocrinus Schultze. The most primitive form of the family, having five
basals, and traces of transverse bisection of three radials as in Heterocrinus.
Devonian ; Europe.
Synhathocrinus Phill. {Lageniocrinus de Koninck). B three, unequal ; B five,
quadrangular or pentagonal. Anal tube long, slender, resting partly upon
the shoulder of the right posterior radial ; it is composed of a longitudinal
series of strong plates with a crescentic section on the dorsal side, and small
plates resembling perisome on the opposite side. Arms long, uniserial, and
composed of comparatively thick ossicles with sharp angular edges. Devonian
and Carboniferous ; Great Britain and North America.
Stylocrinus Sandb. Distinguished from Synhathocrinus mainly by the
character of the radial facets, which are directed obliquely downward and
inward, instead of upward and outward. Devonian ; Europe.
Storting ocrinus Schultze. Devonian.
Family 6. Cupressocrinidae d'Ovbigny.
Dicyclic. Calyx large, basin-shaped, composed of five equal hasals and five equal
radials ; the basals enclosing a central pentagonal plate, which represents five anchylosed
infrabasals. Upper faces of radials broad, truncate, and forming an even horizontal
line. Costals compressed, flange-shaped. A peculiar annular structure, the so-called
" consolidaMng apparatus " situated on the upper interior margin of the calyx between
the arm-bases. Arms five, simple, uniserial and closely folded ; they are composed of
broad, thick plates, united hy close sutures, and are traversed hy a well-developed
VOL. I P
210
ECHINODERMATA— PELMATOZOA
PHYLUM IV
dorsal canal. Column pierced hy a large axial and three, four or five peripheral
canals. Devonian. Represented by a single genus, which probably does not
belong to this suborder, but
whose systematic affinities have
not been satisfactorily deter-
mined.
Cupressocrimis Goldf. (Fig.
311). Tegmen flat ; the greater
part of it occupied by the so-
called consolidating apparatus.
This is composed of five
petaloid, horizontally trun-
cated interradial pieces, which
are laterally in contact, and
enclose a large, central open
space ; these are probably
modified orals, and served in
part for the attachment of
muscles. Five round aper-
tures, through which the
ambulacra entered the calyx,
perforate the divisions between
the consolidating plates ; one
showing plated poveiiiig of ambiilafial furrows, and doisal canals of the latter is pierCCd by the
perforating the ossicles ; f, Interior of calyx from above, showinfc -i • /j-\- qt'i \
the five consolidating plates, the lowermost containing the anal anal Opening (^r Ig. oil, C).
opening ;/, Radial pierced by ambulaeral opening, but with wall A«Tna nrnvirlprl witVi a wirlp
covering the same partly broken away ;./, Side-view of radial in -^imt. piUVlUtiU Wltu d. Wiue
which the ring-like covering of the ambulaeral opening is pre- aii(| cleCD Ventral furrOW, lined
served intact. '- , . . . ,
on both Sides with jointed,
closely abutting appendages ; of these there are several to each arm-plate,
thus showing that they are different from true pinnules. Middle Devonian ;
Eifel, Harz, Nassau and Westphalia.
Fig. 311.
Cu'pressocrlnus o-asxjt.s Goldf. Devonian ; Gerolstein, Eifel.
a, Perfect specimen, natural size ; b, Cross-section of column ;
c, Fused infrabasals ; d, Section through the folded-up arms.
Suborder 2. FISTULATA Wachsmuth and Springer.
Tegmen composed of nmnerous plates, consisting cither of orals with supra-fegminal
ambulacra passing over their edges, and interamlmlacra, or of more or less undiffer-
entiated plates without identifiable orals or ambulacrals. Posterior inter amhidacrum
usually more or less extended into a strongly plated anal tube or ventral sac. Arms
pinnulate or non-pimiulafe, usually uniserial, but biserial in some later genera. Base
monocyclic or dicyclic. Ordovician to Trias.
The Fistulata are characterised, in their typical genera, by a great development of the
jiosterior interradins, which is extended upward in the form of an anal tube or a ventral sac. In
the former case the anus is at the distal end ; orals are moie or less represented in the tegmen,
the posterior one being often i)erforated {'nuidrejiorite). In the latter the extension involves
almost the entire tegmen ; the plates of the sac are often perforated by small, round or slit-
like pores (respiratory pores) ; all traces of orals are lost ; and a curious reversal takes place
in the jiositiou of the anal oi)ening, which, instead of being at the distal end, or posterior, is
on the anterior side of the sac, either at the base, or part way up, sometimes through a
lateral spout.
In some of the early fimilies the radials are transversely bisected in one, two, or three
rays, producing comiiound radials, as in some Larviformia. When three radials are thus
compound they are usually in the right posterior, and right and left anterior rays ; but when
there is only one, it is constantly that to the right of the anal area, the right posterior. The
CLASS III CRINOIDEA 211
latter condition is the longest lived, persisting to late in the Carboniferous, while the former
did not survive the Devonian, and was chiefly confined among the Fistulata to Ordovician forms.
The superradial, or arm -bearing portion of the plate, is in some earlier forms much the
smallest part, resting on the right shoulder of the inferradial, or lower portion ; in others it
is nearer equal to, and directly in line with the inferradial ; in later forms it is pushed to the
right by the gradual increase in width of the posterior iuterradius or ventral sac.
The inferradial, because of its supporting the sac, as is usually the case among the later
forms, has received the name of radianal. Primitively, however, as was shown first by
Wachsmuth and Springer, and subsequently by Carpenter and Bather, the radianal represents
the lower portion of the right posterior radial ; and it has, therefore, nothing in common
with the anal plate, which is a specialised inferradial. The phases exhibited by the radianal
in its progressive structural development furnish excellent diti'erential characters. From its
jirimitive radial position directly under the right posterior ray, it shifts upward to a left
oblique position, and is then eliminated in the later Carboniferous, substantially parallel to its
course in the Flexibilia.
Under the Fistulata are included the following families ; Hyhocrinidae, Heterocrinidae,
Anomalocrinidae, Calceocrinidae, Catillocrinidae, Belemnocrinidae, comprising the monocyclic
forms ; and Dendrocrinidae, Crotalocrlnidae, Cyathocrinidae, with subfamilies Carahocrininae,
Gasterocominae and Cyathocrininae ; Botryocrinidae ; Poteriocrinidae, with subfamilies
Potcriocrininac, Graphiocrininae and Encrininae, comprising the dicyclic forms.
Family 1. Hybocrinidae Zittel.
Monocyclic ; basals five. Badials large ; the right posterior radial compound ;
the inferradial almost as large as the other radials, supporting on its right shoidder
the suj)erradial, and on its left the first plate of the tube, or anal plate, which does not
enter the dorsal cup. Ventral tube or sac in its most primitive form, extending but
little above the rest of t)ie legmen; superradial very smcdl, sometimes 'undeveloped.
Arm facet small, round, less than width of radial; arms simple, uniserial, non-
pinnulate. Orals large, with ambulacra resting on their adjacent edges ; posterior
one pierced by hydropore. Lower Ordovician.
Hybocystis Wetherby. Three of the rays bearing primitive arms composed
of but few joints, with ambulacral furrows passing from the ventral to the dorsal
side of the arms, and continued upon the surface of the R. The two other
rays are without arms, and the ambulacra follow the surface of the calyx, and
may pass down so far as to enter the basals. Anus through a
valvular pyramid surrounded by integument of small plates
between posterior oral and distal edge of the anal plate. Stem
round. Ordovician (Trenton) ; Kentucky and Canada.
Hyhocrinus Billings. Similar to Hybocystis, but with five
regular arms, and no recurrent ambulacra. Anus either
through a valvular pyramid or simple opening. Ordovician
(Trenton) ; Canada and Kentucky. ^^^- ^^2-
Hoplocrinus Grewingk (Fig. 312). Like the preceding, Hopiocrinus_ au
f . ® ^ .® ' . ■'■ ° pentus Gi'ewingk.
but with the inferradial sloping only to the right, and sup- Ordovician ; st.
porting a small, trigonal superradial. On the left it supports seeirfrom^the aiKd
small plates of the ventral sac, without the intervention of a wln^rkv'''^^'''^ *^^'^
larger plate. Ordovician ; St. Petersburg.
Baerocrinus Volborth. Like Hoplocrinus, but the right posterior and the
anterior ray without arms ; apparently inferradials only are developed.
Ordovician ; St. Petersburg.
Family 2. Heterocrinidae Zittel.
Monocyclic ; basals five. Calyx usually elongate conical. One or more of the
radials compound. The superradial of the right posterior ray supporting to the
212 ECHINODERMATA— PELMATOZOA phylum iv
right the primary brachials, and to the left an anal tube or sac ; the first plate of
this, corresponding to the anal x, may be entirely above the level of the radials, or, as
usually, may slightly indent their ujiper corners at the posterior interradial suture ;
hut never fully enters the dorsal cup. Arms non-pinmdate, uniserial, dichotomous or
heterotomous. Badial facets usually wide and straight. Tegmen not well known.
Ordovician and Silurian.
Heterocrinus Hall (Stenocrinus W. and Sp.). Crown subcylindrical, calyx
small. Three radials transversely, more or less equally bisected, or com-
pound ; these being, in addition to the right posterior, the right and left
anterior, or sometimes the anterior in place of the latter. Anal tube delicate
and straight ; first tube-plate resting on the shoulders of both posterior
radials, but not farther entering the cup. Arms irregularly dichotomous,
somewhat divergent. Stem pentagonal, quinquepartite, with interradial
sutures. Ordovician ; North America.
Ohiocrinus W. and Sp. Calyx and stem as in Heterocrinus. Arms hetero-
tomous, having ten main branches not in close contact, and somewhat sinuous,
with ramules which usually branch again. Ventral sac large, and usually
convoluted. Ordovician ; North America.
Ectenocrinus S. A. Miller {Heterocrinus W. and Sp., non Hall). Calyx about
as in the preceding. Arms heterotomous, with ten main branches, straight,
rather closely abutting, composed of a continuous series of syzygies of two
plates each, the epizygals giving off ramules. Stem round, tripartite.
Ordovician; North America.
locrinus Hall. Only one radial compound, the right posterior, the lower
part of which is of about the same size as the other radials, which are all large.
The superradial is short, resembling an axillary brachial, supporting on its
right shoulder an arm and on the left a series of plates forming the arm-like
dorsal ridge of a strong anal tube or sac, of complicated structure ; first tube
plate entirely above the level of radials, and not entering the dorsal cup at all.
Arms dichotomous, branching frequently. Stem pentagonal, quinquepartite,
with interradial sutures, the pentameres radially disposed. Ordovician ;
North America.
Herpetocrinus Salter {Ophiocrinus Charlesw. ; Myelodactylus and (?) Brachio-
crinus Hall). A specialised form with crown of the locrinoid type, habitually
enclosed by the coiled stem, whose structure is modified accordingly. The
crown is rarely seen, being bent backward, and usually closely enveloped by
the stem, which is then coiled arovmd it in the opposite direction. One ray is
dwarfed, either not branching or entirely aborted. The right posterior radial
alone is compound, the superradial supporting the series of tube-plates entirely
above the level of the radials, as in locrinus. Anal tube long and narrow,
composed of a series of heavy plates resembling brachials dorsally, with
perisome on the other side. Arms more or less irregularly dichotomous. The
stem could be tightly coiled, or uncoiled exposing the crown ; but the lattei-
condition is rarely found in the fossils. Eesulting from this the stem has lost
its cylindrical form, being more or less concave at one side, with its columnals
crescentric in section, and bearing on the horns of the crescents two longitudinal
rows of strong cirri. The remarkable resemblance of the coiled cirriferous
stem to a pinnulate arm has misled many students, for the crown is usually
concealed. Silurian ; North America and Europe.
CLASS III CRINOIDEA 213
, Family 3. Anomalocrinidae Wachsmiith and Springer.
Monocijdic ; basalsfive. Calyx broadly rotund in form. Tegmen strong, composed
chiefly of large modified amhvlacrals and interamhilacrals, extending posteriorly into
a large expanding anal tube or sac. Eadials very large, two of them — the right
posterior and left antero-lateral — compound, all of them laterally in contact ; inferradial
rarely larger than the superradial ; the lower tube-plate, or anal x, resting in the
angle formed by the superradial to the right, and the upper end of the simple radial
to the left, but not entering the cup. Radial facets circular and very small. Arms
relatively slender, uniserial, ami bifurcating several times at somewhat irregular
intervals. Small armlets given off from each arm-joint on one side only, alternately
in the successive dichotoms. Column strong, round, attached by an encrusting root.
Ordovician.
Anomalocrinus M. and W. {Ataxocrinus Lyon). The only genus of the
family. The statements heretofore current that one radial is often longi-
tudinally bisected, and that there is a small supplementary piece within
the basal ring, are based on abnormal specimens only, Ordovician ; North
America.
Family 4. Oremacrinidae Ulricli (Galceocrinidae M. and W.).
Monocyclic Inadunata, in which a bilateral symmetry along the left anterior
radius and right posterior interradius has been superinduced in conjunction with
bending of the crown on the stem in such a way that the right posterior interray lies
along the stem ; with the left anterior, right posterior and right anterior radials com-
pound ; with anal x (IRA) shifted over the right posterior radius, usually into the
right posterior interradius, and supporting a massive tube ; with three, rarely four,
arms, of which two are as a rule peculiarly modified and bear armlets or pinnules.
(From Bather, " The Crinoidea of Gotland.") Ordovician to Lower Carbon-
iferous.
Cremacrinus Ulr. (Castocrinus Ringueb.). B distinct, all entering into the
articular surface of the stem. The right posterior, and right anterior super-
radials joined by ill-defined close suture, each abutting with one side on the
adjacent large simple R. The lower plate of the tube supported by the
right posterior superradial only, while the right anterior superradial supports
the first brachial of the right anterior arm. The right posterior and right
anterior superradials separated from one another, and also from the ventral
tube, by the right posterior and right anterior R. Arms four. Ordovician ;
North America. Type, C. punctatus Ulr.
Euchirocrinus Meek and Worthen (Cheirocrinus Hall, non Eichwald ; Pro-
clivocrinus Ringueb.). B unfused, or perhaps sometimes the left posterior fused
with the left anterior one. The right posterior and right anterior super-
radials fused in a T-shaped piece, which abuts with either wing on the
corners of the large simple R. The right posterior and right anterior
inferradials separated from one another and from the tube by the T-piece ;
tube supported by the whole upper margin of the latter. Arms three.
Silurian ; North America. Type, E. chrysalis (Hall).
Deltacrinus Ulrich (Cheirocrinus Salter, nom. nudum ; Calceocrinus Hall em.
Ringueberg). Left posterior basal fused with the left anterior one ; the
214 ECHINODEEMATA— PELMATOZOA phylum iv
fused plates very rarely entering the stem articulation. The posterior and
right anterior basals bounded for some distance by the large B. T-plate
separated from the large simple R by the right posterior and right anterior
radials ; it is low, wide, and occasionally very small. Tv^be supported by
the T-piece and the two inferradials to the right, but not touching the two
large simple radials. Arms three. Silurian and Devonian ; Europe and
America. Type, D. clarus (Hall).
Halysiocrinus Ulrich em. Bather. B as in the preceding, but the fused
posterior and right anterior ones never entering into the stem articulation.
T-piece either obsolete or concealed between the right posterior and right
anterior inferradials, and the two large radials in the stem articulation.
Tube supported by the inferradials to the right, which are in contact, and
abutting by its lower corners on the two large simple B. Arms three. Bur-
lington and Keokuk Groups ; Mississippi Valley. Type, H. dadylus (Hall).
Family 5. Catillocrinidae Wachsmuth and Springer.
Base monocyclic; dorsal cup low and broad ; general symmetry of the calyx
greatly disturbed. Basals more or less fused, their number douUftd ; radials still
more irregular both in form and in size. Most of the arms given off from two of
the radials, which are sometimes five or six times larger than the other three ; they
are simple, quadrangular, non-pinnulate, and rest within small sockets directly upon
the radials. Anal plates wanting. Anal tube heavy, composed of very long,
longitudinally arranged crescent-shaped pieces, and supported directly by the radials ;
it exhibits a wide open groove along the anterior side, which probably was covered by
small delicate plates. Devonian and Lower Carboniferous.
Mycocrinus Schultze. Dorsal cup mushroom -shaped. Plates massive,
irregular, and without ornamentation. B two (according to Schultze), one of
them twice as large as the other, and the two forming a knob-like body. B
five, their inner edges resting upon the angular margin of the basal disk ; they
spread broadly outward from the B, extending far beyond them. The two
larger R separated at the posterior side by two equal smaller plates ; and at
the anterior side by a single plate having a quite narrow upper face. M.
boletus Schultze has apparently fifteen arms, their structure unknown. Middle
Devonian ; Eifel.
CatUlocrinus Shumard ex Troost (Nematocrinus M. and W.). Crown, when
the arms are closed, elongate, cylindrical. Dorsal cup basin-shaped, concave at
the base, truncate at its upper margin. Basal disk small. B five ; those
of the two antero-lateral rays fully six times as wide as the others, and
expanding upwards, so as to encroach upon the smaller ones. The larger B
support each twelve to sixteen arms ; the smaller ones rarely more than one
each. Lower Carboniferous ; North America.
Family 6. Belemnocrinidae Wachsmuth and Sjjringer.
Base monocyclic ; cylindrical to ovoid. B is composed of five large, elongate,
irregular pieces, and is pierced by a small canal which widens slightly at the upper
end. Badials five, quadrangular, and separated posteriorly by a narrow anal.
Ventral sac large, composed of hexagonal plates, the angles of which are perforated.
CLASS III CRINOIDEA 215
Arms long, giving off armlets alternately at intervals. Column round or pentagonal ;
in the latter case having its angles radially directed, and cirri which are interradial.
Lower Carboniferous.
Belemnocrinus White (Missouricrinus S. A. Miller). The only genus, very
rare. Burlington Group ; Mississippian area, North America.
Family 7. Dendrocrinidae Bather.
Dicyclic. Structure of legmen not well known, probably composed chiefly of
undifferentiated plates, more or less extended into a tube or sac, sometimes resembling
an arm proximally, and usually with anal opening at the distal end. Arms uniserial,
either dichotomous and strictly non-pinnulate, or heterolomous with main rami bearing
lateral ramules tending to incipient pinnulation. Loose, irregidar interbrachials
occasionally present in lower part of interradius in some genera. Radianal in
primitive position in form of radial under the right posterior ray. Badial facets
wide or narrow; mode of union with proximal brachials not well known, but
probably by modified or imperfect muscular articulation. Infrabasals five. Stem
■usually round, sometimes pentagonal and quinquepartite. Ordovician and Silurian.
This assemblage of early genera may be considered as a sort of composite family, in which
are embraced a number of characters which later became fixed as valid family criteria. They
are all primitive in the position of the radianal, and therein differ from all later Fistulata.
The presence of interbracJiials irregularly in some genera, e.g. Gupulocrinus and Otfawacrinus,
which are foreign to the Inadunata, indicates a close relation to the Flexibilia ; and as
Springer has shown, there are good reasons for considering the first of these genera as very
close to the ancestral type of the two orders.
Merocrinus Walcott. Arms dichotomous, branching. Eadial facets wide,
shallow, nearly straight. No anal plate in line with radials. Anal tube at
the base resembling an arm branching from the left side of the axillary right
posterior superradial. The genus might be considered as a dicyclic locrinus.
Ordovician ; North America and England.
Cupulocrinus d'Orb. (Scyphocrinus Hall, now Zenker). Arms and radial
facets about as in the preceding. Large anal x in line with radials, truncate
above, supporting a large tapering anal tube, with a median row of large
plates dorsally, bordered by perisome, rising only about half the height of
the arms. Small irregular interbrachials often present in primary axils.
Ordovician ; Canada and Kentucky.
Thenarocrinus Bather. Dorsal cup similar to the preceding, but radianal
slightly to left and touching infrabasals. Anal tube large and long, composed
of transversely folded plates, without median ridge or perisome. Silurian ;
England.
Dendrocrinus Hall. Radial facets narrow and semicircular. Arms dicho-
tomous, branching many times, and very slender. Anal x in line with radials,
angular above. Anal tube wide, long, composed of hexagonal plates in
vertical parallel columns. Ordovician and Silurian ; North America.
Oftaivacrinus W. R. Billings. Arms heterotomous, with ten main branches,
bearing lateral ramules, which may subdivide, or may approach the pinnulate
stage. Anal x in line with radials ; tube wide, rising the full height of the
arms. Radial facets wide and. nearly straight. Ordovician ; Canada.
Gothocrinus Bather. Similar to preceding, but with radial facets narrow
and curved, and shorter ramules. Silurian ; Gotland.
216
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Family 8, Crotaloci-inidae Angelin (emend. Wachsm. and Springer).
Dicyclk. Infrabasals five. Calyx resembling that of Cyathocriiius, but with
lower brachials more or less rigidly incorporated into dorsal cup by lateral contact
among themselves, with the radials, and ^vith tegmen plates. Tegmen composed of
numerous rigid plates, chiefly modified ambulacrals and interambulacrals, with orals
more or less exposed, ami alternating covering plates often very definitely arranged.
No interradials except at anal side. No radianal ; anal x in line with radials ;
anus directly through the tegmen or at the end of a short protuberance. Arms non-
pinnulate, uniserial. Axial canal in arms distinct. Stem large, round. Silurian.
The systematic position of this family is uncertain. The usual rigid incorporation of the
lower brachials in the dorsal cup by inclusion within the radial facet, and by connection
with solid tegmen, analogous to what is seen in camerate genera like Marsipocrinus and
Pterotocrinus, points to a connection with the Camerata, as claimed by Wachsmuth and
Springer. This feature is subject to considerable variation, being usually not so pronounced
in young specimens, in which the brachials are more nearly isolated. On the other hand the
resemblance in habitus of calyx to the Inadunata, as Bather has suggested, is equally
striking ; while the absence of pinnules in the arms seems to this reviser a strong reason
in favour of Inadunate affinities. The structure of the tegmen would place it close to the
Cyathocrinidae.
Enallocrinus d'Orb. Infrabasals five. Anal plate one, not always
truncating the posterior basal. Eadial facets wide and shallow, bearing
Fig. 313.
A, Crotalocrinufi imlcker Hising. (Anthocrinus loveni Miiller). Silurian ; Gotland. Crown witli folded arms.
/;, Portion of stem. C, Cross-section of four contiguous arm-ossicles of the network. D, Dorsal aspect of
arm-plates, showing their intimate union ; those above the two rows figured have been broken away so as to
expose the side-pieces and covering plates of the ambidacral furrows. A', Tegmen of G. rugosufi Miller (after
Angelin).
directly on their distal edge a triangular primibrach and one to three further
orders of brachials at each side. Arms long, frequently dichotomising, and
becoming free above the first few brachials. Silurian ; Gotland, England.
Crotalocrinus Austin (Anthocrinus Mii,ller) (Fig. 313). Similar to Enallo-
crinus, but arm-branches united by lateral processes from each brachial,
CLASS III
CRINOIDEA
217
forming a flexible network, which may be continuous all around the crown
or be divided into five broad, reticulate, fan-like fronds. In the calyx of
some young specimens the radial facet is narrow, semicircular, evidently
bearing the brachials in the usual succession. Axial canal distinct in arms
but not perforating radials, which are thin. Stem terminating in a thick,
branching root. Silurian ; Gotland, England and North America.
Pefalocritius Weller, from the Silurian of North America and Gotland,
with its arms united by lateral fusion into five ponderous fans, has some
resemblance to Crotalocrinus, but seems to have no- anal plate. It may be
nearer to the Gasterocrinidae.
Family 9. Cyathocrinidae Roeiiier (emend. Wachsin. and Springer).'
DicycUc. Tegmen strong, composed of rather large orals more or less exposed,
surrounding but not covering the peristome ; rigid amlndacrals supported on their
adjacent edges, meeting above the oral centre and often greatly modified ; and inter-
amhulacrals, which often encroach upon and obscure the other plates. Posterior oral
frequently a madreporite. Amis located either in the posterior interambulacrum
directly through the tegmen, or at the distal end of a plated anal tube, or dor sally
through the side of the cup. Arms non-pinnulate. Badial facets usually semi-
circular, less than the width of the radial. Union of radials tvith proximal brachials
usually by incomplete articulation upon undifferentiated joint faces, with concavo-
convex surfaces, without true transverse ridge, though with occasional traces of it.
Infrabasals usually five. Stem usually round.
Subfamily A. Carabocrininae.
Arms usually dichotomous ; heterotomous in some of the later genera. Radianal
obliquely to left of right posterior radial. Anal x present. Posterior oral usually
a madreporite. Infrabasals five. Stem usually round. Ordovician to Lower
Carboniferous.
m
Carabocrlnus Billings. PiA completely separating BB, and having a
supplemental plate intercalated below it, touching IBB. Anal x large,
line with radials. Anus directly through the teg-
men. Arms branching. Posterior oral pierced by
hydropore. Ordovician (Trenton) ; Canada and
Kentucky.
Strophocrinus Sardeson. Ordovician ; Minnesota.
Porocrinus Billings (Fig. 314), BA smaller, rhom-
boidal, not separating BB. Arms ten, unbranched.
Calyx plates deeply folded at the angles, but folds
do not cross the sutures or form true pore-rhombs.
Anus in a slight protuberance. Eeferred by some
authors to the Cystids. Ordovician ; Canada, Ken-
tucky and Eussia.
Palaeocrinus Billings. BA as in preceding genus.
Arms branching several times ; slender, rising from
a small curved facet. Anal tube small. Ordovician ; Canada and Kentucky.
Homocrinus Hall. RA as in preceding. Arms branching, strong ; radial
facets wider than usual in the family, nearly straight. Anal tube large,
Fig. 314.
a, Porocrinus conicus Billings.
Ordovician ; Ottawa, Canada.
Nat. size (after Billings) ; b, P.
radiafus Beyr. Ordovician ; St.
Petersburg. Calyx plates show-
ing folds at angles. Considerably
enlarged (after Beyricli).
218
ECHINODEEMATA— PELMATOZOA
PHYLUM IV
Silurian and Devonian ; North America
Similar to Homocrinus, but with
composed of numerous small plates
and Europe.
Badrocrinus Schnur, in Steininger.
narrower facets. Devonian ; Germany.
Etispirocrimis Angelin (Fig. 267). Dorsal cup conical. EA small, pent-
agonal. Anal X rising above level of ER, with a plate of the anal tube
partly in the cup beside it. Anus at the end of a strong tube. Arms
dichotomous, branching. Ordovician ; Canada. Silurian ; Gotland.
Closferocrinus and Ampheristocrinus Hall. Imperfectly known. Silurian ;
North America.
Sphaeroci'inus Eoemer. Dorsal cup globose. BA larger ; x not rising
above BB. Anus directly through the tegmen. Axial canal separate from
ventral groove in radials and brachials. Arms
unknown. Devonian ; Germany and England.
Parisocrinus W. and Sp. (Fig. 315, which is
reversed). Dorsal cup elongate. BA large ; x not
rising above level of BB. Anal tube very broad
and long, rising to height of the arms, composed
of hexagonal plates and profusely perforated with
pores at the sides of the plates ; anus at the distal
end, surrounded by a circlet of strong plates.
Arms dichotomous, branching frequently. Devon-
ian to Lower Carboniferous (Keokuk) ; Germany,
England and North America.
Vasocrinus Lyon. Calyx broad, hemispherical.
Arms heterotomous, with ten main rami bearing
strong ramules which may branch again ; the rami
divergent, and not in contact above the axillary
Anal tube broad below, rather short and tapering,
not divided, and with very small axial canal.
Pig. 315.
Parisoorimis curtus Mull. Devon-
ian ; Schonecken, Bifel. a, Calyx
from tlie anal side, showing ventral
sac and one arm which is recuper-
ated and abnormally small (right
and left sides reversed) ; h, Stem ;
c, Face of stem-joint (after Schultze).
primibrach. BA small.
Stem of moderate size,
Devonian to Lower Carboniferous (Keokuk) ; North America.
Barycrinus Wachsmuth. Calyx and arms as in Vasocriims, but rami and
ramules usually heavier. Eami in contact by one or two brachials above the
axillary. BA small, quadrangular, frequently entirely wanting, in which
case a small specimen cannot certainly be distinguished from Cyathocrinus by
the calyx alone, although in general the arm facets are larger, and directed
upward more than in that genus. Anal tube broad and short. Stem un-
usually large, quinquepartite, with a very wide axial canal. Specimens
attaining a large size. Lower Carboniferous (Lower Burlington to Warsaw) ;
Mississippian area. North America.
Goniacriims Miller and Gurley. Calyx small, elongate. Arms hetero-
tomous, with small ramules borne on ten main branches ; facets directed
upward. BA small. Anal x in line with radials, followed by others in a
prominent series between the posterior rays, passing into a tube. Lower
Carboniferous ; North America.
Atelestocrinus W. and Sp. Calyx elongate. Arms heterotomous, with
delicate ramules. BA of good size. Anterior ray is not arm-bearing.
Lower Carboniferous (Burlington) ; Mississippian area. North America.
CLASS III
CRINOIDEA
219
Fig. 316.
Gasterocoma antiqna Goldf. Devonian ; Priini,
Eifel. a, Calyx seen from one side ; h, Anal aspect ;
c, Tegraen. ^/i (after L. Scluiltze).
Subfamily B. Gasterocominae.
Ci/athocrinidae with no radianal. Anus through the dorsal cup, below level of
arm bases. Arms strong, round; facet horse-shoe shaped, directed outward, and
pierced by a distinct axial canal. Infrabasals usually undivided, exceptionally three
or five. Orals largely covered by modified ambidacrals ; posterior one a madreporite.
Stem round, with central axial caned surrounded by three or more peripheral canals.
A strongly specialised subfamily of short life, being limited, except for
Hypocrinus, to the Middle Devonian.
Gasterocoma Goldfuss {Epactocrinus and Ceramocrimis Joh. Midler) (Fig.
316). Infrabasal disk small, undivided. Anal opening lateral through the
dorsal cup, just above the posterior
basal, at the angle formed by that
plate and the two posterior radials,
usually fringed with a ring of small
plates ; one or more plates may lie
above it, connecting with the tegmen,
or these may be absent, leaving the
radials closely abutting. Axial open-
ing in infrabasal disk complex, consist-
ing of a central and three, four or five
peripheral canals, continued down into
the column. Stem round, with strongly alternating joints, the thin proximal
columnal more or less quadrangular. Arms not certainly known, but
divergent, directed outward, probably round and simple, with short brachials.
Middle Devonian ; Eifel: The remaining genera mostly agree with this in
the essential structures of the calyx.
Schultzicrinus Springer. Arms directed upward, simple, broad, abutting,
with long brachials following one very short primibrach. Devonian
(Onondaga) ; New York.
Arachnocrinus Meek and Worthen. Arms branching more than once.
Devonian (Onondaga) ; New York and Kentucky.
Nanocrinus Joh. Miiller. Only four arm-bearing radials. Arms unknown.
Scoliocrinus Jaekel. Three arm-bearing radials. Middle Devonian ; Eifel.
Achradocrinus Schultze. Infrabasals five, not fused. Axial canal simple,
without peripherals. Middle Devonian ; Eifel.
Hypocrinus Beyrich may belong here. Resembling Achradocrinus, but
with three infrabasals. Classed by authors as a Cystid. Permian ; Timor.
Myrtillocrinus Sandb. Has the general facies of this family ; undivided
infrabasal disk, a central axial with three or four peripheral canals ; round,
simple arms. But there are five large symmetrical orals in a pyramid con-
stituting almost the entire tegmen, leaving only small interoral grooves for
the ambulacra, — not preserved in any specimens. Anal opening not known,
probably minute, and obliterated by infiltration of calcareous matter in
fossilising. Middle Devonian ; Eifel and New York.
Subfamily C. Cyathocrininae.
Cyathocrinidae ivith no radianal. Anus at the ventral side, usually at the end
of a strong tube. Anal x, when present, in line with radials. Arms usually
220
ECHINODERMATA— PELMATOZOA
PHYLUM IV
dicJiotomo'US, and freely branching. Posterior oral usually a madreporite : other
orals often largely hidden by encroaching tegmenal plates. Infrabascds five, excep-
tionally three. Stem usually round. Silurian to Lower Carboniferous.
Gissocrinus Ang. (Fig. 317). IB three. Anal tube compressed, its plates
sliort, wide and folded. Distal margin of brachials usually project. Silurian ;
Gotland, England and North America.
Cyathocrinus Miller (Figs. 318, 319). Infrabasals five. Anal tube short
Fio. 317.
a, Gisf-ocrinits arthriticns Phill. Silurian ; Got-
land. Crown of the uatnral size (after Angelin) ;
h, G. imnctuosus Ang. Tegmen ; c, Ventral and
lateral aspect of the arms (enlarged).
r ft«
m^oo-tTt:i
Fic. 318.
C'yatliurrinn.s. Analysis of dorsal
cup (after Bather).
Fig. 319.
a, Cyathocrinus longimanus Ang. Silnrian ;
Gotland, Crown of the natural size (after
Angelin); h, C. ramosus Ang. Portion of an
arm viewed from the side ; c, Ventral aspect of
same (enlarged); d, C. malvaceiis Hall. Lower
Carboniferous ; Burlington, Iowa. Tegnien
perfectly preserved : e, The same after removal
of the covering pieces and orals (after Meek
and Worthen).
and rounded, or long with a valvular pyramid at distal end ; its plates more
or less hexagonal, not transversely elongate, nor much folded. Arms branch-
ing as many as five to seven times. Radial facets horse-shoe shaped, directed
outward, with occasional incipient transverse ridge. Ambulacral covering
plates well developed, regularly alternating, or modified so as to resemble
budding pinnules. Stem round, strong, short, apparently without cirri. A
well-known and widely distributed genus, occurring from the Silurian to
Lower Carboniferous (Warsaw) ; Europe and America.
Mastigocrinus Bather. Like Cyathocrinus in the structure of the calyx,
CLASS III
CRINOIDEA 221
but with longer arms and anal tube, which is more like that of the Poterio-
crinidae, probably with lateral opening. Stem quinquepartite. Silurian ;
England.
Strepfocrinus W. and Sp. {Ophiocrinus Ang. non Salter). Calyx like that of
Cyathocrinus. Anal tube coiled, opening probably at the side. Arms branching,
coiled inward, with peculiar processes called " false pinnules." Not well
understood. Silurian ; Gotland.
Leajthocrinus Joh. Midler {Taxocrimis hriareus Schultze) {Fig. 320). Arms
branching repeatedly. Anal tube long, with strong
plates in longitudinal columns. Stem subquadrangular,
with central and four peripheral canals. Infrabasals
small, unknown, may be undivided. Middle Devonian ;
Eifel.
Lophocrimis Meyer {Carduocrinus Koenen). Only
one arm to the ray, with small ramuli alternating from
every second brachial. Anal tube of delicate plates.
Upper Carboniferous ; Germany.
Codiacrinus Schultze. No anal plate in dorsal cup.
Infrabasals three. Eadial facets directed obliquely
outward, and with a separate dorsal canal. Arms
dichotomous, short and slightly developed. Calyx
obconical, expanding ,upward. Middle Devonian ; Eifel. ^^^, ^^^
Lecythiocrinus White. Known only from the dorsal i,,y,hncrivuseiMutnu.Mm.
CUD, which has the same elements as the preceding. Pfy'iiian ; Eifei. Restored
1' i-i 11 1 (after hclmltze).
Arm facets directed upward, Avithout dorsal canal.
Calyx bursiform, contracting at the arm bases. Upper Carboniferous ; North
America.
Family 10. Botryocrinidae Bather.
Dicydic. Tegmen composed of irregular plates without definite orals or amhula-
crals, extended posteriorly into a ventral sac. Badianal oblique, not touching h'asals,
variable in size. Anal x in line with radials. Arms usually heterotomous, hut
varying from ramuUferous to complete pinnulation. Articulation of first brae] da I on
radial imperfect, facets usually shallow, curved, not as wide as the radial. Silurian
and Devonian.
Botryocrinus Angelin (Sicyocrinus Aug.). BA small, quadrangular. Ventral
sac large, sometimes coiled, with anus below the coil. Arms heterotomous,
with two main rami bearing ramules which in some species reach the state of
pinnulation. Silurian and Devonian ; Gotland, England and North America.
Bhadinocrinus Jaekel. Calyx small, with very long ventral sac. Arms
relatively long and heavy, with ten main rami, bearing very small, branching
ramules at long intervals. Lower Devonian ; Germany.
Gastrocrinus Jaekel. Similar small calyx, with shorter sac, having longi-
tudinal columns of projecting plates. Arms long, with irregular dichotomy.
Stem with whorls of cirri. Lower Devonian ; Germany.
Cosmocrinus Jaekel (Cyathocrinus ornatissimus Hall). BA large. Ventral
sac very large, reaching as high as the arms. Arms heterotomous, with ten
main trunks having several branches nearly as large, toward the inside of the
dichotom, which in turn bear regular pinnules. Radial facets rather wide.
Devonian (Portage) ; New York.
222
ECHINODEKMATA— PELMATOZOA
PHYLUM IV
Maragnicrinus Whijtfield. From the same locality and horizon as the
last; differing from it in having narrower arm facets, the arms regularly
dichotomous, branching once, and the rami bearing pinnules directly.
Family 11. Poteriocrinidae Eoeiuer (emend. Waclism. and Springer).
Dicydic. Tegmen composed of undifferentiated ■plates, without identifiable orals
or amhulacrals ; more or less extended into a ventral sac, with amis heloiv the distal
end on the anterior side. Union of radials with first brachials usually by complete
muscular articulation, upon straight facets as loide as the radial, with fossae, paired
muscles and ligaments, and transverse ridge {exception in Poteriocrinus, a transition
form). Arms pinnulate, mostly dichotomous. Infra-
basals five, exceptionally three, or coalesced into one.
Stem usually with cirri. Devonian to Permian.
Subfamily A. Poteriocrininae.
Radianal in oblique position. Anal x usually in
line with radials. Arins iisually uniserial, tending to
biserial in later genera ; dichotomous or heterotomous.
Infrabasals usually five. Crown usually elongate,
expanding upward. Stem usually round, occasionally
pentagonal. Devonian to
Upper Carboniferous.
Poteriocrinus Miller.
Radial facet usually
curved, less than width
of B, with imperfect or
no transverse ridge.
Arms dichotomous,
branching frequently.
Ventral sac large and
long, usually rising be-
yond the arras. Stem
usually round, without
cirri, at least in upper
part. (?) Devonian and
Lower Carboniferous
(Keokuk) ; Euroi:)e and
North America.
The Devonian species
referred to this genus are
probably Farisocrinus ;
without the arms being
Fig. 321.
Paohyl OCT inns unicus Hall. Lower
Carboniferous (Keokuk Group) ; Craw-
fonlsvillr, Indiana. Natural size.
Fio. 322.
Pachylocrinus sp. Analysis of dorsal
cup. a, Anal x; a', Right tube-i)late ;
/(, liasals ; (7>, Infrabasals ; -/•, Right and
left jjosterior radials ; ra, Radianal.
Pig. 323.
Pachylocrimia acqualis Hall.
Lower Carboniferous (Keokuk
Group) ; Crawfordsville, Ind.
Complete crown from posterior
side, showing base of ventral sac
and mode of arm-branching.
preserved tliis cannot be
certainly determined. The
genus lacks the complete
muscular articulation characteristic of the family, but is otherwise typical.
Pachylocrinus Wachsmuth and Springer (Scaphiocrinus auctt., non Hall =
Graphiocrinus ; Ilydriocrinus Trautschold ; Abrotocrinus M. and G.) (Figs. 269,
321-3). Radial facets of this and all succeeding genera normal for the family.
CLASS III
CRINOIDEA
223
Calyx obconic to low cup-shaped. Arms branching two to four times, usually
more or less dichotomous, but in some species the inner arms of the dichotom
branch less frequently than the others, or remain simple, tending to the stage
of heterotomy seen in genera like Zeacrinus. Brachials cuneiform. Ventral
sac strong, usually enlarging distally. Stem
round or pentagonal, with cirri moderately devel-
oped. Carboniferous (Kinderhook to Upper Car-
boniferous) ; North America, Europe.
This is a widely distributed form known in collections
genei'ally as Scapkiocrinus, a name which lapses because
the type species belongs to the previously established
Grcqyhiocrinus. It is one of the longest lived Paleozoic
genera, represented by a large number of species, and is
highly typical for this family.
Woodocrinus Koninck (? Philocrinus Koninck)
(Fig. 324). Similar to preceding, but brachials
short, quadrangular, arms usually heavier and
branching two to four times. Ventral sac stout
and apparently short. Stem short, tapering
distally, with scattered cirri. Lower Carbonifer-
ous; England.
Zeacrinus Hall. Crown more or less ovoid,
often short, rounded' above and below. Arms
heterotomous, usually closely abutting and infold-
ing ; the two outer branches of each ray the
stoutest, giving off at intervals successive pin-
nulate arms of nearly equal size and reaching to
the same height, always to the inside of the
dichotom, usually unbranched, but they may
divide. Brachials short, quadrangular. Ventral
sac short, usually diminishing upward. Stem
round, bearing long cirri distally. Carboniferous
(Kinderhook) to Coal Measures ; Mississippian
area, North America.
Coeliocrinus "White. Crown elongate, expand-
ing upward, with conical base. Arms as in
Zeacrinus, but not so closely abutting, and with
brachials cuneiform to interlocking. Ventral sac
inflated, balloon-shaped. Lower Carboniferous
(Burlington) ; Mississippian area. North America;
also Russia.
Hydreionocrinus Koninck. Crown short, flat
above, with concave base. Arms branching some-
what as in Zeacrinus, but very short, not rising
above the expanded rim of the sac ; brachials
interlocking to fully biserial. Ventral sac mushroom-shaped. Upper part of
Lower Carboniferous (Kaskaskia) to Coal Measures ; Belgium, Britain and
North America.
Decadocrinus W. and Sp. Calyx depressed and base flat or concave. Arms
strictly isotomous, branching but once, giving two strong, pinnulate rami to
the ray, more or less angular or zig-zag. Brachials wedge-shaped, the longer
Fio. 324.
Woodocrin lis macrodac-
tylus (de Koninck). Per-
fect specimen from the
Lower Carboniferons of
Yorkshire (after de Kon-
inck).
224
ECHINODERMATA— PELMATOZOA
PHYLUM IV
alternating sides bearing stont pinnules which are well separated, resembling
ramules. Ventral sac large, often almost as long as the arms. Stem rela-
tively small, sub-pentagonal, with rather plentiful cirri. Devonian and
Lower Carboniferous (Keokulv) ; North America and Europe.
Aulocrimis W. and Sp. Like the preceding, but ventral sac forked, with
anal opening from a lateral spout. Stem sharply pentagonal, with cirri.
Keokuk Limestone ; Indiana.
Scytalocrinus W. and Sp. Similar to Decadocrinus, but with calyx usually
elongate, more or less conical base, arms cylindrical, and pinnules closely
packed. Stem large, round, with cirri sparse and mostly distal. Devonian
and Carboniferous (Coal Measures) ; North America and Europe.
Agassizocrinus Shumard ex Troost MS. {Astylocrinus Roemer) (Fig. 325).
Calyx elongate, ovoid to pyriform. Arms ten, with pinnules closely packed,
as in Scytalocrinus ; bi'achials quadrangular, becoming
cuneiform distally. Ventral sac unknown. Lifrabasals
five, in mature specimens fusing to a rounded undivided
base. Stem entirely wanting, but probably present in
early stages. Carboniferous (Kaskaskia to Coal Measures)
Mississippian area ; North America.
Cromyocrinus Trautsch. (Figs. 326,
327). Calyx rounded below, but not
concave. IB large, visible exteriorly.
Arms five, or ten, stout, not branching
beyond the first axillary. Brachials
quadrangular to cuneiform, tending to
become biserial. Ventral sac incon-
spicuous. Stem round. Lower Car-
boniferous ; Russia and Mississippi
Valley area.
Ulocrinus Miller and Gurley. Similar
to Cromyocrinus, but with anal x entirely
above the radials ; that is,
with radianal but no anal
in the dorsal cup. Arms
unknown. Upper Carbon-
iferous ; North America.
Eupachycrinus Meek
and Worthen. Similar to
Cromyocrinus, but calyx
low, rounded, with concave
base ; infrabasals at bot-
tom of a funnel. Arms ten to twenty. Brachials quadrangular to biserial.
Stem round, with cirri. Kaskaskia to Upper Carboniferous ; North America
and Europe.
Tribrachiocrinus M'Coy (Pentadia Dana). Calyx globose. Infrabasals three,
large. Radials irregular in size and form, apparently only three arm-beaiing.
Arms unknown. Permo-Carboniferous ; Australia.
Fio. 32(5.
Cromyocrinus glohulux
M. and W. Lower Car-
boniferous ; Chester, 111.
Natural size (after Meek
and Worthen).
Fio. 325.
Agassizocrinus laevis
(Roemer). Kaskaskia
Group ; Illinois, a, Com-
plete crown, after Roe-
mer in Bronn, somewhat
restored ; b, Ventral as-
pect of the coalesced
infrabasal disk ; c, Side-
view of same, nat. size
(after M. and W.)
<yi^.
Fig. 327
Analysis of plates in the dorsal cuji of
Cromyocrinus. i,b, Infrabasals ; b, Basals ;
7", Radials ; ra, Radianal ; a, a', a", Anal
and lower tnlie plates (after Bather).
CLASS III CEINOIDEA 225
Subfamily B. Graphiocrininae Bather.
No radianal. Anal x more or less between radials. Arms dichotomous, uniserial
to biserial. Infrabasals usually Jive, frequently minute, hidden by the column. Stem
usually round, cirriferous. Lower Carboniferous to Upper Carboniferous.
Graphiocrinus K.on. (Scaphiocrinus I{a\l ; Phialocrinus TrsLutschold ; Aesiocrinus
Miller and Gurley) (Fig. 328). Calyx low, turbinate or obconic to bowl-
shaped. Infrabasals minute to fair size. Arms
uniserial, usually long, slender, branching once,
sometimes unbranched in one or more rays, making
the number variable from five to ten. Brachials
quadrangular. Ventral sac very large and con-
spicuous. Stem round, with long cirri throughout.
A genus of great stratigraphic range and wide . , . ,^'",.' .
o o ° -*■ , ° __ ^ Analysis 01 Graphiocrinuf:. %h,In-
distribution. Lower (Kinderhook) to Upper Car- frabasais;6, Basais ; r, Radiais ;
boniferous ; North America, Belgium and Russia. Bather). ' ' '^^'^"^'' '^^
Bursacrinus Meek and Worthen. Calyx obconic.
Arms rather broad, closely abutting, branching twice or more, to some extent
as in Zeacrinus ; uniserial, with quadrangular brachials. Ventral sac incon-
spicuous. Very rare. Lower Carboniferous (Burlington) ; Mississippian area,
North America.
Delocrinus Miller and Gurley (Cerioerinu.s White, non Koenig). Similar to
Gra'phiocrinus, but with concave base, ventral sac inconspicuous, and heavy
biserial arms. Axillary primibrach frequently protuberant or spiniferous.
Lafrabasals at bottom of a deep funnel, hidden by column. Stem rather small,
round, cirriferous. Upper Carboniferous ; North America.
Cibolocrinus Weller. Dorsal cup low, bowl-shaped. Lifrabasals three.
Other parts unknown. Permian ; Western Texas.
Subfamily C. Encrininae Austin (emend).
Dorsal cup ivith perfect pentamerous symmetry, having no radianal or anal
plate. Arms dichotomous, biserial ; usually heavy, and two to the ray. Ventral
sac inconspicuous or wanting. Lifrabasals Jive, coalesced into one, or atrophied.
Calyx usually low, bowl-shaped, with rounded or more or less concave base. Stem
usually round. Lower Carboniferous to Trias.
Stemmatocrinus Trautschold. Base broadly rounded. Infrabasals coalesced
into a large flat pentagon. No anal x nor tube-plate visible in cup. Arms
ten, thick, closely abutting, and strongly resembling those of Encrinus
liliiformis. Lower Carboniferous ; Russia and North America.
Erisocrinus White. Base rounded, with but little concavity. Infrabasals
five, fairly large, not in a funnel, usually visible outside of the stem. Anal
a; or a tube-plate rests on the upper surface of posterior radials. A close
derivative from Delocrinus, which it resembles in the arms and general form,
differing in the base and absence of anal plate in the cup. Upper Carbonifer-
ous ; North America.
Encrinus C. F. Schulze (Chelocrinus, Calathocrinus v. Meyer ; Flabellocrinus
Klipstein ; (?) Cassianocrinus Laube ; (?) Traumatocrinus Wohrmann ; Porocrinus
VOL. I Q
226
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Dittmar iion Billings) (Figs. 329-331). No anal x noi^ tube-plate visible
Calyx low, with base more or less concave.
Infrabasals five, minute, concealed in the basal
concavity, sometimes reduced to three, or atro-
phied. Arms usually ten, exceptionally twenty;
uniserial at their lower ends, but soon becoming
biserial ; separate axial canal in radials, extend-
ing into the arms. Tegmen not definitely
known. Stem round, apparently without cirri.
Abundant in the Trias, especially in the
Muschelkalk of Germany. The stem fragments
of E. liliiformis frequently form beds of marine
limestone (Trochitenkalk). p^^ g^r,
„, . „ 1 • J- 1 1 ii • -4- DiaL'iam showing course of axial canals
This genus was formerly associated by the majority in the calyx and arms of 7?»cr wins. Canals
of European authors with the Recent Crinoids under the represented by dotted lines when pene-
Articulata. It was shown by Wachsmuth and Sijringer tratinj; the interior of the plates, and by
that its rehxtions are clearly with the later Paleozoic ':::^l^X^^t,^m^'' '"""
Inadunata, and its position as such is recognised by
most recent writers. The type species, E. liliiformis, by reason of its striking appearance
///• 1 2
hr-i
Fig. 330.
Encrinus Uliiformin
Miller. Mnschelkalk ;
Brunswick.
Portions of the calyx and arms of Encrinus. a, Interior
of calyx ; a', Exterior of same ; b, Basal, upper surface ;
r, Radial, inner surface ; j3. One of the uniserial, and (3*, bi-
serial arm-i^lates ; both of them traversed by duiilicate
dorsal canals ; p, Pinnule ossicle (enlarged) ; hi; First
brachial, under surface ; ftfi 2^ First and second brachials
joined together ; inside, seen from below ; hr^, First brachial,
upper surface, showing line of syzygial suture ; hr'^, Second
brachial (axillary), showing articular facets.
and beautiful preservation, early attracted the attention of observers. The generic name
was first applied in 1760 ; and the form is the best known of all fossil Crinoids.
Order 4. ARTICULATA. J. S. Miller (emend. J. Miiller).
Tegmen coriaceous, studded with minute calcareous particles, which may he quite
invisible externally, or may he enlarged into well-defined plates that rarely form a
complete investment. Mouth and food grooves exposed, hut often bordered with one
or two rows of side and covering plates capable of being closed down over them.
Orals present in the young, often also in the adult. Plates of the dorsal cup, except
CLASS III CRINOIDEA 227
in pelagic forms, massive, and, except in the pelagic forms, much reduced in size.
Badials and arm-plates perforated hy separate dorsal canal. Base in most cases
actually or potentially dicyclic ; the infrahasals, and sometimes also the hasals,
being often atrophied, radically altered by resorption and subsequent rebuilding, or
absent altogether.
Proximal columnal always modified, usually enlarged, attached to the
calyx by close suture, to the columnal below it also by close suture (the
so-called stem-syzygy) ; but this pair of columnals in some forms, instead
of maintaining the original connection with the calyx, is separated from it
by varying intervals in the stem, or at least in its proximal portion. Union
between the plates of the dorsal cup is by close suture, between the radials
and the primibrachs by muscular articulation, and between the elements of
the primibrach series by non-muscular articulation. Eadials always in lateral
contact. Eadianal and anal plates may be represented as such in the larval
stages, but never in the adult ; and the anal occasionally develops into a sup-
plementary radial, bearing a typical post-radial series indistinguishable from
those on the other radials. Arms uniserial and pinnulate, though the basal
pinnulation is often defective. No concavity in the apex of the dorsal cup
for the reception of the stem. Stem reduced to a single columnal in the
Comatulid division of this order. Lias to Recent.
In tlie earlier German and English editions of this work, following the example
of previous European authors generally, the Mesozoic and Recent Crinoids (excepting
Marswpites, Uintacrinus, and perhaps Encrinus) were treated as a distinct group from
the Paleozoic under the name Articulata, proposed by J. S. Miller for the Apiocrinidae,
Encrinidae and Penfacrinidae, and extended by Johannes Miiller to include the
Comatulids. The chief characters relied upon to distinguish the order, viz. (1) an
open mouth and food grooves, (2) a separate axial or dorsal canal perforating the
arms, were admittedly indecisive, considering that the first belongs ec^ually to the
entire Paleozoic group Flexibilia, and the second is shared by a Devonian family and
several genera of the Inadunata.
This evident inadequacy of the definition has led to various proposed substitutes
for the plan, such as placing the Pentacrinidae under the Fistulate Inadunata, and
the Comatulids together with the Apiocrinidae, etc., as a subdivision (" Pinnata ")
under the Flexibilia. None of these has proved satisfactory ; least of all the last,
for the lack of any sirfRciently definable connection between the so-called Pinnata and
the Paleozoic Flexibilia. The very j)liant calyx of the latter recurs in the pelagic
Comatulids, Marsupites and Uintacrinus, and the close lateral union or partial
incorporation of lower brachials is found to some extent among the Apiocrinidae,
Pentacrinidae, and some Comatulids. But it has become increasingly evident that
the Flexibilia were a specialised group, derived from the Inadunata, and ending like
the Camerata with the Paleozoic.
The only one of the primary divisions of the Crinoids that seems to have survived
is the Inadunata, the most generalised type, from whij^i all the post-Paleozoic forms
are evidently descended. While, therefore, there is no valid ground for any such
divisions as Paleocrinoidea and Neocrinoidea, as j>roposed by Wachsmuth and Spiinger
and by Carjjenter, but afterward abandoned, yet it cannot be denied that, with the
sole exception of the Triassic Encrinus, the known Crinoids of Mesozoic to Recent
times have an assemblage of features by which they are In'oadly distinguished from
their Paleozoic ancestors. And it is believed that this may be expressed under the
group Articulata as enlarged Ijy Johannes Miiller, distinguished not by any single
character peculiar to itself, but by the fact that a large number of charactei's belonging
228 ECHINODERMATA— PELMATOZOA phylum iv
to different groups of Paleozoic Crinoids, and by which they were differentiated, have
become fixed and generally constant in this. It is by the combination of a number
of well-marked characters, therefore, that the definition of this group, as herein given,
becomes logically effective.
The results obtained during recent years from the study of the Crinoids collected
by a large number of deep-sea expeditions, have thrown an entirely new light upon
the relative importance of the Recent and fossil forms, and have shown that there exists
to-day a wealth of generic and specific types hitherto quite unexpected. In order to
call attention to the relative importance of the fossil and recent types, and to bring to
the notice of paleontologists the work which has been accomplished on the latter, it
has seemed advisable to include mention herein of a considerable number of Recent
genera. As the paleontologist is most directly concerned with the stalked genera
among living forms, short definitions of these are given ; the unstalked living genera,
which are much more numerous, are mentioned by name only.
The Pentacrinids and the Comatulids form two groups which are in every way
strictly parallel, and are of substantially the same phylogenetic value, though depart-
ing in exactly opposite directions from the parent stock. The Pentacrinids are
characterised by excessive stem growth ; the larval stem is lost at a very early age,
but new columnals are continuously formed, with great rapidity, so that a stem of
enormous length results. The distal portion of this stem is continually dying away,
so that the actual length of the stem in any individual is but a fraction of the entire
length which has been formed during growth. In living Comatulids the larval stem is
similarly lost ; but after this takes place no additional columnals are formed ; stem
growth continues within the single columnal which remains attached to the calyx ;
this becomes greatly enlarged, and puts forth numerous cirri. Comatulids may
therefore be described as Pentacrinids in which the entire stem is reduced or limited to
the compass of a single columnal, and in which the cirri (when present), unable to
arrange themselves in whorls on regularly spaced nodals, are closely packed together
on a single nodal.
The genus Thiolliericrinus is exactly intermediate between the Pentacrinids and
the Comatulids ; the stem is developed just to the point at which the two groups
diverge, at that point ceasing further .growth, as in the Comatulids, but being retained
as in the Pentacrinids. The structure of the stem is the same as that of the larval
stem of the Pentacrinids and of the Comatulids.
The Pentacrinids and Comatulids are the dominant Crinoid forms in the modern
fauna. The latter especially are extremely numerous, and exist in a vast array of
diverse types, none of which, however, depart in any great degree from the general
structure of the grouji ; so that their classification necessitates the creation of numerous
subfamilies, families and higher groups which are not systematically comparable to
similar groups in the stalked forms..
In order that the treatment herein adopted may be more easily understood, the
following comparative table is given, which shows in heavy-faced type the names
employed by P. H. Carjoenter in the Challenger reports and largely used by paleon-
tologists, together with their modern equivalents.
1. Pentacrinus : Isocrinus, Ce§ocrinus, Endoxocrinus, Hypalocrinus, Carpenterocrinus.
2. Extracrinus : Pentacrinus.
3. Antedon : All the genera wliich were known to Carpenter now included in the families
Zygonictridae (excepting Eudiocrinus), Himerometridae, Stephanometridae, Pontiometridae,
Mariainetridae, Colobemetridae, Tropiometridae, Calometridae, Thalassometridae, Charito-
metridae and Antedonidae (excepting Promacliocrinus).
4. Actinometra : All genera included in the Comasteridae.
5. Eudiocrinus : The genus Eudiocriniis of the Zygometridae, together with Pentametro-
criniis of the rentanietrocriaidae.
6. Promachocrinus : The genus Promachocrinus of the Antedonidae, together with
Decametrocrinus of the Pentametrocrinidae.
CLASS III
CRINOIDEA
229
Family 1. Bourgueticrinidae cle Loriol.
Column without terminal stem plate, but the distal portion of the stem hears very
numerous radicular cirri. It is slender, composed of joints which may be greatly
elongated with strongly concave sides, or about as long as broad with strongly convex
sides, or of any intermediate form ; but the articulating surfaces ahoays consist of a
strong fulcral ridge (which may be interrupted in the centre by the central canal)
separating two large ligamental fossae ; one or more of the columnals immediately
under the calyx may be discoidcd, with plane surfaces. Dorsal cup small, hut very
variable in size and in the relative proportions of its component plates ; composed of five
basals (lohich may he solidly welded into a single plate), and (usually) five radials.
Infrabasals unknown, probably absent in the adidt. Arms slender, five or ten ; if
the latter, two primibrachs are present. If there are four, six, or more radials, one
undivided arm follows each radial. Cretaceous to Recent,
Bourgueticrinus d'Orb. (Fig. 332). Basals not fiised. Eadials five ; lower
brachials laterally connected. Proximal columnal round, as wide as the calyx
Fig. 332.
Bourgueticrinus elUpti-
cus Mill. White Chalk ;
Wiltshire, a, Calyx with
stem-joints, i/i ; 6, Ventral
aspect, enlarged ; c, Stem-
joints ; d, Articular sur-
face of stem -joint ; e.
Cirrus.
I)
h 'M
Fig. 333.
Khizocrinus pyriformis (Goldf.). Eocene ; Verona.
a, h, Calyx from one side (nat. size and enlarged) ;
c, Same from_ above, with three of the Br in place;
d, Median longitudinal section of calyx, i/i ; e, Calyx
with slightly abraded outer surface, showing suture
lines between B and R ; /, Calyx with five rays, seen
from above (enlarged) ; g-k, Stem-joints, i/i.
at its greatest breadth, those below it diminishing for one or two joints and
becoming compressed, with elliptical joint faces, each columnal twisted so that
one end stands at an angle to the other. Cirri present distally, or perhaps in
middle of the stem. Cretaceous ; Europe and Alabama.
Mesocriniis P. H. Carpenter. Proximale small and circular ; otherwise like
Bourgueticrinus. Cretaceous ; Sweden and Germany.
(?) Dolichocrinus de Loriol. Eadials form an elongate tube. Upper Jur-
assic ; Europe.
Bhizocrinus Sars (Conocrinus d'Orbigny, non Troost) (Fig. 333). Basals com-
pletely fused, forming a very large and elongate base ; radials very small, four
to seven (usually five or six) ; arms undivided ; column slender, composed of
greatly elongated segments of which the distal bear radicular cirri. Cretaceous ;
N"ew Jersey. Eocene ; Europe. Recent ; north Atlantic.
Bythocrinus Doderlein. Similar to Bhizocrinus, but with the basals separated
by distinct sutures ; radials (and arms) invariably five. Recent ; in tropical
Atlantic, and western Indian Oceans.
Democrinus Perrier. Similar to Bhizocrinus, but with the base subcylindrical,
230
ECHINODEEMATA— PELMATOZOA
PHYLUM IV
the basals being separated by distinct sutures ; columnals very short, but
little longer than broad, more or less barrel or bead shaped ; radials (and
arms) invariably five. Eecent ; trojjical Atlantic and East Indies.
Bathycrinus Wyv. Thomson [Illycrinus Danielssen and Koren ; Pterocrmus
Wyv. Thomson). Essentially similar to Rhizocrinus, but with ten arms, each
post-radial series dividing on the second ossicle ; basals usually much reduced,
forming a narrow ring beneath the much larger radials. Eecent, chiefly occur-
ring at great depths, cosmopolitan.
Monachocrinus A. H. Clark. Similar to the preceding, but with the basals
separated by distinct sutures, and usually nearly or quite as large as the
radials, sometimes larger. Lower Muschelkalk ; near Rovegliana. Eecent ;
East Indies, Bay of Bengal, east Atlantic.
Family 2. Phrynocrinidae A. H. Clark.
Similar in general to the Bourgueticrinidae, but with the stem attached to a heavy
terminal stem-plate (dorsocentral) as in the Apiocrinidae. Eecent.
Here are placed the two genera Naumachocrinus and Phrynocrinus Clark,
occurring at depths of from 500 to 650 fathoms in the Pacific Ocean. The
former of these has a calyx superficially resembling that of Bemocrinus, but
composed of very small basals and much elongated radials.
Family 3. Apiocrinidae d'Orbigny.
Column without cirri ; enlarged distally and attached to a heavy terminal plate,
or fixed root ; composed of short, discoidal columnals having their articular faces
marked with radiating striae without fulcral ridge ; those next below the calyx often
increasing greatly in width, forming a proximcd enlargement continuous with the sides
of the calyx. In the more highly
specialised types the proximal colum-
nals may become pentagonal or
stellate, and may bear rudimentary
cirri. Calyx variable, composed of
heavy plates. Infr aba sals greatly
reduced, modified or fused with the
proximal cokimnal ; visible rarely
tvitliin the basal ring (crypfodicyclic).
Lower brachials more or less incor-
porated in the calyx by lateral union,
or by a few interbrachial plates.
Primibrachs two ; arms branching
regularly, usually more than once.
Jura, Cretaceous and Eecent.
Apiocrinus Miller (Figs. 334-
336). Plates of calyx greatly
thickened, especially at the distal
border of the radials, where the typical muscular articulation is modified
by an enormous enlargement of the dorsal ligamental fossa, consequent upon
such thickening ; this expansion aff'ects in addition to the calyx, a series of
the upper columnals, and of the lower brachials. Calyx in typical foi-ms
IJan-
Firi. 334.
Apincnmift 'jiarkivftnni Sehlothcim. Great Oolite
ville, Calvados. <(, Calyx and upper sttiiii-joiuts, viewed J'rorn
the side ; '-, Ventral aspect ; c, Articular surface of one of the
stem-joints (natural size).
CLASS III
CEINOIDEA
231
pyriform, attaining a large size, with proximal columnals flush with the
curvature of its sides ; in some others globose, with little enlargement of
the column. Upper face of the proximale marked by angular ridges corre-
sponding to the interbasal suture lines. Radial facets wide, curved,
occupying entire distal face of plate. Primibrachs two, united by incom-
plete sj^'zygy, closely joined laterally by suture, or occasionally connected
by small interbrachiaJs ; axillary and succeeding brachials united by muscular
Fig. 335.
Fio. 330.
Fig. 335.
Apiocrinus parhinsoni Schloth. Great Oolite; Ranville, Calvados. A, Analysis of calyx, showing eomse
of canals. These are represented by dotted lines when concealed within the plates, and by heavy lines where
visible on the inner surface of the basals. B, Median longitudinal section through the uppermost stem-joints,
.showing empty space included between them ; h, Basal, seen from above ami from the inside ; &*, Lower surface
of same ; r', Radial, seen from without; ri*. Inner aspect of same ; r^, and ?•-*, Corresponding views of first
brachial ; br, Arm-plates. (Canals are invisible in plates above the basals, except where they have become
exposed by weathering or abrasion.)
Fig. 336.
Apiocrinus roissyanus d'Ovh. Upper Jura (Coral-Rag) ; Tonnerre, Yonne. Restoration (after d'Orbigny).
articulation, and all perforated by an axial canal. Arms dichotomous,
branching two or three times, pinnules strong. The column has a large open
space in the expanded portion next to the calyx, the columnals sloping to a
thin edge toward the centre. Jurassic ; England, France and Switzerland.
Millericrinus d'Orb. (Ceriocrinus and Pomatocrinus Desor, ex Koenig). Closely
allied to Apiocrinus, but the swelling of calyx plates affects only one or two
columnals, and not any brachials, nor the distal border of the radials, which
remains narrow, so that the muscular articulation is of the usual type.
Calyx usually more or less globose or campanulate. Base occasionally with
232 ■ ECHINODERMATA— PELMATOZOA phylum iv
five minute iiifrabasals coalesced with the top stem-joint, which is frequently
widened and those below it not usually so. Column more or less pentagonal,
with the angles directed interradially. Lias to Lower Cretaceous ; Europe.
Guettardicrinus d'Orb. Differs from Apiocrinus only in having strong
interbrachial plates between the lower brachials, and the consequent incor-
poration in the cup of a greater number of secundibrachs. Upper Jurassic ;
Europe. This and the two preceding genera shade into one another Avithout
any sharp differentiation.
Dadocrinus Meyer. Calyx conical, of small size. Column sharply
pentagonal proximally, becoming round below, without cirri ; proximal
columnal much smaller than the calyx. Primibrachs sometimes more or less
connected by small interbrachials. Arms branching once. Trias ; Europe.
Holocrinus Jaekel. Trias ; Germany.
Jchrochordocrinus Trautschold (Cyclocrinus d'Ovh., no7i Eichw.; Mespilocrinus
Quenst., non Koninck). Jura and Lower Cretaceous ; Europe. Columnals
only are known.
Proisocrimos A. H. Clark. Rudimentary cirri on proximal portion of the
column ; proximal columnals with crenulate edges ; division series very
broad, in lateral contact. Eecent ; Philippines, 940 fathoms.
Carpeiiterocrmus A. H. Clark. No trace of cirri ; proximal columnals with
smooth edges ; division series narrow, exposing large perisomic areas.
Recent ; southern Japan, 565 fathoms.
Family 4. Pentacrinidae Gray (emend.).
Column either very long, pentagovcd or sidipent agonal, without any terminal plate,
and cirriferous; or represented by a single plate, also usually cirriferoiis ; in very
young stages similar to the stem of Bhizocrinus, but later discarded; the portion
retained in the adult of sessile forms is composed of columnals which have the upper
and lower faces ornamented with a more or less complex quinquelobate figure. Calyx
small, howl- or plinth-shaped, with a dicyclic base, at least in the young, but the
infrahasals either rudimentary or completely resorbed in the adult state; and the
basals may be also resorbed and metamorphosed into a curious rosette-shaped plate
lying entirely within the calyx. Infrahasals {where observed) three or five ; basals
five; radials five (one, the left posterior, sometimes much smaller than the others).
Primibrachs, or costals, one to eight (usually tivo). Tegmen flexible, studded with
small irregular calcareous particles or delicate plates which may be quite invisible to
the naked eye, or may form a solid covering. Arms pinnulate ; strong, from five
simple, to two hundred and fifty or more ultimate branches. Trias to Recent.
Section A. Pentacrinids Gray (emend.).
Column persistent throughout life.
Pentacrimis Blumenb. (Extracrinus Austin ; Polycerus Fischer pars ; ? Chlado-
crinus Agassiz) (Fig. 337). IBB well developed. BB usually prolonged
over the proximal columnals. There are rarely more than two IBr, not bearing
pinnules. Arms heterotomous, with two to four rami, branching only toward
the inside of the dichotom, into large subordinate pinnulate ramules which
rise to the height of the main rami, until the final divisions are all about the
same size ; these divisions are very numerous, in mature specimens as many
as forty oi- fifty to the ray. Column more or less pentangular ; the angles
CLASS III
CRINOIDEA
233
of the axial canal, contrary to the general rule in dicyclic forms, directed
radially, corresponding with the outer angles of the stem. Stem of great
but unknown maximum length, having been traced for twenty feet without
reaching the end ; cirri very numerous, compressed or elliptical in section.
Lias and later Jura ; Europe.
The Crinoids of this genus were
very gregarious, and flourished in
immense colonies. Exquisitely pre-
sci'ved specimens are found in the
Lower Lias of Lyme Regis, Eng-
land, and in the vicinity of Boll
and Metzingen, Wiirteraberg, which
have served as types of illustra-
tions in numerous works on Paleon-
tology. A slab containing no less
than twenty-seven perfect crowns
intertwined with stems and cirri,
may be seen in the U.S. National
Museum at Washington.
Isocrinus Meyer (/sz's Linn.
pars; Encrinus Lamarck ^ars;
Cainocrimis Forbes ; Pideto-
crinus de Loriol ; Neocrinus
Wy V. Thomson ; Fentacrinus
sensu P. H. Carpenter). IBB
so far as known, present in
the adult, but visible only
when stem is removed. BB
forming a complete circlet,
or ^minute and separated by
lower angles of BE. Eadials
not projecting downward over
proximal columnals. Arms
about regularly dichotomous.
Columnals of circular, penta-
gonal or stellate section ;
sectors of joint-face distinctly
petaloid, with coarsely crenu-
late edges. Trias and Juras-
sic ; Europe and North
America. Recent ; West
Lidies (5-531 fathoms).
Balanocriims Agassiz in
Desor. Columnals of circular
or hexagonal section, with crenellae around the edge only, not along the
sides of the sector. Trias to Eocene ; Europe. Known from fragments only.
Austinocrinus de Loriol. Columnals have a joint surface as in Isocrinus,
but with finer striae radiating from the petals. Cretaceous ; Europe.
Cenocrinus Wyv. Thomson. Recent; West Indies (5-531 fathoms).
Endoxocrimis A. H. Clark (Diplocrinus Doderlein). Infrabasals resorbed
in the adult. Arms heterotomous, in two main rami with branches to the
inside of the dichotom ; the divisions are at the outer side of the rays only,
and consist each of two joints, united by syzygy. Recent ; West Indies.
Fia. 337.
Fentacrinus {Extracrinus) fosslUs Blum. Lower Lias ; Lyme Regis,
England (after Goldfuss). a, Stem-joints of P. subangularis Mill.
Upper Lias ; b, Colnmn of P. hasaltiformis Mill. Middle Lias.
234 ECHINODERMATA— PELMATOZOA phylum iv
Metacrimis P. H. Carpenter. Arms dichotomous, multibrachiate ; IBr
four to eight in number. The distal portion of the arms bears only
rudimentary pinnules. Recent ; Pacific Ocean.
Hypalocrinus A. H. Clark. Ten arms only, unbranched ; IBr two. The
distal portion of the arms bears only rudimentary pinnules. Recent; East
Indies.
Comastrocrinus A. H. Clark. Resembles the preceding, but with more
than ten arms, and with the distal edges of the brachials strongly produced.
Recent ; Indian Ocean.
Section B. Thiolliericrinids A. H. Clark.
Column persistent throughout life; but columnar development ceases after the
formation of the first nodal.
Thiolliericrinus Etallon. Column resembling that of the pentacrinoid
larvae of the Comatulids, but greatly enlarged and thickened ; calyx as in the
adult Comatulid. Jurassic and Cretaceous ; Switzerland, France, Portugal.
The genus Thiolliericmms has been considered both as representing a primitive Comatulid,
and a transitional stage between the Apiocrinidae and the Pentacrinidae ; but neither view
is correct. The column of Thiolliericrinus is comparable to that of a Comatulid or of a
Pentacrinid at the time of the formation of the centrodorsal or of the first cirriferous nodal ;
stem development has here abruptly ceased, so that the column has retained its primitive
Bourgueticrinoid character, modified only by an increase in size ; but the calyx has continued
to develop so as to be comparable to the calyx of the Comatulids, or to the calyx of the
more advanced among the Pentacrinids. Thus Thiolliericrinus possesses the calyx structure
of the adult Pentacrinid or Comatulid, combined with the column structure of the larvae of
the same types. It therefore falls naturally between them.
Section C. Comatulids Fleming (emeiid.).i
Column either wanting entirely, or discarded after the formation of the first
nodal, which remains permanently attached to the calyx.
While the Comatulids, as already explained, forin a group strictly comparable in
pliylogenetic value with the Pentacrinids and Thiolliericrinids, this grouj) is
wholly disproportionate to those in complexity and extent. Owing to their enormous
and cosmopolitan development in Recent seas, the Comatulids require for their
classification further subdivision in a way not applicable to any of the fossil families.
The group nuist therefore be taken as a new unit, divisible into subgroups which are
comjiarable in rank only inter se, and not with subdivisions of similar giade or
terminology among the other Crinoids.
Tribe 1. Innatantes A. H. Clark.
Pelagic Comatulids in which the hasals are not metamorphosed hut form an
integral part of the body wall ; the infrabasals are not united with the central plate,
hut frequently, through individiml variation, they are absent. There is no evidence of
attachment in any known material, so that their central apical plate probably repre-
^ Literature : MilUer, J., Ueber die Gattung Comatnla, etc. Abhandl. Berlin. Akad. 18 17. —
Liuhvig, II., Beitriige zur Anatoniie der Criiioidea. Zeitsclu-. wiss. Zool. vol. xxviii. 1877. —
Carpenter, P. II. Report on the Crinoidea. Sci. Results Chall. Kxped., xi. and xxvi. , 1884-88. —
Jaekel, 0., Entwurf einer Morpliogenie und Phylogenie der Criuoideen. Sitzber. iiatnrf. Ges., 1894.
— Clark, A. II., See titles cited under general discussion.
CLASS III
CRINOIDEA
235
sents the single columnal of Comatulids and the entire stem of the Pentacrinids.
The calyx is very large, and its plates, which are very thin, are strongly curved out-
wardly. Cretaceous.
Subtrilje A. Marsupitids d'Orbiguy.
Column wanting, probably represented by a large pentagonal plate called the
centrale,^ within the infrabasal circlet. Calyx large, p)("ifectly p)entameroiis, composed
of large thin plates, without interradials or anals ; greatest bulk belovj radials. Base
dicyclic plus the centrale, one of the largest plates in the calyx. Infrahasals five,
very large. Eadial facets narrow, crescentic, with a perforated transverse ridge.
Lower brachials much less than the width of ^
the radials, connected for a short distance
by interbrachials, but not strictly incorpor-
ated in the dorsal cup. Primibrachs two,
narrow. Arms small, apparently short,
with slender pinnules ; bifurcation on the
second primibrach, further branching un-
known. Tegmen unknown.
The only known genus is Mar-
supites Miller {ex Mantell MS.), occur-
ring in the Upper Cretaceous (White
Chalk) of England, France and Northern
Germany, and in the Tombigbee Sand-
stone of Northern Mississippi. Its
general structure is on the Inadunate
plan, with remarkable development of
the basal portion, the infrabasals and
centrale constituting about half of the entire calyx (Fig. 338)
Fig. 338.
Marsujntes testudinarius (Schlotli). Upper Cre-
taceous ; Ijiineburg, Prussia, a, Calyx, natural size ;
h, Raciial, and a few of the arm-plates ; '•, Tips of arms.
Subtribe B. Uintacrinids Zittel.
Column wanting. Calyx large, perfectly pentamerous, greatest bulk above line
of radials, plates thin; interbrachial system greatly developed. Base dicyclic or
monocyclic; infrabasals present or absent in both young and adult of the same
species ; when present, five (but sometimes by resorption reduced irregidarly to three,
two, or one), very small, enclosing a small centrale, probably representing the stem ;
when absent, the centrale remains of about the same size, surrounded by the basals.
Interbrachials numerous, from the radials up, and often also in the second axil.
Primibrachs two, as large as the radials ; the secoml one axillary, followed by secundi-
brachs almost as large, passing gradually into free arms. Arms ten, unbranched,
very long and strong ; composed of very short, almost circular brachials, with frequent
syzygies, joint faces provided with transverse ridge, and pierced by an axial canal.
Pinnules stout and tapering, the lower ones incorporated into the calyx by lateral
union. Tegmen composed of a carbonaceous skin becoming black in the fossil state,
traversed by uncalcified ambulacra ; mouth margined ; anus subcentrcd, through a
strong, tufted tube.
^ This plate is supposed by Carpenter to represent the distal plate of the stem, ami not the
proximal. A. H. Clark believes it, and the similarly situated plate in Uiniacrinus, to be the
homologues of the distal stem-plate, plus all the columnals of young Recent Comatulids.
236
ECHINODERMATA— PELMATOZOA
PHYLUM IV
Fig. 339.
Uiiitaerinus westplialiciis (Schliit.). Upper Cretaceous ; Reck-
lingshausen, Westphalia, a, Calyx viewed from the side ; h,
Inferior aspect. Natural size (after Schliiter).
Represented by a single genus, Uintacrinus Grinnell (Fig. 339), occurring
in the Upper Cretaceous of Western America (especially Kansas), England
and Westphalia. In the latter
areas it is widely distributed,
accompanied by Marsupites
and B our gueticr inns. In the
Kansas region it is found ex-
clusively in colonies which
had been herding together in
\/ deep water. The genus in its
calyx structure is a survival
of the Flexibilia plan ; it is
strongly in contrast with
Marsupites in this, and in the
length of the arms, which in
mature specimens attained a
length of four feet, giving
when outstretched a spread of upwards of eight feet, the largest known
Crinoid.
Tribe 2. Oligophreata A. H. Clark.
Bottom-inhabiting Comaiulids, stalked when young; basals metamorphosed into
a rosette ; infrabasals unknown ; cavity in the centrodorsal containing the chambered
organ, and overlying structures very small, these being pushed up more or less within
the radial circlet ; disk more or less studded, or even completely covered, with large
calcareous concretions or plates: pinnules, at least the lower, wholly or in part
prismatic, and composed of short segments ; usually more than ten in number.
Generic names have been applied to fossil Comatulids belonging to this
division, but the specimens upon which they are based are rarely well enough
preserved to admit of correlation with generic names based upon Recent types.
The latter include a surprisingly large number of living genera, which are
grouped by A. H. Clark in nearly a dozen different families. Among these
may be mentioned the Comasteridae, Zygometridae, Thalassometridae and
Charitometridae as examples.
Tribe 3. Macrophreata A. H. Clark.
Bottom-inhabiting Comatulids, stalked lohen young ; basals usually metamorphosed
into a rosette ; infrabasals, three, or more usually five, in number, have been detected
in the young of several species, where they fuse with the centrodorsal ; cavity in the
centrodorsal containing the chambered organ and associated structures large ; tegmen
naked, or studded with minute plates which may become grouped in the interradial
angles, particularly between the IBr ; pinnules all cylindrical or more or less
flattened, slender, with very long joints ; arms five or ten in number, except in the
genera in which there are ten radials, in which they may he twenty.
Within this category are embraced three divisions — Atelecrinidae (Bather),
Pentametracrinidae (Clark) and Antedonidae (Norman) — the last-named of
which is again divided into a number of groups having the rank of sub-
families. One of them, Antedoninae, includes the Recent genera Antedon
CLASS III
CRINOIDEA
237
Freminville {GanymedAi Gray ; Hihernula Fleming ; Phytoorinus Bio.) (Fig.
283) ; Compsometra, Toxometra and Iridometra A. H. Clark, etc.
Fossil Comatulid Genera.
The following genera are based wholly or in part upon fossil Comatulids :
AUionia Michelotti ; Asteriatites Schlotheim ; Astrocoma Blainville ; Comatu-
lina d'Orbigny ; Comatulithes
von Schlotheim; Comaturella
Miinster; Decacnemos'Evonn;
Decameros d'Orbigny, Geo-
coma 0. Fraas; Glenotremites
Goldfuss; Hertha Hsigenow,
Microcrinus Emmons ; Ophi-
urites von Schlotheim; Ptero-
coma L. Agassiz ; Solanocrinus
Goldfuss (Fig. 340).
The specimens upon
which the type species of
these genera are founded are
rarely well enough pre-
served to admit of reference
to any one of the Eecent
genera, or even families, and
in some cases it is doubtful
whether they are Coma-
tulids at all. P. H. Car-
penter attempted to differ-
entiate the fossil types into
Antedons and Adinometras ;
but recent discoveries have
shown that the endocyclic
and exocyclic forms are
by no means easy to dis-
tinguish, even with perfect
specimens, and with even
the best Dreserved fossils J"''^; Streltberg, Franconia; b, Ventral; c, dorsal ; and d, lateral
Liic uc jj ^ aspect of calyx ; e, Arm-plate.
the separation of the species
on this basis is very unsatisfactory. A common method of procedure in
dealing with fossil Comatulids has been to refer them all (except those with
five arms, all of which belong to the genus Eudiocrinus of the Zygometridae)
to a single genus, for which the name Solanocrinus is used.
e'
Fig. 340.
a, Siilanocrimis cnstatiis Goldf. Upper Jura (Dicer.is-Kalk) ; Kel-
heiiii, Bavaria. Dorsal aspect of crown ; centrodorsal and xiinuules
not preserved (slightly reduced) ; h-d, S. scrohiculatus Goldf. Upper
Family 5. Plicatocrinidae Zittel.
Basal circlet funnel-shaped, quadrangular, pentagonal or hexagonal, composed of
three (usually), or five bascds which may be solidly anchylosed. Badials four, five,
six or eight (rarely seven), long and thin, bearing the post-radial series of brachials
on a narrow facet, which occupies only a small portion of their distal edge. Arms
long, undivided or branching one or more times ; the first branching iisualhj on the
238
ECHINODEEMATA— PELMATOZOA
PHYLUM IV
first brachial, never on the second. If the arms are undivided the pinnules are
usually excessively long and reach to the arm tips ; hut the length of the pinnules
decreases in proportion to the number of arm divisions ; pinnulars sometimes tending
to fuse into a solid piece. Column as in the Apiocrinidae, but never with a proximal
enlargement.
Plicatocrinus von Miinster (Fig. 341). Radials comparatively thin, their
articular facets crescent-shaped ; the outer faces longitudinally folded into
a median ridge. Arms ten, dividing on the first brachial ; composed of
wedge-shaped ossicles united by perforate muscular articulation. Pinnules
composed of a single piece, except the proximal ones, which consist of three
pieces ; they are angular or keel-shaped along the dorsal side, and deeply
A _ . o _ :i> furrowed on the ventral. Teg-
men unknown. Upper Jura; a
rare form, found in the Fran-
conian and Swabian Alb.
Hyocrinus Wyv. Thomson
(Fig. 342). Three basals ; five
arms, bearing extremely long
pinnules which reach to the
arm tips ; brachials united in
syzygial groups of three. Teg-
men composed of five large
orals, surrounded by heavily
plated perisome. Recent ;
Antarctic Seas.
Gephyrocrimis Koehler and
Bather. Similar to Hyocrinus,
but brachials united in syzy-
gial groups of two ; proximal
portion of column pentagonal.
Recent ; Canaries and Madeira.
Thcdassocrinus A. H. Clark.
Similar to Gephyrocrinus, but
proximal portion of column
hexagonal. Recent ; Philip-
pines.
Ptilocrinus A. H. Clark.
Five arms, unbranched ; each brachial, except the most proximal, bears a
pinnule ; syzygies very infrequent ; pinnules not especially long. Recent ;
Antarctic Seas and west coast of America to British Columbia.
Calamocrinus A. Ag. Five brachials ; the arms branch several times.
Recent ; Galapagos Islands and Central America.
Pig. 341.
Plicatocrinus hexagonus Miinst. Upper
Jura ; Streitberg, Franconia. a, Calyx with
radials and undivided base ; &, c, Dorsal and
lateral aspects of same (slightly enlarged) ;
d-f. First brachial, seen from the inside, out-
side, and from below respectively.
am
-OJ;
Fig. 342.
Hyocrinus hethelUanus Wyv. Thomson. Recent; Atlantic
Ocean. A, Individual twice the natural size. B, Tegmen several
times enlarged ; am, Ambulacral furrows of the arms ; c, Dorsal
canals ; an, Anus ; m. Mouth ; o, Orals (after Wyville Thomson) ;
*', Covering plates of ambulacral grooves.
Family 6. Saccocomidae d'Orbigny.
Calyx small, hemispherical, non-pedunculate, composed almost exclusively of
five radials, which are very thin, elevated into prominent ridges along the median
line, and enclose an extremely small hasal plate. Arms 5x2, slender, widely
separated, and giving off alternately toivards the extremities simple incurving
branches. Arm-plates cylindrical; each side of the ambulacral furrow lined with
CLASS III
CRINOIDEA
239
wing-like or spiniform projections. The entire skeleton exhibiting a reticulated
structure with coarse meshes. Upper Jura.
The only known genus, Saccocoma Ag. (Fig. 343), occurs profusely in
the Lithographic Stone of Eichstiidt and Solenhofen, Bavaria. It is a
Scwrocomu pecllnata Go]d(. Upper Jura (Kiinnieridgian) ; Ek-hstadt, Bavaria, a, Individual, natural size;
h, Side view of calyx ; c, Calyx seen from below, -/j ; </, Two of the lower arm-plates ; e, Two arm-plates of a
higher order with one of the branches ; /, The upper part of one of the arms straightened out ; g. Lower
brachials of S. tenella Goldf. (Figs, d and f/ greatly, the others slightly enlarged.)
free-swimming form, whose affinities with the monocyclic Plicatocrinidae were
first clearly demonstrated by Jaekel in 1892.
Family 7. Eugeniacrinidae Zittel.
(Coadunata Miller; Holopocrinidae p.p. Jaekel.)
Calyx composed of five {rarely three, or four) thick, rigidly united radials, resting
upon a proximate composed of fused hasals and top stem-joint ; basals invisible,
tegmen unknown. Costals compressed, flange-like; united by syzygial sutures, or
fused with one another. Arms robust, and incurving, usually branching on the
second brachial. Stem short, destitute of cirri, and composed of but a few long
cylindrical joints with granulated or striated articular faces ; terminating in a more
or less lobed, encrusting root. Lias to Lower Cretaceous ; Europe.
Eugeniacrinus Miller (Symphytocrinus Konig ; Caryophyllites of pre-Linnaean
240
ECHINODERMATA— PELMATOZOA
PHYLUM IV
authors) (Figs. 344, 345). Dorsal cup small, saucer - shaped, and with
shallow body-cavity. Proximale covered with five radiating ridges. B
invisible when the proximale is attached, but from the course of the axial
canals (Fig. 344) it is apparent that they are pushed upward so as to be
completely enveloped by the B. The latter are very heavy, closely united,
and sometimes completely anchylosed. The lateral margins of their upper
faces are extended upwards so as to form conspicuous projections ; the inter-
mediate spaces are occupied by transverse ridges and deep fossae. Costals
two, the upper one axillary. Structure of arms
unknown. Abundant in the Ui^per Jura, notably
in the Spongitenkalk of Southern Germany,
Switzerland, France and the Carpathians. Less
common in the Dogger and Lower Cretaceous of
the Alps.
Tetracrinus Miinst. B typically four, rarely
three or five ; apparently reposing directly upon
the column, as no B or IB are visible. Upper
face of the proximale marked by four (sometimes
three or five) prominent ridges which are radially
Fig. 344.
Euiieniacriiius airyophyllat'us Miller. Upper Jura ;
Streitberg, Franconia. a, Calyx with eentrodorsal,
seen from one side (nat. size) ; h, c, Ventral and dorsal
aspects, 3/2 ; d, d*, First brachial, inner and upper
surface ; e, Second brachial, seen from the inside (nat.
size), f-h, E. nutans Goldf. ■ Same locality ; /, /*, First
and second Br fused together, seen from the outside
and inside, respectively ; g, Arm-plate, figured in four
positions ; /(, Dorsal and lateral aspects of an inrolled
arm.
Fig. 345.
Eugeniacrinus caryophyllatus
Miller. Upper Jura, a. Restora-
tion, without the arms (after
Fraas) ; b, Calyx broken open to
show the silicifled axial canals
(after Jaekel).
disposed ; lower face bearing radiating peripheral striae, which are not con-
tinued over the median portion of the plate. B with transverse ridges and
large muscular fossae. Stem-joints barrel-shaped. Upper Jura ; Europe.
Gammarocrinus Quenst. {Sderocrinus Jaekel). Dorsal cup massive, concave
below. Upper Jurassic ; Europe.
Gymnocrinus Loriol. First axillary remarkably developed. Upper Jura ;
Europe.
Phyllocrinus d'Orb. Dorsal cup globose ; B with narrow articular facets,
at either side of which are long, upright projections. Upper Jura and Lower
Cretaceous, notably in the Mediterranean district.
Torynocrinus Seeley (Cyrtocrinus Jaekel ; (?) Hemicrinus d'Orb.). Dorsal
CLASS III CRINOIDEA 241
cup and proximale fused ; ventral surface bent to one side. Upper Jura and
Lower Cretaceous ; Europe.
Trigonocrinus Bather. Oxfordian ; Europe. Tormocrinus Jaekel. Small
radial facets, rounded interradial spines, and deep cup cavity ; the former has
less than five rays. Eocene ; Europe.
Eudesicrinus Loriol. Stem reduced to two short, thick segments which bear
the five R directly. Arms stout, branching on the first brachial. Lias ; Europe.
■
Family 8. Holopidae Zittel.
Base monocyclic ; stemless. Dorsal cup heaker-shaped, and formed of five fused
radials, hy which the body was either directly attached, or more frequently it was
supported hy a solid mass representing fused, ^ ^
overgrown or absorbed basals. Tegmen com-
posed of five large triangtdar orals sur-
rounded by a narrow band of perisome.
Arms five x two, unhranched, p)innulate,
strongly incurving, and composed of large
thick plates. Pio. 34(5.
Of the forms belonging to this family a, b, CotyUdenna docens Oeslongch. upper Lias ;
Cotylederma Quenst. (Cotylecrinus Des- ^'^^^■,:\^Ti^^''q:^"^^8\
long.) (Fig. 346) is found in the Lias: Asselllngen; Baden 'c, Ceutrodorsal ;y, circlet of
ri !• 1- n /TXT fused basals. (All tigures of the natuial size).
tyathidium Steenstrup [Micropocnnus
Michelin), in the Cretaceous and Tertiary ; and Holopus d'Orb. occurs both in
the Tertiary of Italy, and Kecent in the Caribbean Sea, where it inhabits
shallow water.
Range and Distribution of the Crinoidea.
The discoveries of recent years have brought to light an unexpected
profusion of crinoidal life in the present seas, showing that instead of being
a decadent and expiring race, as hitherto supposed, the Crinoids still con-
stitute a vigoroiis stock of cosmopolitan distribution. They are represented
by about 650 species, falling into 100 genera, which are distributed among
twenty families and nine additional subfamilies ; about 580 of these species,
included in eighty-five genera and in fourteen families and nine subfamilies,
are unstalked forms or Comatulids, the dominant type of the present fauna,
while about seventy species, included in fifteen genera and six families, are
stalked forms.
The stalked Crinoids attained their maximum development during the
Paleozoic era. Three of the principal orders — the Camerata, Flexibilia and
Inadunata — are, with the exception of the genus Encrinus, wholly confined to
the Paleozoic rocks, although the characteristics of the two last-named orders
have continued in more or less modified forms. The Articulata, on the other
hand, appear first in the Trias, and are represented continuously to the
present time.
Crinoids, as a rule, have but a very local distribution, but occasional
species are common to two continents ; in certain formations detached stem-
joints and calyx plates occur so profusely as to become of considerable rock-
building importance, and strata aggregating many feet in thickness are fre-
quently met with which are almost wholly constituted of Crinoid remains.
VOL. I R
242 ECHINODERMATA— rELMATOZOA phylum iv
While the great majority of Eecent stalked forms are deep-sea inhabitants,
the Paleozoic, on the contrary, often characterise shallow water deposits, and
are especially numerous in the vicinity of fossil coral reefs. Of the Mesozoic
Crinoids, the Eugeniacrinidae and Plicatocrinidae, whose remains are commonly
associated with those of Hexactinellid and Lithistid Sponges, probably lived
at considerable depths ; while, on the other hand, the Encrininae, Apiocri-
nidae, Saccocomidae and Holopidae, were undoubtedly shallow water forms.
Crinoidal fragments have been detected in the Cambrian, but consist of
stem-joints only. The Ordovician of England also yields a variety of stem-
joints, and well-preserved calices of Hyhocrinus and Baerocrinus occur in rocks
of the same age in the vicinity of St. Petersburg. In North America, the
Trenton and Hudson River limestones are locally very rich in Crinoid
remains. The Silurian localities of Dudley, England, and especially the
island of Gotland, Sweden, are famous for the surprising abundance and
exquisite state of preservation of their fossil Crinoids. The Swedish
forms alone comprise forty-three genera and 176 species. The Silurian
of North America, notably the Niagara Group, likewise contains a large
variety of forms, many genera being identical with those of England and
Gotland.
The best -known Devonian localities are the Eifel, Ehineland ; Nassau,
Westphalia ; the Ardennes and Department of Mayenne, France ; the Asturias,
Spain ; and New York, Michigan, and the region about the Falls of the
Ohio River, in North America. The Lower Carboniferous Limestone of Tournay
and Vise, Belgium, and that of England, Ireland, and the vicinity of Moscow,
Russia, are occasionally charged with exceptionally well-preserved crinoidal
remains. But the most famous of all horizons is the Lower Carboniferous
Limestone of North America, where in particular the localities of Burlington,
Iowa, and Crawfordsville, Indiana, have acquired a world-wide celebrity.
The Upper Carboniferous contains large areas of crinoidal limestone, but
well-preserved specimens occur rarely, the most notable being at Kansas City,
Missouri ; some interesting forms from that horizon are found in Australia.
The Permian has yielded but a few genera, and those, so far as yet known,
belong to the Inadunata. A remarkable Crinoid fauna of this age has also
been discovered in the Island of Timor.
^'-From the Trias only the Encrininae and a few species of Pentacrinus are
as yet known. The remaining members of the Articulata make their appear-
ance in the Jura and Cretaceous, and with the exception of the Eugenia-
crinidae and the Saccocomidae, the families are still represented in the existing
fauna.
[The text for the entire subphylum Pelmatozoa has been revised by Mr. Frank Springer
of East Las Vegas, New Mexico, and Washington, D.C. The treatment of the classes Cystoidea
and Blastoidea is substantially the same as in the former edition of this work, but tliat of the
Crinoidea reflects the great progress in onr knowledge of this group that has been made
during the past decade. In that part of the revision which deals with post- Paleozoic Crinoids
Mr. Springer and Mr. Austin Hobart Clark, of the United States National Museum at
Washington, have co-operated with a view toward making the new knowledge of later and
Recent Crinoids more generally available for paleontologists. Lack of space alone prevented
a more detailed discussion of Recent Comatulids, such as had been actually jjrepared
for the present work by Mr. Clark. The student is therefore referred to the independent
publications of these two well-known echinodermologists. — Editoh.]
CLASS III CRINOIDEA
Table showing the Vertical Range of the Crinoidea.
243
Families.
•s
B
6
c
o
'>
O
o
n
0
m
3
£
c
1
Permian.
3
Ha
§
o
o
.1
■4^
o
P5
I. Cameeata
1. Cleiocrinidae
2. Reteocrinidae
3. Dimerocrinidae
4. Rliodocrinidae
5. Melocrinidae
6. Calyptocrinidae
7. Batocrinidae
8. Actinocrinidae
9. Platycrinidae
10. Hexacrinidae
11. Acrocrinidae
II. Flexibilia
1. Lecanocrinidae
2. Sagenoci'inidae
3. Ichthyocrinidae
4. Taxocrinidae
III. Inadunata
1. Larviformia
1. Stephanocrinidae
2. Pisocrinidae
3. Haplocrinidae
4. Allagecrinidae
5. Synbathocrinidae
6. Cupressocrinidae
2. Fistulata
1. Hybocrinidae
2. Heterocrinidae
3. Anomalocrinidae
4. Cremacrinidae
5. Catillocrinidae
6. Belemnocrinidae
7. Dendrocrinidae
8. Crotalocrinidae
9. Cyathocrinidae
10. Botryocrinidae
11. Poteriocrinidae
IV. Articulata
1. Bourgueticrinidae
2. Phrynocrinidae
3. Apiocrinidae
4. Pentacrinidae
(a) Pentacrinids
(&) Thiolliericrinids
(c) Comatulids ^
5. Plicatocrinidae
6. Saccocomidae
7. Eugeniacrinidae
8. Holopidae
i
j *
1
—
1
— -
1
i
..
i
?.
....
:
1
1
1
1 1
^ Including Marsupites and Uintacrimis.
244 ECHINODERMATA— ASTEROZOA phylum iv
SuBPHYLUM B. Aster ozoa Leuckart.'
Stemless Echinoderms loith depressed, pentagonal or star-shaped body, consisting
of a central disk and five or more rays (or "arms"). Mouth inferior and central in
position. Amhulacral tuhefeet restricted to the nnder surface of the rays. Internal
skeletal pieces of the ambulacra articulated together like vertebrae, or apposed like the
rafters of a pent-house. Integument coriaceous, strengthened by small, irregular,
loosely or firmly united calcareous plates, some of which bear spines, protuberances or
papillae, the whole constituting a covering showing the greatest diversity in details.
The Asterozoa comprise the two classes of Asteroidea (Starfish) ; and
Ophiuroidea (Brittle Stars and Basket-fish). In both types the body consists
of a central disk containing the principal viscera, and giving oflf five or more
radiating processes or arms. The radiating ambulacral vessels are protected
by an internal skeleton consisting of a double row of calcareous bodies {ambul-
acral ossicles), the components of each pair being separated and movable to a
slight extent in the Asteroidea, but being welded together so as to form a
series of disks in the Ophiuroidea. The ambulacral grooves are open in the
Asteroidea ; but in the Ophiuroidea they are covered by dermal plates, and
the tube-feet project at the sides of the arms. The integumentary skeleton
sometimes appears leathery on the dorsal surface, but is generally strengthened
by calcareous plates or ossicles some of which usually bear spines or tubercles.
Asterozoans are known as early as the Cambrian era, and have a continuous
history onward to the present time. They are of rather rare occurrence as fossils,
and are found chiefly in slaty, calcareous, or arenaceous strata which have been
deposited in shallow water. The Asterozoans are the most homogeneous and
most persistent type of all the Echinodermata. Both the Asteroidea and
Ophiuroidea are represented in the Ordovician and Silurian by well-differentiated
forms which do not differ materially from those now living. The only notice-
able difference is that many of the Paleozoic Asterozoans exhibit an alternate
arrangement of the ambulacral ossicles, Avhile in all Recent species these are in
a double row, with the ends directly apposed.
Whether this more or less disjunct and alternating condition of the
vertebi'al ossicles in Paleozoic Asterozoa is really a primitive feature of
fundamental importance must still be considered an open question. It is
quite possible that the apparent alternation in Paleozoic starfishes is due
to conditions of preservation, or if not, is an inconstant and insignificant
^ Literature: Mullcr, J., and TroscheJ, F. H., System der Asteriden. Brunswick, 1842. —
Forbes, E., Monograph of the Echinodermata of the British Tertiaries. Palaeont. Soc, 1852. —
Billings, E., Figures and Descriptions of Canadian Organic Remains. Geol. Survey Canada, Decade
iii., 1858. — Wright,^!., Monograph on the British Fossil Echinodermata of the Oolitic Formations,
vol. ii., Asteroidea and Ophiuroidea. Palaeont. Soc, 1863-80. — Hall, J., Twentieth Report on the
New York State Cabinet, 1868. — Quenstedt, F. A., Petrefactenkunde Deutschlands, vol. iv., 1874-
1876. — Liulwig, H., Morphologische Studien an Echinodermeu. Leipzrc, 1877-79. — Newnimjr, 31.,
Morphologische Studien iiher fossile Echinodermen. Sitzungsber. Akad. Wiss. Wien, vol. Ixxxiv.
1881. — Carpenter, P. //., Minute Anatomy of the Brachiate Echinodermata. Quart. Journ. Micro-
scop. Sci., 1881. — Sturtz, B., Beitriige zur Kenntniss paliiozoischer Seesterne. Palaeontographica,
vols, xxxii. and xxxvi., 1886, 1890. — Idem, Uber versteinerte und lebende Seesterne. Verhandl.
(1. naturhist. Vereins Rheinlande, Westpiialen, etc., 5th ser. vol. x., 1892. — Sladen, W. P., and
Spencer, W. K., Monograph on British Fossil Echinodermata from the Cretaceous Formations, vol. ii.
Asteroidea and Ophiuroidea. Palaeoutogr. Soc, 1891-1908. — Oregory, J. IF., The Stelleroidea, in
Lankester's Treatise on Zoology, Part iii., 1900. — .Taekel, 0., Asteriden und Ophiuriden aus dem
Silur Bohmens. Zeitschr. Deutsch. Geol. Ges., 1903, vol. \y. ^Bather, F. A., Guide to Fossil In-
vertebrates, etc. British Mus. Publ. , 1907. — Schondorf, F., tjber einige Oi)hiurideu und Asteriden
des englischen Silur, etc. Jahrb. Nassauischen Ver. Naturk., Jlirg. 63, 1910.
CLASS I ASTEKOIDEA 245
character, as Gregory has claimed. In Ophiurans, however, it is almost
certain that alternation is a primitive and very important character. The
ventral position of the madreporite in Paleozoic Starfishes and the absence of
mouth shields in Paleozoic Ophiuroids point to an intimate relationship
between the two groups ; and this inference is still further confirmed by our
knowledge of several recent and fossil intermediate forms (Astrophiura, Pro-
taster, Ophiamhix, etc.).
If one places a Starfish or Brittle Star with the mouth uppermost, it will
be seen that the actinal side corresponds with the tegmen, and the central
disk with the base of a Pelmatozoan. When oriented in this manner, the
position of the principal organs (ambulacral, circulatory and nervous systems) is
the same in both groups. The homology between the arms of an Asterozoan
and those of a Crinoid or Cystid, or the ambulacral fields of a Blastoid, can
also hardly be doubted. But efforts to interpret a homology between plates
of the dermal skeleton as developed in either group have been only partially
successful ; the reason being that these structures became variously modified
and specialised throughout the different classes at an extremely early period.
A comparison of the ontogenetic stages passed through by the Pelmatozoa
and Asterozoa, so far as at present known, reveals nothing definite in regard
to their close relationship. The Asterozoans are most nearly comparable
with certain of the Cystideans (Agelacrinus and the Callocystidae). But that
they are the direct descendants of the Cystoidea appears very improbable, for
both geological and morphological reasons. The fact is, that both types
appear simultaneously and in a high state of development, each being quite
distinct from the other, as far back as the Cambrian.
While it is clear that a well-marked separation exists between the two
classes of Asteroidea and Ophiuroidea, there is very unsatisfactory evidence
in support of a third group of equal rank, such as Ophiocistia Sollas or Aulu-
roidea Schondorf. The genera composing the former may better be retained
among the Ophiurans, while as for the latter, it is difficult to believe that
the characters assigned to it are real. More likely these supposed characters
rest upon a misinterpretation of the material. Fossil Asterozoans seem to
have been preserved in many cases only after the decay or removal of much
or all of the non-calcareous parts. Sometimes apparently the entire abactinal
side has been destroyed. In other cases only impressions remain, chiefly
of the harder parts, and the actual structure cannot be ascertained. It
is not surprising, therefore, that our knowledge of the Paleozoic forms
is still incomplete, and that erroneous interpretations should have been placed
upon some of their structural characters.
Class 1. ASTEROIDEA Burmeister. Starfislies.i
Asterozoans whose simple and more or less flattened arms are prolongations of
the central disk, and contain the hepatic appendages of the alimentary canal, as ivell
1 Literature: Forhes, E., British Fossil Asteriadae. Mem. Geol. Survey, vol. ii., Part ii., and
Decade iii., 1848 and \SbO.— Salter, J. IF., New Palaeozoic Star-Fishes. Ann. Mag. Nat. Hist., 1857,
vol. XX. — Gray, J. E., Synopsis of the Species of Star-Fish in the British Museum, 1866. — Simono-
luitsch, S., Ueber einige Asteroiden der rheinischen Grauwacke. Sitzungsber. Wieu. Akad., ^^871,
vol. Ixin.Sars, G. 0., Researches on the Structure, etc., of the genus Brisinga. Christiana, 1875. —
Perrier, E., Revision de la collection des Stellerides du Museum d'Hist. Nat. de Paris. Arch, de
zool. experim., iv., v., 1875-76.— Agassiz, A. North American Star-Fishes. Memoirs Museum
246 ECHINODERMATA— ASTEROZOA phylum iv
as the generative organs. Ambulacral feet disposed in rows along deep open grooves
on the under or adinal surface of the arms.
Starfishes have typically five arras (but in some cases as many, as eight,
ten, twenty, forty, or more), which are pi'olongations of the central disk,
usually not sharply marked oif from the same. The integumentary skeleton
consists of plates which are either contiguous with one another along their
edges, overlapping or united in a reticulate fashion, and covered with a leathery
skin. The calcareous plates often bear movable spines, or they may be
tuberculated or granulated. Modified spines with a special function and
called pedicellariae are found in most Asteroidea and are often conspicuous.
They never occur in Ophiurans or Holothurians, and are not known among
Pelmatozoa, but what appear to be homologous organs occur in nearly
all Echini. The abactinal surface usually exhibits a central or sub-
central anus, and also a madreporite, which is situated in one (rarely two
or more) of the interradii. The madreporite is covered with labyrinthic
furrows, and is perforated for the admission of water into the so-called stone
canal, whence it is conveyed into the water-vascular ring surrounding the
mouth. The protrusive caecal processes (papulae), which in the more
primitive forms are restricted to the dorsal surface, but in the more specialised
are distributed over the whole body, serve as respiratory organs, the body
fluids being brought into close contact with the oxygenated water.
The mouth occupies the centre of the ventral surface, and is pentagonal in
contour, owing to the projection of five pairs of interradially disposed oral
plates. Each of the arms is traversed on
the under or oral side by a broad and deep
furrow, which tapers gradually in passing
from the mouth to the tip of the arm, where
Fig. 348. it is terminated by a simple grooved plate
„ ■ ■ , , Detached ambu- (Fig. 347) Called the ocular plate. The roof
Ocular plates ot lacral ossicle of Pen- pii, ,p .»
Pcjitaf/owisier (?) from tagovasfer (?) from 01 each ambulacral furrow IS formed by two
st?eitbOTg! ^k-'' ''^ streitteigy v"!'"' °^ I'ows of rafter -like, rather elongate, ambu-
lacral ossicles, the inner ends of which are
held together by muscles (Figs. 348-350). Running along the centre of the
groove on its ventral side are placed in succession the radial water -tube,
blood-vessel and nerve cord. These are all homologous with the like-named
organs of Ophiuroids.
The form of the ambulacral ossicles differs in different genera. In all
Recent forms the ends are directly apposed against one another in the median
line of the ambulacral grooves ; but in Paleozoic forms they were apparently
arranged in alternate rows, and inclined towards one another at a very small
angle. Each pair of ambulacral plates is excavated at the sides, so as to give
Comp. Zoology, Cambridge, v., 1877. — Viguier, 0., Anatomie comparee du squelettedes Stellerides.
Arch, de zool. experim., vii., 1878. — Sladen, W. P., Report on the Asteroidea. Seient. Results,
Challenger Expedition, 1889, vol. xxx. — Fraas, E., Die Asterien des weissen Jura. Palaeonto-
graphica, 1886, vol. xxxii. — Gregory, J. W., On Lindstroemaster and the classification of the
Palaeasterids. Geol. Mag., 1899, dec. 4, vol. vi. — Lhistow, 0. v., Zwei Asteroiden aus mar-
kischem Septarienton, etc. Jahrb. k. Preuss. Landesanst., 1909, vol. xxx. pt. 2.—Schondorf, F.,
Die Organisation uiid systematische Stelhing der Sphaeriten. Arch. f. Biontologie, 1906, vol. i.
— Idem, Paliiozoische Seesterne Deutschlands. Palaeontogr. 1909-10, vols. Ivi., Ivii. — Idem, Die
fossilen Seesterne Nassaus. Jahrb. Nassauischen Ver. Naturk., Jahrg. 62, 1909. — Hudson G. H.,
A fossil Starfish with ambulacral covering plates. Ottawa Nat., 1912, vol. xxvi.
CLASS I
ASTEROIDEA
24V
I
rise by their apposition to a, series of small apertures, through which the
distensible tube feet or pedicels are emitted. The latter are the downward
md.
,cun.
,n(t.
ad mir.
Fio. 349.
Astropecten aurantiacus (Linn.). Recent;
Mediterranean. Enlarged vertical section of
one of the arms, am, Ambulacral ossicles ;
fid, Adambulacral plate ; inv, Infero-marginal
plate ; md, Supero-marginal plate ; (', Super-
ambulacral plate.
ad.
Fig. 350.
Astcrias rubens Linnaeus. Recent ;
German Ocean. Enlarged vertical
section of one of the arms, am, Am-
bulacral ossicles ; ad, Adambulacral
plates; mv, Infero-marginal plates;
a, Radiating water-tube ; b. Ampullae ;
p, Tube-feet.
prolongations of lateral branches given off by the radial ambulacral vessel ;
the upward prolongations of the same form small sacs called ampullae, by
means of which water is forced into the tube feet.
The lower ends of the ambulacral ossicles rest against a series of
adambulacral plates, and in many forms these are bounded in turn by large
marginal plates (Fig. 349). Intermediate plates are those which are inserted
between the infero-marginal plates and the adambulacral plates. By the
term dorsal plates are understood all calcareous bodies occurring on the dorsal
side of the body.
Perfectly preserved Starfishes are known only from a few localities, such as
Bundenbach in Rhenish Prussia, the usual mode of occurrence being in the form
of moulds, or detached plates. The earliest forms are found in Cambrian rocks.
There is no generally accepted classification of the Starfishes. Not only
do specialists disagree as to the orders and families, but there is the widest
divergence of opinion as to the principles upon which the classification should
be based. Unfortunately none of the zoologists who have in recent years
attempted to formulate a classification for the group, except Sladen,_has taken
fossils into account, and even Sladen was inclined arbitrarily to separate
Paleozoic and Recent forms. The latest authority, Fisher, accepts three
orders but does not consider their limits as satisfactorily determined. The
study of Recent forms has shown that the characters of the tube-feet,
reproductive organs and other soft parts are of real importance in determin-
ing family limits, and that the pedicellariae are possibly of even ordinal
importance, hence it is exceedingly difficult to intercalate fossil Starfishes in a
classification of the living forms. As has been suggested above, Gregory is
very possibly correct in his view that the alternation of the ambulaci'al
ossicles cannot be considered of fundamental importance, but may often be
only a result of pressure during fossilisation. It certainly ought not to be
used to isolate all Paleozoic forms, or most of them, in a class by themselves.
One character upon Avhich stress was first laid by Sladen has come to be
generally regarded as of fundamental importance, i.e. the size and appearance
of the marginal plates. The genera in which these plates are large and
conspicuous have the papulae confined to the space bounded by the upper
series or supero-marginals ; and this group, called Phanerozonia by • Sladen, is
now quite generally accepted although its exact limits, at least among living
248
ECHINODERMATA— ASTEROZOA
PHYLUM IV
Starfishes, are still uncertain. All other Starfishes may be grouped, as was
done by Sladen, in a contrasting order, Cryptozonia ; but this is probably not
a natural group, and Fisher distinguishes two divisions. These, however, are
separated by characters not ascertainable in Paleozoic remains, and for practical
purposes, the paleontologist may well accept the Cryptozonia.
Order 1. PHANBROZONIA.
Asteroidea in which the marginal ])lates are large and conspicuous ; papulae
nearly always confined to the dorsal surface; ambulacral ossicles not crowded, and
tube feet in two rows in each ambulacral groove.
This order includes a large proportion of the Paleozoic and Mesozoic
Starfishes, besides numerous Kecent genera. Fisher groups the Eecent forms
in no less than a dozen families, and Gregory gives four others for Paleozoic
species alone. Many of the Recent families are not known as fossils, and
others may have one or a few extinct representatives. The most important
families and genera from a paleontological point of view are the following.
Family 1. Palaeasteridae.
The typical members of this family have the ambulacral ossicles more or
less completely alternating. The adanibulacral plates are most conspicuous
in the mouth parts. The
marginal plates and many
of the abactinal plates are
conspicuous.
The exact limits of this
family are hard to determine,
as the known forms are all
from the lower Paleozoic.
The typical genus Falaeaster
Hall (Fig. 351) is known
from both Europe and
America. Hudson has re-
cently proposed a new order
and family for an interesting
Starfish (Protopalaeaster)
from the Ordovician rocks of
Canada. It is, however,
probably allied to Palaeaster.
The i^lates which Hudson
calls epineurals are probably
the amhulacrals seen from within, the dorsal side of the animal being lost.
Several genera allied to Palaeaster have been described (Petraster Billings ;
Archasterias Midler ; Argaster Hall ; Ataxaster Jaekel, etc.), while other less
typical forms (Xenaster Simonowitsch ; Tetraster Eth. and Nich.) have been the
subject of debate as to their true position. Whether Lindsfroemaster Gregory
is properly referable to this family is not certain ; it bears considerable super-
ficial resemblance to the Goniasteridae.
rn-.-ri.v
bhi. 351.
Palaeaster enckarls Hall. Devonian; Hamilton, New York. A,
Ventral aspect, natural size. B, Dorsal surface of one of the arms.
(•', Diagrannnatic view of ventral surface of the arms (after Hall").
CLASS I
ASTEROIDEA
249
Family 2. Astropectinidae.
This is one of the largest families of Recent and Mesozoic Phanerozonia,
about twenty Eecent genera being known. The ambulacral ossicles are
opposite but that seems to be the only difference from the Palaeasteridae.
The type-genus, Astropecten Gray (Fig. 349), occurs in the Lias and later
Mesozoic, and is still a large and widespread genus. It is quite possible that
some Paleozoic forms are nearly related, if not actually congeneric, as for
example, Astropecten schlilteri Stiirtz, from the Devonian. The lower Silurian
Siluraster Jaekel is also very probably one of this family.
Family 3. Aspidosomatidae.
This family is characterised by alternate ambulacral ossicles and large
interradial areas. The rays are more or less petaloid or tapering, and the
disk is large. All of the known
forms are from the Paleozoic and
their structure is not only incom-
pletely known, but there is the
widest difference of opinion in inter-
preting such characters as are dis-
tinguishable. The , type -genus
Aspidosoma (Fig. 352) has been
very carefully studied by Schon-
dorf. As a result of these studies,
he proposed a new class called
Auluroidea. The structure of
Aspidosoma shows, however, that
it is probably a phanerozonate Star-
fish. Allied genera are Falaeonedria
and lalaeOStella Stiirtz, and Tncha- lahnstein, Nassau. ^, Ventral aspect, natural size, i;, Arm
, _ . -pi 1 ' viewed from the dorsal side. C, Ventral aspect of arm,
SteVOpSlS IliCK, enlarged (after Simonowitsch).
^v4^>-'
Fid. 352.
Aspidosoma pctalokles Simon. Lower Devonian ; Nieder-
Family 4. Taeniasteridae.
In this family, which is also confined to the Paleozoic,
the disk is very small and the rays are long and tapering.
The adambulacral plates are lai^ge and marginal in position.
The marginal plates bear spines on their free ends. The
principal genera are Taeniaster and Stenaster Billings, from
the Lower Silurian of Canada, and Salteraster Stiirtz, from
the Silurian of England. Perhaps Prof aster acanthioii Stiirtz,
PentagonasterCi) from the Devonian of Germany, also belongs here.
ipre^siis (Quenst.). '' °
1/nip
Upper Jura ; Reiehen-
bacli im Tliale. A,
Supero - marginal
plate. B, Infero-
marginal plate. C,
Plate with supposed
pedicellariae
Quenstedt).
Family 5. Goniasteridae ( = Pentagonasteridae).
These Starfishes are generally recognisable by their flattened
(after form, short rays, very large disk, and very conspicuous
marginal plates. The family is a large one, with more than
forty Recent genera, and its limits are ill defined. It first appears in the
Jurassic, and it is well represented in Cretaceous strata. The genus Pentagonaster
250
ECHINODERMATA— ASTEKOZOA
PHYLUM IV
Gray, was monotypic when described, and as now limited probably contains
no fossil forms ; but a considerable number of species and fragments (Figs.
347, 348, 353) from the Mesozoic have been referred to it. An allied genus,
Mctopaster parkinsoni (Forbes),
(after Forbes).
Fig. 354.
Lower Chalk ; Sussex.
A, Ventral aspect. ' B, Viewed from one side
Mefopaster Sladen (Fig. 354), is represented by numerous species in the
Cretaceous rocks of England. Other Cretaceous genera are Pycinaster Spencer,
and Mitraster Sladen, while Leptaster de Loriol is found in Jurassic strata.
Fig. 366.
SpTiaerites scutatus Goldf.
Upper Jura; Sontheim,
Wiirtemberg.
Fi(i. 35'
A, Sphaerites tahulatus
Goldf. B, Sphaer. imnctahis
Goldf. Upper Jura; Streit-
berg, Franconia.
Fig. 355.
A, Oreasterjurassicus (Zitt). Upper Jura ; Bemfeld, near Ingolstadt,
Bavaria. V- B, 0. thorarifer (Gein.). Planer ; Plauen, Saxony.
Marginal plate. C, 0. primaevus (Zitt.). Upper Jura ; Streitberg.
Several Recent genera, such as Calliderma Gray ; Nymphaster Sladen ;
Compfonia Gray, have been thought to have Cretaceous representatives, and
there is little reason to doubt that many Cretaceous Starfishes of this family
were congeneric, at least in a broad sense, with those of to-day.
CLASS I ASTEROIDEA 251
I'amily 6. Oreasteridae (wrongly Pentacerotidae).
This family includes some of the largest Recent Starfishes, characterised by
a massive skeleton, with large, though sometimes concealed, marginal plates.
Conspicuous spines or tubercles are commonly found on the abactinal plates.
The type genus Oreaster M. and T. (wrongly Pentaceros) (Fig. 355), is wide-
spread in shallow water in the tropics, while geologically it is known at least
as early as the Upper Jura. Numerous species of this genus occur in the
Cretaceous. Arthraster Forbes, and Staiiranderaster Spencer, from the British
Cretaceous probably belong to this family.
Family 7. Sphaerasteridae.
Isolated plates, to which Quenstedt gave the name Sphaerites, from the
Jurassic rocks of Germany, France and Switzerland, have long puzzled
paleontologists, but Schondorf has recently shown that they belong to certain
remarkable Starfishes, which he calls Sphaeraster, allied to the Oreasteridae.
In some cases (Fig. 356) the plates bear large spines, but in others they are
simply punctate (Fig. 357), or quite smooth. The animal was high hemi-
spherical in form, and the large ones were 25 cm. in diameter. They seem to
have been confined to Jurassic seas.
Order 2. CRYPTOZONIA.
Asteroidea in which the marginal plates are small and inconspicuous ; papulae
distributed on the m'ol surface ; ambulacral ossicles are often crowded and tube-feet
may be in four rows in each groove.
Between fifteen and twenty families of cryptozonate Starfishes are now
recognised, but the great bulk of these are Recent forms. The order is rare in
the Paleozoic, and the structure of those forms which are referred to it is im-
perfectly known. Accordingly, their systematic position is doubtful. The
genus Falasterina M'Coy (Cambrian to Devonian ; Europe and North America)
is regarded by some writers as cryptozonate and by others as phanerozonate.
It is probably related to Asterina Nardo, a widespread Recent genus, which
Sladen considered phanerozonate, other writers to the contrary notwith-
standing. The genera Palaeocoma, Bdellacoma and Bhopalocoma Salter are
probably Ciyptozonia but their family position is very doubtful.
Lepidaster Forbes, of uncertain affinities, is an interesting Silurian genus
with large disk and thirteen rays. Etlieridgaster Gregory, from the Carboni-
ferous of New South Wales, is considered by its describer as a related genus,
although it has only five rays and was originally regarded as a Palaeaster.
Med'usaster Stiirtz is notable for having fourteen rays, and Helianthaster Roemer
is another remarkable form with sixteen rays. The latter has been regarded
by some as a Starfish and by others as an Ophiuran ; it is probable that it
belongs in the Cryptozonia, but most unlikely that it is related to the Recent
South American Heliasfer.
It is possible that the Recent family Linckiidae is represented in the Devonian
by Pioemeraster Stiirtz, but the relationship is very dubious. The genera
Palasteriscus and Echinasterella of Stiirtz from the Devonian are said to have the
madrepoi-ite on the oral side, which would alone render them worthy of note.
Loriolaster and Cheiropteraster Stiirtz, also from the wonderful Bundenbach
slates, are possibly allied to the Recent Pterasteridae. Mesozoic and Tertiary
252
ECHINODERMATA— ASTEROZOA
PHYLUM IV
Cryptozonate Asteroids are very rare. The Kecent genus Solaster Forbes is
represented by a species with numerous arms in the Great Oolite of England.
Two important families of Recent Cryptozonia are the Echinasteridae and
the Asteriidae. A species of Echinaster M. and T. has been described from
the Neocomian, and Forbes thought he found in the Red Crag of England
remains of the now common Asterias rubens Linn. It is strange that no good
evidence has been found of the occurrence of Asterias in Tertiary strata.
Class 2. OPHIUROIDEA Gray. Brittle Stars.i
Asterozoans having a more or less sharply defined central disk containing a simple
digestive cavity which does not radiate into the slender rounded arms, and has no anal
opening. Reproductive organs confined to the disk. Arms with an axis composed of
calcareous joints, the elements of which are usually fused to forin "vertebral ossicles,"
encased with plates or covered with a leathery skin, and very rarely ivith open
ambidacral grooves. Madreporite constantly on the actinal (oral) side of the disk.
y Fir;. 358.
A, Vortical section of an Opliiuran ami. w, Vertebral ossicle ; «, Anibulacral vessel, with side-branches lead-
ing into the tube-feet ; h. Blood-vessel ; ii, Nerve-cord ; v, Ventral or lower arm-plate; I, Side-plates ; d, Dorsal
plate. B, Vertebral ossicle, seen from the inward side, with surrounding arm-plates. C, Row of vertebral
ossicles viewed from the side, and slightly enlarged ; x, Apertures where the branches of the ambulacral vessel
enter and emerge from the arm-bones ; y, Depressions for the insertion of intravertebral muscles. D, Mouth-
frame of an Ophiuran, with the proximal vertebral ossicles. The heavy lines bordering the arms represent the
genital slits ; the dark pentagon in the centre marks the course of the nerve-ring.
Ophiuroids are distinguished from the typical Starfishes by their cylin-
drical flexible arms, which are sharply separated from the central disk, and
^ Literature : Liltken, C. F., Additamenta ad liistoriam Ophiuridarum. Kougl. dan. Vidensk.
Selskabs Skrifter, v. and viii., 1858-69. — Lyman, T., Opbinridae and Astrophytidae. Illustr. Cat.
Mus. Comp. Zool. Cambridge, Nos. i.-iii., 1865. — Ludwig, II., Beitriige zur Anatoniie der
Ophiuren. Zeitschr. fiir wissenscli. Zool., vols. x.xxi., xxxiv., 1878-80. — Ludwig, H., Morphologische
Studien an Echinodermen. Leipzic, 1877-79.— Lymcpi, T., Report on the Ophiuroidea. Challenger
Expedition, Zoology, vol. v., 1882. — Picard, K., tjber Ophiuren aus dem oberen Muschelkalk.
Zeitschr. deutsch. geol. Gesellsch., vol. xxxviii., 1886. — Boehm, G., Beitrag zur Kenntniss fossiler
Ophiuren. Berichte naturf. Gesellsch., Freiburg, v., 1889. — Gregory, J. W., On the classification
of the Palaeozoic Ecliinodernis of the group Ophiuroidea. Proc. Zool. Soc, London, 1896. — SoUas,
W. J., On Silurian Echinoidea and Ophiuroidea. Quart. Journ. Geol. Soc. , 1899, vol. Iv. — Ilainann,
0., Die Schlaugensterne. Buch iii., Abt. 3, Bd. 2, of Bronn's Klassen und Ordnuugen des Tier-
reich.s, 1901. — Strassen, 0. zur, Zur Morphologie des Mundskelettes der Ophiurideu. Zool. Anz.,
1901, vol. xxiv. — Jnekd, 0., Asteriden und Ophiurideu aus deni Silur Bohmens. Zeitschr. Deutsch.
Geol. Ges., 1903, vol. Iv. — Parks, W. A., Notes on the Ophiuran genus Protaster. Trans. Canad.
In.st., 1909, vol. vhi.—SoUas, I. B.J. and W. J., Lapworthura : A typical Brittle-star of the
Silurian Age.
Phil. Trans., 1912, vol. ccii.
CLASS II
OPHIUEOIDEA
253
do not contain diverticula of the alimentary canal nor of the sexual organs.
The arms serve as locomotive organs, and are either elegantly plated
or protected by a coriaceous skin, in which minute granules and scales are
embedded. When plated, the covering consists typically of four rows of
calcareous plates, known as the upper, lower and side arm-plates (Fig. 358, A).
The lateral or adamhulacral plates usually carry rows of mobile spines.
The greater part of the interior of the arms is occupied by a linear series of
jointed, vertebra-like sections called the vertebral ossicles or arm bones, each of
which is made up of two, or possibly of four, ambulacral pieces soldered side
by side (Fig. 358, B, C). The halves of the first two vertebral disks ai"e swung
laterally into the interbrachial space, being fused together to form the mouth
angle. The remainder of the arm-bones are movably articulated with one
another by means of bosses Avhich project from the centres of both surfaces,
the interspaces being filled with muscles. The entire series is incised inferiorly
along the median line for the reception of the radial water-tube, beneath
which runs the radial blood-vessel and nerve cord, the whole being closed in by
the integument. The radial ambulacral vessel (water-tube) gives off" a pair of
lateral branches in each arm ossicle which pierce the bone itself, and supply
^^<^-^.
Fig. 359.
Portion of central disk of Ophiura viewed
from the dorsal side, a, Radial shields ;
h, Upper arm-plates ; c, Side arm-plates.
Fig. 360.
Portion of central disk of Ophiura
viewed from the ventral side, a, Mouth
shield ; h, Side mouth shield ; c, Jaws
bearing papillae ; g, Genital slits ; h, Side
arm-plates ; (', Pores for the emission of
the tube -feet, surrounded with tentacle
scales ; fc, Spines.
the tentacle-like tube-feet with water. The tube-feet are without either
ampullae or terminal suckers, and the orifice of the plates through which they
protrude is often protected by one or more minute tentacle scales {papillae
ambulacrales), which serve to cover the tentacles when they are drawn in.
On the under side of the disk is seen the central, star-shaped aperture of
the mouth (Fig. 363), which leads into a large sac-like stomach. The latter
terminates blindly, there being no intestine. The body cavity also contains
the ambulacral, blood and nerve rings, as well as the generative glands, whose
ducts open into folded pouches or bursae. The bursae are arranged in five
pairs, one to each interbrachial area, and communicate with the exterior by
means of slit-like fissures (genital slits), which skirt the arm bases inferiorly,
and are bounded by genital or bursal scales. Sometimes the fissures are
discontinuous (Ophioderma), appearing as two slits, one behind the other ; and in
some fossil forms they are represented by rows of pores.
The integument covering the entire upper surface of the disk and the
'interbrachial area on the ventral side is frequently beset with calcareous
plates ; but this scale coat may be covered in turn with a thick skin, or bear
spines or granules. A large central plate is sometimes recognisable on the
dorsal aspect of the disk, together with five pairs of plates, which, from their
254 ECHINODERMATA— ASTEROZOA phylum iv
position at the points of origin of the arms, are called radial shields
(Fig. 359). On the ventral surface of the disk, the inner angle of each
interbrachial space is occupied by a single large plate termed the mouth
shield (scutum buccale) (Fig. 360), one of which serves as the madreporic body.
But in the Cladophiuroida the mouth shields are often feebly developed, or may
be wanting altogether ; and in place of them a madreporite is found in one or
all of the interrays. The mouth shields are bounded proximally by a pair of
somewhat smaller plates called the side mouth shields. Finally, within the
side mouth shields, and usually pressing against them, are the jatos which are
sometimes covered by the skin or by granulations (Fig. 360). Teeth are
constantly present, being attached to the jaw-plates by small muscles, and
other tooth-like processes (tootli-])apillae and oral-papillae^ are generally present
at the inner angle or along the sides of the jaws.
A natural classification of the Ophiuroidea remains to be established.
Those who have worked principally on Eecent forms have not, as a rule,
proposed any completed system ; and so while our knowledge of the number
and variety of Recent species has increased enormously, no progress has been
made toward a rational arrangement of the class. On the other hand, some
valuable work by paleontologists has been vitiated by ignorance of the Recent
forms, while the difficulties of the material with which such work must be
done has led to radical differences of interpretation and opinion.
The proposed groups Protophiuroidea and Euophiuroidea may be natural
divisions, but as the character upon which the class is differentiated is the struc-
ture of the arm and the development of " vertebral ossicles," the classification
proposed by Bell and elaborated by Gregory may better be adopted as a
basis for further study. Under this system four orders may be recognised,
but family limits are uncertain and unsatisfactory. The termination of
Gregory's ordinal names is altered to end in -oida.
Order 1. LYSOPHIUROIDA.
Ophiuroidea in which the vertebral ossicles are incomplete, the two halves not
being united, but separate and alternate. There are no ventral arm-plates and thus
a more or less distinct ambulacral furrow is present.
This order includes a group of Paleozoic Asterozoans, intermediate
between Ophiurans and Starfishes. They differ from the latter only in the
general form, the arms being sharply set off from the disk, but probably the
alimentary canal and reproductive organs were confined to the disk. The
characters of the ambulacral plates are often uncertain, but they may be
either subquadrate or "boot-shaped." The character of the mouth-parts in
this order and the next has been well worked out by the Sollases, and their
primitive character clearly shown. The principal genera are Protaster Forbes
from the Silurian, and Bundenbachia and Palaeophiura Stiirtz, from the Devonian
of Europe. The Ophiurans from the Lower Silurian strata of Bohemia,
whose structure is discussed by Jaekel, are undoubtedly members of this
order. The most important genus is Bohemura.
Order 2. STREPTOPHIUROIDA.
Ophiuroidea in which the vertebral ossicles are more or less complete, and in
any case, the ttvo halves are opposite. The ossicles articulate with each other by ball-
CLASS II
OPHIUROIDEA
255
and-socket joints. The arm-plates are move or less completely developed and the side
arm-plates may carry spines. Arms may be very short with relatively enormous
tuhe-feet, as is apparently the case in Eucladia.
This order includes a number of Paleozoic forms and not a few Eecent
species. Important genera are Ophiurina Stiirtz, Devonian, with separate am-
bulacral ossicles and no ventral arm-
plates ; Lapworthura Gregory, Silurian,
with barely fused ambulacral ossicles,
and no ventral arm-plates ; Sympterura
Bather, Devonian, similar to Lap-
ivorthura, but with narrower rays and
spinulose disk ; and Eoluidia Stiirtz,
Devonian, with fused ossicles, and with
ventral arm -plates. The genus Ony-
chaster Meek and Worthen (Fig. 361),
Lower Carboniferous, has usually been
regarded as representative of the
■1 Tji Tj -u i it, 1, i„ „£ Omieliaster flexilis M. and W. Liower (Jarbonit'erous :
modern Euryallds, but the character of Crawlonlsville.I.id. (after Meek and Worthe,.). .4,In-
the ambulacral ossicles necessitates its dividual of the natural size with roUed up arms;
the dorsal covering of the central disk is removed,
inclusion in this order. The remarkable exposing; the mouth frame. £, Mouth frame enlarged,
o • 1 • n 7 7 • ^TT 111 viewed from above : C, Vertebral ossicle, enlarged.
Silurian genera Lucla\iia Woodward, and
Euthemon Sollas, are exceedingly diflficult to place, and their relation to other
Ophiurans is problematical.
Fig. 361.
Onyehaster flexilis M. and W. Lower Carboniferous ;
Order 3. CLADOPHIUROIDA.
Ophiuroidea in lohich the vertebral ossicles are complete and articulate with each
other by means of hourglass- shaped surfaces. The arms are often dichotomously
branched and lack regular series of arm-plates.
This order includes a large number of Recent forms, those with branched
Fig. 362.
Aspidura loricata (Goldfuss). Muschelkalk ; Waschbach, Wiirtemberg. A, group of individuals of the
natural size (after Quenstedt). B, Ventral aspect, enlarged (after Pohlig).
arms {Astrophyton, Gorgonocephalus, Euryale) being known as " Basket-fish " or
" Sea-spiders." Fossil forms are rare, but certain Mesozoic remains of doubt-
ful position have been referred to the Recent genera Astrocnida and Euryale.
Onyehaster, the Streptophiuran referred to above, has peculiarities that suggest
256
ECHINODERMATA -ASTEROZOA
PHYLUM IV
this order, but the form of the ossicles certainly seems to exclude it.
Moreover, Eudadia, so far as its structure is known, is capable of very diverse
interpretations, and the possibility that it is a Starfish rather than an
Ophiuran, must not be wholly ignored.
Order 4. ZYGOPHIUROIDA.
Ophiuroidea with simple anns, perfecMy regular series of arm-p>lcites and vertebral
ossicles fully developed. The movement of the ossicles on each other is greatly limited
by the development of lateral processes and pits on their articulating surfaces.
This order includes the great bulk of the Recent Ophiurans as well as
those of the Mesozoic and Tertiary.
Indeed some of the Recent genera seem
to have been differentiated as far back
as the Jurassic, and Ophioderma appar-
ently occurs in the Triassic. No
Paleozoic forms can certainly be re-
ferred to this group.
The genera Aspidura (Fig. 362)
and Acrura Agassiz are occasionally
abundant in the German Muschelkalk,
and certain Liassic Ophiui'ans were
also, like many Recent species, notably
gregarious. In the Lower, Middle
and Upper Jura are found Brittle Stars
closely allied to the Recent Ophiolepis
B
Pig. 363.
Opliiocten kelheimense BiJhm. Lithographic Stone ;
Kelheim, Bavaria. A, Ventral aspect of dislj. B,
Dorsal surface of one of the arms. (Both figures en-
larged ; original in Munich Museum.)
Fig. 3ti4.
Geocowi carinnta Goldf. Lithographic Stone ; Zandt, near Solenhofcn, Bavaria. A, Individual of the
natural size. B, Dorsal aspect of disk, showing granulations and central depression. C, Ventral surface of one
of the arms. (Figs. B and C enlarged.)
M. and T. ; Ophiocten Ltk. (Fig. 363); Ophiura Lamk. (Figs. 359, 360); and
Ophiomusium Lyman. It is possible that some of these are really congeneric
with Recent species. The Mesozoic genus Geocoma d'Orb. (Fig. 364) is related
to the Recent Amphiura Forbes, but there can be little doubt that some of
the species referred to it are based on material which cannot be determined
so precisely. Liitken considers Ophiurella elegaiis Ag., from the Lithographic
Stone of Solcnhofen, to be a member of the Recent genus Ophiocoma Ag., but
CLASS I ECHINOIDEA 257
it is doubtful whether it may not be quite as properly assigned to one of
several other genera. Other Jurassic and Cretaceous forms have been
assigned by Liitken to Ophmra Lamk. (Ophioglypha Lym.), and there is good
reason to believe that the genus, in a broad sense, is one of the oldest now
living. Fossil Ophiurans, whose disk-covering or mouth parts cannot be
determined, ought not to be assigned to Recent genera, but all such and all
others which cannot be accurately characterised may well be designated by
the broad term Ophiurites.
[The text for the foi-egoing section on Asterozoa has been revised for the present work
by Dr. Hubert Lyman Clark, of the Harvard Museum of Comparative Zoology, at Cambridge,
Massachusetts. — Edito ii. ]
SuBPHYLUM C. Echinozoa Leuckart.
Armless and non-pedunculate Echinodermata, with glohdar, cordiform, discoidal
or worm-like bodies, which are either encased in a plated test or are invested with a
leathery integument, embedded within which are small-sized detached calcareous bodies.
Class 1. ECHINOIDEA Bronn. Sea-Urchins.i
Animals possessing a wide range of structure, but hating alimentary, reproductive,
nerve and water vascular systems within an enclosing superficial pentamerous plated
skeleton, which bears movable spines. There are from two to twenty columns of plates
in each of the five ambulacral areas, and from one to fourteen columns of plates in
1 Literature : Agassiz, L., and JJesor, £., Description des echinides fossiles de la Stiisse, 1839-
1840. — Catalogue raisonne des families, genres, et des especes de la classe des echinides. Ann. des
Sci. Nat., 1846-47. — d'Orbign//, A., Paleontologie fran^aise. Terrains cretaces 1853-55, vol. vi. —
Cotteau, G. II., and Triger, Echinides du departement de la Sarthe, 1857. — Desor, E., Synopsis
des echinides fossiles. Paris, 1858. — Wright, T., Monograph on the British fossil Echinodermata
of the Oolitic Formations. Palaeontograph. Soc, 1857-78. — Idem, Cretaceous Formations. Palaeont.
Soc, 1864-82. — Cotteau, G., Paleontologie fran9aise, vols. vii. , ix. andx., 1862-79.— Lmibe, G. C,
Echiuodermen des viceutischen Tertiiirgebietes. Deukschr. Akad. Wiss. Wien, vol. xxix., 1868.
— Loriol, P. de, and Desor, E., Echinologie helvetique, vols, i.-iii. Geneva, 1868-85. — Quenstedt,
F. A., Petrefractenkunde Deutschlands (vol. iii., Echiniden), 1872-75. — Agassiz, A., Revision of
the Echini. 111. Cat. Museum Comp. Zool. Cambridge, No. 7, 1872-74. — Reports on the Echini
of the Hassler (1874), Challenger (1881) and Blake (1883) ExiJeditions. — Zow'm, S., Etudes sur les
echinoidees. Sveusk. Vetensk. Akad. Haudl., vol. xi., 1874. — Cotteau, Peron, and Gauthier,
Echinides fossiles de I'Algerie. Paris, 1876-91. — Loriol, P. de, Monographic paleontologique, etc.
Abhandl. Schweiz. Pal. Gesellsch., 1876-81, vols, iii., viii. — Dames, W., Die Echiniden der
viceutischen vmd verouischen Tertiar-Ablagerungen. Palaeontographica, 1877, vol. xxv. — Agassiz,
A., Palaeontological and Embryological Development. Proc. Amer. Assoc. Adv. Sci., 1880.
— Duncan, P. M., and Sladen, W. P., Monograph of the fossil Echinoidea of Western Sind.
Palaeont. Indica, Ser. xiv., 1882-84.- — Scklilter, C, Die reguliiren Echiniden der norddeutschen
Kreide. Abhandl. zur geolog. Special-Karte von Preussen, vol. iv., 1883. — Idem, Neue Folge,
Heft 5, 1892. — Loriol, P. de, Descrij^tiou des echinides. Commission des travaux gcol. du Portugal,
1887-88, vol. ii. — Loven, S., On Pourtalesia. Sven.sk. Vetensk. Akad. Haudl., 1884, voL xix. —
Pomel, N. A., Classification methodique et genera des echinides vivantes et fossiles, 1883. — Duncan,
P. M., Revision of the Genera and Great Groups of the Echuioidea. Journ. Linn. Soc, 1889,
vol. xxiii. — Loven, S., Echiuologica. Bihaug till Svensk. Vetensk. Akad. Haudl., 1892, vol.
xviii. — Clark, W. B., Mesozoic Echinodermata of the United States. Bull. U.S. Geol. Survey,
No. 97, 1893. — Tornquist, A., Das fossilfiihrende Untercarbon am ostlichen Rossbergmassiv
iu den Siidvogesen, iii., Beschreibung der Echiniden-Fauna. Abhandl. Geol. Special-Karte Elsass-
Lothringen, 1897, vol. v. — Morteusen, T., Siam Echinoidea. Danske Vidensk. Selsk. Skrift.,
1904, vol. i. — Bather, F. A., Triassic Echinoderms of Bakony. Resultate der wiss. Erforsch. Bala-
tousees, 1909, vol. i. — Lambert, J. and Thiery, P., Essai de nomenclature raisonne des echinides.
Chaumont, 1909-12. — Jackson, R. T., Phylogeny of the Echini. Mem. Boston Soc. Nat. Hist.,
1912, vol. vii. — Hawkins, II. L., Classification of the Holectypoida, etc. Proc. Zool. Soc.
London, 1912.
VOL. I S
258
ECHINODEEMATA— ECHINOZOA
PHYLUM IV
each interamhulacral area. N'ew coronal plates are formed at the ventral harder of
the five ocular plates, amhulacral pores pass through amhulacral plates, rarely
(Clypieastroids) in part between plates.
The peristome is on the under or actinal surface, and in all but the
Exocycloida bears from one to many rows of ambulacral plates with or with-
out non-ambulacral plates. There are five oculars (apparently in part or
wholly wanting in some of the Pourtalesiidae), and five genitals or fewer, the
whole being fused into a mass in certain types of Exocycloida. The genitals
typically have each one or more pores as exits of the interradially situated
reproductive glands. In addition, typically, madreporic poi'es exist in genital
2, but are not recognizable in most Paleozoic forms. The periproct is more
or less plated, situated within the oculogenital ring, or in irregular types out-
side of that area in the posterior interambulacrum ; the anus is in the peri-
proct. The masticatory lantern is composed of forty pieces (or Clypeastroids
thirty pieces) ; it is wanting in adult Spatangoids. Respiratory organs consist
of Stewart's organs, peristomal, or ambulacral gills. Locomotion is effected
by ambulacral feet, or by spines, or both.
The Test. — The test or main skeleton of the Echini is composed of numerous
calcareous plates, firmly united by their edges so as to form a more or less
rigid case or box and disposed in certain
regions or systems. In some genera,
however, the plates overlap one another
in an imbricating manner so as to im-
part a certain degree of flexibility to
the test. When coronal plates are
imbricate, the ambulacral plates overlap
adorally and the interamhulacral over-
lap aborally and from the centre out-
ward and over the ambulacrals on the
adradial suture (Fig. 365). When peri-
Leindedhe.'i ooUetti White. Synthetic figure show- stomal plates are imbncate, all Overlap
ing method of iiubrication of coronal plates (after adorallv (Fiff 371 I^)
Jackson). mi • i '
ine mam element of the test is
termed the corona, which is composed of five ambulacral and five interam-
hulacral areas. At the summit is situated the apical disc, or oculogenital
plates, which in regular Echini surrounds the periproct and anal opening.
The periproct is usually plated, always carries the anal opening, and in
irregular Echini lies outside of the apical disk in the posterior interam-
bulacrum. Ventrally is situated the pei'istome, a membrane which is usually
more or less completely plated, or may be naked, and extends from the
mouth opening to the base of the corona. The peristome is either central in
position or anterior to the centre in some of the Exocycloida.
Echini are oriented by an antero-posterior axis drawn through an ambul-
acrum and opposite interambulacrum in such a plane that the madreporite lies
in the right anterior interambulacrum. This is the axis on which bilatcrality
is attained in the Exocycloida, and the same axis is indicated in regular Echini
by the order in which ocular plates reach the periproct when such occurs.
With known axes Loven devised a nomenclature of areas which is of very
great value in brevity and clearness of expression. He numbered the ambul-
Fio. 365.
CLASS I
ECHINOIDEA 259
acral areas from I to V, Roman, and the interambulacra from 1 to 5, Arabic.
The enumeration passes from left to right, revolving like the hands of a
watch, the specimen being viewed from below and the odd anterior ambulacrum
being III (Fig. 370). When viewed from above, the order of enumeration is
necessarily reversed (Fig. 434). Lov6n showed that the size and character of
the primordial ambulacral plates give data by which a sea-urchin can be
oriented in young regular Echini, and usually in adult Exocycloida. He
showed that of these ten plates, the la, lla, Jllb, lYa, Yb are larger ; on the
contrary the lb, lib, Ilia, lYb, Ya are smaller (Figs. 370; 377, A).
The mouth opens into an oesophagus which conducts into a capacious
stomach, and thence into a convoluted intestine. The digestive tract winds
around the interior of the test, being attached to the inner surface of the
latter by muscles, and terminates in the anus. Surrounding the oesophagus
is a circular vessel filled with water, which is admitted by the so-called stone-
canal, opening externally in a madreporife. This is a porous or sieve-like
structure, consisting of a variable number of canals, and though commonly
restricted to genital 2, madreporic pores as a variation may extend to additional
genitals or to ocular plates.
The circular vessel gives off five branches, known as the radiating canals,
which pass along the ambulacral areas on the interior of the test, and con-
nected with it in the interambulacral areas are five distensible membraneous
reservoirs, termed tho Polian vesicles. The radiating canals give off numerous
lateral branches or tube -feet {tentacles) which are extended through the
pores of the ambulacral plates. Dilation is effected by means of secondary
vesicles or ampullae which by contraction force their contained fluid into the
tube-feet and distend them. The ampullae, as a rule, communicate with the
tube-feet by two canals perforating the plates separately, a single tentacle
being placed over a pair of ambulacral pores. The tube-feet serve usually
as locomotive organs, when they are prehensile and end in a suctorial disk ;
but in many forms, especially those having petaloid ambulacra, they are
modified so as to be partly branchial in function. Sometimes the tentacles of
the same ambulacrum differ in shape, structure and function, as in Arbacia.
Respiration is apparently effected by Stewart's organs in certain Echini.
These organs are internal, five in number, and situated radially, they are
given off' from the periphery of the lantern membrane and beneath the com-
passes. In the Cidaroida, Stewart's organs are frondescent ; in the Echino-
thuriidae, vermiform or sausage-shaped. External branchiae or gills exist in
the Centrechinoida as outward extensions of the oral integument. They exist
as ten small or larger branched fleshy organs interradially situated. Their
presence is marked by indenting cuts in the basicoronal plates so that their
presence is recognizable in fossils where they exist (Centrechinoida). In
Clypeastroids and Spatangoids, as well as partially in some of the Centre-
chinoida {Arbacia), the function of respiration is maintained by modified
dorsal ambulacral tentacles which have lost their function as locomotive
organs. For distinction these are called ambulacral gills.
The vascular system consists of a ring-like vascular plexus surrounding the
oesophagus, and immediately underlying the cii'cular ambulacral vessel. This
ring gives off five radial vessels, and also two others which send off branches
to the stomach and generative organs. The central nerve ring, with its five
principal nerves running down the rays, is external to the two other systems.
260 ECHINODERMATA— ECHINOZOA phylum iv
The generative organs are superficially alike in both sexes, and are in the form
of glands (usually five, sometimes four, three, or even two), situated dorsally
and interradially on the inner surface of the test. The genital ducts terminate
in pores in the so-called genital plates, to be described presently.
Coronal Plates. — The plates of the corona are arranged in ten meridional
areas. Five of these, the ambulacral areas, are composed of perforated plates,
and correspond in position to the radiating ambulacral vessels ; the remaining
five, the interambulacral or interradial areas, alternate with the first, and are
imperforate.
In all Recent and in the majority of fossil Echini the ambulacral areas are
each composed of two columns of alternately arranged plates, the inner
edges of which meet in a zigzag median suture, and the actinal and abactinal
edges in horizontal sutures. In some Paleozoic genera there are more than
two columns in an ambulacral area, and there may be as many as sixteen, or
even twenty, at the mid-zone (Fig. 367, o). The interambulacral areas are
each composed of from one to fourteen columns of plates, but nearly all
post-Paleozoic and all Recent types have two columns. Interambulacral plates
are usually larger than ambulacrals and meet the latter in vertical adradial
sutures. There are therefore from fifteen vertical columns of coronal plates,
Bothriocidaroida (Fig. 377, A), to twenty columns Cidaroida, Centrechinoida,
Exocycloida, or more than twenty, as in the Paleozoic Echinocystoida and
Perischoechinoida (Figs. 429, 432), and the Triassic Plesiocidaroida. One
additional case of more than twenty columns is known in the peculiar
Cretaceous Tetracidaris. The number of columns of plates is the same for an
individual in each of the ambulacral areas, and usually for each of the
interambulacral areas as well, but the two systems are entirely independent
of one another as respects the size and number of plates in a vertical column,
also, especially in the Paleozoic, as regards the number of columns in an area.
In the Cidaridae, for example, the ambulacra are very narrow and are
composed of numerous, thirty to sixty low plates in a column ; the inter-
ambulacra are broad with few, five or six to fifteen high plates in a column.
On the other hand, in the Paleozoic Lepidesthes colletti, the ambulacra are
broad, with sixteen columns of plates in each area, and the interambulacra
are narrow with four columns in each area (Fig. 434). In the regular or
endocyclk Echini, all of the ambulacra and all of the interambulacra are
essentially similar in the individual ;' but in irregular or exocyclic Echini, the
anterior ambulacrum and the posterior interambulacrum often differ consider-
ably from the corresponding areas.
Interambulacral (interradial) plates are always simple ; ambulacral plates
may be either simple or compound. In the latter case, they are formed of
two or of several component elements, all of which are joined by sutures and
form a more or less geometrical plate. Most simple plates, and some of the
components of compound plates are primaries — that is, they extend from the
outer edge of an ambulacrum to the median suture of the ai^ea. Demi-plates
is a name applied to those component elements which reach the inter-
ambulacrum but do not extend 'to the median suture (Fig. 39G). Isolated
plates are component elements which do not reach either to the interam-
bulacral or median suture. Occluded plates are component elements which
reach the median suture, but do not reach the interambulacrum. These
terms, based on compound jilate elements, can be also applied to the
CLASS I
ECHINOIDEA
261
characters seen in Paleozoic types which have many columns of simple plates
(Fig. 367, l-o).
The growth of the corona of all Echini is effected by new plates being
successively added at the dorsal termination of the ambulacra and inter-
ambulacra, and by their increasing in size. In the young, and in adults
where the ventral border of the corona has not been resorbed in the advance
of the peristome, there is a single plate, which is the primordial interambulacral,
in the basicoronal row bordering the j)eristome in each area (Clypeastroids,
Spatangoids, many Paleozoic genera) (Fig. 366, a, h, f-h, etc.). Excepting
the Bothriocidaroida, we find passing dorsally from the primordial inter-
ambulacral plate that new columns are progressively added until the full
number characteristic of the order, genus or species is attained. The new
columns come in in a perfectly definite order and system, although, where a
large number of columns is attained, there is some local variation as regards
the point of introduction and also the number of columns. As progressive
development is marked by the addition of columns, senescent or regressive
development is marked dorsally in some types by the dropping out of columns
(Figs. 429, B ; 432). The primordial interambulacral plate ventrally represents
Fio. 366.
Characters of the base of tlie interambiilacium in representative Echini : a, Bothriocidaris archtika Jackson .
Ordovician. b, Goniocidaris canaliculata A. Aiia.iis\z. Young, c, Eucidaris tribuloides (Lsimarc^). Bahamas.
d, Melonechinus multiporus (Norwood and Owen). Lower Carboniferous. «, Archaeocidaris wortheni Hall.
Lower Carboniferous. /, Echinocyavms pitsillus (Mtiller). Recent, g, Rotula dentata (Lamarck). Recent.
h, Perisclwdomus hiserwUs M'Coy. Lower Carboniferous. In figures a, b, f-h, the primordial interambulacral
plate is in the basicoronal row ; in c-e, it, with or without additional plates, has been resorbed (after Jackson).
a single column, and may be compared with the adult of the Ordovician
Bothriocidaris which retains a single column in each area throughout life.
The ventral boi'der may in the adult be retained intact, or it may have been
more or less extensively resorbed in the advance of the peristome. When
this occurs, the primordial interambulacral, with or without additional rows
of plates, are cut away. Such occurs in the Cidaroida, most of the Centre-
chinoida, and a number of Paleozoic genera (Fig. 366, c-e).
Ambulacra. — Each ambulacrum has two columns of simple or compound
plates, or in some Paleozoic genera, more than two columns of simple plates.
The ambulacrum is always composed of two halves which are equal on either
side of the median suture. Ambulacral pores are typically in pairs, rarely
(some Spatangoids) unpaired. Pore-pairs usually lie nearer to the inter-
ambulacral suture than to the middle of the plate in which they occur,
therefore as a result, where there are two columns of ambulacral plates,
there is a median interporiferous area between two marginal poriferous areas.
The pores of a pair may be vertically superposed, or usually the upper pore
of a pair revolves outward, through an angle of 90 ' or less, and toward the
interambulacrum, so that the axis of the pair is inclined or horizontal, the
inner pore being the lower of the two. A pore-pair is typically surrounded
by an elevated rim or peripodium, and the pores of a pair may be united by
transverse furrows, when they are said to be conjugate.
262
ECHINODERMATA— ECHINOZOA
PHYLUM IV
The arrangement of pore-pairs is uniserial when one pair is placed over
the other in a continuous line from the peristome to the apex ; hiserial when
so placed that there are two vertical rows of pore-pairs in each half-area,
and poll/serial when there are three to many vertical rows of j^ore-pairs in a
half-area. When ambulacral plates are compound, the pore-pairs of each
component element may be arranged in an arc, when there results a biserial
or polyserial arrangement. In Paleozoic genera, where the structure of the
ambulacrum is complex with many columns of plates (Melonechinus), the
ventral portion is simpler, presenting stages of development through which
the animal has passed. In the same types the dorsal area of young last
added plates also shows simplicity as a localised stage in development. In
those types that have compound ambulacral plates, the young plates dorsally
are simple for a short distance, as seen well in Centrechinus.
Fig. 367.
Character of the aralmlacrum in representative Echini ; left half represented. The horizontal dotted line is
on the plane of tlie mid-zone (after Jackson), ft, Bothrwcidarh urchaku Jackson. Ordovician. /*, Gnnincidaris
omaVicAilata A. Ag. Young, c, Eucidaris tnhuloides (Lamarck). Bahamas. d,Strongylocentrotns drohachiensis
(O. F. Miiller). Young, e, The same ; Adult. York Harbor, Maine. /, Micraster cor-anfjuineiim (Lamarck).
Cretaceous, England, g, KchinaracJmiiis 2Xirina (huTnarck). Eastport, Maine, h, Metalia pectoralls (hanitiTck).
Bahamas ; showing plates of two areas, i, Palaeechinus deijans M'Coy. Lower Carboniferous, fc, Maccoya
hurlinntonensis (Meek and Worthen). Lower Carboniferous. I, Lovetierhinus missouriennh (Jackson). Lower
Carboniferous, m, (lligojiorus danae (Meek and Worthen). Lower Carboniferous, n, Mdonechinus muUiporus
(Norwood and Owen). Lower Carboniferous, o, Lepidcsthes colletti White. Lower Carboniferous.
Ambulacra are usually band-shaped and continuous from the peristome
to the apical disc. Petaloid ambulacra are those which enlarge between
the apex and the circumference (ambitus), and contract again more or
less perfectly before reaching that region. Subpefaloid ambulacra are more
elongated than the petaloid, and the series of pairs of pores do not tend to
close distally. The pores do not cease altogether at the end of the petaloid
parts, but remain traceable for some distance beyond, often as far as the
peristome. In such cases, however, the pores are greatly reduced in size, or
present other marked differences from those of the petaloid parts. The
poriferous areas are said to be discontinuous, or interrupted, when 'the pairs of
pores cease at the ends of the petals, and reappear in the vicinity of the
peristome.
Oculor/enital or Apical System. — This is abactinal or dorsal, and is ordinarily
composed of ten plates, five oculars and five genitals, forming ixsually (ex-
cepting some Echinothuriidae, always in regular Echini) a continuous ring.
The genitals are typically large angular plates interradially situated and
perforated hy one or more pores communicating with the genital glands. One
of the genitals, the right anterior, is also perforated by madrejDoric pores
CLASS I
ECHINOIDEA
263
which serve in orienting a specimen. These madreporic pores are rarely
recognizable in Paleozoic Echini, and may have been wanting in some genera.
In the Exocycloida the posterior genital is usually imperforate or wanting,
and two or more to all genitals may be fused in a mass. Genital plates
may be in contact dorsally, forming a closed ring, or may be in part or wholly
separated by the oculars.
Ocular plates dorsally cover the ambulacra and laterally the inter-
ambulacra in part on either side. Each ocular has a single pore. In
Paleozoic forms, oculars are apparently imperforate or rarely with two pores.
The pores are related to a primitive large tentacle and not to an ocular organ.
Ocular plates may all separate the genitals, reaching the periproct, when they
are described as insert, the usual Paleozoic character (Fig. 433, B) ; or they
may be all excluded from the periproct by the contact of the genitals, when
B
D
Fio. 368.
Typical ocular plate arraiigeiuent in regular Bcliini (after Jackson). A, Cklaris eoronata Goldfuss. Upper
Jura; Sontheim. All oculars exsert; plates sliaded. B, SaUnocidaris profundi (Duncan). Recent; Tristan
da Cunha. (Jcular I insert ; plates shaded. C, Acrosaleniaspinosa A^^vissvi. Cornbrash ; Chippenham, England.
Oculars I, V, insert. D, Centrechimis setosus (Leske). Recent ; Bermuda. Oculars I, V, IV, insert.
they are described as exsert, the usual Mesozoic character (Fig. 368, A).
Oculars are all exsert in the young of probably all Recent and Mesozoic
regular Echini. In adults the same character may obtain, or one or more to
all oculars may travel in with development, separating the genitals so as to
be insert. As shown by Jackson, when oculars become insert, they do so in a
definite sequence in relation to the antero-posterior axis. The first ocular to
become insert is either I, or V. If ocular I comes in first, then V follows, or
the converse, thus marking the posterior pair or the bivium ; next ocular IV
becomes insert, then II, thus marking the posterior pair of the anterior
trivium ; lastly, if at all, ocular III becomes insert (shown in part in Fig. 368,
A-D).
The apical disk is relatively large in very young Echini and in primitive
types {Bofhriocidaris, Cidaroida). It decreases rapidly proportionately in size
with growth, and is relatively small in specialised regular Echini [Echinometra,
Melonechinus, Lepidesthes, Fig. 434).
In the Exocycloida the genital plates may be in contact at their sides,
forming a compact system (Fig. 369, D) ; or they may be separated by some of
the ocular plates which meet along the median line and separate the posterior
genitals, forming an elongate system (Fig. 369, C). When the two posterior
ambulacra (bivium) do not terminate at the summit in line with the other three
264
ECHINODEEMATA— ECHINOZOA
PHYLUM IV
D
\
A,
^••i.
(frivmm), and are surmounted by oculars placed far posteriorly, the system is
said to be disjunct or disconnected. The posterior oculars are then separated
from the postero-
lateral genitals by
a number of inter-
ambulacral plates
"" intercalated along
the dorsum^ (Fig.
369, A).
In the Clypea-
strina and many
of the Cassidulidae,
the apical system
consists of five
minute ocular
plates, and one
large, pentagonal,
central plate, which .
probably represents
the fused genitals
and is usually
pierced in four or
in all of its inter-
radial angles by
genital pores (Fig.
369, ^, F).
Periproct. — This structure which bears the anus is within the apical disk
in all regular Echini, when the test is termed endocyclic ; and at a variable
distance beyond it in the median line of the posterior interambulacrum in
irregular Echini, when the test is termed exocyclic. Periproctal plates are
rarely preserved in fossil Echini. They are numerous, angular, thick, and
fill the area in Paleozoic genera and the Cidaroida ; they are numerous, or
few and dissociated, often reduced to granules in other Echini ; or the
periproct may be largely leathery (Cent r echinus). In the Saleniidae there is a
large suranal (Fig. 368, £}, with additional large plates (some Acrosalenias) or
with small plates only. A suranal occurs in the young of some types as the
Echinidae and Strongylocentrotidae. The periproct is usually Icircular, but may
be angular, or in the Exocycloida varies from circular to elliptical or pyriform.
The position of the periproct in the test is of great systematic importance.
Peristome. — This is actinal and central in regular Echini, and is circular,
decagonal or pentagonal in outline. Along its margin in the basicoronal
interambulacral plates of the corona there are ten incisions for the extension
of the peristomal gills which exist in certain Echini, the Centrechinoida and
Holectypina. In the Exocycloida the peristome is variable in shape and
position, but it is actinal and is centi-al or more or less anterior from the
centre. The oral membrane of the peristome is attached to the lantern when
present, otherwise the inner edge is free.
The peristome may be more or less extensively plated or may be naked,
and the character of the plates is of systematic importance. In the young of
probably all regular Echini there is one row of primordial ambulacral plates
Fii.. 309.
Apical systems of irregular Sea-urchins. A, CollijrUcs. li, Hohctypus.
C, Hyboclypeus. D, Micraster. E, Conoclypeus. F, Clypeaster.
CLASS I
ECHINOIDEA
265
which are found in phice and fill the area (Fig. 370). From this primitive
condition various departures exist. The area may be filled with two or many
rows of ambulaci'al plates only (Bothrioci-
daris, Fig. 377, A ; Hyattechinus, Fig. i29, A ;
Fhormosoma, Fig. 371, A). These plates
after the first row have doubtless been de-
rived by migrating down from the coi'ona
as shown by Loven. There may be many
rows of ambulacral with interradial non-
ambulacral plates (Cidaroida, Fig. 371, B ;
Archaeocidaris, Fig. 371, C; Melonechinus,
Fig. 371, D). There may be one row of
ten primordial ambulacral plates with more
or less solid, scaly, or isolated non-ambu-
lacral plates, or rarely no non- ambulacral
plates (most Centrechinoida). Theu'e may be
scaly non -ambulacral plates only (Spatan-
goids), or the peristome may be quite naked
of plates (Clypeastroids).
Aristotle's Lantern. — All Echini with the
exception of Spatangoids (and possibly some
Holectypoids) are provided with a powerful
masticatory apparatus known as the Aristotle's lantern, which, with the muscles
and their points of insertion in the test are of high systematic value. The
lantern is composed of forty pieces in all Echini except Clypeastroids. There
Fig. 370.
Goniocidaris canaliculata A. Agassiz. Re-
cent; Falkland Islands. Young, 1.45 nim. in
diameter. Primordial ambulacral plates till
the peristome, primordial interambulaoral
plates in the basicoroual row succeeded by
two plates in the second row in each inter-
radial area (after Jackson).
Fig. 371.
Characters of peristome and base of the corona in representatix'e Echini. A, Phurmosona pkwenta
Wyville Thomson. Recent ; off Cape May to Cape Sable. On the peristome many rows of ambulacral plates.
B, EiicidarU tribuloides (Lamarck). Bahamas. On the peristome many rows of ambulacral and iu addition
interradial non-ambulacral plates. C, Archaeocidaris irortkeni Hall. Lower Carboniferous. Partially restoi'ed.
On the peristome many rows of ambulacral and in addition interradial non-ambulacral plates. B, Melonechinus
muUipnrus (Norwood and Owen). Lower Carboniferous. Restored. On the peristome many rows of ambulacral
and in addition two rows of interradial non-ambulacral plates ; ambulacrals pass from two plates orally to
many on the periphery of peristome in each area. E, Stro-ngylocentrotus drdhachiensis (O. P. MUUer). York
Harbor, Maine. On the peristome one row of ambulacral and scattered, small, non-ambulacral plates. F,
Echinocard i am flavescens {MiWler). Recent. On the peristome many non-ambulacral plates only. In figures
.1 and F the primordial interambulacral plates are in place in the basicoronal row ; in the other figures they have
been resorbed, with or without additional plates (after Jackson).
are five teeth ; five pyramids, each composed of two halves, joined by suture ;
ten epiphyses ; five braces ; and five compasses, each comjDosed of two j^arts,
joined by suture. The lantern is inclined, subtending an angle of about
90°, in the young of modern and adult of Paleozoic Echini ; erect with sides
approaching the vertical in most Recent regular Echini ; or procumbent in
most Clypeastroids. Teeth are grooved (Paleozoic genera, Cidaroida and
Aulodonta) ; or have a keel on the inner face (Stirodonta, Camarodonta,
266
ECHINODERMATA— ECHINOZOA
PHYLUM IV
Holectypina, Clypeastrina). Pyramids, each composed of two halves, are
roughly triangular in section, present a median suture, above which is a
shallow or a deep
open space, the
magnum.
foramen
On the inner face
the pyramid sup-
n ports and embraces
^ the tooth, and
laterally in regular
Echini has ridges
for the attachment
of interpyramidal
muscles. The
Dental apparatus of the Recent Strongyloeenlrotus drobMhknsis (O. F. Miiller). upper faCC of the
.1, Lantern showing teeth, pyramids, interpyraniidal muscles, styloid processes of ■'• ^ . ,
dental slides, epiphyses, crests and compasses. B, Pyramid showing ou one side pyramid, aS seen
protractor and retractor muscles, epiphysis removed on left side. C, top of ,„],p,, i-V,p pninhv-
lantern, at areas 2, 3 a whole tooth in place ; at 1 puljiy i)art of tooth removed ; at wnen LllL epipiiy-
4 tooth removed. At area III compass, brace and epiphyses in place ; at V com- gjg jg remOVCd is
pass removed ; at IV brace also removed ; at I the epiphysis of one side is removed '
to sliow pits in top of pyramid. 2/j (after Jackson). a smOOth IlOOr
B
Pig. 373.
(Paleozoic genera,
Cidaroida) ; or is pitted (Centi'echinoida). An epiphysis caps each half-
pyramid, to which it is joined by close suture, it presents a glenoid
cavity and tubercles for interlocking with the
brace. The epiphyses are narrow in all Echini
except the Camarodonta in which they are wide
and meet in suture over the foramen magnum ;
here also they bear crests which support the teeth
dorsally. The brace is a block-shaped plate which
rests on and interlocks with the epiphyses. The
compass rests on the brace and consists of an inner
and an outer part, joined by suture ; the outer
part is usually bifid but may be rounded. The
angle of inclination of the lantern, the teeth
grooved or keeled, the depth of the foramen mag-
num, absence or presence of pits in the top of the
pyramids, and narrow or wide epiphyses and their
meeting in suture are important features in classi-
fication.
The jaws of the Holectypoids are similar to
those just described, but in the Clypeastroids they are low, often asym-
metrical, and the teeth are aslant or even nearly horizontal (Fig. 374).
Compasses are absent, and the bi^aces are rudimentary. The pyramids are
solid almost to their upper part, more or less concave, or re-entering on the
outer side, and are not always of the same size in each area. Jaws of
Echini are rarely preserved in the fossil state.
The muscles of the lantern are numerous and complex, and their insertion
in the test is of systematic importance. There are sixty lantern muscles in
regular Echini which in brief are, ten protractors inserted on the outer face
of the pyramids and base of the test ; they extend the lantern ; ten retractors
similarly situated which open the jaws (Fig. 372, B) ; five interpyramidal
Strongylocen-
In side view
Pyramid of Recent
ti\it.ns drdbachiensis. A,
showing corrugations for attachment
of interpyramidal muscle, epiphysis
with crest, glenoid cavity, external
and internal tubercles. B, Pyramid
from centre showing dental slide and
other parts as in A (after Jackson).
CLASS I
ECHINOIDEA
267
Fio. 374.
.4, Clypeaster retkulatus Loven.
Recent. The dental system entire, seen from
above. The braces are placed upon the sutures of adjoining pyramids, with an
epiphysis on either side. Teeth in line with the mesial sutures of half-pyramids,
an<l within the ring formed by the supra-alveolar crests (after Loven). B, a, Front
view of a single pyramid ; 6, side view of one of the half-pyramids.
muscles (Fig. 372, A) which contract the jaws; ten internal and ten external
brace muscles, which are tiny and extend from the brace to the epiphyses ;
five circular compass muscles which dorsally connect the compasses ; ten radial
compass muscles
which extend
from the com-
pass to the base
of the test.
These last are
wanting in Cly-
peastroids as in
that group com-
passes are ab-
sent.
Perignathic
Girdle. — Cer-
tain muscles of
the lantern, namely, the retractor, protractor and radial compass, pass to and
are inserted on the base of the test, and certain important processes, the
perignathic girdle, may be built for insertion of these muscles. Loven showed
that in young Goniocidaris the lantern muscles are all attached directly on the
base of the interam^^ulacra, and the same method probably existed in the
Perischoechinoida, as in that order no perignathic processes have been seen.
In adult Cidaroida elevated processes, the apophyses exist as strong internal
upgrowths of the ventral border of the basicoronal interambulacral plates ; to
these apophyses in this order alone are attached the retractor, protractor and
radial compass muscles. In the order Centrechinoida the apophyses or up-
growths of the interambulacral plates may be feebly or strongly developed, and
to them are attached the protractor and radial compass muscles. In this order
a new structure appears consisting of two separate calcareous plates, the
auricles, which are united by close suture to the basicoronal ambulacral plates.
The auricles exist as separate styles or in some genera in development may
grow into large plates which arch and join in suture over the ambulacral area.
Auricles give insertion to the retractor muscles, which combination of
apophyses and auricles is known in this order only. In the Holectypoids
low apophyses and auricles, or auricles alone may exist ; as this groui?
occurs fossil only, the muscles can only be inferred. In Clypeastroids
apophyses are wanting, but low or high aui'icles exist on the ambulacral
plates, or even may be transferred to the basicoronal interambulacral plates
as seen in Echinarachnius. In Clypeastroids retractor and protractor muscles
are both inserted on the auricles, a condition peculiar to the group.
Tubercles and Spines. — The plates of Echini bear more or less numerous
tubercles and granules of various sizes which bear larger or smaller spines.
The larger and completely developed tubercles are called primaries ; those
of a smaller size are secondaries; and very small tubercles, sometimes
incomplete in their development, are miliaries. Grannies are irregular or
nodular projections of the test ; they may be large and widely separated,
or very numerous and of various sizes. The base of a tubercle is termed
the boss, and its upper part may be either plain or crenulated. The boss
supports a rounded mamelon, which is said to be perforated when pierced by a
268
ECHINODERMATA— ECHINOZOA
PHYLUM IV
t
m
Fig. 375.
Cidarid Sijines. A, B, Cidaris. D, Acrocidaris.
E, Forocidaris (natural size).
central foramen for a slight distance, or imperforate when it is not, A plain
or sunken space surrounding the base of the tubercle is called the scrobicule,
or areola ; its outer limit, the scrohicular circle, is generally marked by a ring
^ D £ ^^ granules, but in many cases the
T scrobicules of the same meridian are
continuous. Secondary tubercles may
or may not be scrobiculate.
All the tubercles of Echini bear
movable spines, which differ greatly in
dimensions, and in the shape and'
nature of their cross-sections. They
are usually cylindrical, acicular, clavate
or spatulate in form, and consist of
the following parts : A more or less
elongate distal portion or shaft ; a base,
to which ligaments are attached for
keeping the spine in place ; and an
articulating joint or conchjle {acetabulum),
forming a ball-and-socket joint with
the tubercle proper. When the base
of the mamelon is crenulated, the base
of the spine is incised in the same
manner, and above the latter is usually a milled ring or collar, the indenta-
tions of which are continuous with the striae of the shaft. The function of
spines is to support the test, to aid in locomotion, and for defence. In rare
cases some of the spines are fixed, and arise directly from the test (Recent
Podocidaris).
Fascioles are narrow bands of close granular ornamentation which
support rudimentary spinules and pedicellariae. They occur only in the
Spatangoids, and are restricted to certain parts of the test. The peripetalons
fasciole follows the margin of the petaloid parts of the ambulacra. The
anal fasciole surrounds the anus, and the suhanal fasciole encloses a space or
plastron beneath the anus, but may send anal branches upward. The internal
fasciole crosses the ambulacra at a variable distance from the apical system,
and the marginal fasciole encircles the test above the ambitus. For those
Spatangoids with subanal fascioles, Lov6n has proposed the name Prymno-
desmia ; genera without them, and with other fascioles, are Pnjmnadetes, and
those without any fascioles are Adctes.
Pedicellariae are small specialised organs articulated upon granules and
scattered between the spines over the whole test. At the end of the stem
is a head consisting of two or more pincer-like valves which function as
grasping and cleansing organs. Pedicellariae are very rarely preserved in
the fossil state.
Sphaeridia are opalescent spheroidal bodies which may be partially or
entirely covered by the test. They exist singly near the ventral border of
the ambulacra, or if moi:e than one, the series extends dorsally, even to the
ocular plate. Morphologically, sphaeridia may be considered as modified
spines having sensory functions. They are known only in the Centrechinoida
and Exocycloida.
Ontogeny. — The early larval stages of Echini are similar in many respects
CLASS I
ECHINOIDEA 269
to those of Ophiurans and Starfishes, but have little in common with the
larvae of Crinoids. The later stages in development are of great morpho-
logical and phylogenetic interest. Stages in development can, of course, be
best obtained by studying young individuals, but, as shown by Jackson,
they can also in a measure be obtained from a study of adults. The plates
at the ventral portion of the test are the oldest and first formed, excepting
as some may have been resorbed in the advance of the peristome. Ventrally,
therefore, stages in development are often observable in both the ambulacra
and interambulacra, this condition being especially marked in the Perischo-
echinoida. Dorsally are found the youngest plates of the test, and it is here
that we observe localised stages in development. For, as we pass ventrally
to the progressively older plates, it is found that characters are taken on
in regular sequence which present stages directly comparable to those seen
in the youthful development of the individual. Dorsal localised stages are
especially marked in the ambulacra of those types where a complex structure
is attained, as in the Palaeechinidae and the Centrechinoida. The apical disk,
periproct, peristome, lantern and perignathic girdle all show stages in
development with suitable material, which stages are directly comparable
to adult conditions of simpler members of the group, and therefore are of
great phylogenetic significance.
Among Echinoids, as elsewhere in invertebrate groups, evidence is accumu-
lating that evolutionary variation is not radial in all directions, but rather is
in definite directions, or orthogenetic. It would appear that the majority of
variations are either arrested, in which cases the variant retains characters
displayed in its own youthful stages and typical of the adults of more primi-
tive allies ; or progressive, when the variant has characters not typical of the
species, but which are further evolved in the direct line of differential develop-
ment. These latter are seen typically in more highly evolved closely related
species or genera. In order to study variation intelligently it is of prime
importance to be familiar not only with the characters of the associated
species and genera when considering any given case, but also with the develop-
mental characters of the same. Variation needs to be especially considered in
undertaking phylogenetic studies.
Homologies. — The Echinoidea differ radically from the Pelmatozoa and
Asterozoa in that arms are completely wanting. They differ from Crinoids in
that reproductive glands are within the test and interradial, that ambulacral
and interambulacral plates originate on the ventral border of a fixed plate, the
ocular, and in the possession of a lantern. Echinoids differ from Starfishes
essentially in that radial water, nerve and blood canals are on the proximal not
distal side of the ambulacral plates ; that ambulacral pores pass through, not
between the plates ; and in the possession of a lantern.
Habits. — Echini are exclusively marine, and are more or less gregarious.
Many species occur in littoral zones, and from that region various species and
genera extend to continental and abyssal depths. Echini commonly live on
the surface of the sea flooi-, or cling to rocks. Some Echini burrow in sand,
others {Strong ijlocentrot us, Echinometra) along the coast occur in cavities which
they bore in solid rocks. The same species does not excavate in sheltered
places.
About 500 recent species are known, as compared with fully 2500 fossil.
The earliest types appear in Ordovician rocks (Bothriocidaris), and continue to
270
ECHINODEEMATA— ECHINOZOA
PHYLUM IV
be represented sparsely throughout the Paleozoic era. They multiply enor-
mously in the Mesozoic, and certain families reach their climacteric in that
period ; other families attain their maximum in the Recent. As a rule, the
species have a very limited vertical range, and hence serve admirably as index
fossils. The test is often perfectly preserved, but even small fragments are
capable of accurate determination, owing to the regular radial repetition
of parts.
The classification here followed is based on that given in Jackson's
Phylogemj of the Echini ; no subclasses are recognised, but the group is
divided into seven orders. The generic descriptions of the Cidaroida and
Centrechinoida and the generic and family descriptions of the Exocycloida are
essentially those as given in the earlier edition of this work, or in Duncan's
Revision of the Genera and Great Groups of the Echinoidea.
Order 1. BOTHRIOCIDAROIDA Duncan.
Test regular, more or less spherical. Interamhulacra with one, and ambulacra
with two vertical columns of plates, which do not imbricate. Feriproct within the
apical system.
Family 1. Bothriocidaridae Klera.
IFith characters of the order.
The solitary known genus is Bothriocidaris Eichwald (Figs. 366, a ; 367,
a; 376; 377), from the Ordovician of Esthonia. The test is small, and the
Fig. 37C.
Bothriocidaris pahleni Schmidt. Ordovician ; Nomniis, Esthonia. A, Test of the natural size,
system, enlarged. C, Peristome, enlarged (after P. Schmidt).
B, Apical
apical system consists of five large ocular and five small genital plates ;
periproct plated, peristome with ambulacral plates only.
Of this important genus, tlie oldest of known Echini, there are tlirce sjiecies, B. archaica,
pahleni and globulus. The ambulacra have two columns of high hexagonal plates in each
area with pore- pairs superposed in a central peripodium. Interambulacra with one column
of [)lates only in each area. Ocular plates relatively large and meeting in a continuous ring
{B. archaica), or partially or wholly separated by the small genitals. Genitals in B. archaica
dorsal to the oculars (Fig. 377, B) or in other species partially or wholly separating them and
reaching the interambulacra. Bothriocidaris is structurally imj)ortant because in its high
ambulacral plates, with pores superposed, its single column of interambulacral plates, its
simjile peristome and its large oculars, it presents features like the young of later Echini. All
other Echini start with a single interambulacral plate ventrally, representing a single column,
and later add one or more columns. Those types with only two colunuisof plates in an inter-
ambulacral area show no evidence of being derived from types with many colunnis, and are
therefore considered as next related to the Bothriocidaroida.
CLASS I
ECHINOIDEA
271
Order 2 CIDAROIDA Duncan.
Test regular, endocydic, two columns of plates in each ambulacral area, amhiila-
cral plates loio, simple; two (in one genus, Tetracidaris, partly four) columns of
A, Botliriocidaris archaka Jackson. Ordovician ; Island of Dago, Russia. Height, 12 mm. Two rows of
peristomal plates. Two eohmins of hexagonal plates in each ambulacrum. One column of plates in each inter-
ambulacrum. x3/i. B, the same, apical disk, oculars meeting in a ring, genitals small, d(jrsal to the oculars, peri-
proctal plates, x Vi (after Jackson).
plates in each interamhulacral area. Coronal plates rarely imbricate [Miocidaris).
Primordial inferamhidacral ptlates resorhed. Peristome with many rows of ambulacral
and interradial non-ambidacral plates, or rarely ambulacral plates only. Lantern
erect, teeth grooved, foramen magnum very shallow ; epiphyses narrow. No pits in
the top of pyramids. Perignathic girdle consisting of apophyses only. Stewart's
organs jyresenf, but no peristomal gills. Primary spines with a cortical layer.
Primary tubercles perforate. Sphaeridia absent.
272
ECHINODERMATA— ECHINOZOA
PHYLUM IV
Family 1. Cidaridae Gray.
JFith characters of the order.
The apical disk is rare in fossil Cidarids (Fig. 368, A); when preserved, the
ocular plates are typically all exsert. The same condition exists in the young
of Recent species and often in adults. When oculars reach the periproct,
they do so in the sequence Y, I, IV, II, III, or V, I, IV, III, II. Young
Cidarids approach Bothriocidaris closely in many structural details. De-
vonian (?), Lower Carboniferous to Recent ; maximum in Jura and Cretaceous.
Section A. Ambidacral pore-pairs uniserial.
Miocidaris Doderlein. Ambulacral and interambulacral plates imbricating.
Two Paleozoic species, M. keyserlingi (Geinitz), from the Permian of Europe,
Fig. 378.
Cidarls coronata Qoldt. Upper Jura (-y) ; Hossingen, Wurtemberg. A, Dorsal aspect of test with perfectly
preserved apical system. B, Profile. '', Portion of Amh, magnified. D, Partially restored view with spines
attached.
and M. cannoni Jackson, from the Lower Carboniferous of America, are the
only certain Paleozoic representatives of the order. Several species in the
Trias and Jura of Europe.
Cidaris Leske, ex Klein (Figs. 368, ^ ; 378-380). Amb undulating or nearly
straight, the pores variable in their distance, and united by a groove or not.
lArnh coronal plates five to fifteen in each column. Apical system large.
Primary spines very variable, even in the same species. Trias to Recent ;
chiefly Jurassic and Cretaceous.
Of this genus more than 200 species have been described. These are grouped into seven
or eight artificial divisions, which are regarded by some as of sub-generic, or even generic
importance. Some of the groups may be briefly noticed as follows : —
CLASS I
ECHINOIDEA
273
(a) Rhahdocidaris Desor (Figs. 381, 382). Test large and swollen. Poriferous areas wider
than in Oidaris, the two pores of a pair being distant and conjugated. A7nb in general
straight. Tubercles large, strongly crenulated, and more numerous than in Cidaris. Spines
very stout, some cylindrical or prismatic, often spiniferous. Chiefly Jura and Cretaceous ;
less common in Tertiary and Recent.
Pi(i. 379.
Eucidaris tribulo'ides (Lam.). Repent. Enlarged view of base of the
test and peristome, showing plated covering of the latter.
Cidarid spines. A,
C. alnta Ag. B, C.
dorsnta Braun. Trias ;
St. Cassian, Tyrol.
C, (-'. fioriiicmiiiii Phill.
Fifi. 381.
RhididocUJarh nrhignyaiia Desor. Upper
Jura; Kelheim-Winzer, Bavaria. ^, Fiag-
ment of test, Vi. L', Amb plates enlarged.
Fi(!. 382.
Rhahdocidaris horridn
Merian. Middle Jura.
Spine, i/i-
(b) Lciocidaris Desor. Like the preceding, but with uncrenulated tubercles. Spines
large, smooth, cylindrical. Cretaceous to Recent.
(c) Stephanocidaris A. Ag. Test thin ; ajiical system larger than the peristome, the
plates feebly united. Recent.
(d) Phyllacanthus Brandt. Test large, swollen, and with eight to eleven lAmh plates
in a column. Amh broad, pores conjugated. Primary tubercles large, smooth. Recent.
(e) Porocidaris Desor (Fig. 383). Arab broad and straight ; pores wide ajiart, conjugated.
Primary tubercles perforate and crenulate. Scrobicules transversely oval, with shallow
grooves radiating from the periphery toward the centre, with or without pores at the outer
extremity of the grooves. Tertiary and Recent.
(/) Goniocidaris Desor. Test high, with numerous coronal plates, and narrow Amb.
The median sutural regions of both areas are sunken, forming with the horizontal sutures
a zigzag, with pit-like depressions at the angles. Recent.
VOL. I T
274
ECHINODERMATA— ECHINOZOA
PHYLUM IV
Orthocidaris Cotteau. Apical system small, pentagonal. Amb narrow,
straight ; pore-pairs in simple straight series, the pores separated by a
granule. lAmb very broad, numerously plated. Primary,
tubercles small, plain, perforate and distant. Lower Creta-
ceous ; Europe.
Temnocidaris Cotteau. Upper Cretaceous. Polycidaris
Quenst. Upper Jura.
Section B. Amhulmral Pore-pairs Biserial.
Diplocidaris Desor. Test large, spheroidal. A^nb narrow,
straight. Pore-pairs very numerous, close, alternating more
or less. lAmh broad, with seven to eight plates in each
column. Primaiy tubercles large, perforate, scrobiculate.
Upper Jura ; Europe.
Tetracidaris Cotteau (Fig. 384). Remarkable in having
four columns of plates in each lAmh at the ambitus, but
diminishing to two at the apex. Ar)ib straight, moderately
broad. Poriferous areas depressed, pairs incompletely
biserial ; interporiferous areas narrow, granular, with a row
of plain small tubercles, placed near the borders of the
poriferous zone. lAmh primary tubercles very large,
crenulate and perforate. Spines narrow, elongate. Lower Cretaceous (Bar-
remien); Europe.
Fig. 383.
I'orocidans schmiedeli
Goldf. Nnmmulitic
Limestone; Mokkatain,
near Cairo. /.4m;) plate
and sjiine.
Fni. 384.
TetiucUlarin reynesl Cotteau. Neocomian ; Vergans, near Castellane, Bas.ses AliJSS. A. Test reduced
one-half. /?, Portion of Jm/j, enlarged (after Cotteau).
Xenocidaris Schultze. Founded upon clavate, fusiform spines from the
Devonian of the Eifel. Licompletely known, possibly belongs in this family.
Orders. CENTRBCHINOIDA ^ Jackson.
Test regular, endocyclic, two columns of plates in each amhulacral area,
amhulacral plates compound, rarely simple; two columns of plates in each inter-
^ This name is based on Oentrechinus, a new name for Diadema which was preoccupied for a
Crustacean.
CLASS I
ECHINOIDEA
275
amhulacral area. Primordial ambulacral plates around the mouth in the peristome.
Primordial inter amhulacral plates in the basi-coronal row, or usually resorbed.
Peristome ivith ten primordial amhulacral, also non-ambulacral plates, or in one
family many rows of ambulacral plates only. Lantern erect or rarely inclined;
teeth grooved, m- keeled : foramen magnum deep. Pits in the top of pyramids.
Perignathic girdle consisting of low or high apophyses, and auricles. Peristomal gills,
rarely with Stewart's organs in addition. Primary spines without a cortical layer.
Sphaeridia present.
Compound ambulacral plates are the most striking feature of this order ;
such plates are composed of from two to ten elements, each of which has
a pore-pair. The young of the Centrechinoida present stages in development
which closely resemble the Cidaroida and also Bothriocidaris. The Centre-
chinoida are divisible into three suborders on the basis of the structure of the
lantern, which is in brief, teeth grooved, epiphyses narrow, Julodonfa ; teeth
keeled, epiphyses narrow, Stirodonta ; teeth keeled, epiphyses wide, meeting in
suture over the foramen magnum, Camarodonta. Trias to Recent.
Suborder A. AULODONTA Jackson.
Teeth grooved. Epiphyses narrow, not meeting in suture over the foramen
magnum. Ambulacral plates simple or compound. Ocidars all exsert, or becoming
insert in the sequence I, V, IV, II, III. Periproct with many plates or granules,
or largely leathery. Lantern erect or inclined. Primary tubercles usually perforate.
Trias to Recent.
Family 1.
Hemicidaridae Wright.
Ambulacral plates compound ventrally, simple above the mid-zone, or in some
genera compound throughoid. Coronal plates thick, not imbricating. Base of
corona resorbed. Ocidars all exsert, or one, or two may he insert. Periproct
unknown. Peristome unknown. Lantern erect. Trias
to Tertiary.
Hemicidaris Agassiz (Fig. 385). Amb narrow ;
plates near the apical system very numerous, small,
low primaries, succeeded by plates formed of from
two to four components, together with additional
primary or demi-plates. Tubercles in two vertical
rows, perforate and crenulate. lAmh broad, with
two vertical rows of tubercles similar to those of
the Amb, but much larger. Oculars all exsert or
I, or I, V insert. Peristome large, with well-
developed branchial incisions. Trias to Cretaceous.
The following subgenera are recognised : —
(a) Hemidiadema Ag. Amb tubercles large, and few in number below the ambitus,
alternating distinctly. Jura and Cretaceous. H. stramonium Ag.
(6) Hypodiadema Desor. Amh narrow, straight ; their tubercles of nearly the same size
throughout. Peristome and branchial incisioiis small. Trias to Cretaceous.
(c) Psetidocidaris Etall. Amb very undulating abactinally, with primary tubercles near
the peristome, granules elsewhere. Jura and Cretaceous.
Acrocidaris Ag. (Fig. 386). Test large, spheroidal dorsally, fiat actinally.
FiCf. 385.
Hemicidaris crenularis (Lam. ).
Coral Rag; Chatel Ceiisoire, Yonne.
i/i-
276
ECHINODERMATA— ECHINOZOA
PHYLUM IV
Amb straight, broad at the ambitus ; pore-pairs uniserial and in simple series
near the apex, in arcs of from four to seven pairs near the larger tubercles,
crowded and polyserial actinally. lAmb with two vertical rows of primary
Acroddaris nobilis As.
Fic. 386.
Upper Jura ; St. Sulpice, near Loole, Neuchatel. ^1, Dorsal view, B, Ventral view.
C, Spine, Vi- D, Three compound Amb plates, enlarged.
tubercles ; only the largest are perforate and crenulate. Spines cyclindrical,
often tricarinate. Upper Jura and Cretaceous.
Goniopygus Agassiz. Apical disk large, plates more 'or less ornamented ;
oculars insert, genital plates punctured on adoral margin.
Peristome very large, with small branchial incisions.
Cretaceous and Eocene.
Glijpticus Ag. (Fig. 387). Amb straight, and narrow
except at the peristome, where the poriferous areas are
expanded ; with two vertical rows of small, smooth, primary
tubercles. lAmh tubercles replaced abactinally by warty
or irregular elongate elevations. Epistroma much developed.
Abundant in Upper Jura.
Pig. 387
Family 2. Aspidodiadematidae Duncan.
<'»!ivfi'''us Merogiigih- Amhulcicral plafes simple. Coronal plates thin, not imbri-
icns Goldf. Coral Ras ■ r, r
(Giyptician) ; Fringeii, eating. Bttsc of cowna resovbed. Oculars all exsert, or all may
1- j^ insert. Peristome with ten large primordial ambulacral
plates. Lantern erect. Lias to Recent.
Orthopsis Cotteau. Amb much narrower than the I Amb, straight, and with
numerous pairs of pores in straight series. Amb with two, lAmb with several
vertical rows of small, plain, perforate tubercles. Jura and Cretaceous.
Eodiadema Dnncan. Lias; England. Echinopsis Ag. Eocene; Europe and
Egypt. Aspidodiadema A. Ag. Apical disk very large, oculars insert. Recent.
Family 3. Centrechinidae Jackson (Diadematidae Peters).
Ambulacral plates, compound. Coronal plates not imbricate {Mesozoic), or more
or less imbricate (Becent). Base of corona resorbed. Oculars exsert, or one to all
insert. Feriproct more or less plated, to nearly leathery. Peristome with ten
CLASS I
ECHINOIDEA
27'
The Amh are
primordial amhulacral, also non-amhulacral plates. Lantern erect, or (Astropyga)
inclined. Stewart's organs slight, or absent. Lias to Recent.
Centrechimis Jackson (Diadema Schynvoet) (Fig. 368, D).
narrow, often projecting; two vertical ^
rows of small, primary, crenulate and
perforate tubercles extending from
peristome to apex. lAml with two
or more vertical rows of primary
tubercles resembling those of the
Amh, but larger. Secondary tubercles
and granules surrounding the scrobi-
cules. Spines long, hollow, longitu-
dinally striated. Lias to Recent.
Hemipedina AVright. Jura, Creta-
ceous and Recent. Differs from Centre-
chimis in having simple AmJi plates
near the apex, and perforate, but
not crenulate tubercles.
Pseiidodiadema Desor (Fig. 388).
Includes small species having wide
Amh, tubercles of uijiform size in
Amh and lAmb areas, and oculars
typically all exsert. Jura to Ter-
tiary.
Heterodiadema Cotteau. Like
Centrechinus, but Avith the apical
system greatly extended into the depressed posterior lAmh
H. lilnjcmn Cotteau.
Codiopsis Ag. (Fig. 389). Primary tubercles of both areas small, smooth.
Fii5. 38S.
Pseudodiadema neglectum Thunii. From the Bernese
Jura. -I, B, Profile and ventral aspect of test, l/i.
C, Ambulacrum, enlarged. ' D, Spine, Vi-
Cretaceous.
Fic. 3811. ■
Codiopsis doma (Desm.). Cenomanian (Tourtia) ; Tournay, Belgium. ^, Side-view of test, i/i- 5, Ventral
aspect of same. C, Apical system, enlarged.
nearly equal in size, and only occurring actinally and for a short distance
toward the ambitus. Pore-pairs uniserial. Cretaceous.
Cottaldia Desor. Cretaceous and (?) Recent. Pleurodiadema de Loriol.
Jura. Magnosia Michelin. Jura and Cretaceous.
Diplopodia M'Coy. Amh narrow, with two vertical rows of perforate and
crenulate primary tubercles. Pore-pairs in double vertical series near the
poles, uniserial at the ambitus. Jura and Cretaceous.
Pedinopsis Cotteau. Cretaceous. Phymechinus Desor. Jura.
278
ECHINODERMATA— ECHINOZOA
PHYLUM IV
Pedina Ag. Atnb narrow, poriferous areas wide. Both areas with two
vertical rows of small, perforate, primary tubercles. Upper Jura.
Pseudopedina Cotteau. Like the preceding, but with larger primary
tubercles, which are present in the Amb near the ambitus only. Upper Jura.
Micropedina Cotteau. Amb with several, and I Amb with numerous vertical
rows of very small primary tubercles. Cretaceous.
Leiopedina Cotteau {Chrysomelon Laube). Test large, melon-shaped. Amh
long, straight, very broad. Poriferous areas broad, pore-pairs triserial, and
almost horizontal. Plates very numerous, low, broad, compound. Tubercles
small, plain, finely perforate, in two distant vertical rows. lAmh broad, with
f^h
Fit!. 300.
Stomedhinus lineatus {QiO\d.U). Coral Rag; Sontlieim, Wiirtemberg. ^4, Side- view of test, i/i. £, Portion
of actinal surface.
two rows of tubercles similar to the ambulacral, and with intermediate
granules. Eocene.
Stomecliinus Desor (Fig. 390). Distinguished from Pedina by its wider
Amb, and imperforate, non - crenulate primary tubercles. Secondary
tubercles and granules often present. Jura and Cretaceous.
Codechinus Desor. Tubercles very small, plain, irregularly distributed.
Cretaceous.
Polycyphus Agassiz. Jura, Astropyga Gray. Recent.
: Family 4. Echinothuriidae Wyville Thomson.
Ambidacral plates compound. Coronal plates very thin, imbricate. Primordial
interambulacral plates in basicoronal row. Base of corona not resorbed. Ocidars
insert, often separated from the genitals by interspaces. Genitals more or less split
by secondary sutures. Periproct leathery but partially plated. Peristome with many
rows of ambulacral plates only. Lantern inclined. Radial peristomal and somatic
muscles. Stewart's organs present. Jurassic to Recent.
This family is represented by several living and two extinct genera, the
latter being known only by fragmentary specimens. Pelanechinus Keeping
is found in the Upper Jura, and Echinothuria Woodward in the Upper
Cretaceous of England. Phormosoma Wyv. Thomson (Fig. 371, A) and
Asthenosoma Grube. Recent, occurring chiefly in depths below 100 fathoms.
CLASS I
ECHINOIDEA
279
Suborder B. STIRODONTA Jackson.
Teeth keeled. Epiphyses narroiv, not meeting in suture over the foramen
magnum. Amhulacral plates compound or largely simple. Coronal plates not
imbricate. Primordial interamlndacral plates resorhed or retained in the hasicoronal
roiv. Base of corona resorhed or not. Oculars all exsert or becoming insert in the
sequence I, V, or V, /, IV, II, III. Periproct with prominent suranal, or with
many small plates, or four, or five large plates only. Peristome ivith ten primordial
ambidacral, also non-ambulacral plates. Lantern erect. Primary tubercles
imperforate, or exceptionally perforate. Jurassic to Recent.
Family 1. Saleniidae Desor.
Ambidacral plates compound, or largely simple. Primordial interambulacral
plates resorbed. Base of corona resorbed. Oculars exsert or becoming insert in the
sequence I, V, IV, II, III. Periproct with a permanent large suranal, or more
large plates, with small anal plates. Primary tubercles imperforate, or perforate.
No spurs from pyramids supporting teeth dorsally. Jura to Recent.
Peltastes Ag, (Fig. 391). Amb straight or slightly flexuous, with simple
....^/'
Fig. 391.
Pdtastes, apical system ;
m, madreporite. ''^g^^^^ Fto qq.^
Salcnia scut'ujara Gray. Wliite Clialk ; Charente
(after Cotteau). .4, Lateral and dorsal aspects of
tests, ^l\. B, Apical system, enlarged.
plates abactinally and with small primary tubercles near the poriferous
areas. lAmb broad, with large, imperforate primary tubercles, diminishing
in size toward the poles. The suranal plate is small, in contact with the
lateral genitals, but not touching the posterior one. Upper Jura and
Cretaceous.
Salenia Gray (Fig. 392). Test small, globose, or depressed. Amb plates
compound or largely simple. The suranal plate is in contact with all the
genitals ; oculars all exsert or ocular I reaching the periproct, perforated at
the adoral edge. Cretaceous to Recent.
Goniophorus Agassiz. Upper Greensand ; Europe. Heterosalenia
Cotteau. Cretaceous ; Europe.
Acrosalenia Ag. (Fig^s. 3Q8, C ; 393). Test depressed. ^7?i5 plates simple
primaries near the apical system, compound near the ambitus and actinally.
I Amb tubercles large, perforate, and crenulate ; those of the Amb much smaller,
and in two vertical rows. Periproct large, bounded anteriorly by the suranal
plate, which is in contact with the four large anterior genitals, or more
280 ECHINODERMATA— ECHINOZOA phylum iv
than one large periiDroctal plate. Oculars all exsert or one to all insert,
Fig. 393.
Acrosalenia hemicidaroides yfright. Middle Jura; Stanton, Wiltshire. Dorsal, lateral and ventral aspects
of test, i/i (after Wright).
commonly I, V insert. Spines cylindrical, striated or plain. Represented
by numerous species from the Lias to the Lower Cretaceous.
Family 2. Phymosomatidae Meissner.
Ambulacral plates compound. rrimordial interambulacral plates resorted.
Oculars becoming insert in the sequence I, F, IF, II, III. Periproct with
numerous small plates onli/. Primarij tubercles imperforate. Spurs from pyramids
support the teeth dorsalli/. Jura to Recent.
Cyphosoma Agassiz (Fig. 394).
Fio. 394.
Cyphosoma kueni III Mantell. White Chalk
Sussex. Ventral aspect, '/i-
Test depressed, with few coronal plates.
Amb with well-developed poriferous areas
undulating. Pore -pairs biserial at the
apex, crowded at the peristome. I Amb
broader than the Amb, wnth two or more
vertical rows of primary tubercles, which
are imperforate and crenulate, like those
of the Amb. Apical system encroaching
upon the posterior lAmb. Jura to Ter-
tiary.
Glyptocidaris A. Agassiz. Recent. This
genus shows the character of pyramidal
spurs given as a family character.
Micropsis Cotteau. Amb with three to
five elements to a compound plate, and
two or more vertical rows of small primary
tubercles, wdiich are perforate and crenu-
late. Cretaceous and Eocene.
Family 3. Stomopneustidae Morteiisen.
Ambulacral plates compound, composed of three elements each, at the mid-zone
every four or five ambulacral plates are bound together and grown over by one
primary tubercle. Primordial interambulacral plates and base of corona resorbed.
Oculars becoming insert in the sequence I, V, IV. Periproct loith many small plates
only. Primary tubercles imperforate. Spurs from pyramids support the teeth
dorsally.
CLASS I
ECHINOIDEA
281
Stomopneustes Ag. Amb straight, with pores in arcs of three pairs dorsally
crowded and triserial below the ambitus. Both areas with two vertical rows
of plain tubercles. Formerly classed with the Echinometridae, from which it
ditfers radically, especially in structure of the lantern. Tertiary and Recent.
Family 4. Arbaciidae Gray.
Amhulacral plates compound. Primordial interamhulacral plates in the hasi-
coronal row. Base of corona not resorhed. Oculars all exsert or becoming insert
in the sequence F, I, IF. Periproct with four or Jive large plates only. Primary
tubercles imperforate. No spurs from pyramids supporting teeth dorsally. Tertiary
to Recent.
Arbacia Gray. With three elements in an ambulacral plate. Tertiarj'
and Recent.
TetrapygiLS Agassiz. With five elements in an ambulacral plate. Recent.
Coelopleurws Ag. (Fig. 395). Amb with two vertical
rows of plain, primary tubercles placed on flat scrobi-
cules, diminishing in size toward the apex, and some-
times replaced there by granules. lAmb with a large
bare median area abactinally ; the tubercles largest at
the ambitus, sometimes disappearing toward the apical
system. Tertiary anfl Recent.
Podocidaris A. Agassiz. Recent ; Caribbean Sea and
Philipi^ines.
Fid. 395.
Coelufilenrus oquis Ag.
Eocene : Biarritz, France.
Suborder C. CAMARODONTA Jackson.
Teeth keeled. Epiphyses wide, meeting in suture over
the foramen magnum. Ambulacral plates compound. Coronal
plates not imbricate. The ambitus is circular, or elliptical
through a sidewise axis. Primordial interambulacral plates
resorbed. Base of corona resorbed. Oculars all exsert or
becoming insert in the sequence F, I or I, F, IF, II, III. Periproct usually plated
with many small plates (in one genus, Parasalenia, wifJi four large plates).
Peristome tvith ten (in one species five) primordial ambulacral plates and more or
fewer non-ambulacral plates ; rarely the latter are absent. Lantern erect. Primary
tubercles imperforate. Cretaceous to Recent.
Family 1. Echinidae Agassiz.
Ambitus circular. No pits or sculpturing in the coronal plates dorsally.
Ambulacral plates at mid-zone composed of three elements each, rarely dorsally of
two elements. Oculars all exsert, or becoming insert in the sequence I, F, IF, II,
III. Cretaceous to Recent.
Echinus Linn. Amb straight, with narrow poriferous zones ; pore-pairs in
more or less vertical arcs of triplets. Interporiferous areas with two vertical
rows of small, plain, primary tubercles with or without irregularly placed
secondary tubercles and primaries. I Amb with two vertical rows of primaries,
and few or numerous rows of secondary tubercles and miliaries. Peristome
small, circular. Cretaceous to Recent.
282 ECHINODERMATA— ECHINOZOA phylum iv
Stirechinus Desor. Both areas with two rows of large, plain, primary
tubercles situated on raised keel-like projections. Pliocene ; Europe.
Glyptechimis de Loriol. Cretaceous. Tripneustes Agassiz. • Miocene and
Eecent.
Hypeclunus Desor. Tertiary. Tozopneustes Agassiz. Recent. Boletia
Desor. Recent.
Family 2. Temnopleuridae Desor.
Ambitus circular. Pits, or sculpturing in coronal plates dorsalhj. Amhulacral
plates at the mid-zone composed of three elements each. Oculars usually all exsert.
Cretaceous to Recent.
Glyphocyphus Haime. Test small, depressed spheroidal. Amh narrow,
straight, with two vertical rows of small, perforate, crenulate, primary
tubercles, and numerous miliaries. I Amh broad, with two rows of primaries
somewhat larger than those of the Amh. Transverse and median sutures
grooved. Oculars all insert. Cretaceous and Eocene.
Dictyopleurus Duncan and Sladen. Eocene ; Asia, Europe and Egypt.
Paradoxechinus Laube. Miocene ; Australia. Echinocyphus Cotteau, and Zeuglo-
pleurus Gregory. Cretaceous ; Europe.
Temnopleurus Ag. Transverse sutures of all plates grooved and pitted.
Apical system small, compact, slightly projecting. Tertiary and Recent.
Temnechinus Forbes. Test small, subglobose, depressed abactinally.
Both areas with two vertical rows of plain primaries. Apical system
prominent, compact, the sutures between the plates more or less grooved.
Late Tertiary and Recent.
Salmacis Ag. Eocene, Pliocene and Recent. Alicrocyphus, Amhlyjmeustes,
and Holopneusfes Agassiz. Recent.
Family 3. Strongylocentrotidae Gregory.
Amhitus circular. No pits or sculpturing in the coronal plates. Amhulacral
plates at the mid-zone composed of from four to ten elements each, rarely (some
Echinostrephus) of three elements each. Ocidars all exsert or hecoming insert in the
sequence I, V, IV, II. Tertiary to Recent.
^-=_,,_^___ r— , Strongylocentrotus Brandt (Figs. 371, E ; 372-3,
'^T^s^^j^) ^ — -\ ^v, 396). Test symmetrical and polyporous. ^-^//ift straight,
broad at the ambitus and peristome, and with broad
poriferous areas. Pore-pairs in oblique arcs or almost
transverse series of from four to ten pairs, and crowded
actinally. Interporiferous areas Avith two vertical
Fiu. 396. rows of plain imperforate primary tubercles; secondaries
strongylocentrotus drobach- and miliaries also present. lAmb with two rows of
Jound Sm?) piate""*''^^' ^°'"' Primary, and four or more of secondary tubercles.
Late Tertiary and Recent.
Sphaerechinus Desoi\ Amh straight, wide. Pore-pairs in arcs or oblique
lines of four to eight pairs, polyserial actinally. Interporiferous areas with
two to six vertical rows of plain, imperforate primaries, and horizontal rows
of secondary tubercles and miliaries. lAmh with two to twelve vertical rows
of primaries. Pliocene and Recent.
Eurypueustes and Aeolopneustes Duncan and Sladen. Eocene ; Asia.
CLASS I
ECHINOIDEA
283
Family 4. Echinometridae Gray.
Ambitus eUiptkal in a sicleivise axis. No pits or sculpturing in coronal plates
dorsally. Amhulacral plates at mid-zone composed of four or more elements each,
rarely (Parasalenia) of three elements each. Oculars all exsert, or becoming insert
in the sequence V, I, IV. Recent.
Echinometra Gray ; Heterocentrotus and Colobocentrotus Brandt ; with highly
specialised spines. Eecent.
Order 4. EXOCYCLOIDA Jackson.
Test irregidar, exocyclic, periproct outside of oculogenital ring in interambulacrum
■>. Two columns of plates in each ambulacral area and two columns of ptlates in
each interambulacral area. Begular in form, or more frequently more or less
markedly bilaterally symmetrical through the axis III, 5. Slight or no resorption
of base of corona by the advance of the peristome. Lantern present or absent.
Peristomal gills, or ambulacral gills only. Sphaeridia present. Jura to Recent.
This order includes all exocyclic Echini excepting the Paleozoic
Echinocystoida. The order shows structural characters associating it with
the Arbaciidae.
Suborder A. HOLECTYPINA Gregory.
Ambulacral plates compound, or largely simple, areas not petaloid dorsally.
Primordial ambulacral plates unknown. Primordial inter ambiolacral plates in basi-
coronal row, or in part resorbed. Base of corona slightly resorbed. Oculars and
genitals all present and distinct, or fused, or genital 5 absent ; when present it is
imperforate. Periproct unknown. Peristome central, structure unknown. Lantern
inclined so far as known. Teeth keeled, epiphyses narrow. Foramen magnum
moderately deep. Pyramids ivith ridges on lateral wings. Perignathic girdle con-
sisting of apophyses and auricles, or auricles only. Peristomal gills present. Jura
to Tertiary.
Family 1. Discoidiidae Gregory.
Perignathic girdle consisting of apophyses and auricles.
Discoidea Gray (Fig. 397). Test hemispherical above the margin, flat
Fig. 397.
Discoidea cylindrica Agassiz. Upper Cretaceous ; Liineburg. A, Side-view. B, Test broken open to sliow
the inner partitions, l/j.
actinally. Amb narrow, with some compound plates near the ambitus and
aK;tiiially ; pore-pairs very numerous, small. lAmb with distinct median
284
ECHINODEEMATA— ECHINOZOA
PHYLUM IV
sutures, and small, perforate and crenulate tubei'cles. Plates within the
actinal surface with radiating ribs, ten in all, extending as far as the peri-
stome ; appearing on casts as deep depressions. Periproct small, infra-
marginal. Cretaceous.
Conulus Leske (Galerites Lam.). Amh flush or slightly raised, apetalous,
straight ; some of the plates compound. Peristome sunken, slightly decagonal,
Fig. 398,
Conoclypeus conoidcus (Goldf.). Eocene ; Kressenberg, Bavaria (2/3 natural size).
symmetrical. Perignathic girdle indicated by a thickening of the lAmh as a
low false ridge. Abundant in the Lower and Middle Cretaceous.
Lanieria Duncan. Cretaceous or Eocene ; Cuba.
Conodypeus Ag. (Figs. 369, E ; 398). Test large, thick ; conical or vaulted
dorsally, flat actinally. Amb long, open, with broad poriferous areas nearly to
ambitus, narrowing thence to peristome. Pores wide apart and in pairs where
the areas are broad ; the pairs separated by costae. Pores continued in single
series over the ambitus as far as the central, pentagonal peristome. Periproct
infra-marginal, oval (?). Cretaceous and Eocene ; Europe.
J\aiiiily 2. Pygasteridae Gregory.
Perignathic girdle <ipparentlij consisting of auricles only.
Holecfypus Desor (Figs. 369, B ; 399). Amh narrow, straight, widest at
I'lc. 399.
A.H, IIolectypnsoryir.alngSc]\\oth. Upper .lura; Streitlx^rs, I'Yancoiiia. '', />, 7/. '^cyiros!;.'-' (TiPske). Middle
Jura ; France. Apical system and ventral surface (after Cotteau).
CLASS I
ECHINOIDEA
285
ambitus ; some of the plates compound. lAmh with rather large plates, and
many rows of tubercles. Peristome large, decagonal, with well-marked branchial
incisions, jaws, and feeble perignathic girdle.
Periproct large, pyriform, situated between the
peristome and posterior edge of the test. Apical
system small, central. Jura and Cretaceous.
Pileus Desor. Test large, sub-hemispherical
dorsally, flat actinally. Tubercles small, ir-
regularly arranged. Periproct supra-marginal,
small, broadly ovoid. Upper Jura.
Pygaster Ag. (Fig. 400). Test large, de-
pressed dorsally, concave actinally. Amb straight,
similar, flush or slightly raised, widest at the
ambitus. Poriferous areas straight, simple,
narrow ; tubercles of interporiferous areas in
two or four vertical rows ; those of the lAmh in
horizontal rows. Peristome large, decagonal,
with jaws and feeble perignathic girdle. Peri-
proct immediately beyond the apical system.
Jura and Cretaceous.
Galeroptjgiis Cotteau ; Pachydypeus Desor.
Upper Jura ; Europe.
Pig. 400.
Pyiiu-^ter umbclla Agassiz. Dxtbrdian ;
Chatillon-sur-Seine. Young indiviiUial,
Vi (after Cotteau).
Suhorder B. CLYPEASTRINA Gregory.
Ambulacral plates simple, areas petaloid dorsally. Ventrally amlndacral pores
are minute and specialised. Primordial ambulacral plates in basicoroual row.
Primordial interamhulacral plates in basicoronal row, or exceptionally (Arachnoides)
pushed dorsally and wi part resorhed by intracoronal resorption. Base of corona not
resorbed. Ocular and genital plates fused in a mass, usually no genital pore in area
5. Genital pores within the fused m,ass or outside in interambulacra 1, '2, 3, 4,.
Periproct plated. Peristome central, leathery. Lantern procumbent, highly modified,
teeth keeled, foramen magnum very shallow, small epiphyses and braces, but no com-
passes. Pyramids usually without ridges on lateral wings. Perignathic girdle con-
sisting of auricles only, on ambulacral, or on interambulacral plates. No peristomal,
but ambulacral gills only. Cretaceous to Recent.
Family 1. Clypeastridae Agassiz.
Test small to very large, depressed, flat or high. Petaloid parts of the ambulacra
highlif developed, usually uneqiud ; the actinal furrotvs straight. Interambulacra
actinally discontinuous ; one peristomal plate in each area. Perignathic processes
tall, narrow, two on each ambulacrum, fitting in below the large jaws. Peristome
central, pentagonal ; periproct small, marginal or infra-marginal. Internal structure
with needles, pillars, and other processes extending from floor to roof, especially near
the edge of the test ; sometimes these are fused to form concentric partitions, and the
ambulacra may also be protected by an inner wall. Tertiary and Recent.
Clypeaster Lam. (Figs. 369, i^ ; 374, 401, 402). Actinal surface flat, with the
peristome deeply sunken ; edge thin, undulating in contour, with or without
286
ECHINODEEMATA— ECHINOZOA
PHYLUM IV
re-entering angles. Petals long, broad, tumid ; pores wide apart, unequal,
conjugated. Periproct near or at the edge. Internal structure not forming
a double wall covering the
Amh. This genus includes
some of the largest known
Echinoids. Eecent species
are littoral, or shallow-
water inhabitants. Tertiary
and Recent.
Anomalantlms Bell. Ee-
cent. Lagannm Gray. Be-
longs propei'ly to a separate
family or subfamily. Ter-
tiary and Eecent.
Family 2. Fibulariidae
Gray.
Test small, with nidi-
menlary, widely open, few-
pored petals. Interamhvlacra
small, with a single apical and a single peristomal plate. Ambulacra limited
actinally on the interior of the test by low vertical partitions at their sides, radiating
Clypeaster aegyptlcus Mich. Pliocene ; Gizeli, near Cairo. Fragment,
showing internal calcareous deposits, au, Auricles.
Clypeaster grandiflorus Bronn.
Fill. 402.
Miocene ; Boutonnet, near Montpellier. i/o natural size (after Desor).
toward the peristome. Perignathic p>'>'ocesses broad, low, situated on each inter-
ambulacrum. Periproct usually actinal. Cretaceous to Eecent.
Echinocyamus Leske (Fig. 403). Test thick, depressed, pyriform or sub-
circular in outline, concave actinally. Amb broader than the lAmb, short
CLASS I
ECHINOIDEA
287
where slightly petaloid, widely open distally : pore-pairs few and increasingly
far apart. Peristome central, pentagonal, with small
jaws. Periproct between the peristome and posterior
edse of the test. Cretaceous to Recent.
Subgenus ScuteUina Ag. Periproct small, marginal or more
or less supra- or infra-marginal. Tertiary. Pn,_ 403.
Sismondia Desor. Test sub -pentagonal or ovoid, Echinocyamus piacentus
1 ■ r, 1 1 • Ti J 1 -J 1. £ (Goldf.) ( = E. siculus Ag.).
depressed, niflated at the margni. retaloid parts 01 piiocene; Siciiy. i/j.
the Jinh usually long, more or less open ; pore-pairs
not continued actinally. Tubercles minute. Eocene
and Miocene.
Fihularia Lam. (Fig. 404). Test thin, ovoid, tumid
dorsally and at the side. Jmh short ; pore-pairs very
few, continued wide apart to the margin, non-con-
jugated. Peristome and periproct small, sunken, close
together. Upper Ci'etaceous and Recent.
Euna Ag. Tei'tiary ; Europe.
Family 3. Scuteliidae Agassiz.
Test very flat, with entire or incised margin ; lunules or slits in the areas or
not. Jmhulacral furrows bifurcating and branching. Peristome flush ; jaws flat.
Fig. 404.
Fihulariasuh(jldbosa{Go\Ai.).
Upper Cretaceous ; Maast-
richt, Belgium. 1/1.
Fio. 405.
Scutella suhrotwiidata Lam. jVIioceiie ; Bordeaux. .1, B, Ventral and doi'sal aspects ; C, Section, i/i-
teeth superior. Badiating partitions between the floors internally. Tertiary and
Recent.
Scutella Lam. (Fig. 405). Test circular or sub-circular in outline, some-
times undulating or notched, broadest behind. Petaloid parts of the Amb
288 ECHINODERMATA— ECHINOZOA phylum iv
unequal, well-developed, nearly closed. Peristome small, central, sub-circular.
Periproct very small, infra-marginal. Apical system central, more or less
pentagonal. Tertiary.
Subgenus Echinarachnius Leske {Dcndraster Ag.). Apical system eccentric in front or
beliiud. Periproct actinal or marginal. Recent.
Echinodiscus Leske. Like Scutella, but truncated posteriorly, and with two
round or elongate lunules or slits, one in each of the median lines of the
postero-lateral Amb. Tertiary and Eecent.
Encope Ag. Test with a broad notch or a lunule in the median line of
each Amb, and a lunule in the posterior lAriih. Miocene and Recent.
Mellita Agassiz. Test very Hat, with five or six usuall}'^ closed lunules,
more rarely cuts ; one in the median line of the posterior lAmb, the others
in the Amb. Amb petaloid dorsally, the posterior pair the longest. Pliocene
and Recent.
Lenifa Desor. Eocene. Botula Ag. (Fig. 366, g). Recent. Arachnoides
Leske. Pliocene and Recent.
Suborder C. SPATANGINA Jackson.
AmJndacral plates simple, areas commonly petaloid dorsally ; in some types piores
are absent in part of the plates. Ambulacrum III often, differs markedly in character
from other areas. Ambiilacral plates often highly specialised in form and size.
Primordial ambulacrcd plates in the basicoronal row, or (Fourtalesia) in part pushed
dorsally. The basicoronal plates la, I la, I I lb, IVa, Vb, are larger and with two
pairs of pores or two separate single pores, whereas the lb, lib. Ilia, IVb, Va are
smaller with one pore-pair or one single pore. Primordial interambulacral plates in
the basicoronal row or {Lovenia, Pourtalesia) pushed dorsally. Base of corona not
resorbed. Oculars and genitals separate, or genitcds partially fused. Ocxdars-
apparently absent in some Pourtalesias. Genital 5 absent, and some additional
genitals rarely absent. Periproct plated. Peristome eccentric, plated with non-
ambulacral plates only. Lantern and perignathic girdle absent (present in the young
of Echinoneus, A. Agassiz, 1909). No peristomal, but ambulacral gills only.
Tribe A. CASSIDULOIDEA Duncan.
Ambulacra abactinally petaloid or sub-petaloid, usually similar. Some or all
of the inter ami mlacra with a single peristomal plate ; the postero-lateral areas
symmetrical actinally, xvithout any fusion of plates; no plastrons. Peristome
variously shaped, with or without floscelles.
Family 1. Echinoneidae Wright.
Test tall, or low and tumid dorsally; tumid and rarely flat actinally. Apical
system central, compact, with four perforated genitals. Ambulacra similar, dorsally
apetalous or sub-petaloid. Pores in simple pairs or in oblique triplets actinally ; no
floscelle. Peristome oblique or transversely elliptical, rarely symmetrical. Periproct
actinal, marginal or supra-marginal. Cretaceous to Recent.
Subfamily A. Echinoneinae Desor.
I'est low, tumid, and more or less pulvinate actinally ; pieristome central or sub-
central and oblique.
CLASS I
ECHINOIDEA
289
Echinoneus Leske. Amb narrow, actinally unequally broad, owing to the
obliquity of the large, triangular peristome. Miocene to Recent.
Caratonms Ag. Cretaceous. Amhlypygus Ag. Tertiary.
Fygaidus Ag. (Fig. 406). Test small, thick ; apical system slightly
Fi(i. -106.
ryiinnliis desmoulinsi Aj;'. Urj;'onian
(Schiattenkalk) ; Siiiitis, Switzerland, i/j.
Fi(!. 40r.
Pyrina iiiscia (Ag.). Ni'oeoiuian (Hils) ; Bwklingen,
Brunswick. Vj.
eccentric in front. Anhh narrow, widest at the ambitus ; pore-pairs in simple
series, conjugated ; the pores of a pair sometimes differently shaped. Cre-
taceous.
Pyrina Desm. (Fig. 407).' Like the preceding, but pores non-conjugated,
and tlie pairs separated by costae. Cretaceous and Eocene.
Subfamily B. Eghinobeissinae Duncan.
Test depressed, elongate, tumid. Ambulacra suh-petaloid. Apical system and
peristome eccentric ; jloscelle absent or rudimentary. Interambulacra entering the
peristomal margin with a single plate. Periproct supra-marginal.
Nmleolites Lam. {Echinohrissus Breyn.) (Fig. 408). Test ovate, rounded in
front, broadest and more or less truncated behind ; or rectangular, with the
Fig. 40a'
A, B, Niiclcolitus rluiui-idKri.s (Ijlhwyd). Cornbrash ; Egg, Aargau. Vi- ''. D, N. smtatas (Lani.). Upper
Oxfordiau ; Trouville, Calvados. C, Ventral aspect of large individual. D, Apical system, enlarged (after
Cotteau).
angles rounded ; or sub-circular ; concave actinally. Amb unequal, open at
the end of the sub-petaloid parts ; pore-pairs in simple series, more or less
unequal in shape and size, the outer ones elongate ; below the sub-petaloid
parts the pores are in small oblique pairs, conjugate or not. Periproct at
upper end of a groove situated on the abactinal area of the test. Abundant
in Upper Jura and Cretaceous ; present also in Eocene and late Tertiary.
VOL. I U
290
ECHINODERMATA—ECHINOZOA
PHYLUM IV
Subgenus Docfiviostoma Duncan {Trematopygus d'Orb.). Like the preceding, but with
oblique peristome. Cretaceous ; Europe and North America.
Botriopygus d'Orb. Cretaceous. Ilariona Dames. Eocene.
Family 2.
Oassidulidae Agassiz.
Test variable in shape. Ambulacra petaloid, sub-petaloid or apetalous dorsally,
and with crowded doubling of the pairs of pores close to the peristomal margin,
forming with the single, swollen and ornamented interambulacrcd peristomal plates a
floscelle. Jura to Recent.
Cassidulus Lam. (Fig. 409). Test small, oblong, depressed, convex
dorsally, flat actinall3^ Amb narrow,
sub-petaloid, not closing ; pores con-
tinued from the middle part to the
well-developed floscelle. Peristome
eccentric in front ; periproct supra-
marginal, longitudinally elongated.
Cretaceous and Eocene.
Subgenus Rhynco2nj(]iis d'Orb. Periproct
transversely elongate, with overhanging
rostrum. Cretaceous to Recent.
Subgenus Fygorhynchus Ag. Test con-
cave actinally, with long petals. Peris-
tome and periproct longest transversely.
Cretaceous to Miocene.
Stigmatopygus d'Orb. Cretaceous. Eurhodia'd' Arch, and Haime. Eocene.
Paralampas and Neocatopygns Duncan and Sladen. Eocene. Catopygus Ag.
Cretaceous. Studeria Duncan. Tertiary and Recent. Phyllobrissus Cotteau.
Jura and Cretaceous.
Clypeus Agassiz. Test large, low, nearly flat actinally. Ainb wide,
petaloid, not closing dorsally, narrow at the ambitus and actinally. Pore-
Fifi. 409.
Cassidulus lapis-cancri Lam. A, Test in three positions.
B, Floscelle, enlarged.
I'l/gurus roi/cria/m.s Colteau. Kiiumcrid^'ian ; Tiinnjesberg, iii.'ai llanuvor. -J, B, Dursal aiid ventral views
of test, '^U natural size. L', Apical system, enlarged. D, Ambulacral plates, magnified.
pairs in the petaloid parts with the inner pore small and circular, the outer
CLASS I
ECHINOIDEA
291
transversely elongate, and in a long groove. Periproct high up, usually in a
groove along the median line of the posterior lAmh. Upper Jura.
P'ljgurus Ag. (Fig. 410). Test large, angular, rounded or cordiform in
marginal contour ; depressed or rather tall and sub-conical dorsally. Amh
V .-->..■ S-.'.'°
,".•-?>-■';'
"^^^M-
\\-^'^^'^ -^^M.^?:^ *^..i,i-:^ ■'*/-> "^
-■■^■■i-^
■.-■^.-^ ■'■i'.
%
;.'; - ~ ''// '^ /<'>'/»•./• <- '.' '•. »a . I .^
Fio. 411.
Echinolampas Ideini Go\di. Oligocene ; Doberg, near BUnde. i/i.
flush dorsally, unequal, wide ; the petaloid parts contracting but not closing
marginally, and expanding again actinally, where the Amh are grooved. Peri-
proct infra-marginal, pyriform or ovoid, in a special area, or rostrum, close to
the posterior edge of the test. Upper Jura and Cretaceous.
Echinolam'pas Gray (Fig. 411). Test variable in size and shape, more
or less ovoid or circular at the tumid ^ c
marginal outline ; tall and conical or
depressed dorsally. Amh petaloid for
a variable distance; pores of the petals
differing in shape, conjugated and con-
tinued beyond in simple series. Peri-
stome slightly in front, or sometimes
central. Periproct transversely ellip-
tical, infra-marginal. Widespread in
Tertiary and Kecent.
Conolampas and N'eolampas A. Ag.
Recent. Plesiolamixis Duncan and
Sladen. Eocene. Palaeolampas Bell.
Upper Cretaceous to Recent.
Family 3. Collyritidae d'Orbigny
(^Dysasterinae Gray).
Apical system disconnected, either
elongate or suh- compact. Ambulacra
similar ; hivium widely separated from Pi,;. 412,
the trivium ; floSCelle absent. Jura to CullyriteselUptka'DeHm. Callovian ; Mamers, Sarthe.
p, ^ , .1, B, Test in profile and from above, i/i- t', Apical
UretaceOUS. system, enlarged.
292
ECHINODERMATA— ECHINOZOA
PHYLUM IV
CoUyrites Desm. (Fig. 412). Test ovoid, tumid, more or less truncated
posteriorly. Amh disjunct, the anterior one sometimes in a slight groove.
Width of the Amb increasing towards the ambitus ; pore-pairs in low primary
plates. Periproct posterior, supra-marginal, placed in a groove. Apical
system elongate, separated by numerous small plates belonging to the
postero-lateral lAmh. Very abundant in the Middle and Upper Jura and
Cretaceous.
Dysaster Ag. Difl^ers from CoUyrites in details of the aj)ical system, the
genitals not being separated by the antero-lateral ocular plates. Upper Jura
and Lower Cretaceous.
Hyhodypeus Agassiz (Fig. 413). Jura. Tnfradypeus Gauthier. Upper
Cretaceous. Grasia Mich, Jura.
Hyioclyijeus gibberulus Ag
Fk;. 41
Middle Jura ; Soleure, Switzerland. A, B, Dorsal and ventral views.
C, Profile. D, Apical system, enlarged.
Metaporhinus Mich. Test very tall, slightly longer than broad, sub-cordi-
form, projecting upwards anteriorly, grooved and oblique behind. Anterior
Amh in a groove, with small, simple, distant pairs of pores ; the other Amh
flexuous, with comma-shaped pores placed obliquely to one another. Periproct
supra-marginal. Upper Jura and Lower Cretaceous.
Tribe B. SPATANGOIDEA Duncan.
Peristome eccentric in front, rarely i^entagonal in the adult, usiially with a
posterior lahrum, behind which is a long plastron bounded laterally hy the posterior
ambulacra. Ambulacra dissimilar. Inferamhidacra with a single plate at the
peristomal margin; the postero-lateral areas usually unsymmetrical actinally.
Fascioles piresent or absent.
. Family 4. Ananchytidae Desor.
Test ovoid or suh-cordiform in marginal outline, tall or depressed, and with large
plates. Ambulacra in a bivium and trivium, nearly similar, flush, apetalous ; pore-
pairs largest near the apex and at the peristome, may be uniporous. Periproct
variable in position. Cretaceous to Eecent.
Ananchytes Lam. {Echinocorys Breyn.) (Fig. 414). Test large, oval in marginal
outline ; high, rounded or keeled apically, flat actinally. Amb biporous, the
pore-pairs well developed abactinally, but becoming smaller, closer and
CLASS I
ECHINOIDEA
293
oblique toward the ambitus, where they are more distant. Posterior Amb
actinally long and broad, the pairs small, and pores oblique. Peristome oval,
broader than long. Periproct
infra -marginal, posterior, oval.
Apical system elongate. Very
abundant in the Upper Cretac-
eous. A. ovata (Leske) often
attains a very large size.
Holaster Ag. (Fig. 415). Test
ovoid in marginal outline, flat
actinally, tumid and high abac-
tinally. Anterior Amb in a shal-
low groove. Peristome elliptical,
broadest transversely. Periproct
supra-marginal, and oval. Apical
system elongate. Cretaceous
and Miocene.
Offaster Desor. Test small,
tumid. Anterior Amb sometimes
in a shallow groove. Peristome
oval, broadest transversely. Peri-
proct supra-marginalj circular or
ovoid. Apical system elongate.
Cretaceous. 0. pilula (Ag.).
Hemipneustes Ag. Test large,
ovoid in marginal outline, high Ananchytes ovata (Leske). White chalk; Haldeni, West-
1 . •■! 1 n a *. „*.,-„„li„ phalia. ^, B, Profile and ventral view. Vs- C, Apical system,
and tumid dorsally, flat actinally. Enlarged. i>, Portion oiAmb and lAmb areas, i/i-
Anterior Amb in a deep, narrow
groove extending to the elongate apical system, its pairs of pores numerous
D
'^,m'^
•'■ 'i ■' \\- C-- '■■-0"."-\_
W^SMm^
m^'
Fio. 414.
Fig. 415.
A, B, Holaster suhglohosus Ag. Cenomanian ; Rouen, i/j. C, H. siiborbieulnrisBefT. Apical system, enlarged.
and small, the vertical rows wide apart. Paired Amb more or less cvirved,
open distally, with dissimilar pores. Peristome much sunken, crescent-
294
ECHINODERMATA— ECHINOZOA
PHYLUM IV
shaped, broad. Periproct supramarginal. Upper Cretaceous. H. radiatus
(Lam.).
Cardiaster Forbes. Similar to Holasfer, but anterior groove deeper and
with angular margin. Periproct oval, placed in a depression in the truncated
posterior face. A more or less complete marginal fasciole passing below the
periproct. Cretaceous.
Subgenus Infulasfer Hagw. Test higli in front, narrow ; anterior groove deep and with
strong lateral keels. Fasciole absent. Upper Cretaceous.
Urechinus and Cystechinus A. Agassiz. Late Tertiary and Recent. Calymne
Wyv. Thomson. Eecent. Enichaster de Loriol. Oligocene. All with uni-
porous Ami).
Stenonia Desor. Like Ananchytes, except that the apical system is com-
pact, and the Amb equal. The solitary species, 'S. ttihercidcda (Defr.), is
abundant in the Upper Cretaceous (Scaglia) of the Southern Alps and the
Apennines.
Family 5. Spatangidae Wright.
Test ovoid or cordiform, longer than broad, with numerous plates, and usually
with an anterior groove. Ambulacra in a biviiim and trivium, the anterior differing
from the others in shape and construction. Pore-pairs of the petaloid parts differing
from the others. Fascioles present or absent. Cretaceous to Eecent.
Section A. Adetes. All fascioles absent.
Isaster Desor. Petals not closed. Peristome large, with a posterior
labrum. Cretaceous,
Eptiaster d'Orb. {Macraster Roemer). Anterior Amb in a groove ; paired
Amb petaloid dorsally, with
elongate, unequal pores. lAmb
tumid dorsally. Peristome trans-
verse, tumid in front, and usu-
ally with a projecting labrum.
Periproct longitudinal, supra-
marginal. Cretaceous.
Toxaster Ag. (EchinosjMtagus
Breyn.) (Fig. 416). Anterior
Amb in a broad shallow groove,
with unequal pore-pairs. Paired
Amb sub-petaloid, flexuous, with
unequal poriferous areas and
unequal pore - pairs. Peristome transverse, sub - circular or pentagonal.
Tubercles small, perforate and crenulate. Abundant in Lower and Middle
Cretaceous.
Ennalaster d'Orb. (Heteraster d'Orb.). Petaloid parts of antero-lateral Amb
divei'gent, flexuous, tending to close, and with very unequal poriferous areas,
of which the posterior are the largest ; pore-pairs oblique. Postero-lateral
Amb short, divergent. Peristome labiate, wide, arched in front. Periproct
in posterior truncation. Cretaceous.
Hemipatagus Desor (Fig. 417). Test small, cordiform. Anterior Amb
Toxaster complanatus Ag.
Fl(i. 416.
Neocomian :
Auxerre, Yonne. i/j
CLASS I ECHINOIDEA 295
with small pores in a shallow furrow. Paired Amh long, petaloid, nearly
& ©Q*
Ilemipiitagus hofmaiini Gold f. Oligocene ;
Doberg, near Biinde. A, Dorsal view.
B, Profile. C, V'entral a.speet. i/i (after
Qoldfu.ss).
flush. The lateral lAmh with a few large perforate and crenulate tubercles
in deep scrobicules. Periproct supra-marginal. Tertiary.
Flatybrissus Grube. Eecent. Falaeopneustes A. Ag. Recent, and perhaps
Eocene.
Section B. Prymnadetes. Suhanal fasciole absent, other fascioles present.
Hemiaster Desor (Fig. 418). Anterior Amh in a shallow groove, the pores
D
<i
a
Fi<i. 418.
Hemiaster orhignyanus Desor. Upper Cretaceous ; Martigues, Proveuee (after d'Orbigny). A-C, Ventral, dorsal
and side views of test, Vi- D, Pores of the anterior Amh. E, Pores of the paired Ami, enlarged.
Pig. 419.
Linthia hehcrti Cotteau. Eocene ; Lonigo, near Vicenza. Sj^ natural size (after Dames).
oblique, and in pairs on either side. Antero-lateral Amh petaloid dorsally,
sunken, diverging, and much longer than the postero-lateral. Pores of the
296
ECHINODEEMATA— ECHINOZOA
PHYLUM IV
petaloitl parts conjugated, the outer ones usually the largest. Peripetalous
fasciole present.
Subgenus Triiiylus Fhill. {Jbatus Tvuachel). Recent.'
Faorina Gray. Eecent. Fericosmus Ag. Cretaceous and Tertiary.
Linthia Merian (Desoria Gray) (Fig. 419). Anterior Amb in a deep
groove, the pores round and small, in pairs on either side. Antero-lateral
Amb longer and more divergent than the others, with petals sunk in grooves.
Pores conjugated. A peripetalous and lateral fasciole present. Cretaceous
to Recent.
Schisaster Ag. (Figs. 420, 421). Resembling Linthia, but the apical system
is posteriorly eccentric, and the Amb very diverse.
Tertiary and Recent.
Prenaster Desor; Oniithaster and Corasfer Cotteau.
Eocene.
Agassizia Val. ; Moira A. Ag. Tertiary and Recent.
Moiropsis A. Ag. Recent.
Fig. 420.
Scliizasler archiaci Cott.
Eoceue ; San Giovanni Ila-
rione, near Vioenza.
Fig. 421.
Schizaster fragilis Ag. Apical sys-
tem, greatly enlarged (after Loven).
J Fig. 1 422.
Micraster coranganius
(Lam.). Apical system.
Section C. Prymnodesmia. Subanal fasciole present.
Micrasfer Ag. (Figs. 422, 423). Test cordiform, tumid, rather depressed.
Anterior Amb apetaloid, in a shallow depression ; antero-lateral Amb sub-
petaloid dorsally, diverging ; postero-lateral shorter than the others, Avith
Fig. 42.3.
Micraster eortestuMiiarius Goldf. WUiti- Clialk ; Minidon, near Paris. Natural size.
Fio. 424.
CLASS I ECHINOIDEA 297
elongate, conjugated pores. Periproct supra-marginal; apical system eccentric
in front. Broad subanal fascicle. Abundant in Middle and Upper Cretaceous ;
less common in Eocene and Miocene.
Brissus Gray (Brissomorpha Laube) ; Meoma and Metalia Gray. Tertiary
and Eecent. Bhinobrissus A. As. Eecent.
Brissopsis Ag. {Deakia Pavay) (Fig. 424). Amb unequal, bare and large
near the peristome. Anterior Amb slightly sunken, with
small pairs of close pores. Paired Amb sunken, the
antero-lateral pair sub-petaloid, equal to or larger than
the postero-lateral, straight or curved. A subanal and ^i^j^^^;^§^>>^^^<^|\ij^
peripetalous fasciole. Tertiary and Recent.
Subgenus Cyclaster Cotteau. Antero - lateral Amh divergent.
Eocene.
Brissopatagus Cotteau. Allied to Brissopsis. Eocene.
Spatangus Lam. Anterior Amb in a broad, deep groove,
with distant pairs of small pores. Paired Amb petaloid, Brissop',sis lyH/era
with broad, sunken poriferous areas. Periproct large, fX^^'^ed (!rfte\^Lov6n)^'"'
supra-marginal, transverse. lAmb with large crenulate
and perforate primary tubercles, and fine granulation. Subanal fasciole only.
Tertiary and Recent.
Maretia Gray. Tertiary and Recent.
Eupatagus Ag. Anterior Amb in a shallow, abactinal depression, narrow,
and with small, distant pore-pairs. The paired Amh petaloid dorsally, long,
wide, closed ; poriferous areas broad, more or less sunken ; pores dissimilar.
Peripetalous and subanal fasciole. Tertiary and Recent.
Subgenus Macropneustes Ag. (Peripneustes Cott. ) (Fig. 425). Test large, thick, cordiform.
Petals elongate or broad, grooved or semi-flush, open or im]ierfectly closed. Poriferous areas
of equal width with the interporiferous. Eocene and Recent.
GuaUieria Desor ; Eocene. Echinocardium Gray (Eig. 371, F) ; Breynia
DesOr ; Lovenia Ag. and Desor. Tertiary and Recent.
Section D. Apetala.
Ambulacra flush, apetalous, generally uniporoiis, and either similar or diverse ;
plates high, few, often hexagonal. Fascioles usually present.
Under this head are included the following Recent genera, all but the first
two of which have fascioles : Genicopatagus and Palaeobrissus A. Ag. ; Aceste
Wyv. Thomson ; Aeropsis Mortensen ; Palaeotropus Loven ; Homolampas,
Argopatagus A. Ag. ; and Cleistechinus de Loriol. Miocene.
Family 6. Palaeostomatidae Mortensen.
Test thin, ovoid. Apical system with three genital plates fused into one.
Peristome eccentric in front, pentagonal, with five angular plates.
Palaeostoma Lov6n (Leskia Gray). Recent ; China, East Indian Islands.
Family 7. Pourtalesiidae Loven.
Test very elongate, sub-cylindrical or obconical, truncated anteriorly, flat actinally.
Peristome in a deep anterior recess ; periproct actinal, or above the projecting posterior
298
ECHINODERMATA— ECHINOZOA
PHYLUM IV
rostrum token such is present. Ambulacra flush.
apetalous, sometimes discontinuous ;
pores single or slit-like.
Pourtalesia, Spatagocystis
and Echinocrepis A. Agassi z.
Recent.
Order 5. PLESIOCIDA-
ROIDA Duncan.
Test regular, endocyclic.
Genitals largely covering the
dorsal surface. Two columns of
loiv simple plates in each avi-
hulacral area and three columns
of plates in each interambulacral
area. Plates not imbricate.
Primordial interambulacral
plates in hasicoronal row. Base
of corona not resorbed. Oculars
small, strongly exsert by the con-
tact of large genitals. Peri-
proct central, structure unknown.
Peristome central, structure un-
known. Lantern and perigna-
thic girdle unknown.
Family 1. Tiarechinidae
ZWiA.
The single primordial plate
of the interamhulacra followed
hy three elongated plates only,
one on either side of a narrow
median plate. Trias.
Tiarechinus Neumayr (Fig. 426). The test of this unique genus is very
small, flat actinally, and sub-hemispherical dorsally. Below the ambitus and
actinally the ornament consists of a plain
primary tubercle to each plate ; elsewhere the
test is coarsely granular, including the very
large apical system. The solitary species,
T. princeps (Laube), occurs in the Trias of St.
Cassian, Tyrol.
Our knowledge of this genus and family is
based largely on Lov6n's study of a single
minute specimen. As it has three columns
of plates in an interambulacral area, it is
considered a further remove from the primi-
tive than those types with two columns. Three plates, representing three
columns, immediately succeeding the primordial interambulacral plate, is a
unique character in Echini.
Fig. 4-Jo.
Macropneustes inencghinii Desor. Eocene ; Monte Spiado, near
Vicenza.
Fig. 426.
Tiarechinus p-?r!cc/)>- (Laube). Upper Trias ;
St. Cassian, Tyrol. Venti-al and lateral
aspects, much enlarged (after Loven).
CLASS I ECHINOIDEA 299
Order 6. ECHINOCYSTOIDA Jackson.
Test irregular, periprod apparently in an inter ambulacrum. Two to four
columns of plates in an ambulacral area, and eight to nine columns of plates in an
interamlmlacral area. Plates thin, imbricating. Oculars and genitals doubtfxd.
Silurian.
Members of this order have been considered primitive, but structural
evidence is opposed to this view. This order includes the only exocyclic
Echini excepting that of the Exocycloida. The species are incompletely
known.
Family 1. Palaeodiscidae Gregory.
Two columns of plates in an ambulacral area and eight to nine columns of plates
in an interambulacral area. Primordial interamlmlacral plates in basicoronal row.
Base of corona not resorbed. Peristome with ambulacral plates only. Lantern
inclined, typically echinoid. Numerous fine spines.
Palaeodiscus Salter. With characters of the family. The only genus
known, many rows of ambulacral plates on the peristome. Silurian ;
England.
Family 2. Echinocystidae Gregory.
Four columns of plates in an ambulacral area, and eight columns of plates in an
interambulacral area. Small primary spines and tubercles. Jaws.
Echinocystites Wyv. Thomson (Cystocidaris Zittel). With characters of the
family. The only genus known. Silurian ; England.
Order?. PERISCHOECHINOIDA M'Coy.
Test regidar, periproct within the oculogenital ring. Two to twenty columns of
simple plates in each ambulacrcd area, and three to fourteen columns of plates in each
interambulacral area. Plates imbricate or not. Primordial ambulacral plates on
peristome. Primordial interambulacral plates in basicoronal row, or resorbed. Base
of corona not resorbed or resorbed. Oculars usually all insert. Genitals small,
typically with more than one piore each ; rarely {Lepidechinus) with one pore each.
Madreporite usually not recognisable. Periproct covered with many thick plates.
Peristome with many rows of ambulacral plates only, or in addition with interradial
non-ambidacral plates. Lantern inclined, composed of forty pieces, teeth grooved,
foramen magnum moderately deep, epiphyses narrow, no pits in top of pyramids.
Spines primary and secondary, or the latter only. Primary tubercles perforate,
secondary tubercles imperforate. Silurian to Permian.
This order includes the majority of Paleozoic Echini. All are specialised
in having multiple columns of interambulacral plates, and in many genera
multiple columns of simple ambulacral plates as well ; the order is therefore
considered a further remove from the primitive than are those orders
with two columns of both interambulacral and ambulacral plates.
300
ECHINODEEMATA— ECHINOZOA
PHYLUM IV
Family 1. Archaeocidaridae M'Coy.
Two columns of plates in an amhulacral area. Four to eight columns of plates
in an interambulacral area, imbricating. Primordial and additional interambulacral
plates are resorhed in the advance of peristome. Oculars, genitals and periproct
imperfectly known. Peristome with many rows of amhulacral and interradial non-
ambidacral plates. Spines large primaries with perforate tubercles in the centre of
each interambulacral plate, also secondary spines and imperforate tubercles. Devonian
to Permian.
Eocidaris Desor. Known from fragmentary interambulacral plates and
spines, primary tubercles of plates without a basal terrace. Only one species
is recognised, E. laevispina (Sandb.). Devonian ; Germany.
Archaeocidaris M'Coy. Ambulacral plates all alike, of equal height. Four
columns of plates in an interambulacral area. Primary spines large, tapering
or inflated, smooth or with lateral spinules. Primary tubercles with basal
terrace and scrobicular ring. Many species fragmentarily known. The most
completely known are A. wortheni Hall (Figs. 366, e ; 371, C ; 427, A-C),
A. rossica (Buch), A. urii (Flem.). Lower Carboniferous and Carboniferous;
Europe and North America. Permian ; North America and India.
Pig. 427.
Arrhaeociilaris irortheni Hall; Lower Carboniferous; Burlington, Iowa. A, Portion of ventral region,
showing jaws, i/i- 1j, An lAmb plate viewed from above and from the side. C, Portion of Amb, enlarged.
D, Spine of A.ikeokuk Hall. Lower Carboniferous ; Warsaw, Illinois (after Hall).
Lepidocidaris Meek and Worthen. Ambulacral plates low, Avith also higher,
wider and wedge-shaped plates. Six to eight columns of plates in an inter-
ambulacral area. Primary spines cylindrical. Primary tul^ercles with no
basal terrace, but with a scrobicular ring. Lower Carboniferous ; North
America.
Family 2. Lepidocentridae Loven.
Two columns of plates in each amlmlacral area. Five to fourteen columns of
plates in an interambulacral area. Primordial interambulacral plates in basicoronal
roio. Base of corona not resorhed. Oculars insert. Genitals loith many pores each.
Peristome with many rows of andmlacral plates only. Spines small eccentrically
CLASS I
ECHINOIDEA
301
Silurian to Lower
placed primaries with secondaries, or the latter only.
Carboniferous.
Koninckocidaris Dollo and Buisseret. Test high, probably spheroidal ;
ambulacral plates high, two or three equalling the height of an adambulacral
Fig. 42S,
A, LeiMoccntnif rhenanus (Beyr.)- Devonian ; Wippert'iirth, Eifel. Cast of the interior of test sliowing
jaws, i/i (after J. Miiller). B-D, Lepiilocentrus mUlleri Schultze. Devonian ; Gerolstein, Eifel. Ji, Tortion of
Amb, enlarged. C, Several lAinb plates, i/j D, Two detached lAmb plates, showing oblique edges, Vi-
plate, pore-pairs uniserial. Seven to eight columns of nearly rhombic plates
in an interambulacral area. K. silurica Jackson. Silurian ; North America.
K. cotteaui Dollo and Buiss. Lower Carboniferous ; Belgium.
Lepidocentrus Miiller (Fig. 428). Test high, spheroidal, ambulacral areas
narrow throughout; ambulacral plates low, about eight equalling the height
QOtT^ E
Fig. 429.
A, Hyattechinus pentagorms Jackson. External sandstone moulds. Lower Carboniferous; Meadville,
Pennsylvania. Ventral view showing introduction of columns and accelerated development of interambulacra.
B, The same, dorsal view, showing fourteen cohimns in each interambulacral area and the dropping out
of some coluiims dorsally. Both figures s/io natural size (after Jackson).
of an adambulacral plate, pore-pairs uniserial. Five to eleven columns of
plates in an interambulacral area. Small primary spines and tubercles with
secondaries on interambulacral plates. Devonian ; Germany and North
America. Lower Carboniferous ; North America.
Hyattechinus Jackson (Fig. 429). Test depressed to flattened; through
the ambitus circular, pentagonal or clypeastriform. Ambulacral areas broad.
302
ECHINODERMATA— ECHINOZOA
PHYLUM IV
petaloid ventrally, narrow dorsally, pore-pairs uniserial. Eleven to fourteen
columns of plates in an interambulacral area. Small primary and secondary
tubercles on interambulacral plates. This genus is highly specialised,
particularly as regards the interambulacra which attain the greatest number
of columns of plates and the most accelerated development of the same known
A, Palaeechinus qiiacMserialis Wright. Lower Carboniferous ; Rathkeale, County Limerick, Ireland, i/j.
B, Apical disk of same, 2/j. Restorations indicated by dotted lines. C, Same species, Middleton, County
Cork, Ireland. Ambulacral detail, enlarged (after Jackson).
in Echini. H. rarispinus (Hall) is a greatly flattened species, H. pentagonus
Jackson is pentagonal in outline, and H. beecheri Jackson is ventrally
flattened and bilaterally symmetrical. Lower Carboniferous ; North America.
Pholidechinus Jackson. Test high, spheroidal, ambulacral areas narrow
throughout, pore-pairs moderately biserial. Nine to ten columns of plates in
an interambulacral area. Secondary spines and tubercles only. Lower
Carboniferous ; North America.
CLASS I ECHINOIDEA 303
Family 3. Palaeechinidae M'Coy.
Test elliptical, obovate, sjyherical or subspheroidal. Two to twelve columns of
plates in each ambulacral area, three to eleven columns of plates in each inter-
.ambulacral area. Plates not imbricate, but ambulacral plates bevel over the
interambulacral on adradial sutures. Primordial interambulacral plates resorbed.
One row only of interambulacral plates resorbed in advance of the peristome. Oculars
usually all insert, genitals usually with three to five pores each. Peristome with
many rows of ambidacrcd and some interradial non-ambulacral plates (Fig. 371, D).
Secondary spines and imperforate tubercles only. Silurian (?), Lower Carboniferous.
This family includes more species than any other in the Paleozoic. It
contains genera with complex ambulacra composed of more than two columns
of simple plates in an area, and the species in development pass through
stages like those of adults in all lower species or genera in the family. The
interambulacral plates are very definite in form, and the incoming of columns
indicate stages in development.
Palaeechinus M'Coy (Figs. 367, i; 430; 431). Two columns of plates in
d'
Fig. 431.
Palaeechinus elegans M'Coy. Lower Carboniferous Limestone ; Ireland. A, Test, i/i (after M'Coy).
B, Apical system, more than twice enlarged (after Jackson).
each ambulacral area, consisting of plates which are all primaries ; pore-pairs
uniserial. Four to six columns of plates in each interambulacral area. In
this lowest genus the ambulacral detail is like that seen as a developing stage
in the higher genera of the family. The test is elliptical, P. quadriserialis,
or nearly spherical, P. elegans. Lower Carboniferous ; Europe and North
America.
Maccoya Pomel (Fig. 367, k). Two columns of plates in each ambulacral
area, consisting of plates which are alternately primaries and partially or
completely occluded ; pore-pairs biserial. Four to eight or nine columns of
plates in each interambulacral area. In this genus, ventrally and dorsally,
ambulacral plates as stages in development are all primaries as in Palaeechinus.
M. phillipsiae Forbes is attributed to the Silurian (?) of England, other species
Lower Carboniferous ; Europe and North America.
Lovenechinus Jackson (Figs. 367, I; 432). Four columns of plates in each
ambulacral area, consisting of demi- and occluded plates ; pore-pairs biserial.
Four to seven columns of plates in each interambulacral area. While in this
genus there are four columns of ambulacral plates at the mid-zone, primary
plates as a stage occur ventrally and dorsally, L. septies. In L. missiouriensis
(Jackson) primary with occluded plates exist both ventrally and dorsally as a
304
ECHINODERMATA— ECHINOZOA
PHYLUM IV
second developmental stage. Lower Carboniferous ; Europe and North
America.
Oligoporiis Meek and Worthen (Fig. 367, m). Four columns of plates in
each ambulacral area, consisting of demi-, occluded, and in addition scattered
isolated plates ; pore-pairs multiserial. Four to nine columns of plates in each'
J
Fig. 432.
Loticiiechinus scpties Jackson. Lower Carlioniferous ; Boouvillf, Missouri. .1, In llie centre, spread out to
show structure and development, dotted lines indicate restorations. IS, Lower lel't-liand tigurc, developing
ambulacrum ventrally. C, Lower right-hand tlgure, anibnlacrum near mid-zone. I), Upper right, developing
ambulacrum dorsally. E, Upper left, apical disk witli coronal contact. A, Natural size ; other figures tliree
times enlarged (after Jackson).
interambulacral area. This genus differs from Lovenechinus in that it has
isolated plates in addition to the four columns of ambulacral plates. Lower
Carboniferous ; North America.
Melonechinus Meek and Worthen {Melonites Norwood and Owen). (Fi
^. d: 367. n: 371. D -, 433). Six to twelve columns of plates in ei
SfS.
366, il; 367, n; 371, D ; 433). Six to twelve columns of plates in each
ambulacral area, consisting of demi-, occluded and one to four irregular
CLASS I
ECHINOIDEA
305
columns of isolated plates in each half-area at the mid-zone ; pore-pairs
multiserial. Three to eleven columns of plates in each interambulacral area.
This genus has fourteen species with a wide range of characters. The lowest
species, M. dispar (Fischer von Waldheim) has six columns of ambulacra!
plates, and is thus only one remove from Oligoponis. The highest species,
31. giganteus (Jackson) has twelve columns of ambulacral plates. At the
ventral border of the ambulacra there are typically four columns of plates
like the adult of Lovenechinus. From this stage passing dorsally isolated
plates first appear like Oligoporus, then additional columns, until the number
Fio. 433.
Melonechinus inultlponix (Norwood and Owen). Lower Carboniferous ; St. Louis, Missouri,
i/o natural size. B, Apical system, slightly enlarged (after Meek and Woithen).
A, Test,
characteristic of the species is attained. Dorsally some primary plates occur
next the oculars. Each species of Melonechinus presents developmental stages
in the ambulacrum like the adults of all lower genera, and lower species in
the family. The interambulacrum may have as few as three columns of
plates, as in M. obovahis Jack., which is the least known in the family, though
this species has ten columns of ambulacral plates ; or there may be eleven
columns of plates as in the extreme form, M. giganteus (Jackson). Between
the extremes every step is represented in the genus by developmental or
adult characters, or both. Plates of the test are often very thick, and usually
more or less strongly elevated melon-like ribs occur in both ambulacra and
iiiterambulacra, though these may be obsolescent or wanting, M. etheridgii
(Keeping). The peristome is known only in this genus for the family
(Fig. 371, D). Lower Carboniferous; Europe and North America.
Lepidesthidae Jackson.
Test elliptical, obovate, spherical or suhspheroidal. Two to twenty columns of
plates in each ambulacral area. Three to thirteen columns of plates in each inter-
ambulacral area. Plates imbricate. Primordial interambidacral plates in basicoronal
row. Base of corona not resorbed. Oculars usually all insert, genitals with one to
many pores each. Periproct j)lated with many thick plates. Peristome ivith many
rows of ambiUacral plates only. Primary spines with perforate tubercles, usually
VOL. I X
306 ECHINODERMATA— ECHINOZOA phylum iv
eccentric and irregularly distributed on interamhulacral plates, with secondary spines
and tubercles, or the latter only. Devonian to Permian.
This family presents a wide range of characters, and includes species with
very specialised features, particularly as regards an extreme development of
ambulacral areas.
Lepidechinus Hall (Ehoechimis Keeping). Two columns of plates in each
ambulacral area. Four to eight columns of plates in each interamhulacral
area. Plates quite thick, imbricating moderately. Secondary tubercles only.
Genital plates as far as known with only one pore each, the only instance
known in the Paleozoic. This genus, the lowest of the family, differs from
Palaeechimis which it approaches, principally in the fact that the plates are
imbricate. The genus has been misunderstood because Hall referred to
it the species rarispinus, which is now referred to Hyattechinus. Lower
Carboniferous ; Europe and North America.
Perischodomus M'Coy (Fig. 366, h). Two columns of plates in each am-
bulacral area. Five columns of plates in each interamhulacral area. Plates
imbricating strongly. Eccentric perforate primary with secondary tubercles
on interamhulacral plates. Genital plates with many pores. The most
completely known species is P. biserialis M'Coy, Lower Carboniferous of Great
Britain ; a second imperfectly known is F. illinoiseiisis Worthen and Miller,
Lower Carboniferous ; North America.
Perischocidaris Neumayr. Six columns of plates in each ambulacral area.
Five columns of plates in each interamhulacral area. Plates apparently
imbricating moderately. Eccentric primary tubercles on certain adradial
plates, with secondary tubercles on the same and usually alone on other
interambulaci'al plates. Lower Carboniferous ; Ireland.
Proterocidaris Koninck. Four columns of plates in each ambulacral area.
Twelve to thirteen columns of plates in each interamhulacral area. Plates
strongly imbricating. Small primary with secondary spines and tubercles on
interamhulacral plates. Lower Carboniferous ; Belgium.
Lepidesthes Meek and Worthen {Hybocchimis Worthen and Miller) (Figs.
365, 367, 0 ; 434). Eight to sixteen columns of plates in each ambulacral
area. Three to seven columns of plates in each interamhulacral area. Plates
are strongly imbricating and are all of uniform size. Secondary spines and
tubercles only. Test elliptical, obovate or spherical. This genus has more
species and a wider geological range than any other of the family. Ambulacral
plates are very regular in form, either rhombic or hexagonal. There may be
as many as sixteen columns of ambulacral plates in an area, e.g. L. colletti
White, in which species with an extreme ambulacral development there are
only four columns of interamhulacral plates (Fig. 434). In one species,
L. wortheni Jackson, there are eight columns of ambulacral plates with only
three columns of interamhulacral at the mid-zone, but there are four columns
ventrally as a youthful stage. Devonian ; Great Britain. Lower Car-
boniferous ; Russia, Great Britain, North America. Carboniferous ; North
America.
Pholidocidaris Meek and Worthen (Protocidaris Whidborne). Four to six
columns of plates in each ambulacral area. Five to six columns of plates in
each interamhulacral area. Plates strongly imbricating. Ambulacral plates
large ventrally, small dorsally ; interamhulacral plates dorsally very large in
CLASS I
ECHINOIDEA
307
adambiilacral columns, smaller within. Eccentric primary spines and tubercles
with secondaries on dorsal adambulacral plates, and secondaries only on
interambulacral plates of dorsal median columns. This peculiar and specialised
genus is known best from the type species P. irregularis (Meek and Worthen).
Devonian ; Great Britain. Lower Carboniferous ; Europe, North America.
IV
H
Lepidestlies colletti White. Lower Carboniferous ; Montgomery County, Indiana, x 21/2-
Madreporite and periproctal plates distinct (after Jackson).
MeekecJiinus Jackson (Fig. 435). Twenty columns of plates in each
ambulacra! area. Three columns of plates in each interambulacral area.
Plates of uniform size, imbricating strongly. Small central primary spines
and tubercles with secondary spines and tubercles on ambulacral and inter-
ambulacral plates. Teeth distally serrate, a unique character. This genus
with a single species is one of the most specialised of known Echini, also it
is the geologically latest representative of its family. The twenty columns
of ambulacral plates occur only near the mid-zone, as further dorsally less
columns exist. This is the only Echinoid from the Paleozoic in which
pedicellariae have yet been found. Permian ; North America.
308
ECHINODERMATA— ECHINOZOA
PHYLUM IV
Geological Range and Distribution of the Echinoidea.
Fossil Echini make their first appearance in the Ordovician, but are then
represented .by but a single genus, Bothriocidaris, which on structural grounds
is a highly primitive type. In the Silurian of Great Britain occurs
the order Echinocystoida, and in the American Silurian, Koninckocidaris, first
of the Lepidocentridae. In the Devonian one possible Cidarid occurs in
Europe and a number of genera of the Perischoechinoida in Europe and North
Fig. 435.
Mcckechinus elcfians Jackson. Permian ; Grand Summit, Kansas. Dorsal \-iew of test with a distinct
madrt'porite and oilier apical ])lates, enlarged, 2/j. Lower left-hand figure, ambulacral plates with spines more
enlarged. Lower right-hand ligure segment of interambulacrum with spines .still more enlarged. Upper left-
hand figure, jiedicellaria much enlarged, *-'/i (after Jackson).
America. In the Lower Carboniferous the Cidarids are represented by one
species of Miocidaris ; otherwise the whole Echinoid fauna is composed of the
Perischoechinoida, which order finds here its greatest development in genera
and species.
CLASS I ECHINOIDEA 309
In the Carboniferous very few Echini are known, and these belong to the
Perischoechinoida. The same order is repi'esented by a few types in the
Permian which, with a single species of Miocidaris representing the Cidaroida,
are the only Echini known.
In the Trias, Cidarids occur and also the earliest representatives of the
Centrechinoida. In the same horizon also occurs Tiarechinus, representing
the peculiar order Plesiocidaroida.
Especially rich in regular Sea-urchins, as well as in members of the
Echinoneidae, Cassidulidae and Collyritidae are the Middle and Upper Jura
of England, France, Germany, Switzerland, the Alps and Northern Africa.
The Lower Cretaceous of the same region exhibits no essential change in
the Echinoid fauna ; but the advent of large numbers of the Ananchytidae
and Spatangidae in the Middle and Upper Cretaceous of Europe, Noi'thern
Africa, Asia and North America imparts to these horizons a characteristic
appearance.
During the Tertiary the Cidaridae notably decline, the Echinoconinae
l)ecome entirely extinct, and the Clypeastroids and Spatangoids advance con-
spicuously into the foreground, taking on more and more the semblance of
Recent species. Tertiary Echinoids are of world-wide distribvition and are
particularly plentiful in the Nummulitic Limestone of Europe, Northern
Africa, Asia Minor and India.
As to phylogenetic' relationships, it is believed that structure and develop-
ment should be the basis for such studies. While it is earnestly desired that
we should find fossils in the proper geological horizons representing every
step in a genealogical sequence, it must be remembered that in the older
Paleozoic formations (Silurian and Devonian) Echini are extremely rare.
Recent studies have yielded many new Paleozoic forms and have considerably
extended the geological range of genera, families and orders, so that it is not
too much to expect that future discoveries will yield material of first
importance to a knowledge of the group. Echini are an essentially circum-
scril)ed group and no known type presents a close approach to any other class
of Echinoderms. Though the ancestor of the class is unknown, it seems that
it might fairly be sought among the Cystids.
The most primitive known Echinoid structurally is the Ordovician
Bothriocidaris, sole representative of its order, which in the adult has
characters that appear as stages in development in all other orders of Echini.
Bothriocidaris, with ten columns of ambulacral and five columns of inter-
ambulacral plates, in these characters represents the simplest known type.
The next step structurally is ten columns of ambulacral and ten of inter-
ambulacral plates. This structure is the character of the Cidaroida,
Centrechinoida and Exocycloida. Of these orders the Cidaroida with simple
ambulacral plates is certainly the most primitive as well as geologically the
oldest. The Centrechinoida typically have compound plates formed by the
coalescence of simple plates. Of this order the Aulodonta are the most
primitive group, make the nearest approach to the Cidaroida structurally, and
also geologically are the oldest of the order. The Stirodonta as regards the
structure of the lantern (keeled teeth) are further removed from the primitive
than the Aulodonta. The Camarodonta are the last expression of differentia-
tion of the Centrechinoida in regard to the structure of the lantern (keeled
teeth with wide epiphyses joining in suture over the foramen) and also in
310 ECHINODERMATA— ECHINOZOA phylum iv
ambulacral differentiation. This group appears last geologically and has its
fullest expression at the present time. The Exocycloida with an eccentric
periproct is a homogeneous group. The structure of the lantern (keeled
teeth) with other characters affiliate the basal members with the Stirodonta.
Of this order the Holectypina on the basis of the lantern structure, perignathic
girdle and ambulacral detail, make the nearest approach to the Stirodonta.
The Clypeastrina, by the characters of the lantern, perignathic girdle and
petaloid ambulacra composed of simple plates, are further removed from the
primitive than the Holectypina. The Spatangina, which have lost the lantern
in adults and have attained an extreme of differentiation in ambulacral
structure, bilaterality and an eccentric peristome, may well be considered the
most specialised group of the Exocycloida, and therefore the furthest removed
from the primitive.
Up to this point each order is characterised by having two columns of
ambulacral plates, and either one or two columns of plates in each inter-
ambulacral area. The next step in structural differentiation is two columns
of ambulacral and three columns of interambulacral plates. This is the
character of the Plesiocidaroida which is further marked by an exce2:)tionally
large apical disc which is a primitive feature.
The next step structurally is types wath two or more columns of simple
ambulacral plates and three or more columns of interambulacral plates, with
a small apical disk which is a progressive character. The Echinocystoida
with eight or more columns of interambulacral plates fall in this group.
This order is incompletely known, especially as regards the apical disk and
the periproct, which last appears to be eccentric in an interambulacrum,
separating it radically from all of the Perischoechiuoida. The Palaeodiscidae
is the more primitive family, with two columns of ambulacral plates ; the
Echinocystidae is the more specialised family with four columns of ambulacral
plates.
The Perischoechiuoida include all remaining Echini ; primitive as regards
the lantern, they are specialised in the interambufacrum, frequently in the
ambulacrum, and also in having a small apical disk. The Archaeocidaridae
have two columns of ambulacral plates and in so far are primitive, but they
have from four to eight columns of interambulacral plates ; very large spines
(for the Paleozoic) ; ambulacral and non-ambulacral plates on the peristome
and much resorption of the base of the corona, specialised. The Lepido-
centridae have also two columns of ambulacral plates. The family attains
many (5 to 14) columns of interambulacral plates, progressive; ambulacral
plates only on the peristome and no resorption of the base of the corona,
primitive. The Palaeechinidae may have two columns of ambulacral plates
only, but typically more (up to twelve) with three to eleven columns of
interambulacral plates ; plates not imbricate, secondary sjiines only, ambu-
lacral with non-ambulacral plates on the peristome, slight resorption of the
base of the corona. The Lepidesthidae may have two columns of ambulacral
plates only, but typically more (up to sixteen or twenty) with three to
thirteen columns of interambulacral plates, plates imbricate, primary and
secondary spines, or the latter only, ambiilacral plates alone on the peristome,
no resorption of the base of the corona as far as known.
In almost all of the above orders and families by the study of stages in
development, characters have been found in which the individual repeats the
CLASS I
ECHINOIDEA
311
characters seen in the adults of the preceding series, or lower members of its
own series.
Geological Range of the Echini
Orders and Families of Ecliini.
1
o
i
O
c
'u
S
3
0)
■Jl
O
a
X
c
u
5
c
'S
u
03
I
!
o
§
2
o
O
I
Order 2. Cidaroida
Order 3. Centrechinoida
Suborder A. Aulodonta
1. Hemicidaridae
2. Aspidodiadematidae
3. Centrechinidae
4. Echinothuriidae
Suborder B. Stirodonta
1. Saleniidae i
2. Phyniosomatidae
3. Stomopneustidae
4. Arbaciidae '
Suborder C. Camarodonta
1. Echinidae
2. Tenmopleuridae
3. Strongylocentrotidae
4. Echinometridae
Order 4. Exocycloida
Suborder A. Holectypina
Suborder B. Clypeastrina
1. Clypeastridae
2. Fibulariidae
3. Scutellidae
Suborder C. Spatangina
1. Echinoneidae
2. Cassidulidae
3. Collyritidae
4. Ananchytidae
5. Spatangidae
6. Palaeostomatidae
7. Ponrtalesiidae
1
1
1
Order 5. Plesiocidaroida
Order 6 Echinocvstoida
Order 7. Perischoechinoida 1
1
1
1
I
[To Dr. Robert Tracy Jackson, of the Boston Society of Natural History, acknowledgments
are due for having revised the preceding chapter on Echinoidea. A number of new illustra-
tions have been reproduced from this author's recently published monograph on the Phylogeny
of the Echini. — Editok.]
312
ECHINODERMATA— ECHINOZOA
PHYLUM IV
Class 2. HOLOTHURIOIDEA von Siebold.^
The Holothurians, or Sea-cucumbers, differ markedly from all other
Echinoderms in their elongated bodies with little or no skeleton. The mouth
and anus are with rare exceptions more or less nearly terminal at opposite
poles, and the former is always surrounded by a circle of tentacles, 8-30 in
number. The skeleton is represented by calcareous particles in the body
wall, which are commonly microscopic and dissociated, but are sometimes
several millimetres across, and in rare cases may even be closely united with
each other to form a rigid body wall. In some species skeletal particles are
nearly or quite wanting.
The paleontological evidence bearing on the history of Holothurians is
very slight. Fossils occur in two forms, either as impressions or casts of the
Eldonia ludwigi Waleott. Middle Cambrian (Burgess shale formation) ; British Columbia. Specimen
flattened in the shale and showing traces of internal organs, cr and re, Central ring and radial canals of
vascular system ; i, Intestine ; o, Oral aperture ; oc, Oral chamber ; oe, Oesopliagus ; s, Stomach ; t,
Tentacles ; id, Umbrella lobes, crushed and macerated ; x-x, Junction - point of' stomach and intestine ;
a. Position of anus. Natural size (after Waleott).
whole animal, or as dissociated skeletal particles preserved in very fine
limestones or shales. Of impressions or casts, the earliest described are
^ Literature : Giehel, C, Zur Fau
rienreste. Zeits. f. gesammt. Naturw
fossiles (lu Calcaire Grossier. Bull,
sur les Holotliuridees fossiles. Bull
Seewalzen. Bronii's Klassen unci Or
£., Die Echiiioilermeu des deutschen
fossile Holotluuie. Oj). clt., 1900,
and Medusae. Smiths. Misc. Coll.,
Science, 1912, n.s. vol. xxxv. — Clark,
na des litliographi.sclien Schiefers von Solenhofen. Holothu-
,, 1857, vol. ix. — Schlumherger, C, Note sur les Holothuridees
Soc. Geol. France (3), 1888, vol. xvi. — Idem, Second Note
See. Geol. France (3), 1890, vol. xviii. — Ludwig, H., Die
■dnuugeu des Thierreichs, vol. ii., part 3, 1889-92. — Spmidel,
Zechsteins. Abh. Ges. Niirnberg, 1898, vol. xi. — Jdem, Eine
vol. xiii. — JFalcott, C. D., Middle Candjrian Holothurians
1911, vol. Ivii., no. 3. — Clark, H. L., Fossil Holothurians.
A. H., Restoration of Eldonia. Zool. Anz., 1912, vol. xxxix.
CLASS II HOLOTHURIOIDEA 313
those made known by Giebel from the Lithographic limestone of Solenhofen.
These he called Protholoturia, and though the material does not permit of exact
generic determination, it bears a resemblance to certain Eecent species of
Holothuria and Pseudostichopus. The impression formed by the general appear-
ance of these specimens that they really represent Holothurians is confirmed
by the presence of characteristic calcareous particles on their surface.
Recently, in the remarkably well-preserved fauna from the Middle
Cambrian shales of British Columbia, Walcott has discovered some complete
specimens of typical Holothurians, preserving many details of the original
animals. Most of these species are i-eferred by A. H. Clark to the family Elpi-
diidae (a group of very remarkable Holothurians at the present time confined to
the deep sea), but one of them, Eldonia (Fig. 435 his), representing the new family
Eldoniidae, was free-swimming like the Eecent PeJagothnria, though structurally
entirely different from that type, being most nearly related to the Elpidiidae.
Dissociated calcareous particles referred to Holothurians have been
described by a number of writers from the British Carboniferous rocks, the
Zechstein of Germany, the Lias and Dogger of Lorraine, the Upper Jura of
Franconia, the Cretaceous of Bohemia, the Eocene of Paris, the Oligocene of
Oftenbach, the Pliocene of Italy and the post-Tertiary of Scotland. A very
large majority of these cannot be assigned to any particular genus or even
family of Holothurians, and it is probable that many if not most are of other
than Holothurian origin. There can be no question, however, that a part
of this material is of real paleontological value. In particular the forms
described by Schlumberger and by Spandel are worthy of attention.
Spandel's discovery of what seem to be unquestionable Holothurian
spicules, like those characteristic of the genus Chiridofa, in the Zechstein of
Germany, is noteworthy. These spicules are distinctly wheel-shaped, but
ditFer noticeably from those of Recent Chiridota in having 10-14 spokes instead
of six. They thus show a certain resemblance to the wheels of Trochoderma
and the first formed calcareous deposits of the larvae of Chiridota rotifera and
certain Auricularias. Spandel's later discovery of an Oligocene Spiapta, and
Schlumbevger's studies on the Eocene Holothurian spicules of the Calcaire
Grossier, show that during the Tertiary period the Synaptidae were already
diff'erentiated into the three Recent subfamilies, Synaptinae, Chiridotinae and
Myriotrochinae. Beyond this grouping we cannot speak with any certainty.
Our actual knowledge of fossil Holothurians may be summed up as follows :
1. Holothurians allied to living membei's of the class existed in the Jurassic
seas of Europe, and, according to Walcott's interpretation, there is evidence
that the typical expression of the group was already differentiated as early
as the Cambrian.
2. Holothurians of the family Synaptidae, allied to Chiridota or Trochoderma
occurred in the Permian seas of Europe ; and at least as early as the Eocene,
all three of the Recent subfamilies of Synaptidae were differentiated.
3. The Permian Holothurian spicules are wheel-shaped but have numerous
spokes as in Trochoderma, and resemble those of the larval Chiridota, not those
of the adult.
[The account here given of Holothurians, with the exception of the paragraph in regard
to Cambrian representatives of the class, has been contributed by Dr. H. L. Clark of the
Harvard Museum of Comparative Zoology. — Editor.]
Phylum V. MOLLUSCOIDEA.
Under the term Molluscoidea, Milne Edwards included the Bryozoa and
Tunicata, of which the first had been previously regarded as Zoophytes, and
the second as Molluscs. Huxley afterwards assigned the Brachiopoda to the
same phylum. The Tunicata have more recently been regarded as an in-
dependent animal type, and as possible progenitors of the Vertebrate phylum.
Their remains, however, are unknown in the fossil state. Bryozoans, also
called Polyzoa, are by some authors regarded as constituting a distinct phylum
of invertebrates, but are here retained in association with Brachiopods.
The typical Molluscoidea either secrete a calcareous shell, or are invested
with a membranaceous or corneous covering. The respiratory organs lie
anterior to the mouth, and are in the form of tentacles or fleshy spiral
ai^pendages. The mouth conducts into a closed alimentary canal. The
nervous system is highly organised, and proceeds from a central ganglion,
situated in most cases between the mouth and the anus. Reproduction is
either sexual or, in Bryozoa, also takes place by budding. The ontogeny of
the Molluscoidea is most nearly comparable with that of the Annelids.
All of the Molluscoidea are water inhabitants ; the Bryozoans are largely,
and the Brachiopods exclusively, marine forms.
Class 1. BRYOZOA Ehrenberg.i
Small, almost always composite animals forming by gemmation variously shaped
colonies, each zooid of tvhich is enclosed in a membranaceous or calcareous doiible-
^ Literature: d' Orhigny, A., 'PsX^outologie. francaise; Terrain cn'tace, vol. v., 1850-51. — Hagenoio,
F., Die Bryozoen der Maestriclier Kreidebildung. Cassel, 1851. — Haime, J., Description des
bryozoaires fossiles de la formation jurassique. Mi'in. Soe. Geol. de France, 2nd ser. vol. v., 1854.
—Busk, O., Catalogue of Marine Polyzoa in the Collection of the British Museum (Parts i. and ii.,
Cheilostomata), 1852-54. (Part iii., Cyclostomata), 1875. — Busk, G., Monograph of the fossil
Polyzoa of the Crag. Palaeont. Soc, 1859. — Oabb, W. M., and Horn, G. H., Monograph of the
fossil Polyzoa of the Secondary and Tertiary Formations of North America. Journ. Acad. Nat. Sci.
Philad., 2nd ser., vol. v., 1862. — Beissel, I., Ueber die Bryozoen der Aachener Kreidebildung.
Haarlem, 1865. — Reuss, A. E., Several important papers in Denkschr. Akad. Wis.s. Wien, vols,
xxiii., xxxiv. , 1863-74 ; and Palaeontographica, vol. xx., 1872-74. — Manzoni, A., Several im-
portant contributions on Tertiary Bryozoans in Denkschr. Akad. Wiss. Wien, 1869-78, vols,
xxix.-xxxviii. — Waters, W. A., Numerous papers on Tertiary and Recent Bryozoa in Ann. and
Mag. Nat. Hist, and Quar. Journ. Geol. Soc, 1879-92. — Iflncks, T., History of the British Marine
Polyzoa, 2 vols., 1880. — -Vine, G. R., Reports on fossil Polyzoa. British Assoc. Reports, 1881-85.
— (jlrich, E. 0., American Palaeozoic Bryozoa. Journ. Cincinnati Soc. Nat. Hist., v.-vii., 1882-84.
— Busk, G., Report on Polyzoa. Scient. Results Challenger Exped., Zoology, vols. x. and xvii.,
1884-86. — Hall, J., Lower Helderberg, Corniferous, and Hamilton Bryozoa (Palaeont. N.Y., vol.
vi.), 1886. — Ulrich, E. 0., Palaeozoic Bryozoa. Geol. Survey Illinois, vol. viii., 1890. — Ulrich,
E. 0., Lower Silurian Bryozoa. Geol. Survey Minnesota, Final Report, vol. iii., 1892. — Canu, F.,
314
CLASS I BRYOZOA 315
walled sac (soo&cium), and possesses typically a freely suspended alimentary canal
with mouth and anus. Mouth surrounded by a crown of hollow, slender, ciliated
tentacles o^rranged in the form of a circle or crescent. Usually hermaphroditic.
The Biyozoa resemble certain Corals (Tabulata) and Hydrozoans in tlieir
external configuration, but differ from them radically in the possession of a distinct
body cavity, a closed alimentary canal, a highly developed nervous system, and
delicate resj)iratory tentacles surrounding the mouth. With the exception of the
solitary genus Loxosoma, all Bryozoans live associated in colonies or zoaria, of greater, or
less extent, and of either calcareous, corneous or membranaceous composition. These
colonies, which are formed by frequently repeated gemmation, present a multitudinous
variety of form, habit and structure. Sometimes they grow into plant-like tufts,
composed of a series of cells variously linked together ; very commonly they spread
over shells and other foreign bodies, forming delicate interwoven threads, crusts of
exquisite pattern, or hemispherical, globular or nodular masses of considerable size ;
often they rise into branching stems, and fronds of varying width ; and at other times
the cell-jjearing branches form most regular and beautiful open-meshed lace-work.
Each zooid or polypide is enclosed in a separate chamber (zooxium) of either
utricular or more or less tubular form. Occasionally the zooscia are quite distinct
from their neighbours ; more commonly, however, intercommimication is effected,
either by means of minute " connecting foramina " jjiercing the chamber walls, or
by a common canal to which all the zooids are attached. A true coenenchyma,
such as is found among the Coelenterates, never occurs, and coenenchymal gemmation
is accordingly unknown ; but a somewhat similar " vesicular tissue " not infrequently
occuj)ies the interzocccial spaces which have resulted from the erection of the zooecial
tubes.
Such vesicular tissue occurs constantly in the Fistuliporidae and Cystodictyonidae, and in
the latter the primary, or even the prostrate cells, are not entirely contiguous. The upper
walls of the vesicles, at least, are abundantly perforated ; and when with increasing age the
vesicles become tilled with a secondary deposit, these pores are not obliterated, but, continue to
pass through such deposits in the form of minute vertical tubes. Precisely the same kind of
tissue occurs in other Bryozoans, notably among adult colonies of certain Fenestellidae, in
which the expanded base of the colony is largely vesicular, and the fenestrules and spaces
between tlie carinae of the branches are filled witli vesicles for some distance up. The real
purpose of this tissue is to support the zocecia and to strengthen the zoarium.
However diverse the external aspect of the composite structure, the small animals
themselves conform to a simple and quite definite type. Briefly, the soft parts consist
of an alimentary canal, in which three distinct regions, an oesophagus, stomach and
intestine, are recognisable. This is enclosed in a sac, and so bent upon itself that its
two extremities, or openings, approximate ; one of them, the oral, being either entirely
or jiartially surrounded by a row of slender, hollow and ciliated tentacles, which serve
for respiration and for sweeping food toward the mouth. In most cases the anal
opening is situated without the ring of tentacles (Ectoprocta), rarely within the same
(Entoprocta). Heart and vascidar system are wanting, but a nervous ganglion, sending
Numerous papers on Mesozoic and Cenozoic Bryozoa in the Bull. Soc. Geol., France, 1897-1910. —
Ulrkh, E. 0., Eocene Bryozoa. Eocene volume, Md. Geol. Surv., 1901. — Ulrich, E. 0. aud Sassier,
R. S., Miocene Bryozoa. Miocene volume, Md. Geol. Surv., 1904. — Ulrich, E. 0. and Bassler, R. S.,
Revision of the Paleozoic Bryozoa. Smith. Misc. Coll., vols, xlv.-xlvii., 1904. — Nickles, J. M. and
Bassler, R. S., Synopsis of American fossil Bryozoa. Bull. 173, U.S. Geol. Surv., 1901. (Contains
a list of all bryozoan literature and a bibliography of fossil forms.) — Bassler, R. S., Bryozoan Fauna
of the Rochester Shale. Bull. 292, U.S. Geol. Surv., 1906.— Gregori/, J. W., Cat. Cretaceous
Bryozoa in British Museum, 2 vols., 1899 aud 1909. — Levinsen, G. M. R., Cheilostomatous
Bryozoa (Recent). Copenhagen, 1909. — Bassler, R. S., Early Paleozoic Bryozoa of the Baltic
Provinces. Bull. 77, U.S. Nat. Mus., 1911. — Hennig, A., Gotlands Silurische Bryozoen. Arkiv
Zool., 1908, vol. iv. — Canu, F., Iconograjihie des bryozoaires fossiles de I'Argeutine. Anal. Mus.
Nac. Buenos Ayres, 1909-11, ser. 3, vol. x. — Lee, G. W., British Carboniferous Trepostomata.
London, 1912.
316 MOLLUSCOIDEA phylum v
out delicate nerve filaments to the tentacles and oesophagus, lies between the mouth
and anus. The upper or anterior part of the sac is generally flexible and admits of
being invaginated by the action of numerous, longitudinal and transverse muscles,
which traverse the fluid-filled visceral cavity.
Eej)roductive organs are developed in various parts of the cavity, the spermatozoa
usually in the lower, the ova in the upper portion. The ova may be developed in a
special receptacle {marsiqnum) attached to the zocecium, or in an inflation of the
surface of the zoarium (gonocyst) ; in other cases, a modified zocecium {gonoecium) is set
apart for reproductive functions. The general term ocecium or ovicell is applicable to
all of these structures.
Many Bryozoans are provided with ajipendiciilar organs known as avicularia and
vibracula (Fig. 436). Their functions are somewhat doubtful, some authors regarding
them as food-procuring agents, and others as organs of defence.
The avicularia may be immovably attached to the zocecium ;
1jut, as a rule, especially among Recent forms, they are peduncu-
late, and capable of considerable swaying motion. Often, as in
Bugula and Bicellaria, they resemble the head of a bird, con-
sisting of a helmet-shaped upper piece, with a formidable hooked
beak, and a mandible worked by powerful muscles. The jaws
open and close wdth a perpetual snapping motion, and small
organisms or other foreign particles happening in their way are
seized and held with a tenacious grasp. The vibracula are
flexible, bristle-like appendages, generally set in the excavated
summit of a knob-like elevation, or on a blunt spine.
The avicularia and vibracula are themselves incapable of
Fig. 430. preservation, but their former presence on fossil specimens may
Selenaria maculata be generally determined by the slight pore-like excavations in
porMon^oTu°ppef slfrlce which they were lodged. The tubular spines, or acanthopores,
showing a vibracuium which are of sucli common occurrence in Paleozoic Bryozoans,
were, in part at least, probably the supports of similar structures.
The term lunarium is applied to a more or less thickened portion of the posterior
wall in many Paleozoic Bryozoans, which is curved to a shorter radius and iL?ually
projects above the plane of the zooecial aperture. Mesopores are angular or irregular
cells occupying interzooecial spaces in certain Paleozoic genera.
Most Bryozoans are attached, either by the greater part of their surface, or only
basally, to extraneous objects ; or they are moored to the bottom by root-like appen-
dages. In many forms the zoarium is regularly jointed. The majority of genera
inhabit the sea, and occur in all zones and at all depths ; only a few genera live in
fresh water. The animals subsist chiefly on Diatoms, Infusorians and larvae.
Classification. — The classification of the Bryozoans remains as yet in an unsatis-
factory condition. D'OrViigny's comprehensive system is largely artificial, and
although numerous modifications and improvements have been suggested by later
authors, further revision has still to l)e undertaken.
Lankester divides the class into two very unequal subclasses as follows : (1)
Holobranchia, in which the lophophore or row of tentacles is unbroken, and either
circular or horse-shoe shaped ; and (2) Pterobranchia, containing the single genus
EJtabdopleui-a, which has the lophophore produced on either side into a plume-like
process, so that the tentacles form a discontinuous series.
A more modern system is to regard Bryozoans as a primary group or phylum,
which is divided into two unequal classes, named l)y Nitsche, Ectoprorfa and Ento-
procta, according as the lopho])hore surrounds the mouth only, or encloses both the
oral and anal orifices. The first of these classes contains the bulk of the known
Bryozoa. Furthermore, the marine forms, and practically all genera capable of pre-
servation in the fossil state, are included in the subclass Gymnolaemata Allman.
CLASS I
BRYOZOA
317
This is distinguished from the remaining subclass, Phyladolaemata AHman (which
includes the freshwater forms), by the complete abortion of the foot, and by the
circular arrangement of the tentacles.
The Mesozoic and Recent marine Gymnolaeniata are almost universally divided
into the three orders proposed by Busk : the Cydastomata, Cheilostomata and Cteno-
stomata. To these Vine has added a fourth, the Gryptostomata, and Ulrich a fifth,
the Trepostomata ; both of which serve mainly for the reception of Paleozoic forms.
The detailed classification of the Mesozoic and Cenozoic Bryozoa, especially of the
Cheilostomata, is less settled than that of the ancient types. This nonconformity is
due in part to the widely different views prevailing among authors as to the relative
value of the various characters upon which the groups arc founded ; and partly
because the mode of growth and zoarial characters in general are much less constant,
and, therefore, less reliable than is the case among Paleozoic representatives of the
group.
Subclass 1. GYMNOLAEMATA AUman.
Order 1. CTENOSTOMATA Busk.
Zocecia usiudly isolated and developed by budding from the internodes of a distinct
tubular stolon or stem. Orifice terminal, with an operculum of setce. Zoarium horny or
membranaceous. Marsupia wanting.
All of the known Paleozoic Gtcnostomata have been described by Ulrich and Bassler in their
Revision of the Paleozoic Bryozoa, to which the student is referred for a discussion of these
peculiar fossils. Mesozoic and Cenozoic Ctenostomatous Bryozoa are apparently rare and little
study has been put upon them. In the Recent seas, the order Ctenostomata is s]>ecifically the
least represented group of Bryozoa, although some of the species are quite abundant and
widespread.
i
Family 1. Rhopalonariidae
Nickles and Bassler.
Fusiform segments arranged
in a more or less pinnate
manner, impressed or almost
embedded in the host.
Rhopalonaria Ulr. (Fig.
437, &'). Ordovician to Lower
Carboniferous.
? Terebripora d'Orb. Ter-
tiary and Recent.
Family 2. Vinellidae
Ulrich and Bassler.
Creeping base of zoarium
of simple or locally jointed,
delicate, tubular threads ar-
<3
Fio. 437.
--"-—> A, Allonemafusiforme (N. and E.t, 6/1. B, C, Vinella repens Ulr., 2/.j
ranned either imthout order or and is/j. d, AscodictyonsteUaUm(-s.?,nA-E.^,vii, e, A.p^^^^^^
,Kvivj^K<j and B., 6/1. F, /MeroHema «?j)i7toce U. and B., 6/1. G, Bhopulonana
proceeding from more or less te,m("s U. and B., e/i (after ulrich and Bassler).
definitely marked centres. In-
ternodes ivith a single roio of pores or, in one genus, closely punctate ; zocecia unknown.
Vinella Ulrich (Fig. 437, B, G). Zoarium of very slender parasitic tubular threads
318 MOLLUSCOIDEA— BRYOZOA phylum v
or stolons arranged radially ; surface with a single row of pores. Ordovician to
Lower Carboniferous.
Heteronema Ulr. and B. (Fig. 437, F). ' Zoaria as in Vinella but threads are with-
out radial arrangement. Ordovician to Upjier Carboniferous.
Allonema Ulr. and B. (Fig. 437, A). Zoaria composed of distinct, minutely
punctate vesicles or connected internodes. Silurian to Lower Carboniferous.
? Ptychocladia Ulr. and B. Upper Carboniferous.
Family 3. Ascodictyonidae Ulrich.
Zoaria parasitic, of pyriform porous vesicles arranged in radial clusters, or isolated
and connected by delicate hollow threads.
Ascodictyon Nich. and Etli. (Fig. 437, D, E). Silurian to Lower Carboniferous.
Order 2. CYCLOSTOMATA Busk.
(Bryozoaires centrifugines d'Orbigny p.p.)
Zocecia very simple, cylindrical, calcareous, tubular, usually without transverse parti-
tions ; the orifices plain, inoperculate, not contracted, occasionally expanded ; walls thin,
minutely porous ; apertural portion of zooscial tubes more or less raised, bent outwards,
free or in bundles ; the interspaces with or without solid or tubular strengthening deposits.
Marsupia and appendicular organs wanting. Ocecium a large cell set apart for repro-
ductive functions, or a mere inflation of the zoarial surface.
Tlie families and genera of this order are founded almost entirely upon tlie form of the
zoarium, and the arrangement of the zocecia. The presence or absence of interstitial or
accessory cells and vesicular tissue (all strengthening deposits) is also an important cliaracter.
For many years it was customary to regard all Paleozoic Bryozoans as Cyclostomata, but
the labours of Ulrich and Vine have clearly demonstrated the fallacy of such an assumption.
The families Ceramoporidae and Fistuliporidae, often regarded as Trepostomata or " AlonticuU-
j3oro?c?s," are referred to the Cyclostomata because they agree with its most typical members in
having amalgamated and minutely porous walls. In 1890 Ulrich discovered ovicells in certain
genera of the Fistuliporidae, while more recently Bassler has shown the occurrence of the
same structures in the more primitive Ceramoporidae.
Suborder A. TUBULIPORINA Hagenow. {Tubulata Gregory).
Zocecia monomorphic, of elongated, cylindrical tubes grouped into bundles, sheets or
linear series. The Tubuliporina comprise the typical Cyclostomata and in all probability
give rise to the other suborders.
Family 1. Crisiidae Busk.
Zoaria dendroid, attached by radical tubes and composed of segments united by corneous
joints. Zowcia tuhilar, disposed in single or double series.
Grisia Lamx. {Crisidia Johnst. ; Filicrisia d'Orb.). Zoaria more or less distinctly
articulated, the zooecia in a single or in two alternating series. Cretaceous to Recent.
? Unicrisia d'Orb. Cretaceous.
Family 2. Diastoporidae Busk (emend.).
Zoaria adnate, adhering by the entire base or only at the centre, at other times rising
into bifoliate leaves or hollow stems. Zocecia tubular, the aperture salient, rounded, never
clustered. Interstitial cells wanting. Ovicells mei'c irregular inflations of the surface of
the zoarium, with one or more openings. OrdoAdcian to Recent.
ORDER II
CYCLOSTOMATA
319
Stomatopora Bronn {Alecto Lamx. non Leach) (Fig. 438). Zoaria delicate, adnate,
dicliotomously brandling. ZocEcia sub-tubular or elongate-ovate, arranged in a single
Fio. 43S.
Stomatopora diclwtoma (Lamx.).
GreatOolite; Ranville, Calvados.
A, Zoariuiu, Vl- }J, same, en-
larged.
A, Corynotrypa Mkatula (James). Utica Group ; Cincinnati, Ohio.
Zooecia, iB/i. B, C. injlata (Hall). Lorraine Group ; Cincinnati, 6/1.
C, Probosciwi f random Nich. Lorraine Group ; Cincinnati, Oliio. Portion
of a large zoarium, 12/j (after Ulrich).
series ; apertures sub-terminal, usually smaller tban the width of the cell. Ordovician,
Jura, Cretaceous, Tertiary and Recent.
Corynotrypa Bassler {Stomatopora in part, auct.) (Fig. 439, A, B). Zoarium
unilinear, adnate, with short to elongate, clavate zoa3cia. Ordovician to Devonian.
Prohoscvna Audouin (Fig. 439, G). Like Stomatopora but zoa'cia arranged in two
or more series. Ordovician, Mesozoic to Recent.
Berenicca Lamx. {Diastopora Busk, non Lamx.) (Fig. 440). Zoaria forming thin,
discoid, flabellate or irregular crusts upon foreign bodies. Zocecia arranged in
irregularly alternating lines. Rare in Ordovician and Silurian, very abundant in
Jura and Cretaceous, less frequent in Tertiary and Recent.
Fig. 440.
Bemiicea dlluviana Lamx. Great Oolite ;
Ranville, Calvados. A, Young expansion,
1/1. B, same, enlarged (after Haime).
Fig. 441.
Diastopora foUacca (Lamx.). Great Oolite ;
Ranville, Calvados. A, Fragment of zoarium,
1/1. B, Enlarged portion of same.
Discosparsa d'Orb. Differs from Berenicea in having obconical or cup-shaped
zoaria, attached by centre of the base only. Cretaceous and Tertiary.
Filispar sa d'Oih. Zoarium ramose, branches compressed dorso-frontally; apertures
irregularly disposed. Cretaceous to Recent.
Diastopora Lamx. {Mesenteripora Blv.) (Fig. 441). Like Berenicea, except that
the zoarium rises into broad, simple or convoluted leaves, composed of two layers of
320
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
zoojcia grown back to back. Very abundant in the Jura, less common in Cretaceous
and Tertiary.
Bidiastopora d'Orb. Like Diastopora, but the zoaria forming only narrow, parallel-
edged branches. Cretaceoiis.
Reptomultisparsa, Cellulipora and Filicrisina d'Orb. Cretaceous.
Diastoporina Ulricli. Ordovician. Hederella and Hernodia Hall ; and Beptaria
Rolle. Devonian.
Family 3. Idmoneidae Busk.
Zoaria forming free or adnate, variously compressed branches. Zocecial apertures
rounded, more or less elevated, usually arranged in transverse roios on two faces of the
branches ; sometimes the two faces are confluent. Dorsal surface of the branches without
zooecia, but often occupied by numerous small tubular pores, ivhich may also occur near
the apertures. Sac-like ovicells with but a single opening. Ordovician to Recent.
Idmonea Lamx. Zoarium adnate with apertures opening in transverse series.
Jurassic to Recent.
Grisina d'Orb. (Fig. 442). Zoarium erect, simple or branching. Branches
usiially triangular, two of the faces carrying the zocecial ajjertures, which are generally
arranged in alternating transverse series. Jurassic to Recent.
Bisidmonea d'Orb. Quadrate,
simple or branching stems, bear-
ing zocecial apertures on all faces.
Cretaceous.
Betecava d'Orb. Zoaria reti-
culated ; branches greatly com-
pressed laterally ; reverse side
occupied by an axial rod. Cre-
taceous.
Bicrisina, Bitubigera, Bepto-
fascigera, Semiclausa, Sulcocava
(Laterocava) d'Orb. : and Perqen-
Protocrisina exigiia ,, ^ ^,
uirich. Trenton sella Oregory. Cretaceous.
N.Y."'Branche"'o7a Phalangella Gray. Creta-
large expansion, i^/i. ceoUS to Recent.
Protocrisina Ulr. (Fig. 443).
Narrow, bifurcating branches, celluliferous on one side only. Zooecia sub -tubular,
with prominent circular apertures arranged in intersecting diagonal series. Small
pores, apparently communicating with interior of the zooecia, irregularly distributed
over both faces of the branches. Ordovician and Silurian.
Family 4. Entalophoridae Reuss.
Zoaria ramose ; branches free, sub-cylindrical, with
rounded and more or less prrominently exserted zocecial
apertures opening on all sides. (?) Without accessory or
interstitial pores of any kind. Ordovician to Recent.
Entalophora Lamx. {Glavisparsa d'Orb. ; Pergensia
Walford) (Fig. 444). Zocecial tubes disposed about an
imaginary axis, and with rounded, more or less prom-
inent apertures. Jurassic to Recent.
Fig. 442.
Cnslna dorsata Hagenow. Uppermost
Cretaceous ; Maestricht. A, Branch, nat.
size. B, Upper, and C, Lower side, highly
magnified.
Pig. 443.
Fig. 444.
Entalophora vi'r-
Spiropora Lamx. {PustuloiJora and Cricopora Blain- ^l^-^-- ^.^,?'''
agenow.
Fio. 445.
Spiropora vcr-
ticilkita Goldf.
Upper Cretace-
ous ; Maestriclit
e) {big. 445). Like the preceding, but apertures Plauen, Saxony. (after Hagenow).
ORDER II
CYCLOSTOMATA
321
aimnged in regular, spiral or transverse linear series, and closely situated. , ZocEcial
tubes disposed aljout a definite central axis or axial tube. Jurassic to Recent.
Diploclema Ulr. Similar to Entalophora, but Avith branches spreading in the
same i)lane, slightly compressed, and divided into two equal parts by a wavj' mesial
lamina. Silurian.
Haplocecia Gregory. Like Spiropora, but distal ends of zocccia are angular.
Jurassic and Cretaceous.
Mitoclema Ulrich. Ordovician. Clonopora Hall. Devonian. Peripora d'Orb.
Cretai/eous.
Rhipidojjora and Glinopora Marsson; Siphoniutyphlus Lonsdale; Clypeina Michelin;
Umbrellina Roemer. Cretaceous and Tertiary.
Family 5. Fasciporidae d'Orl)igny (emend.).
Zoojcia tubular, opening in clusters at the
(jrowing extremities, and in linear or quincuncial
series on the sides of the lamelliform, or obconical
zoaria. Accessory pores wanting. Cretaceous.
Fascipora d'Orb. (Fasciporina d'Orlx). Zoaria
compressed, sub-ramose to lamelliform. Aper-
tui'cs arranged quincuncially or somewhat ir-
regularly on both sides, and on the more or less
expanded growing extremities of the branches
and lamellae. The lamelliform species resemble
Diastopora, but are without a mesial lamina.
Semifascipora d'Orb. (Fig. 446). Zoaria cup
or funnel-shaped, with only the outer surface
poriferous, the inner covered by an epitheca.
Poriferous face thrown into vertical ridges
bearing the salient tubular mouths of one or
more rows of zocecia. At the upper edge the ridges pass into large clusters of apertures.
Gonotuhigera and Serietuhigera d'Orb. Closely related to the preceding.
Fio. 446.
Semifascipora variabilis d'Orb. Cretaceous ;
France. Side view of zoarium, lo/j.
Fig. 447.
Fasciculipora incrassata d'Orb. Upper
Cretaceous ; Meudon, near Paris. Terminal
fragment, nat. size and enlarged (after tiarv
d'Orbigny). •''
Family 6. Fascig-eridae d'Oibigny.
Zoarium composed of bundles of long, parallel
zooccia free for most of their length, with the aper-
tures in groups at the ends of the bundles.
Fasciculipora d'Orb. (Fig. 447). Zoarium of
long, simple or divided branches.
Tertiary.
Gorymbopora Michelin. Like
but sides of branches marked by numerous jiores.
Cretaceous.
Apsendesia Lamx. Zooccial bundles arise from
a small cup-shaped disk. Jurassic and Cretaceous.
Discofascigera d'Orb. Cretaceous and Ter-
Jurassic to
Fasciculipora
Family 7. Theonoidae Busk.
Zoarium adnate or erect ; zooecia simple, short, open tubes with apertures confined to
crowded bands along raised ridges or on the edge of the fronds.
VOL. I Y
322 MOLLUSCOIDEA— BRYOZOA phylum v
Acti%iopora d'Oib. (Pavotubigera, etc., d'Orb.) (Figs. 448, 449). Zoariuiii an
Pig. 44S.
Actinopora liiadema (Goldfu.ss).
etaceous ; Mi
Profile of same.
Upper
B,
C, Upper surface, enlarged.
FiQ. 449.
Actinopora disticha (Hag.).
Upper Cretaceous ; Prance.
Upper surface, ^li.
Theonoa, Lamx. {Tilesia Lamx.
aclnate disk witli apertures opening on ridges radiating from a central depression.
Cretaceous to Recent.
Multitubigera d'Orb. Zoariuni compound, the elements structurally resembling
confluent Actinoporae. Cretaceous.
Phyllofrancia Marsson) (Fig. 450). Zoarium
massive or frondose ; surface
crossed by broad ridges bear-
ing the apertures. Jurassic
to Tertiary.
Patenaria, Locularia
Hamm ; Betenoa Gregory.
Cretaceous.
Family 8. Osculiporidae
Marsson,
Fio. 450.
M. Edw. Crag ;
Theonoa {?)(> aiirantlmn
broken open in a vertical plane, Vi-
surface.
Sussex. .4, Zoariuni
li, Enlarged portion of ujiper
Zoarium ramose, cylindri-
cal or adnate ; zomcia simple,
long, in bundles with the
apertures opening in clusters
on the surface or sides of the
zoarium.
Filifascigera d'Orlj. (Fig.
451). Zoarium of simple or
Ijranched, creeping stolons.
Cretaceous and Tertiary.
Lopholepis Hagw. Zoar-
ium a broad incrusting
sheet. Cretaceous.
Cyrtopora Hagw. Semi-
cylindrical stems with pro-
minent clusters of four or
more zofficial apertures open-
ins on all sides. Cretaceous
to Recent.
Osculipora d'Orb. (Fig.
452). Ramose, with clusters
of zocecia opening alternately on the sides of the obverse face of the branches.
Cretaceous.
Fig. 451.
Filifasciijera mcgaera
Lonsd. Upper Cretace-
ous ; Vincentown, N.J.
Specimen seen from above
and from the side
(after Ulrich).
12
Fig. 452.
OsciiUpura tnin-
rata Hagw. Up-
per Cretaceous ;
Maestricht, Hol-
land. Fragment
Vi, and enlarged
(after Ulrich).
Fig. 4oa.
Trxincat ala re pens
Hagw. Upper Cretace-
ous ; Maestricht. Lower
and upper sides of zoa-
rium, enlarged (after
Hagenow).
OUDEll II
CYCLOSTOMATA
323
Trancatula Hagw. (Fig. 453). Like Osculipora, l)ut convex sides exliiljitiiig
luniierous pores longitudinally arranged. Cretaceous.
Homoeosolen Lonsdale {Supercytis, Unicytis d'Orb.). Cretaceous.
Discocytis d'Orb. (Pelagia Mich., non Lam.) (Fig. 454). Zoariuni cnpuliform ;
tf' ' ' VAyy*Mi'^i,i ■"■■■ ■"'^
Pig, 454.
Discocytis euiiesii d'Oii). Upper Cretaceous'; France. Zo.iiium, 3/^, and three views of
same enlarj^ed (after d'Oibigny).
u|i])er surface concave with radiating ridges having apertures at their outer ends ;
under surfixce poriferous. Cretaceous.
Gytis, Badiofascigera, Bicavea d'Orb. Cretaceous.
Family 9. Oeidae d'Orbigny
Zoaria ramose, bifoliate or uni-lamellate. Zocecia tubular, sub-equal, their ivalls
thin at first, but thickening gradually toward the periphery, cohere the cavity suddenly
dilates in such manner that the rounded or ellipticg,l aperture lies at the bottom of an
hexagonal depression. Interstitial cells wanting. Cretaceous.
The systematic position of this family is highly problematical. It appears to have certain
affinities with the Trepostomata, but its removal to that vicinity is hardly feasible until a
thorough comparison of Paleozoic and Mesozoic Bryozoans shall have been made.
Semicea d'Orb. {Reftocea d'Orb. p.p.) ; Discocea Pergens.
B
Fig. 455.
Filicea velata (Hagw.). Upper Cretaceous ; Maestricht, Holland. ^4, Branch, i/i- jB, Surface
of same enlarged. C, Vertical section (after d'Orbigny).
Cea d'Orb. Zoaria forming flattened l)ranclies or broad lamellae, celluliferous on
both sides.
Filicea d'Orb. {Laterocea d'Orb.) (Fig. 455). Zoaria erect, with sub-cylindrical
branches bearing apertures on all sides.
324 MOLLUSCOIDEA— BRYOZOA phylum v
Family 10. Eleidae d'Oibigny.
Zoaria ramose, bifoliate or imi-lamellate. Zooecial tubes dilating outivardly, with
j^erf orated walls. Apertures lateral and, sub-terminal, many of them dosed by thin
calcareous films. Vicarious avicxdaria and spines scattered among the zoacia in some of
the genera. Cretaceous.
The members of this family differ widely from the true Cyclostomata, and the presence of
avicularia indicates strong affinities with the Chilostomata. The Eleidae undoubtedly
represent connecting links between the Cyclostomata and Chilostomata. The simplest type
of Eleid structure is found in the Jurassic genus Ilaploaxia Gregory, now placed in the
Entalophoridae, in wlucli the aperture is subterminal, instead of terminal, and is constricted
laterally.
Reftelea d'Orl). Zoariuni adnate, no avicularia.
Elea d'Orb. Zoarium erect, bifoliate ; no avicularia.
Meliceritites Roemer (Inversaria Hagenow ; Escharites Roemer). Cylindrical
brandling steins ; avicularia present.
Foricula d'Orlj. Like Meliceritites but Las walls pierced by pores.
Semielea, Nodelea d'Orb. ; Reftoceritites Gregory.
Suborder B. CANCELLATA Gregory.
Zooecia monomorphic with \oalls perforated by cancelli, that is, by rounded or elongate
pore-like cavities different from the usual interspaces or mesopores.
This suborder which is more convenient than natural, developed in early Cretaceous
times from certain specialised species of the Idmoneidae.
Family 11. Horneridae Hincks.
Zoarium erect and branched ; zooecial apertures only on the obverse side and irregular
or arranged in simple lines. Walls of zoarium traversed by fine canals luhich appear
at the surface as minute pores. Cretaceous to Recent.
Hornera Lamx. ; Siphodictyum Lonsdale; Hemicellaria d'Orb.; Phormopora Marsson.
Family 12. Petaloporidae Gregory.
Ramose Cyclostomata with zooscia opening on all sides of the branches and walls
perforated by numerous mural pore structures, somewhat resembling mesopores.
Petalopora Lonsdale {Cavea d'Orb.) ; Sparsicavea d'Orb. ; Gavaria Hagenow ;
Reptocavea d'Orb. Cretaceous and Tertiary.
Suborder C. DACTYLETHRATA Gregory.
Cyclostomata with long cylindrical zocecia separated by dactylethra, that is, by short
aborted zooecia closed externally. No cancelli, mesopores or avicularia.
Family 1 3. Clausidae d'Orbigny.
Zoarium adnate or erect with the zocecia distributed uniformly and separated by
circles of shallow interstitial cells (dactylefhrae) closed at the surface.
Clausa d'Orb. {Claviclausa d'Orb.). Zoarium erect and dendroid. Cretaceous and
Tertiary.
ORDER II
CYCLOSTOMATA
325
Cryptoglena Marsson. Zoariuni adnate, tliick and unilaminar. Cretaceous.
Ditaxia Hagw. {Polytaxia Haiuin). Zoarium erect, lamellar and frondose.
Cretaceous and Tertiary.
Reticulipora d'Orb. (Retelea d'Orb.). Zoarium reticulated ; branches greatly-
compressed laterally. Cretaceous to Recent.
Eeptomulticlausa, Multidausa d'Orl). Cretaceous.
Terebellaria Lanix. Jurassic. Zonopora d'Orb. {Spiroclausa d'Orb.). Cretaceous,
Suborder D. CERIOPORINA Hagenow (emend.).
Von Hagenow in 1851 maintained the Cerioporina for Ceriopora and allied genera but
included a few other Cyclostoniata. Hannn in 1881 recognised the same name, limiting the
group, however, to the families Cerioporidae and Radioporidae.
The name is thus available for the post-Paleozoic Bryozoa
agreeing with the Trepostomata in having well - developed
immature and mature regions but differing in the amalgamated,
minutely porous structure of their walls.
Family 14. Radioporidae Gregory.
Zoccria simple or composite, discoid or massive, adhering
by more or less of the under surface. Zooecial apertures on
the upper surface, arranged in radial series separated hy
mesopores. ,
Discocavea d'Orb. (Fig. 456). Zoarium of simple
discoid groups, with apertures in radial uniserial lines.
Cretaceous to Eecent.
Lichenopora Defrance (Figs. 457, 458) {Tecticavea and
Rculiocavea d'Orb.). Like Discocavea but apertures ar-
ranged in elliptical groups. Jurassic to Recent.
Fio. 456.
Discocavea pocillum d'Orb. Cre-
taceous ; France (after d'Orbigny).
Fin. 457.
Lichenopora(?)tu,huUfera(Roemei).
Oligocene ; Astrupp, Westphalia.
.4, Zoarium, i/l- -B, Cluster of
zo(ecial apertures, enlarged.
Lidtcnopora stellata (Goldf.). Planer; Plauen, Saxony. A,
Zoarium, i/j. B, Same, enlai'ged. C, Vertical section of specimen
from Greeusand of Essen.
Stellocavea d'Orb. {Garinifer Hamm). Zoaria discoidal, the upper surface
exhibiting the salient edges of numerous radially arranged plates, few of them
326
MOLLUSCOIDEA— BEYOZOA
PHYLUM V
reaching the centre. Zooecial tubes opening on the two opposite sides of plates.
DejDressecl interspaces occupied by interstitial cells. Cretaceous.
Radiopora d'Orb. Zoarium massive with zooecia arranged in radial series separated
by wide areas of mesopores. Cretaceous.
Actinotaxia Hamni ; Trocliiliopora, Tholopora Gregory ; SemimuUicavea, Multi-
cavea, Pyricavea d'Orb. Cretaceous.
Family 15. Cerioporidae Busk.
Zoaria multiform, encrusting, lamellar, bulbous, lobate, digitate or ramose, compiosed
of closely arranged thin-ivalled tubes. The latter sometimes completely separated by
angular interstitial cells. IValls of neighbouring tubes thoroughly amalgamated and
pierced by numerous pores. Trias to Recent.
Under this family are grouped tlie genera referred by Gregory to the Cerioporidae in
which mesopores are absent, the Heteroporidae with numerous mesopores, and the Zonatulidae
with mesopores grouped in spiral bands or rings. The internal and otlier features of tliese
three families are identical, and it is believed that the distribution of the mesopores is in
this case not of family importance. Gregory assigns these three families, as well as the
Radioporidae, to the Trepostomata, but, although it is true that they resemble the earlier
order in some features, the complete amalgamation and porous nature of their walls is
exactly the same as in typical Cyclostomata.
Reptomulticava d'Orb. (Semicava d'Orb.; Reptocea Keeping) (Fig. 459). Zoarium
massive or branched, multi-
lamellar ; zoQJcia short, meso-
pores absent. Cretaceous.
Defranciopora Hamm.
Zoarium of suj^erjjosed, discoid
colonies ; mesopores wanting.
Cretaceous.
Geriopora Goldfuss (Gerio-
cava d'Orb.). Zoarium massive
or branched, with long zooecia
and no mesopores. Trias to
Recent.
Heteropora Blainville (Fig.
460). {Polytrema, Grescis,
Like Geriopora but with numeroiis mesopores. Jurassic to
Fio. 459.
Reptomulticava spongites Goldf. Greensand ; Essen. A, Zoarium, V]
B, C, Upjier and lower aides, enlarged.
Nodicrescis d'Orb.).
Recent.
Biflabellaria Pergens. Like Hetero-
pora but zoarium bifoliate. Cretaceous.
Zonatula Hamm. Zoarium dendroid
with spiral or annular constrictions
composed of mesopores. Cretaceous.
Plethopora Hagw. Like Zonatula but
zooecia open in knob -like elevations.
Cretaceous.
Ghilopora Haime. Jurassic. Multi-
aonopora d'Orb. ; Bivestis Hamm ; Spar-
sicytis Filliozat. Cretaceous.
Suborder E.
CERAMOPOROIDEA,
nom. nov.
€«^^j^fi;
Fio. 400.
This new suborder is proposed for the
Paleozoic Bryozoans included in the two
Hctrroporn pustulosa Miclu (heat Oolite ; Ranville,
Calvados (after Hainio). A, I!, 'Aoarmm, '/i- <^, Vertical
section. D, lljiper surface, enlarged.
ORDER IT
CYCLOSTOMATA
327
families Ceramopoiidae and Fistuliporidae, wliicli were formerly assigned to the
Trepostomata and latterly to the Cyclostoniata. They agree with the Trepostomata
in having well-defined immature and mature zones but their minutely porous walls
of irregiilarly laminated tissue, large mural communication pores and finally, ooecia
tyi^ical of the Cyclostoniata seem to ally them more closely with the latter order.
This suborder is possibly the Paleozoic representative of the Cerioporina.
Family 16. Ceramoporidae Ulrich.
Zoaria variable; maculae or clusters of mesopores and of zooecia, larger than the
average, occnr at regular intervals. Zocecial apertures usually oblique, of sub-triangular,
ovate or polygonal form; lunarium present, appearing at the surface as a prominent
overarching hood, or as a slightly elevated portion of the margin, of crescentic form
ivith the ends projecting more or less into the aperture. Mesopores or interstitial cells
Via. 461.
a, Ceramopora spongiosa Bass. Tangential section, 20/j. b, c, AnoloticMa rhmnUca Bass. Vertical sections
showing mural pores, 20/i. d, Crepipora incraaxata Bass. Vertical section with ovicell-like structures, lO/i
(after Bassler).
generally present, always irregular, and usually without diaphragms. A few horizontal
diaphragms often present in the zocecial tubes. Walls minutely porous, composed of
intimately connected and irregularly laminated tissue. Large mural commAinication
pores sometimes present. Ordovician to Devonian.
This is one of the largest and most important of the families of Paleozoic Bryozoans, and
is especially common iu the Middle and Upper Ordovician. The
earliest forms resemble Bercnicca and Apsendesia ; while Ceramo-
porella, Chiloporella, and especially FavositcUa, may be regarded
with reasonable confidence as tbe progenitors of the Fistuliporidae.
At any rate the connection between the two families is so intimate
as to forbid any wide separation.
Ceramopora Hall (Fig. 461, «;. Discoidal, free, lamellate,
massive or parasitic. When free, under surface with one or
more layers of small irregular cells. Zooecia opening on the
upper surface, large, irregular, oblique, imbricating, and radially
arranged about the dep)ressed centre. Mesopores irregular, short,
numerous. Large communication pores in walls of both zocecia
and mesopores. Ordovician to Devonian.
Geramoporella Ulr. (Fig. 462). Zoaria encrusting,
tubes short, walls thin, apertures more or less oblique, hooded,
commonly of oval shape. Mesopores abundant, often completely isolating the zooecia,
Ordovician and Silurian.
Fio. 462.
Ceramoporella distiiicta
Ulrich. Lower Trenton,
Minne.sota. Surface of para-
Zocecial fl^ic expansion, I'^/j (after
Ulrich).
328
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
Goeloclema Ulr. (Fig. 463). Hollow branches, lined internally with a striated
epitheca. Zocecia as in Ceramoporella, Ijut with thicker walls. Ordovician and
Silurian.
Crejnpora Ulr. (Figs. 461, d ; 464). Mesopores almost entirely restricted to the
Fid. 403.
Coeloclema tren-
tonensis U 1 r.
Trenton ; Minne-
sota. Two frag-
ments, 2/3, and
one 6/1.
i&IS^
Fig. 464. ■
Crepipora 2^era'>npla Ulricli. Lower Trenton ; Minnesota. A, Vertical
section. B, Transverse section, 7/j. c, Same, i4/j, showing lunaria. D, Sur-
face of C. simulans Ulrich, S/j (after Ulrich).
maculae, which are distributed over the surface as minutely porous elevations or
depressions. Apertures very slightly oblique, angular or sub-pyriform. Lunarium
well-defined in perfect specimens, best shown in tangential sections. Ovicell-like
bodies known in one species. Ordovician and Silmian.
Anolotichia Ulr. (Figs. 461, 6, c ; 465). Zoaria large, ramose or digitate. Lunarium
Fi(i. 460.
Anoloticliia impnlita Ulr. Black River Shales ; Minnesota. A, Surface,
•i/j. B, Vertical section, 6/1. t', Tangential section, 12/j, showing tubes
of lunarium. /*, Tangential section of A. ponderosa Ulr., from the
Richmond formation at Wilmington, 111., showing numerous lunarial
tubes (after Ulrich).
slightly elevated at the surface, traversed internally l)y
two to six minute, vertical, closely tabulated tubes.
Mural communication pores present. Ordovician and
Silurian.
Ceramoplbijlla Ulr. (Fig. '466),
FKi. 466.
Cemmophylla frondosa Ulr
. Black
.4, Zoa-
Kiver Shales ; Minnesota.
rium, 2/.j.
(', Two zoojcia of a tangential sec-
j ■■, ri 11 tion, 12/]. i), Right half of a verti-
Lilke Ueramoporella g^i section, 12/1 (after Ulrich).
but zoarium is bifoliate. Ordovician.
Favositella Ether, and Foord {Bythotryfci Ulr.) (Fig. 467). Mesopores numerous,
open at the surface, forming interiorly a very loose vesicular tissue. Walls j)ierced
by communication pores. Ordovician and Silurian.
Ghiloporella Vh: Ordovician.
Scenello'pora Ulr. Zoaria simple, pedunculate ; under surface with an eiiitheca,
the uj)per slightly concave and celluliferous. Zocecia with slightly oblique, sub-
circular apertures, radially arranged on the summits of low I'idges. Ordovician.
ORDER II
CYCLOSTOMATA
329
Spatiopora Ulr. (Fig. 468)
Apertui'es irregular ;
Imiariuni scarcely per-
cej^tible. Mesopores,
when present, chiefly
in maculae. Inter-
spaces often with large
blunt S2)ines (? acan-
thopores). Ordovician
and Silurian.
Family 17. Fistuli-
poridae Ulrich.
Zoaria massive,
laminar or ramose, the
Zoaria forming thin crusts, especially ou Orthoceras.
IS
Favositella laxaia (Ulr.).
B, Vertical section, ^/j.
Flo. 467.
Lower Trenton ; Minnesota. .1, Surface, J-*/i.
'_', Transverse section, n/i (after Ulrich).
ABC
surface exhibiting at regular intervals
" maculae " or " monticules " comjwsed
of clusters of vesicles and of zooecia
slightly larger than the average. Luna-
rium more or less developed. Zooecial
tubes never angular, thin-walled, and
with horizontal diaphragms ; apertures
closed by perforated 0])erc;ulum. Inter-
spaces occupied by vesicular tissue. Cell
walls minutely porous. Ordovician to „ . ,^, '' . " ^. „ ,, .,^
„ . 1 • • T-. ■ Spatiopora aspera Ulr. Cincinnati Group ; Hamilton, O.
i'ermian ; climax m Devonian. a, Surface. B, Vertical section. C, Tangential section ; all
w i^r ^ 1 1 .1, X. »/i (after Ulrich).
VVaagen, vVentzel and others have
referred certain members of this family to the Corals, but the reasons for doing so rest
obviously upon insuthcient observation. Not only are the members of this family
derived from the Ceramoporidae, as noted above, which are undoubted Bryozoans,
but some of them possess ovicells, thus abundantly proving their Bryozoan nature.
Fistulipora M'Coy {Didymopora Ulr. ; Bybowskiella Waag. and W.) (Fig. 469).
Zoaria massive, lamellate, more
rarely ramose, parasitic or free ;
under surface with wrinkled epi-
theca. Zooecia sub-radially arranged
about the surface maculae ; aper-
tures ovoid, sub-triangular or
pyriforni, according to the degree
in which the lunarium is developed ;
interiorly with thin walls, and a
small number of complete horizontal
T 1 -t , ^ , Fistulipora astrica Ulrich.
diapliragms. interspaces smooth or Devonian (Hamilton Group) ;
granular, occupied internally by ;^^'t''io^"f4,'°' ^°''''^- tangential
one or more series of vesicles. Bare
in the Ordovician. Common from Silurian to Lower Car-
Iwniferous less frequent in Coal Measures and Permian.
Gyclotrypa Ulr. (Fig. 470). Like Fistulipora, but the
lunarium obsolete, and zooecial tubes circular in transverse
, . -p. . ' Pig. 470.
section. JJevonian .
7-1 -7 TT1 /T-.-7 . TT nv r, . , Cyclot ry pu comwunis Ul-
Uridopwra Ulr. {Ftleotrypa Hall). Zoaria thin, imrasitic. rich. Hamilton; New Buf-
Zocecia with oblique,' sub - triangular or ovoid apertures. '^^,^- ^^^ %
Lunarium very prominent. Siluiian to Coal Measures, (after Uhieh).
Pio. 469.
330
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
Ghilotrypa Ulr. Zoaria small, ramose, witli a narrow, irregularly contracting and
expanding axial tube. Silurian to Lower Carboniferous.
Meekopora Ulr. (Fig. 471). Zoaria bifoliate. Oblique apertures all directed
;;
f
j» * ^ «■
i
^
tki^:mJ&
Pio. 471.
A M
Meekopora cximUi Ulr. Chester Group; Monroe Co., 111. A, Specimen
from the side and edge, -Vj- />', Surface of same, "iji. (', Port-ion showing
ovicell, w/j (after Ulrich).
IP * •
«..•
i
Fi(i. 472.
Strtitopora fofcolatu Ulr.
Keokuk Group ; Bentons-
port, Iowa. Part of ex-
pansion, 3/^, and surface of
same, "i/i, showing zofHcial
apertures and broken ovi-
cells (after Ulrich).
toward the distal margin of the zoarium or branch. Lunarium moderate or obsolete ;
diaphragms numerous and often recurved. Ovicell rather large, showing at the
surface as a convex space with a small apical opening.
Silurian to Coal Measures.
Strotopora Ulr. (Fig. 472). Zoaria ramose. Large, abruptly
spreading cells (regarded as broken ovicells), distributed
among the zocecia on ordinary specimens; when perfectly pre-
served they appear as strongly convex elevations with a small
opening on one side. Devonian and Lower Carboniferous.
Lichenotrypa Ulr. First stages like Fisttdipora, after
which large spines and irregulaj' thin walls are thrown up
alwut the apertures. Devonian.
Buskopora Ulr. {Odontotrypa, Glossotrypa Hall) (Fig.
473). Like Fistulipora, but lunarium remarkably de-
veloped, projecting as a strong, l)identiculate process nearly
half across the ajjerture. Devonian.
Pinacotrypa Ulr. ; (?) Botryllopora Nich. ; Selenopora
Devonian ; Hexagonella W. and W.
Fig. 473.
Buskopora dentata Ulr.
Devonian (Onondaga Group) ;
Falls of the Ohio. Portions and Favicella Hall
of .surface, 7/ and ^Vl (after -p, . i /-. , -p
Ulrich). Devonian and Carbonnerous.
Order 3. TREPOSTOMATA Ulrich. ^
Zocecia directly superimposed ^ipon one another so as to form long tubes intersected
by straight or curved partitions {diaphragms and cystiphragms) representing the covers
^ Two regions of the zooecial tubes are (li.stiuguishaljle, an axial or " immature " region, in
which the diaphi-agms are remote, the walls thin, and the tubes prismatic through contact ; and a
peripheral or "mature" region, in which the tubes bend outward, the walls ai-e thickened and
otherwise modified, the transverse partitions more abundant, and interzooecial elements (acanthopores,
mesopores, or mere strengthening tissue) are developed.
Waagen and Wentzel and others erroneously assert that the mesopores and acanthopores,
occurring so commonly in the Trepostomata, are young zooecia or "corallites." With very few
exceptions, these really very different elements are not developed until the zoarium has reached the
mature stage, in which new zooecia cease to be given off. Tlie origin of mesopores {i.e. all cells
occupying interzooecial spaces, whether invested with separate walls or not) is due to the .same
necessity wliich leads to the distal thickening of tlie zorecial tubes, namely, that of filling up space
occasioned by the growtli of tubes at the jjeriphery, and by the change in the direction of the tubes.
Some of the tubes provisionally included under the term mesopores, like some of tlie acantho-
ORDER III
TREPOSTOMATA
331
and floors of successive layers. Zocecial covers loith a small, usually sub-central orifice.
Monticules or maculae (containing cells differing from the average in size, or in having
their apertures elevaAed) regularly distributed over the surface.
The Treijostomata include the greater portion of the " Monticuliporoids " which
by some writers, particularly ]\Iilne Edwards and Haime, were regarded as Anthozoans.
Nicholson assigned them to the Octocoralla because the corallites apparently agreed
with Heliolites in their microscopic structure, and in addition were supposed to have
imperforate walls and to increase by intermural gemmation or by fission. Ulrich
has insisted upon the bryozoan nature of these organisms, and has published many
facts militating against Nicholson's views. Bassler has added a number of points
confirmatory of their bryozoan affinities, and recently Cumings has worked out the
primitive budding stages of at least six characteristic genera. He finds that the
budding 2Jlan of Prasopora and allied genera is jJi'ecisely the same as in typical recent
Bryozoa, namely that it consists of (1) a inotiecium, or minute circular disk ; (2) the
ancestrula, a tubular zocecium of the type seen in the Cyclostomata ; and (3) several
primary buds arising from and adjacent to the ancestrula. These primitive structiires
are separated from the rest of the colony by a considerable thickening of their
posterior walls. In the Corals, development from the planula is direct, the moment
it becomes sedentary and therefore the presence of the protoecium alone is practically
conclusive as to the systematic position of the Trejiostomata A\ith the Bryozoa.
Suborder A. AMALGAMATA Ulrich and Bassler.
Trepostomata in which the boundaries of adjacent zocecia are obscured by the more or
less complete amalgamation of their walls.
Family 1. Monticuliporidae Nicholson (emend. Ulrich).
Zoaria multiform. ZoKcial apertures polygonal, rounded or irregularly petaloid.
Mesopores occasionally wanting, in other cases numerous, angula,r and crossed by
crowded diaphragms. Acanthopores a /;
abundant, iisually small. Gystiphragms
always present in the mature region.
Ordovician to Devonian.
The incomplete, curved, transverse
partitions, termed cystiphragms by
Uh'ich, are the principal peculiarity of
this I'amily. It is possible that they
represent ovicells, but their significance
can only be conjectured.
Monticulipora d'Orb. (Fig. 474).
Zoaria incrusting to massiA^e. Zocecia
Monticulipora arborea Ulr. Trenton ; Minnesota. Vertical
(A) and tangential (75) sections, i-i/i (after Ulrich).
polygonal, with minutely granulose
walls. Cystiphragms lining both
mature and immature regions. Mesopores very few or absent.
granulose, more or less numerous. Ordovician and Silurian.
Orbignyella U. and B. Ordovician to Devonian.
Atactoporella Ulr. (Fig. 475). Zoaria generally encrusting,
Acanthopores small,
Zocecia with very
pores, were doubtless occupied by specially modified polypides, which probably find their
homologues in the aviciilaria and vibracula of recent Chilostomata. But many of the mesopores
which are not invested by separate walls are to be regarded as mere interspaces between the
zooecial tubes, and the purpose of their transverse partitions is to support the walls of the latter, as
well as to assist intercommunication by means of the zoarial parcnehynial cord.
332
MOLLUSCOIDEA— BEYOZOA
PHYLUM V
tliin inflected walls, tlie apertures irregularly jietaloid. Mesopores numerous, frequently
isolating the zocecia, largely filled by a secondary deposit. Acantliopores small and
very numerous. Ordovician and Silurian,
Fic. 475.
Atactaporella typicalis Ulr. Black River Group ; Minnesota. Surface (A), tangential (7;),,
and vertical (' ") sections, i-»/i (after Ulrieli).
Peronopora Nich. Similar to the preceding but zoaria bifoliate, and zooecial walls
thicker, not inflected by the acan-
tliopores, and more ring -like in
transverse section. Ordovician
and Silurian.
Homotrypa Ulr. (Figs. 476,
477). Generally ramose, some-
times frondescent. Zooecial tubes
with very thin and finely crenu-
lated walls, and remote diaphragms
in the axial region. Cystiphragms,
isolated or in series, developed in
peripheral region only. Apertures
structure of walls and parenchymal cord in (A), Homotrypa
callosa Ulr., 35/j ; (£), ^tkioporella fro7iilifem Ulr., as/j'; and (C),
Retepora columni/era Busk. Recent, 60/i.
A
B
polygonal or sub - circular. Mesopores
usually few and restricted to the maculae.
Acantliopores generally present. Ordovician
and Silurian.
Homotrypella Ulr. Like Homotrypa but
mesopores numerous and cystiphragms
usually confined to the early part of the
mature region. Ordovician and Silurian.
Prasopora Nich. and Eth. (Fig. 478).
Zoarium massive, free. Zoojcial tubes
prismatic or cylindrical, thin - walled,
A B
Fio. 477.
Homotrypa subramo.m Ulr. Black River ; Minnesota.
A, Surface. B, Tangential section. i\ Vertical sec-
tion, iJ/i. D, H. xp.jKU-ata Ulr. Tangential section,
X 17.
Fin. 478.
I'rasopora simulatrix Ulr. Trenton ; Ken-
tucky. .1, Transverse, and B, Vertical section,
i-i/i (after Ulricli).
ORDKR III
TREPOSTOMATA
333
sej)fii'<ited from one anotlier by smaller angular mesopores, and containing cystiphgrams.
Acantliojiores visually pre-
sent. Ordovician and
Silurian.
Mesotrypa Ulr. (Fig.
479). Asindofora Ulrich.
Ordovician and Silurian.
Family 2. Heterotry-
pidae Ulrich.
Zoaria frondescerd,
ramose, massive or i^ara-
sitic. Zocecia polygonal,
v'ith moderately thin icalls.
Acantlioporesf resent, some-
times of large size. Diaphragms numerous, horizontal. Cystiphragms tcanting. Ordo-
vician to Devonian.
Dekayella Ulr. (Fig. 480). Zoarium always frondescent, mesopores numerous,
> '' / '■' A'^'-*
Fig. 479.
Mesotrypa infida Ulr. Black River Group ; Minnesota. A, Transverse
section. B, C, Vertical sections, n/i (after Ulricli).
Fk;. 480.
Dekayella dbscura (Ulr.). Ordovician ; Cincinnati, Ohio.
Tangential and vertical sections, n/i (after Ulrich).
Fi<;. 481.
Di'Xayia aspera Edw.
and H. Ordovician ; Cin-
cinnati, Ohio. Tangential
section, i4/j.
and acantliopores of two sizes, the smaller ones the more abundant, and present
only in the peripheral region. Ordovician and Silurian.
Heterotrypa Nich. Zoarium frondescent, and acanthopores all of uniform size.
Ordovician and Silurian.
Dekayia E. and H. (Fig. 481). Distinguished from Heterotrypa by the absence of
A B
Fig. 48-2.
Stigmatella foordi (Nich.). Ordovician ; Es-
thonia. A, Tangential section, w/i. B, Vertical
section, 22/j (after Bassler).
Fig. 483.
Atactoponi maculata Uli. Ordovician; Cincinnati,
Ohio. Transverse and vertical sections, i-i/i, showing
greater part of a solid macula (after Ulrich).
the smaller set of acanthopores, and lesser number of mesopores and diaphragms.
Ordovician.
Petigopora Ulrich. Stigmatella Ulr. and B. (Fig. 482, A, B). Ordovician and
Silurian.
334
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
Atadopora Ulr. (Fig. 483). Zoaria thin, growing on Ortlwceras. Zocecial apertures
indented or floriform, according to jjosition of the very numerous acanthopores. Eather
large, solid elevations, composed of abortive cells, and completely filled by calcareous
deposit, stud the surface at regular intervals. Ordovician and Silurian.
Leptotrypa Ulr. Ordovician. Gyphotrypa U. and B. Ordovician to Devonian.
Family 3. Oonstellariidae Ulrich.
Zoaria ramose, frondescent, laminar or encrusting. Zooscial tubes thin-walled and
prismatic in the axial region, thicker and sub-cylindrical in the peripheral; apertures
rounded, the peristomes slightly elevated. Mesopores angular, abundant, generally
isolating the zooecia, at intervals gathered into usually stellate clusters; closed at the
surface, the closure tvith numerous perforations. True acanthopores loanting, but small
hollow spines or granules often very abundant. Diaphragms straight and complete in
both sets of tubes. Ordovician and Silurian.
Constellaria Dana (Fig. 484). Zoaria growing erect from
attached basal
D
w&^
?S!I
Pifi. 4S4.
Constellaria florida \Jlr. Cincinnati, Ohio. J, Vertical section. i>', Tangential, sliowing aged condition.
C, Average tangential section, all i4/j. D, Branch of the natural size (after Ulrich).
expansion. Surface with depressed stellate maculae, the spaces between the rays
elevated and occuijied by two or three short rows or clusters of closely approximated
zocecial apertures. Mesopores aggregated in the maculae, internally with gradually
crowding diaphragms. Ordovician.
Stellipora Hall {non Hagw. nee Haime). Differs from the above in its encrusting
or lamellate habit, and in having only mesopores in intersjiaces between the raised
zocecial clusters. Ordovician.
Nicholsonella Ulr. (Fig. 485, A-G). Laminar expansions, sometimes giving off'
^^f*
Flc. 485.
NieJiolsoiieUii pnlchra Ulr. Stones River; Tennessee. A, fSiirface, 7/j. £, Vertical section, w/v C, Tan-
gential sections at diflerent levels, K/j (after Ulrich)- 1^, JJianulites fastigiatus Bichw. Silurian ; Baltic
Provinces. Tangential section, I'l/j (after Bassler).
flattened, intertwining branches or fronds. Interzooecial spaces wide, and with
numerous mesopores, whicli have thicker and more numerous diaphragms than tl.ie
ORDER III
TREPOSTOMATA
335
zooecial tuljcs ; tlie spaces become filled up with age by a calcareous deposit, rendering
walls of inesopores unrecognisable. Ordovician.
Dianulites Eichwald (Fig. 485, D). Zoaria massive ; zocccia and mesopores pris-
matic, ttin walled ; walls and spines with minute granulose structures as in
Nicholsonella. Ordovician and Silurian.
Tdiotrypa Ulr. Silurian ; North America.
Family 4. Batostomellidae Ulrich.
Zoaria usually ramose, occasionally sub-lobate, massive, laminar or parasitic, often
consisting of superimposed layers. Zocccia with thick walls in the mature region, usually
appearing here as fused. Diaphragms horizontal, those in peripheral region tvith central
perforation. Acanthopores and mesopores usually present; the latter small, often
intermittent. Ordovician to Permian.
The amalgamate nature of the zooecial walls is most marked in this family.
Bythopora Miller and Dyer. Small branching stems. Apertures oblique,
attenuate above. Interspaces canaliculate, with an occasional mesopore or none.
Ordovician and Silurian.
Gallotrypa Hall. Silurian and Devonian
Devonian.
Batostomella Ulr. (Geinitzella W. and W. ; Trematella Hall) (Fig. 486),
1 l/fft
Ordovician to
Slender
Large
Fl(i. 486.
Batostomella splnidosa Ulr. Chester Group ; Kentucky. A, B, Vertical sections, one with and the other
without diaphragms, n/i- C, Tangential section, i^i- D, Surface, I'l/j. On either side of (.' are branches of the
natural size (after Ulrich).
branches, without monticules. Apertures small, circular or oval. Interspaces
rounded or canaliculatej spinulose, the acanthojDores small and usually very numerous.
Mesopores small, sub-circular. Diaphragms few. Silurian to Permian.
Stenopora Lonsd. (Fig. 487). Zoaria ramose, sub-lobate, massive, laminar or
parasitic. Zooecial walls periodically thickened in the mature region
acanthopores at many of the
angles between the zooecia.
Mesopores never very numerous,
irregularly distributed. Dia-
phragms sometimes very scarce,
but m most American species
abundant in the peripheral
region, and with a large central
perforation. Lower Carboni-
ferous to Permian.
Anisotrypa Ulr. Divisional
line between adjoining tubes Fn;. 487.
iiir.TP cliarnW rlpfinprl mid Stenopora americana Vlv. Keokuk Group ; Illinois. Vertical (.4)
moie sudipiy uemieu, ciiiu ^nd tangential (Z;) sections showing roonilifonu waUs and perforated
periodic swellings of the walls diaphragms, w/j (after Ulrich),
336
MOLLUSGOIDEA— BRYOZOA
PHYLUM V
iiiucli less distinct than in }itcno]3ora. Acautliopores and mesopores absent ; perforated
diaphragms numerous. Lower Carboniferous.
Liodema Ulr. (Fig. 488). Ordovician to Coal Measures. Lioclemella Foerste.
Ordovician and Silurian. Orhifora Eichwald (Fig. 489, a, h). Ordovician.
Fl(i. 488.
Liodema foliata 'U\t. Keokuk Group; Illinois. ^-1, Vertical section, 21 /j. /;, Tangential section, '-^l^.
C, Portion of wall and acanthopore, 38/^. D^ Interstitial cell,i-'Vi (after Ulricli).
Fig. 489.
a, Orbipora distineta Eichw. Section, i4/j. h^ 0. acanlhoponi Bass, i-i/i. c, d, Esthoniopora communis Bass.
Ordovician ; Baltic Provinces, s/j (aftei- Bassler).
Esthonioimra Bassler (Fig. 489, c, d). Zoarium massive ; zocccia with semi-
diaphragms ; no mesopores or acantliopores. Ordovician ; Esthonia.
Suborder B. INTEaHATA Ulricli and Bassler.
Trepostomata in which the boundaries of adjoining zooecia are sharply defined by a
ivell-marked, dark-coloured divisional line.
Family 5. Amplexoporidae Ulrich.
Zoaria ramose, discoidal, massive or bifoliate. Zooicial tubes comparatively simple,
prismatic, with a well-marked divisional line between adjoining tubes. Mesopores
practicidly absent, but small abortive cells sometimes found among the large zooxia
forming the inonticules. Acanthoiwres generally abundant, sometimes quanting. Ordovician
to Devonian.
Amplexopora Ulr. Zoaria ramose. Acanthopores always present, varying m size
and number. Diaphragms complete, horizontal. Ordovician and Silurian.
Monotrypclla Ulr. Like the above, but without acanthopores. Ordovician to
Devonian.
ORDER III
TREPOSTOMATA
337
Rhombotrypa U. and B. Silurian. Petalotrypa and Jlixmfrjijm Ulr. Ordovician
to Devonian.
Family 6. Halloporidae Basnler {Galloporidae Ulricli).
Zoaria ramose, sub-frondescent, massive or discoidal. Zocecial apertihres generally
sub-circular and separated more or less completely by angular mesopores ; at other times
polygonal, ivlien the mesopores are few or wanting. Zoacial tubes thin-ivalled, attaining
tlu'ir fall size slowly. Aranthopores wanting. Ordovician to Devonian.
In this lainily the proximal ends of the tubes arising in the axial or "immature" region
have the character of mesopores. The diaphragms are rather closely arranged in the tapering
7?
iisy/^"
•a,^ o
Fic. 49U.
Hallopora ramosa (E. and H.). Ordovician (Cincinnati Group); Cincinnati, Ohio. .1, Zoarium, natural
size. B, Surface slightly magnified. (', Tangential section, parallel to external surface, ""/j. D, \'ertical
section, 20/j. (c'and D after Nicholson.)
proximal end, then few or wanting for a considerable distance, and finally become crowded in
the peripheral or mature region.
Hallopora Bassler {CaUopora Hall preoccupied) (Figs. 490, 491). Zoaria usually
ramose and liusliy, the brandies often anastomosing. Ai^ertui'es closed in tlie perfect
state by perforated, often ornamented, covers, wliicli are left behind, as growth proceeds,
Fic. 491.
A, B, Hallopora eU(jantula(Ji.&\\). Niagara; Indiana. Vertical and tangential sections, w/j. C, D, H.multi-
tabuluta Ulr. Lower Trenton ; Minnesota. C, Vertical section, "/i. D, Surface having zocecia open (7/j), and
preserving zocecial covers (i*/i).
to form floors (diaphragms) of succeeding layers. Zooecial tubes of two sizes in the axial
region, the larger ones with six to eight sides, the smaller set four- or five-sided.
Ordovician to Devonian.
Halloporina, nom. nov. (proposed for Calloporina Ulrich and Bassler, preoccupied
by Neviani in 1895). Like Hallopora but diaphragms wanting and walls strongly
crenulated. Ordovician.
Calloporella Ulr. Silurian ; North America.
VOL. I Z
338
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
Family 7. Trematoporidae Uliicli.
Zoaria ramose or encrusting. Zooecial tuhes irregular in the axial region, their
proximal ends with diaphragms, and usually constricted ivhere the latter occiir ; walls
A B
Fig. 492.
Tangential sections ot BatoKtovm from the Black River Group of Minnesota. A, B. fertile Ulr., '>'i/j.
B, Same, var. circulare, l-*/j. C, B. tinnchelli var. spinulosam Ulr., 38/j (after Ulricli).
thickened in the mature region, lines of contact distinct. Mesopores generally abundant,
usually of large size, their apertures closed. Acanthopores more or less abundant.
This family is principally distinguished from the Halloporidae by the presence of acantho-
pores and closed mesopores. The Trematoporidae, moreover, have a general looseness and
obscurity of structure quite unlike that of any other Trepostomata.
Batostoma Ulr. (Fig.
A
492).
B
Hemiphragma irrasum Ulr. Lower Trenton ; Minnesota,
A, Vertical section, T/j. B, Tangential, "/i (after Ulricli).
Branches irregular, springiirg from a large basal
expansion. Zooecial walls of varying
thickness, in contact only at limited
IJoints, and of two sizes in the axial
region. Diaphragms strong, horizon-
tal, complete. Species numerous and
mostly very abundant. Ordovician
and Silurian.
Hemiphragma Ulr. (Fig. 493).
Like Batostoma, but diaj^hragms in
peripheral part of tubes incomijlete.
Ordovician and Silurian.
Diplotrypa Nich., emend. Ulr.
(Fig. 494). Zoaria massive, generally
free. Zooecial tubes comparatively
494.
Diplotrypa westoni Ulr. Richmond Group ; Manitoba.
Tangenti.al and vertical sections, i-^/j (after Ulricli).
Fi(i. 495.
Mnnritryprt wagiia Ulr. Lower Trenton ; Illinois.
Transverse and vertical sections, l/i (after Ulricli).
ORDER IV CRYPTOSTOMATA 339
large, prismatic, witli horizontal diaphragms. Mesopores few to numerous, varying
in size. Ordovician and Silurian.
Monotrypa Nich. (Ptychonema Hall) (Fig. 495). Distin-
guished from the preceding by the absence of mesopores and
fewer diaphragms. Ordovician to Devonian.
Anaphragvia U. and B. Ordovician and Silurian. Ditto-
fora Dybowski (Fig. 496). Ordovician.
Trematopora Hall (emend. Ulr.) ; Stromatotrypa Ulr. Or-
dovician and Silurian. Fig. 496.
Dittopora colliculata
Eieliw. Ordovician ; Es-
Order 4. CRYPTOSTOMATA Vine. thonia. Tangential .sections
with two sets of acantlio-
Primitive zocecium short, pyriform to ohlong, quadrate or P°"^''' 'i ^■^
hexagonal, sometimes tubular, the aperture anterior. In the
mature colony the aperture is concealed, occurring at the bottom of a tubular shaft
{^^ vestibule"), which may be intersected by straight diaphragms or hemisepta, owing
to the direct super-imposition of layers of polypides. Vestibular shaft surrounded by
vesicular tissue, or by a solid calcareous deposit; the external orifice rounded. Mar-
supia and avicularia wanting.
The Cryptostomata differ from the Trej)ostomata chiefly in that the " immature "
region (primitive cell) is usually much shorter and the passage to the mature region
more abrupt.
Some of the Cryptostomata are ramose, and have long, thin-walled prismatic
tubes in the axial region, with or without diaphragms, precisely as in tlie ramose
TrejDostomata and Cyclostomata ; but they are distinguished from the latter by the
presence of hemisepta, similar to those occurring in the vestibule of Escharopora and
Phaenopora, two of the most tyjiical genera of the Cryptostomata. That these axial
tubes are not of primary importance is shown by individuals of such genera as
Ooeloconus, Rhombopora, etc., in which a second layer of zooecia has grown over the
first. This is a rare condition, and is probably to be attributed to an accidental
interruption of growth. But, where observable, it is to be noticed that the inner
extremities of the zooecia of the second layer are not drawn out into tubes like
those of the primary set, but are short, and in all essential respects like those of
Escharopora.^
The Cryptostomata are probably nothing more than Paleozoic Cheilostomata,
differing, however, from the typical members of the latter, (1) in having neither
marsupia nor avicularia ; (2) in the mv;ch greater deposit of calcareous matter upon
the front of the zooecia, thus producing the vestibule ; (3) in that successive layers of
l^olypides are often developed, one directly over the other, in a continuous tube ; and
(4) in that whenever a zoarium attains an uninterrupted width of more than 8 mm.,
it exhibits clusters of cells differing more or less, either in size or elevation, from the
average zooecia. The last two distinctions are suggestive of the Trepostomata ; and
the presence of a vestibule reminds us of certain Mesozoic and Recent Cheilostomata,
which have the same tubular prolongation of the aperture. Thus, the Recent
Adeonella atlantica Busk, has not only a vestibule, but hemisepta as well. Hemisepta
are never found in the Cyclostomata and Trepostomata, bitt are a very common
feature of the Cryptostomata. They occur at the bottom of the vestibule, and doubt-
less served as supports for the movable operculum,
^ The almost universal practice has beeu to accept the presence of tubular zooecia as fully
demonstrating the Cyclostomatous affinities of the species producing them. Investigations, how-
ever, show that the mere form of the zocecium cannot be relied upon as a subordinal character any
more than is the presence of tabulae in a tubular organism a certain indication of an Anthozoan.
340
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
Family 1. Phylloporinidae Ulrich.
Zoaria branching, cellulijerous on one side only, the other side striated ; branches
free or anastomosing. Zooscia more or less tubular, often with diaphragms. Hemisepta
wanting. Ordovician to Coal Measures.
a, h, Chasmatopora sublaxa (Ulr.). i'/l-
Fk;. 497.
d, Transverse and longitudinal sections, if"/j (after Ulvich).
Chasmatopora Eicliwald {Phylloporina Ulr.) (Fig. 497). Branches inegnlarly
anastomosing, with two to eight ranges of zocecia on the celluliferous side. Taljulated
interstitial spaces generally present, closed at the surface. Ordovician and Silurian.
Pseudohornera Roemer (Drymotrypa Ulr.). Ordovician to Devonian. Chaino-
dictyon Foerste. Coal Measures.
Family 2.
Fenestellidae Kiug.
Zoaria forming reticulate expansions, celluliferous on one side only. TJiey are com-
posed of rigid branches united by regular non-poriferous bars {dissepiments); or may be
sinuous and anastomose at regular intervals ; or may remain free. Zocecia enclosed in
a calcareous crust, which is minutely porous, especially on the non-cell uliferotts side.
Primitive portions of zooncia oblong, quadrate or hexagonal in outline. Superior hemi-
septum usually present, the inferior one less frequently. Primary orifice anterior, semi-
elliptical, trimcated behind. External apertures rounded, with peristome, and covered,
when perfect, by centrally perforated closures. Silurian to Permian.
The zoarial cliaracters of the Fenestellidae are extremely constant, and are of tlie greatest
systematic importance. The zocecial cavity in this family is very similar to that of the
Ptilodictyonidae and Rhinidictyonidae ; and the same is also true of both tlie primary and
external orifices.
Fic. 4i)8.
Fencstellti retifarmisHi-hUAh. Permian Doloniitir ; Piissneck, Tlniiin-ia. .1, Fra,L;nu-nL cil' /oariuni, natural si'/e.
B, Portion of external surface, slightly enlarged. C, Magnilied jxirtion of interior celluliferous surface.
ORDER IV
CRYPTOSTOMATA
341
Fenedella Lonsd. (Fenestrella d'OrJj. ; Actinostoina Young) (Fig. 498). Zoaria
Habellate or funnel-shaped, poriferous on the inner side. Branches connected at
regular intervals by dissepiments. Zooccia in two rows, separated by a plain or
tuberciilose median keel. Silurian to Permian.
Semicoscinium Front {Carino23ora Nich. ; C'ry2:)topora "Sich.; Cycloporina Simpson).
(Fig. 499, e). Zoaria funnel-shaped, poriferous on the outer side. Dissepiments
wide, very short, the branches appearing to anastomose on the non -poriferous face,
where the fenestrules are sub-rhomboiilal or rounded. Zooecia in two ranges, median
keel very liigh and expanded at the summit. Silurian and Devonian.
Fenestrapora Hall. Like the preceding, except that the reverse of the zoarium
and the expanded summits of the carinae bear large, scattered pores, or pits.
Devonian.
c""^
#>%Wfl
» W f*"** imm «.«• ^
Pio. 499.
(I, Archimedes distansVh-. l/i. h, Polypora simnlatrix Vlr. i/i and S/i- c, Hi'.mitrypa prontana Vh: i>/i.
d, Unitrypa acaiiUs Hall. ti/i. e, Semicosctnium interruptum H. and S. "/i. /, Fenestralia compacta Ulr. "/]
(after Ulricli, Hall, and Simpson).
Helicopora Claypole ; Isotrypa, Loculipora, Unitrypa Hall (Fig. 499, d). Silurian
and Devonian.
Hemitrypa Phill. (Fig. 499, c). Differs from Fenestella in having a reticulated
superstructure, whose meshes correspond in position and number with the zooecial
apertures in the branches beneath. Silurian to Lower Carboniferous'.
Archimedes Lesueur (Fig. 499, «.). Distinguished from Helicopora liy its solid
central axis. As a rule, the fenestrated expansion is broken away, leaving only the
screw-like axis. Lower' Carboniferous.
Lyropora Hall. Zoaria flabellate, the fenestrated portion spread between the
arms of a non-celluliferous U- or V-shaped support ; free or pedunculate at the base.
ZocEcia in from two to five rows. Lower Carboniferous.
Fenestralia (Prout Fig. 499, /). Having a median keel as in Fenestella^ but with
four ranges of zooecia instead of two. Lower Carboniferous (St. Louis Group).
Polypora M'Coy {Protoretepora Koninck) (Fig. 499, b). Differs from Fenestella
in having two to eight rows of cells on a branch, and in wanting a median keel.
The latter is sometimes represented by a row of strong tubercles. Silurian to
Permian.
Tlucm.niscns King. Like Pohjptora, Ijut branches Infurcating more freely, and with
only a few disse^jiments or none. Silurian to Permian.
Phyllopora King. Zoaria funnel-shaped, celluliferous on the outer side, and con-
342
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
sisting
of anastomosing brandies, which form a regular, round -meshed network.
Zocccia in two or more rows. Devonian to Permian.
Ptiloporella, PHloporina Hall. Silurian and Devonian. Reteporina d'Orb.
Devonian and Lower Carboniferous. Anastoviopora Simpson. Devonian.
Family 3. Acanthocladiidae Zittel.
Zoaria poriferous on one side only, pinnate or formimj fenestrated expansions ; con-
sisting of strong, central stems ivhich give off numerous, smaller, lateral branches from
their opposite margins. The lateral branches are free or unite with those of the next
stem. Non-poriferotis dissepiments absent. Zocecial characters mosthj as in the Fene-
stellidae. Silurian to Permian.
Pinnatopora "Vine.
^^f!M
^
{Glauconome auct., non Goldfuss) (Fig. 500, b, c). Zoaria
small, delicate, with short, free, lateral
branches given off frequently at regular
intervals. Cells in two rows, one on
each side of a moderate median keel.
Silurian to Permian.
Septopora Prout. Zoaria fenestrated,
flabellate or leaf-like. Primary branches
numerous, increasing by bifurcation or
interpolation ; the lateral branches
\ '^^ff ^Bd!^*'^^ ^ %/^ uniting with those of adjacent stems.
V "^Ir y^ ^^^^ l.m-i^ Reverse iisually with fine striae and
scattered dimorphic pores. Celluliferous
side with two rows of zooecia arranged
as in Pinnatopora. Chester Group and
Coal Measures.
Acanthocladia King (Fig. 500, a).
Like Pinnatopora, liut larger, stronger, and with three or more ranges of cells. Coal
Measures and Permian.
Synocladia King. Differs from Septopora in the same manner as the preceding
differs from Pinnatopora. Permian.
Ptilopora M'Coy {Dendricopora Koninck). Zoaria pinnate, the central branch
much stronger than the oblique lateral branches, which are united hj dissepiments.
ZocEcia in two ranges. Devonian and Lower Carboniferous.
Diploporaria N. and B. {Diplopora Young). Essentially a Pinnatopora without
lateral branchlets. Carboniferous.
Fig. 500.
a, Acanthocladia fruticosa Ulr. i/j.
tenuiramosa Ulr. '/i. c, P. vinei Ulr.
Ulrich).
\b, Pinnatopora
i/i and 9/i (after
Family 4. Arthrostylidae Ulrich.
Zoaria articukUed, co7isisting of numerous sub-cylindrical segments united into small
pinnate or bushy colonies, or of continuous, dichotomonsly divided branches. Zoo-cia sub-
tubular, more or less oblique, radially arranged about a central axis, and opening on all
sides of the segments ; or one side may be non-celluliferous and longitudinally striated.
Ordovician and Silurian.
Arthrostylus Ulr. (Fig. 501, d, e). Zooecia bushy, dighotomously branching, the
whole consisting of numerous exceedingly slender, equal, subquadrate segments,
united by terminal articulation. Zooecia usually arranged in three rows between
longitudinal ridges ; the fourth face with longitudinal striae only. Ordovician.
^Helopora Hall (Figs. 501,/; 502). Like the preceding, but the segments are
larger, and have zooccial apertures on all sides. Ordovician and Silurian.
ORDER IV
CRYPTOSTOMATA
343
Sce'ptro'pora Ulr. Segments short, greatly exi^anded above, celluliferous all around.
Ordovician and Silurian.
f
fA^^-''
V>V
Fi(i. 5(11.
a, Arthrodema hlUimjsi Ulr. %. 6, --1. nrmatum Ulr. Sef;ment, i2/j. e, Nematopora muferln. Ulr.
d, e, Arthrostijhis conjunctus Ulr. i2/i. /, Hchporu harrisi Ulr. l^/j (after Ulricli).
'Vi
Arthrodema Bill. (Fig. 501, a, b). Segments sub-cylindrical, cellidiferous on all
sides, arranged pinnately. Articulation both terminal and lateral. Ordovician.
Nematopora Ulr. (Fig. 501, c). Zoaria very slender,
ramose, continuous above the pointed basal extremity. Zooecia
sub-tubular, arranged radially about one or two minute axial
tubes. Ordovician and Silurian.
Glauconome Goldf. {Penniretepora d'Orb.). Zoarium branch-
ing continuously ; reverse side non-celluliferous ; zooecia as in
Nematopora. Ordovician and Silurian.
Family 5. Rhabdomesontidae Vine.
Pig. 502.
Zoaria ramose or simple, not articulated, sometimes tvith a
large or small axial titbe, and generally solid. In the latter
case the axial region is occupied by thin-walled primitive tubes, Helopom spini/ormis uir.
vjith or loithout diaphragms. Hemisepta usually present, but ^i°"verticai'^^section°*'*'i'-vt.'
never conspicuotis. External zocccial apertures oval or circular, b, Segment, Vi and i-t/i
regularly arranged, and usualhj at the bottom of a rhombic or
hexagonal sloping area, or between longitudinal ridges. Mesopores absent. Ordovician
to Permian.
Bhomhopora Meek (Fig. 503, b). Zoaria slender, ramose, solid. Zooecial tul)es
with the outer or vestibular region thick-walled, apertures arranged in diagonal
or longitudinal lines. Strong acanthopores and smaller spines generally present.
Ordovician to Permian.
Bactropora Hall. Zoaria simple or only slightly branched, the lower extremity
pointed. Lower Carboniferous.
Rhabdomeson Young. Differs from Rhombopora only in having a slender axial'
tube, to which the proximal ends of the zooecia are attached. Coal Measures and
Permian.
Goeloconus Ulr. (Fig. 503, a). Zoaria simple, hollow, expanding gradually from
the striated base; substance thin. Primitive portion of zooecia short, with well-
developed hemisepta. Lower Carboniferous.
344
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
Neviat axis HsiW. Devonian. Nemafotry2M ^a^Bulev. Ordovician. Orthojyora }ia.]].
Fig. 503
a, (.'iielocnnuf: rhomhtciiji Ulr. Vi and surface i-/]. h, Rh(wibripora inonissatii Ulr. i/j anil "^/j. c, Strehlotrypa
major Ulr. i/i and is/j. d, Amnthodema conjiue.ns Ulr. i/i and --i/i (after Uliicli).
Silurian and Devonian. Hyphasmopora Etlieridge. Carbonifei-ous. Acanthoclema
Hall (Fig. 503, d). Silurian to Lower Carboniferous.
Trofidopora Hall. Devonian. Strehlotrypa Ulrich (Fig. 503, c). Devonian and
Lower Carboniferous.
Family 6. Ptilodictyonidae Ulricli.
Zoaria bifoliate, composed of two layers of zooxia groivn together back to hack, usually
joined at least at the base, and forming leaf-like expansions, or comjjressed, branching
or inosculating stems. Mesial plates without median tihbuli ; hemisepta usually present.
Inner orifice generally semi-elliptical, the outer more rounded, usually ovate, and
surrounded, by either a slopiing area or ct ring-like peristome. Vestibules separated by
thick walls. Ordovician to Devonian.
Ptilodictya Lonsd. (Heterodictya Nicli.). Zoaria lanceolate or falciform, with a
small basal eximnsion. In the young condition the zoariuni consists of longitudinally
arranged, narrow, olilong-quadrate zorecia, new zooccia, of different width and arrange-
a.
W
^e^)
^
"*^»^^e ^
Fn:. 504.
a, Esi-liaropovd anguluris IJlr. l/i and surface i'/i- '', E. suhrerta Ulr. "/j. (■, </, Stictojiorella criljmm Ulr. l/j
and surface i8/j. Black River of Minnesota (after Ulrich).
nient, being added subsequently on each side. In the vestibulai' or outer region the
walls are more or less thickened, solid, and with a double row of exceedingly minute
dots. Silurian and Devonian.
ORDKR IV
CRYPTOSTOMATA
345
Escharopora Hall (NicJiolsonia Waag. and Wentz) (Fig. 504, «, h). Like Ptilodictya
but apertures are in diagonally intersecting series. Ordovician.
Phaeiwpora Hall. Zoaria as in Ptilodictya, except that there are two mesopores in
each interspace between the ends of the zocecial apertures. Ordovician and Silurian.
Arfhro'pora Ulr. Zoaria Ijushy, spreading in a plane, composed of numerous
equal segments. Zocecial apertures elliptical, surrounded Ijy a delicate jieristome.
Interspaces with one or more threadlike ridges, variously disposed, and with a row of
minute papillae. Ordovician and Silurian.
Graptodictya Ulr. Ordovician. Glathroporu Hall. Silurian. Stictoporina Hall.
Devonian,
Family 7. Stictoporellidae Nickles and Bassler.
This family differs from the Ptilodictyonidae mainly in that the zoarium is not
articulated, but grows upward from, and is continuous with, a spreading base.
Stictoporella Ulr. (Fig. 504, c, d). Zoaria variously formed, with elliptical
apertures placed at the bottom of a sloping area. Thick- walled intabulated mesojiores
occur between the zocecial a])ertures and line the zoarial margins. Ordovician and
Silurian.
Stictopora Hall. Ordovician. Ptilotrypa Ulrich. Silurian. Intraponi Hall.
Devonian and Lower Carboniferous. Coscinella Hall. Devonian. Taeniodictya Ulrich.
Devonian and Lower Carbonifei'ous. Heliotrypa LTlrich. Lower Carboniferous.
Family 8. Rhinidictyonidae L^lrich.
Zoaria bifoliate, continuous or jointed, forming compressed, branches or leaf-like
expansions; occasionally trifoliate. Primitive cells sub-quadrate, arranged longitudinally.
Both primitive and superficial apertures elliptical or snb-circnlar, sometimes a little
truncated piosteriorly. Inferior hemiseptum and lunarium wanting. Median tubuli
present between the median laminae, and between the longitudinal rows of zocecial tubes.
Mesopores absent, but vesicular tissue often present. Chiefly Ordovician.
Rhinidictija Ulr. {Stictopora Ulr., non Hall) (Fig. 505, a, c). Zoaria composed of
Fu:. 505.
a-c, Rhinidictya mutabiUs Ulr. i/j and surface 9/j. c, Several zocecia »5/]. d, c, Cystodictya gilbcrti Meek.
Surface i8/i and tangential section i8/j (after Ulrich).
narrow, compressed, dichotomously dividing, straight-edged branches, attached to
foreign Ijodies by a continuous exjianded base. Ordovician and Silurian.
Eurydictya, Bicranopora, Goniotrypa Ulr. Ordovician and Silurian.
Euspilopora Ulr. Small, irregularly divided branches, with serrated or wavy
edges. Devonian.
346
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
Phyllodictya Ulr. ZocEcial tubes long, with complete cliaphragm.s, Imt no
lieniisepta. Ordovician.
Pachydictya (Fig. 506), Trigonodictya Ulr. Ordovician and
Silurian.
Family 9. Oystodictyonidae Ulricli.
Zoaria consisting of two or three layers of cells grown together
hack to bach, forming branching, perforated or entire leaf -like ex-
pansions, or triangular branches. Primitive cells semi-cordate or
obovate-acuminate in outline, arranged longitudinally. Primitive
afcrture sub-circular, but becoming drawn out into a, tubular
vestibule as groivth proceeds. Superficial aperture with peristome,
and more or less well - developed hinaritim. Interzooscial spaces
occupied, by vesicular tissue, often filled, with a calcareous deposit
near the surface. Silurian to Permian.
Fig. 506.
Pachydictya foliata
Ulr. Black River; Min-
nesota. Tangential sec-
tion, 14/j (after Ulrich).
Gystodictya Ulr. (Arcanopora Vine ; Stictocella Simpson) (Fig. 505, (7, e). Zoaria
ramose, brandies sharply elliptical, with sub-parallel, non-poriferous margins. Intei'-
apertural space finely striated, granulose or smooth ; pits and cells showing (uily in
a worn condition. Silurian to Permian.
Coscinium Keyserling {Goscinotrypa Hall) ; Dichotrypa Ulr. Silurian to Permian.
Taeniopora Nich. {Pteropora Hall ; Btictoporidra Simpson). Distinguished from
Gystodictya by having a longitudinal ridge or keel, which divides each face into two
equal parts. Devonian.
Thamnotrypa, Semiopora, Acrogenia, Geramella, Phractopora, Prismopora, Scalaripora
Hall ; Goniocladia Etheridge ; Ptilocella Simpson. Devonian and Lower Carboniferous.
Evactinopora Meek and Worth. (Fig. 507, b, c). Zoaria free, consisting of four or
more vertical leaves arranged in a stellate or cruciform fashion. Lower CarboniferoiLS.
Fic. 507.
a, Glyptopora sagenella-lata Ulr. l/j. 6, Evactinopora quinque radiafa Ulr. Vi-
Meek and Wortlien i/j (after Ulrich).
c, d, E. radiata
Glyptopora Ulr. (Fig. 507, a). Zoaria consisting of thin expansions traversed on
both surfaces by salient ridges, or of uni-laminate bases on which the coalescing ridges
of the upper surface are greatly developed and fornx large leaves. These lidges or
ORDER V CHEILOSTOMATA 347
leaves are comjjosed of two layers of cells growing in opposite directions from a mesial
lamina. Upper surface with solid maculae or "dimples." Lower Carboniferous.
Family 10. Rhinoporidae Ulrich.
Zooscia simple, ohlong or rhomhoidal, j}rone along the haml membrane; vestibules
direct, hemisepta iDanting ; front of zooecia beloiv vestibule usually strengthened with solid
or vesicular tissue. Silurian.
Rhinopora Hall. Zoarium of undulating, bifoliate expansions ; surface smooth
and traversed by slender bifurcating ridges. Silurian.
Lichenalia Hall. Like Rhinopora but unilaminar. Silurian.
Diamesopora Hall ; Stictotrypa Ulrich. Silurian.
Family 11. Cycloporidae (provisional).
The following genera, all from the Lower Carboniferous, and of doubtful affinities,
are placed in this family : Cyclopora Prout ; Gycloporella Ulr. ; Proutella Ulr. ;
Worthenopora Ulr.
Order 5. CHEILOSTOMATA Busk.
(Bryozoaires cellulines, d'Orlngny).
Zooecia oval, turbinate, urceolate, qtiadrate or hexagonal, arranged usually side by
side. Orifice more or less anterior, of smaller diameter than the zocecium, closed by a
movable cover. Ova commonly matured in external marsupia. Appendicular organs
frequently present.
The earliest Cheilostomata appear sparsely in the Jura of Normandy, but their
progenitors are undoubtedly to be looked for in the Paleozoic Cryptostomata. They
attain an astonishing development in the Upper Cretaceous, and in the Tertiaries and
existing seas they greatly surpass the Cyclostomata in number and variety of species.
Not all of the Cheilostomata have a completely calcified zoarium, some being
corneous and flexible (Flustridae), and others having the front wall of the zoa3cia
more or less memliraneous and the rest calcareous (Memliraniporidae). Consequently,
in fossil examples of the latter, the zooecia are entirely open on the upper or front
side (Fig. 477). Avicularia and vibracula are very commonly present, and are
indicated in fossils by the " special pores " in which they were lodged. External
ovicells are more commonly developed than in the Cyclostomata, and usually occur as
rounded, blister-like cavities in front of the zocecial apertures. Eeproduction by
gemmation takes place at the growing edge of the colony, the young cells arising
from the anterior end or from either side of the parent cell ; and repeated gemmation
almost always results in a more or less regular arrangement in series. Direct
commvmication between adjoining zooecia is effected by means of small perforated
plates {communication plates, Rosettenplatten), set in corresponding positions in the
side walls of each zocecium.
In the classification of the Cheilostomata, the presence or absence of the compensa-
tion sac is of great importance. This is a thin- walled sac opening outward through
a pore, the ascopore, and provided with muscles whose contraction distends the sac
with the result that the polypide is extended.
Although much work has been done in recent years upon the morphological and
systematic study of the Cheilostomata, their classification, particularly the genera of
the fossil forms, is still in an unsettled condition. The older systems of d'Orbigny
and Busk were highly artificial, undue prominence having been given to zoarial
modifications ; but through the labours of Smitt, Hincks and Waters, who have
348
MOLLUSCOIDEA-^ BEYOZOA
PHYLUM V
deiuoiistiated tlic luucli greater importance of zooocial characters, a decided advance
was made. Levinsen's studies upon the recent Cheilostoniata have resulted in a
splendid, detailed classification which unfortunately depends upon characters making
it difficult of application to the fossil forms. Only l)rief descrijitions of the more
imp(jrtant genera, or those having numerous fossil representatives, can be introduced
here.
Suborder A. ANASCA Levinsen.
Gompcnsation sac wanting; frontal ivall membraneous or calcareous, defressed and
surrounded by raised margins; ofercukor and subo'percular areas not sefarated by a
calcareous bar.
Family 1. Aeteidae Hincks.
Zoarium unilinear, adnate ; zocrcia partially erect, ivith membraneous apertures.
Aetea Lam. Tertiary and Recent ; Euroi^e.
Family 2. Eucrateidae Hincks.
Zoaria branching, erect and free, or recumbent. Zooecia uniserial or biserial,
■pyriform, vnth a sub-terminal and usually oblique aperture. Avicularian and
vibracular appendages wanting. Cre-
taceous to Recent.
Eucratea Lamx. (Fig. 508).
Zoaria entirely decumbent, or com-
posed of a creeping adherent base
and erect branching shoots. Zooecia
calcareous or sub-calcareous, rising
one from another so as to form
single series. Branches springing
from the front of a zocecium below
Fio. 508. the aperture. Cretaceous to Recent.
Kucratea lahiaUi (Novak). Cenonianian ; Velim. Boliemia. Gemellaria Savigny ; Notamia
A, Zoariiiiii, l/j. B Zooecia, tliree of them with IVactured -r<i • mi- i -n j.
walls, higiiiy magnified (after Novak). Fleming. Tertiary and Recent.
Family 3. Scrupocellariidae Busk.
Zoarium erect, 'usually jointed, dichotomously branching, phytoid,. Zooxia in two
or more series, closely united and arranged in the same plane. Sessile avicularia and
vibracula generally present. Tertiary and Recent.
Menipea, Caberea Lamx. ; Hcrupocellaria Van Bened. Eocene and Recent.
Family 4. Cellulariidae Levinsen. {tialicornariadac Busk).
Zoarium erect, sub-cylindrical, dichotomously branching, usually jointed. Zoaxia
rhomboidal or hexagonal, each corresponding to an area, and, disposed in series about an
imaginary axis. Front depressed, usually concave. Orifice crescentic or semicircular,
situated slightly above the centre of the cell. Ooscia inconspicuous, opening at or near
the summit of the area above the orifice. Avicularia iisually j)resent. Cretaceous to
Recent.
Cellularia Paihis {Cellaria Lam.; Salicornuria Cuv.) (Fig. 509). Zoarium jointed.
ORDER V
CHEILOSTOMATA
349
tlie
segments
sub-cylindrical and connected by flexible, horny tuljes. Zooecia
immersed, snrronnded l)y a raised V)order, disposed in quincunx.
Fio. 50! I.
' 'dhdii rid rlmmhifciu
(Goldfnss). Oligoceiie ;
Kaufungen, near Cassel.
Enlarged (after Reuss).
Avicularia irregu-
larly distributed,
situated above a cell.
or occupying
place of one.
tin
Fio. 510.
Encrusting zoarium of Membniniponi, witli
non-calcified /.(xecial walls. Magnified.
Family 5. Membraniporidae Busk.
Fig. 511.
Mem hm n vponi plcheia
(G. and H.). Cretaceous;
N. J. Several cells highly
magnified (after Gabb and
Horn).
Zoarium calcareous or memhrano-calcareous, encrasfing or erect, in the latter case
bifoliate, or sub-cylindrical. Zooecia placed side by side, and forming an irregular
continuous expaiision, or in linear series. Margins raised, the depressed front more or
less membranous.
Membranipora Blainv. (? Marginaria Eoenier ; (?) Dermatopora Hagw.) (Figs.
510-511). Zoaria encrusting, calcareous or sub-calcareous. Zooecia arranged
irregularly or in rows, without a calcareous lamina on the front, or only partially
covered by one, leaving a variously shaped apertuie. Jurassic to Eecent.
Tremopora Ortmann. Like Membranipora, but has a large avicularium and
bifurcated spine on the border. Tertiary to Recent.
Hagenowinella Canu. Cretaceous.
Family 6. Selenariidae Busk.
Zoaria circular or irregular in outline, the celluliferous side convex, the lower concave
or Jlat, irrobably free in the mature condition. Upper surface areolated, the zooicia
Pig. 512.
LunuUtcx ijohlfusii Hagw. Upper Cretaceous ; Luneburg. a-c, Zoarium of the natural size.
d, Upper surface, enlarged, c, Lower surface, enlarged.
350
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
immersed, their borders elevated. Orifice rounded or semi-elliftical, situated more or less
in advance of the depressed front. Small vibracidar cells usually p-esent. Cretaceous
to Recent.
Lunulites Lamx. (Fig. 512). Zooecia arranged in series radiating from the
centre and bifurcating as they advance toward the border. Vibracular cells usually
elongate, lying in linear series between the rows of zooecia. Very abundant in the
Upper Cretaceous and Tertiary ; also Recent.
Stichopora Hagw. emend. Busk. Vibracular cells wanting. Zooecia equal,
hexagonal, not arranged in radiating series.
Cretaceous.
Selenaria Busk. Cretaceous to Recent.
■-c>
■^fc^^^ii^^
Pig. 513.
Membraniporella
ahhotU (G. and H.).
Cretaceous ; N.J.
Zocecia highly mag-
nified (after Gabb
and Horn).
PlQ. 514.
Cribrilina liecrmanni
(G. and H.). Post-Plio-
cene ; Santa Barbara
Co., Cal. Zooecia highly
magnified (after Gabb
and Horn).
Family 7. Oribrilinidae Hincks.
Zoaria encrusting or erect. Zooecia having
the front wall more or less fissured, or traversed
by radiating furrows. Cretaceous to Recent.
Membraniporella Smitt (Fig. 5 1 3). Zoaria
encrusting or rising into free foliaceous ex-
pansions, sometimes consisting of superim-
posed layers. Zocecia closed in front by a
number of flattened calcareous ribs more or less consolidated centrally. Cretaceous
to Recent.
Cribrilina Gray (Fig. 514). Zoaria usually encrusting. Zooecia having the
front more or less occupied by radiating or transverse rows of punctures, each row in
a furrow ; orifice semicircular or sub-orbicular. Cretaceous to Recent.
Family 8. Onychocellidae Jullien (emend.).
Zoaria encrusting or erect, ramose, continuous, the branches more or less compressed
and bilaminar ; surface areolated. Zoxcia usually hexagonal, their margins raised,
the front not entirely calci-
fied. Opesial aperture of
moderate size, generally semi-
elliptical, sometimes spread-
ing below, in other cases sub-
circular. Oral opening
small, usually crescentic or
semicircular. Ocecia in-
conspicuous ; intercalated
vicarious avicularia gener-
ally present ; special pores
'Wanting. Jurassic to Re-
cent ; chiefly Cretaceous.
Pig. 515.
Onychocella angii-
?osa (Reuss). Upper
Eocene ; Nortliern
,^ Italy. Surface, 20/j
Mem- (after Waters).
Pig. 516.
Vincidaria virgo Hagw. Upper Cretaceous ;
Riigen. a, Portion of zoarium, i/j. h. Cross-
section, c, Vertical section, enlarged.
Onychocella Jullien (^s-
chara, Flustrellaria, p.p.
d'Orb. ; Cellepora,
branipora, Vincularia, etc
auct.) (Figs. 515, 516). Zoaria encrusting or erect. Oral opening semicircular or
crescentic." Avicularian openings simple, oval ; the area in wliich they are situated
drawn out above. Jura of Normandy, and Cretaceous to Recent.
ORDER V
CHEILOSTOMATA
351
Vibracclla Waters {Flustrellaria, p.p., d'Orb.). Differs from Onychocella in having
a larger aperture, wliich is often somewhat expanded below, and having vibracular
cells instead of avicularia. Cretaceous and Tertiary.
(?) Gumulifora Miinst. (Fig. 517). Zoaria irregularly massive. Zooecia partly
M i li
B
vfxrX : Mii't^'
:j^.^
;JJ-
^^>^3i^ilp^.
Fig. 517.
Cwmulipora angulata '^lixn^i. Oligocene ; Dobevg, near Biinde. ^-1, Zoarium, natural size. B, Upper
surface, enlarged. (', Vertical section, enlarged (after Reus.s).
recumbent, partly erect, and jjlaced one above the other, so tliat they appear to form
tabulated tubes. Tertiary.
Floridina Jullien. Like Onychocella liut opesium trifoliate. Cretaceous to
Recent.
Smittipora Jullien ; ' Euritina Canu. Cretaceous to Recent.
-^
i:
Family 9. Microporidae Smitt.
Zooecia having the front wall entirely calcareous ; usually with sharply elevated
margins, fissures or perforations. Cretaceous to Recent.
'Mr
Micropora Gray (Fig. 518). Zoaria encrusting. Zooecia with
prominent raised margins; the front depressed, with a perforation
at each upper angle below the semicircular or rounded orifice.
Cretaceous to Recent'.
Steganoporella Smitt ; Setosella Hincks ; Rhagasostoma Kos-
chinski ; Cupularia Lam. ; Gargantua Jullien. Tertiary to Recent.
Suborder B. ASCOPHORA Levinsen. p^g- ^is-
Micropora disparilis
Compensation sac present, opening most often on the proximal side ^jg^g^g -^'anta^ar-
of the operculum, more rarely further bara Co., Cai. Zooecia
7 7 ,7 7 7. / s highly magnified
back through ct, median pore {ascopore). (after Gabb and
A calcified transverse bar between the Horn).
opercular and sub-opercular areas.
Family 10. Microporellidae Hincks.
Zoaria encrusting or erect, foliated or dendroid.
Zoa'cial orifice more or less semicircidar, with the loioer
margin entire ; a crescentic or circular pore on the front
wall usually just beneath the orifice. Cretaceous to Recent.
Fio. 519. Microporella Hincks (Fig. 5 1 9). Zoarium encrusting
Micropordia rudis (Reuss). Oli- or erect, bilamiuar. Margin of zocccia not elevated.
ocene ; &'■"■' ^^ ' —
enlarged.
gocene ; Siillingen. Upper surface, .,^ -r. .,i , • i , j_- i in e ,j-i
" ■ ° ^* ' Orifice with a straight, entire lower border, frequently
352
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
with oral spines. Usually one senii-lunate or circular pore lieneatli the orifice,
occasionally two or three. Tertiary and Recent.
Family 11. Porinidae d'Orbigny.
Zoaria encrusting, or erect and ramified. Zooecia with a raised tubular or sub-tubular
orifice, and frequently with a special pore on the front wall. Cretaceous to Recent.
Poriiia d'Orl). Zoaria consisting of flattened or sub-cylindrical branches, celluli-
ferous on both sides, or encrusting. With age the spaces between the raised apertures
become filled with a porous calcareous dej^osit. Avicularia and ooecia occasionally
distinguishable.
Cretaceous to Recent.
Family 12. Smittinidae Levinseu.
For this and the next following family only provisional diagnoses can be given at
the present time, and for that reason none is attempted here.
Smittina Norman (Smittia Hincks). Zoaria encrusting, or erect and foliaceous.
Primary orifice of zooecia sub-orbicular, the lower margin with an internal median
denticle. Secondary orifice canaliculate below ; generally a small avicularium either
within or just Ijeneath the sinus. Cretaceous to Recent.
Mucronella Hincks (Fig. 520). Similar to Smittina, but with simpler orifice,
and the low-er jiart of the peristome elevated into a more or
less prominent mucro. Cretaceous to Recent.
Porella Gray. Zoaria encrusting or erect. Zooecia with a
Fig. 520.
Mucronella coccinm
Abildg. Miocene ; Eisen-
.stadt, Haiij;ury. Anuiii-
ber of zoojcia enlarged
(after Reuss). The aper-
tures are denticulated,
and each zoiecium has a
pair of avicularia. o,
Ovicell.
Fio. 521.
Lepralia pallusiana Moll.
Recent ; England. Zowcia
highly inagnitied (after
Hinciss).
ScMzo porella corituta
(G. and H.). Po.st-
I'liocene ; Santa Bar-
bara Co. , Cal. Zooecia
highly magnified
(after Gabb and
Horn).
semicircular pi'iinary orifice; tlie secondaiy (adult) orifice elongate, inversely sub-
triangular, or liorseshoe-shaped, and enclosing an aviculaiium witli a rounded or
Cretaceous to Recent.
sub-triangular mandible
Family 13. Lepraliidae Smitt.
This family, like the preceding one, can be only provisionally defined at present.
Lepralia, Johnson (Fig. 521). Zoaria encrusting or rising into simj)le or branching
expansions, composed of one or two layers of cells. Zooecia usually ovate, the orifice
with a thin peristome and entire lower margin. Rare in Cretaceous, more abundant
in Tertiary and Recent.
Hipipoporina Neviaui. Like Lepralia luit aperture constricted l)y two lateral
teeth. Tertiary.
Hchizoporella Hincks (Fig. 522). Zoaiia variable ; /.ucjocial oi'ifice varying from
ORDER V
CHEILOSTOMATA
353
semicircular to sub-orbiculai', the lower margin with a distinct sinus. Cretaceous to
Eecent.
Family 14. Meniscoporidae Cann.
This family is characterised by the occurrence of three kinds of zocecia : (1)
typical zocecia, (2) genesies or zooecia bearing internal ooecia, and (3) avicularia.
Alumdant in Tertiary.
Meniscopora Gregory. Aperture constricted as in Hippo forina.
Schizostoma Canu. Like Schizoporella but with genesies.
Poristoma, Poricella, Smittistoma and Galvetina Canu ; Lobopora Levinsen.
Family 15. Reteporidae Smitt.
Eefepora Imperato {Phidolophora Gabb and Horn) (Fig. 523). Zoaria consisting
usually of inosculating branches which spring from an encrusting base. Zocecia
disposed on one face of the branches only, in most cases immersed. Primary orifice
;.V'..-V:.v.'x.;-:.-;^-;
'■':;-V.s?ifi
Fig. 524.
Fig. 523.
Retepora cellulosa Linn. Crag ;
Suffolk, England.
Myriozoum pwndatuiii (Phill.). Miocene ; Ortenburg, Bavaria. A,
Zoarium, i/i- B, Upper surface, enlarged. In the forward portion the
apertures are open ; in the rear, covered over by a calcareous deposit.
C, Cross section of a branch.
rounded or semi-elliptical with entire border. Afterwards the peristome becomes
much raised and multiform ; usually there is a fissure below, or there may be a
prominent rostrum bearing an avicularium. Tertiary and Recent.
Family 16. Myriozoidae Smitt.
Myriozoum DoTiB.ii (Myriopora Blainv. ; Vaginopora Reuss) (Fig. 524). Zoaria
consisting of thick, dichotomously dividing branches, obtuse at their growing ex-
tremities, and rising from an attached basal expansion. Zooecia disposed about an
imaginary axis, even at the surface, their boundaries scarcely distinguishable. Entire
surface and also the inner walls minutely porous. Orifice above the centre of the
zooecium, sub-orbicular, notched or canaliculate below. As a rule, the openings are
closed on the lower j^arts of the branches by a calcareous pellicle. Tertiary and
Recent ; perhaps also Cretaceous.
Family 17. Celleporidae Busk.
Zocecia urceolcote, more or less erect, and irregularly crowded together ; often forming
several or many superimposed layers.
Cellepora Fabricius, emend. Busk (Spongites Oken ; Celleporaria Lamx.) (Fig.
525). Zoarium multiform, encrusting, or erect and ramose. Zocecia in the older
VOL. I 2 A
354
MOLLUSCOIDEA— BRYOZOA
PHYLUM V
portions nioie or less erect and very irregularly disposed. Orifice terminal, entire
or sinuated, with or without internal denticles ; in connection with it are usually one
or more rostra Ijearing avicularia. Inter-
calated avicularia generally present also. The
surface of weathered specimens dotted by
the unequal apertures of vesicle -like cells.
Tertiary and Recent.
Subclass 2. PHYLACTOLAEMATA
Allman.
The Bryozoa referred to this subclass
are soft - bodied, and therefore cannot be
expected to be found fossil except under
unusual conditions of preservation. The
fresh -water Cenomanian beds of Bohemia
have yielded an organism in crusting a TJnio,
resembling the Recent genus Plmnatella.
Although the structure is too imperfectly preserved for certain identification, this
specimen (Plumatellites proMferus Fric) may Avell be a fossil rejjresentative of the
Ph y lactolaei uata.
Fig. 525.
Cellepora conglomerata Goldfuss. Oligocene ;
Astrupp, near Osnabriick. A, Zoarium, i/j.
B, Upper surface, enlarged.
Range and Distribution of the Bryozoa.
The class Bryozoa begins in the earliest Ordovician, and is represented con-
tinuously up to the present time. The older Paleozoic forms belong chiefly to two
oixlers — the Cyclostomata and Trej)ostomata.
A considerable number of Cyclostomatous genera are present in the Ordovician,
most of them being closely related with Mesozoic and Recent types ; but throughout
the remainder of the Paleozoic, and in the Trias also, the order is very sparingly
represented (except for the Ceramoporidae and Fistulij5oridae), and in some parts quite
absent. In the Jura and Cretaceous, however, a remarkable increase took place,
hundreds of species being known from these formations. During the Tertiary their
strength was again materially reduced, and the living Cyclostomata barely exceed
100 species in number.
The Trepostomata appear suddenly and in great variety in the Ordovician, from
which over 400 species are known, but entered almost immediately upon a period of
decline. From the Trenton and Cincinnati groups alone more species have been
described than from all of the later Paleozoic formations put together. There is at
present no evidence to show that the group siirvived later than the Paleozoic era, but
it is not unlikely that their descendants may be found among certain Mesozoic
families, such as the Ceidae, which are jirovisionally assigned to the Cyclostomata.
The Cryptostomata are likewise confined to rocks of Paleozoic age, but, as has
been remarked above, may be very confidently regarded as the forerunners of the
Cheilostomata. True members of the latter group are first met with in the Jura, but
they develop rai)idly, and from the Cretaceous onward remain the dominant type.
The Triassic and Liassic liryozoans belong chiefly to the Cerioporidae. This
family, together with the Diastoporidae, Fascigeridae, and other members of the
Cyclostomata, is abundantly rei:)resented in tlie Middle Jura of Lorraine, Southern
Germany, England and Normandy. Tlie Upper Jura, on the contrary, yields com-
I^aratively few Bryozoan fossils.
The Cyclostomata still predominate in the NeocoAiian and Gault, but in the
CLASS II BRACHIOPODA 355
Cenomanian a number of Clieilostomatoiis genera make their appearance. The fauna
is especially well developed in the vicinity of Le Mans, Havre and Essen, and in
Saxony, Northern Germany and Bohemia.
Bryozoans are surprisingly abundant in the Upper Cretaceous, particularly in the
Upper Planer of Northern Germany, Saxony and Bohemia, in the AVhite Chalk, and
tlie facies of Aix-la-Chapelle and Maestricht. D'Orbigny alone has described not less
than 547 species of Upper Cretaceous Cyclostomata, and about 300 Cheilostomata ;
many of these, however, are synonyms or unrecognisable.
The Cheilostomata retain their supremacy throughout the Tertiary period. The
Eocene and Oligocene deposits of the northern and southern slopes of the Alps are
remarkable for the abundance of their Bryozoan remains ; some of the most noted
Eocene localities being Kressenberg, Hammer and Neubeuern in Upper Bavaria ;
Mossano, Crosara and Priabona, near Vicenza ; and Oberburg in Styria. The
Oligocene of Northern Germany, and the Miocene of Touraine, the Rhone Valley,
Upper Swabia, and the Vienna Basin, are also remarkably rich in Bryozoan remains.
The Pliocene fauna of Italy, Rhodes, Cyprus and England (notably the Coralline
Crag) is made up almost entirely of existing genera, and in many cases of existing
species.
[The revision of the preceding chaptel- on Bryozoa has been prepared for the present
edition by Dr. R. S. Bassler, of the United States National Museum at Washington, D.C. —
Editor.]
Class 2. BRACHIOPODA Dumeril.^
(Revised by Charles Schuchert.)
Bivalved MoUuscoidea ivith inequivalved, equilateral shells attached to extraneous
objects by a posterior prolongation of the body, or pedicle, throughout life or during
1 Literature: A. Anatomy and Embryology. — Hancock, A., On the Organisation of Brachio-
poda. Pliil. Trans., 1858, vol. cxlviii. — Morse, K S., On the Early Stages of Terebratulina
septentrionalis. Mem. Boston Soc. Nat. Hist., 1873, vol. ii. — On the Systematic Position of the
Brachiopoda. Proc. Boston Soc. Nat. Hist., 1873, vol. xw.—Kovalevski, A. 0., Observation on the
Development of Brachiopoda. Proc. Imp. Soc. Amateur Nat. Moscow, 1874, vol. xiv. — Brooks,
W. K., The Development of Lingula and the Systematic Position of the Brachiopoda. Sci. Results
Chesapeake Zool. Lab. 1878. — Shipley, A. E., On the Structure and Development of Argiope.
Mittheil. Zool. Station Neapel, 1883, vol. iv. — Oehlert in Fischer s Manuel de Conchyliologie.
Paris, 1887. — Beecher, C. E., and Clarke, J. M., The Development of some Silui-ian Brachiopoda.
Mem. New York State Museum, 1889, vol. i. — Beecher, C. E., Development of the Brachiopoda.
Amer. Journ. Sci., 1891-9*2, vols, xli., xliv. — Revision of the Families of Loop-bearing Brachiopoda.
Trans. Conn. Acad., 1893, vol. ix. — Beecher, C. E., and Schuchert, C, Development of the Shell
and the Brachial Supports in Dielasma and Zygospira. Proc. Biol. Soc. Washington, 1893,
vol. viii. — Buckman, S. S., Homoeomorphy among Jurassic Brachiopoda. Proc. Cotteswold Nat.
Field Club, 1901, vol. xiii. — Brachiopod Homoeomorphy : Pygope, Antinomia, Pygites. Quart. Journ.
Geol. Soc. London, 1906, vol. Ixii. — Brachiopod Homoeomorphy : " Spirifer glaber." Ibid., 1908,
vol. Ixiv. — Blochmann, F., Untersuchungen iiber den Bau der Brachiopoden. Jena, 1892, 1900.
B. Distribution of Recent Forms. — Schuchert, C, Paleogeographic and Geologic Significance of
Recent Brachiopoda. Bull. Geol. Soc, America, 1911, vol. xxii.
C. Bibliography. — Ball, W. H., Index to the Names which have been applied to the Sub-
divisions of the Class Brachiopoda. Bull. U.S. Nat. Museum, No. 8, 1877.— Baviclso7i, T., and
Bcdton, W. H., Bibliography of the Brachiopoda. Palaeont. Soc, 1886. — Schuchert, C, Synopsis
of American Fossil Brachiopoda. Bull. U.S. Geol. Surv., 1896, No. 87.
D. Systematic Wovka. — Walcott, 0. D., Cambrian Brachiopoda. Mon. 51, U.S. Geol. Surv.,
1912. — Davidson, T., Monograph of British Fossil Brachiopoda. Palaeontographical Society,
1851-86, vols. i.-v. — Idem, A Monograph of Recent Brachiopoda. Trans. Linn. Soc, 1886-88,
vol. iv. — Waccgen, W., Salt Range Fossils. Palaeont. Indica, ser. 13, 1882-85, vol. \.—Bittner, A.,
Brachiopoda der Alpinen Tiias. Abhandl. k.k. geol. Reichs-Anst., Wien, 1891-92, vols, xvi., xvii. —
Hall, J., and Clarke, J. M., Introduction to the Study of Palaeozoic Brachiopoda. Palaeont. New
York, 1892-95, vol. viii., parts 1, 2. — An Introduction to the Study of the Brachiopoda. Rept.
New York State Geologist, 1892-93, parts 1, 2.— Schuchert, C, Synopsis, etc., see above.—
356 MOLLUSCOIDEA
PHYLUM V
only a portion of their existence, or cemented ventrally. Valves ventral and dorsal.
In composition, phosphatic or calcareous or both. Animal enveloped by two pallial
membranes intimately related to the shell. JFithin the mantle cavity at the sides of the
mouth are inserted the two, more or less long, oral, usually spirally enrolled, cirrated
brachia, which are variously modified, and are supported in the Terebratulacea and
Spiriferacea by an internal calcareous skeleton, or brachidium., attached to the dorsal
valve. Anus present or absent. Central nervous system consisting of an oesophageal
ring with weakly developed brain and infra-oesophageal ganglionic swellings. Blood-
vascular system probably present with the sinuses developed into vascular dilatations
at the back of the stomach and elsewhere. Sexes separate. Exclusively marine.
The class begins well represented in the Lower Cambi'ian, attains its
maximum development in the Silurian and Devonian, and is represented by
about 158 living species. Probably upwards of 7000 fossil and recent species
have been described ; these are distributed in 450 genera, grouped in 42
families, 14 superfamilies, and 4 orders.
Cuvier (1792 and 1802) was the first to distinguish the Brachiopods from
the Acephala, and created for them a fourth family in his class of Molluscs.
To Dum6ril (1806) we owe the now generally accepted class name Brachio-
poda, or arm-footed animals. Since the arms, or brachia, are not homologous
with the foot of Molluscs, Gray (1821) changed the name to Spirobranchiopoda ;
Blainville (1824) to Pa/to5rowc/wate ; Risso (1826) to Branchiopoda ; Broderip
(1839) to Brachiopodidae ; Agassiz (1847) to Branchionopoda ; Bronn (1862) to
Brachionocephala ; Paetel (1875) to Branchionobranchia ; and Haeckel to Spiro-
branchia. None of these has displaced Dum^ril's term, though the latter is
founded on a false physiological interpretation of the brachia.
External Characters : Form. — The shells of Brachioj^ods are very
variable in form. Usually both valves are convex, but they may be nearly
flat, with the interior cavity extremely shallow, or the dorsal valve may be
concave and follow closely the curvature of the convex ventral valve. The
ventral valve may be cone-shaped, with the dorsal operculiform, or the
former may be so modified by cementation as to assume the apj:)earance of a
Cyathophylloid coral. The shell is commonly rostrate, with the ventral beak,
or apex, more or less incurved over that of the dorsal valve, or the valves
may be very greatly extended transversely. In fact, the form of the shell of
Brachiopods is so variable that, as a rule, no greater value than specific can
be attached to this feature.
Fixation. — The animal is generally attached to extraneous objects by a
muscular pedicle which projects either from between the contracted posterior
margin of the two valves (Fig. 536, A), through an opening in or under the
beak (Fig. 535, B), or through the ventral valve (Fig. 556, A). With
increasing age, however, the pedicle opening frequently becomes closed, and
the pedicle itself atrophied. The animal may then be anchored by spines
Schellwien, E., Die Fauna der Trogkofelschicliteu. Abliandl. d. k.k. geol. Reichs-Aiist., 1900,
vol. xvi., pt. 1. — Skupin, II., Die Spiriferen Deutsclilands. Geol. -pal. Abliandl., 1901, vol. viii. —
Tschernyschew, T. , Die obercarbouischen Bracluopoden d. Ural iind d. Timan. Mem. Comite Geol. ,
1902, vol. xvi., No. 2. — Girty, G. H., The Guadalupiau Fauna. Profess. Paper 58, U.S. Geol. Surv.,
1908. — Buckman, S. S., Brachiopod Nomenclature. Ann. Mag. Nat. Hist. (7), 1906, vol. xviii.
— The Genotype of Terebratula. Ibid., 1907, vol. xix. — Brachiopod Morphology : Cincta, Eudesia,
and the Development of Ribs. Quart. Journ. Geol. Soc. London, 1907, vol. Ixiii. — We.ller, S.,
Internal Characters of some Mississippian Rhynchouelliform Shells. Bull. Geol. Soc. America,
1910, vol. xxi. — Genera of Mississippian Loop-Bearing Brachiopoda. Journ. (Jeol., 1911, vol. xix.
CLASS IE
BRACHIOPODA
357
(Chonetes, Produdus) or be cemented by the whole or a part of the surface of
the ventral valve {Crania, Davidsonia, Thecidea, Streptorhynclms). In some cases
(Glottidia and Lingula) Brachiopods live throughout life partially buried in the
sand or mud of the sea-bottom.
Ornamentation. — The external form and ornamentation of the shell afford
important characters for determining the species. The anterior margin of
one valve is frequently indented by a median sinus, and the other usually
exhibits a corresponding /oZ(/, or elevation.
In the earliest shell growth stages Brachiopod shells are invariably smooth,
and may remain so throughout life, but the greater number develop radial
striae, ribs or undulations, and these are usually crossed by concentric growth
lines, or lamellae, which are sometimes of great width, or may be extended into
spines. There may be more or less long tubular spines scattered over one or
both valves, or sometimes restricted to a single row along the cardinal line.
Under the term Loricatae, Leopold von Buch included all Brachiopods in which
the radial folds, or costae, are arranged in regular succession in such manner
that elevated ridges at the anterior margin of one valve coincide with the
indentations of the other. In the Biplicatae, a median fold or sinus is
bordered on either side by a broad fold. In the Cinctae, the plications of the
two valves meet at the anterior margin in such manner as to form a straight
instead of a crenulated line, as in the Biplicatae. In young specimens the
ribs and folds are less prominent and numerous than at maturity. In very old
or senile individuals the shell is usually thickened and obese, and the growth
lines are much crowded anteriorly. At this stage inherited specific characters
are seen to disappear, and at the same time new ones may be introduced.
Shell Structure. — The test of Brachiopods is composed of laminae of various
structure and composition, but differs considerably from that of Molluscs.
The shell may be wholly calcareous or alternately calcareous and corneous.
When entirely calcareous the laminae are never more
than three in number : an inner thick prismatic layer,
an intermediate laminar layer, and an outer epidermal
film. The inner layer is made up of flattened prisms of
calcite arranged parallel to one another with great regu-
larity, and forming an acute angle with the surface of the
shell (Fig. 526). In the Thecidiidae these fibrous prisms
are so intimately united with one another that the shell
substance appears almost homogeneous. Very often the
fibrous layer is perforated by a series of minute canals
which pass from one surface of the valve to the other
in a more or less vertical direction, and are somewhat
dilated externally. These canals contain tubuli, or certain
prolongations derived from the mantle, but never com-
municate with the exterior, owing to the fact that the
laminar layer of the shell is always covered with a
chitinous epidermis (periostracum). With the aid of a magnifier the openings
of these canals are visible in fossil forms, and they may be also seen in recent
specimens after the epidermis has been removed by an application of caustic
potash (Fig. 527). According to the presence or absence of tubuli, Brachiopods
are distinguished as punctate or impunctate.
The Craniidae have thick shells composed of concentric layers of carbonate
Fio. 526.
Prismatic fibrous struc-
ture of shell ofR/)2/ncfto;te??«
(Hemithyris) psittacea, lOOy'j
(after Carpenter).
358
MOLLUSCOIDEA
PHYLUM V
of lime. In Crania the shell substance is homogeneous, and punctured by
distally branching canals. In the Lingulidae and Obolidae the shell consists
of alternating layers of phosphate of
lime, admixed with lime carbonate,
and a lustrous horny substance known
as ceratin. The calcareous layers are
prismatic, and are traversed by fine
tubuli (Fig. 528). It
is believed that the
function of the punc-
tae is for respiration,
but the fact that these
extensions of the
mantle are not ex-
posed to the water
sLrvint'liteS may not accord with
corneous (a) and this explanation
calcareous (h) layers. J-
Fi(i. 527.
A, Punctate exterior of a Terebratuloid shell,
slightly enlarged. B, Vertical section of shell of
Magellania fla uescens, showing distally enlarged tubules,
JOO/j. c. Inner surface of Magellania shell, showing
ends of tubules and oblique calcareous prisms, loo/j
(after Carpenter).
Fig. 528.
Vertical section
Strongly magnified
(after Gratiolet).
Valves. — Brachio-
pods are delicately
constituted animals, covered by two very vascular mantle lobes which secrete
the calcareous or corneo- calcareous valves, of which one is dorsal and the
other ventral in position. The valves are often thin and of unequal size, but
the inequality is rarely of such a nature as to disturb the bilateral symmetry
of the shell.
During life the ventral valve, which is commonly the larger of the two, occu-
pies typically a superior position, and the dorsal is down. But in describing
the shell, it is always so oriented that the posterior margin, or hinge-line, is
placed above, and the anterior one below. A line drawn from the beak to the
anterior margin describes the length ; and one at right angles to the same, in
the direction of right and left, the width ; a third line drawn perpendicularly
to the other two, and passing through the centres of the valves, measures the
thickness. In the Protremata and Telotremata the ventral valve is convex, and
curved in such manner at the posterior margin as to form a heak. The beak
may be pointed, or it may be perforated by a round opening, or foramen, for
the protrusion of the pedicle. In many cases, however, the pedicle opening
lies underneath the apex of the beak, and sometimes encroaches upon a
portion of the dorsal valve. In the Atremata the pedicle emerges from
between the two valves ; in the Neotremata the posterior margin of the
ventral valve is notched, or there may be a small, circular, eccentric per-
foration, or a more or less long, narrow slit. In the Telotremata the pedicle
opening, or delthyrium, which is originally triangular in form, becomes either
wholly or partially closed by the growth of deltidial plates. In the Protremata
the delthyrium is closed by a true deltidium., while in the Neotremata and
Atremata a similar looking plate may be present, but as it is of a different
origin, being secreted by the mantle, it is called the homceodeltidium.
The cardinal area is a term ai32:)lied to the flattened or curved triangular area
which is frequently observable Ijetween the liinge-line and the Leak (Fig. 529). It
is more highly developed in the ventral than in the dorsal valve, and is bisected
medially liy the triangular delthyrium. A true cardinal area is absent in the
Atremata and Neotremata ; but when a small area is present in these orders, it is
CLASS II
BRACHIOPODA
359
Fi(i. 529.
Cyrtina hHeroclyta
(Defr.). High car-
dinal area of ventral
valve showing del-
called a false cardinal area (Fig. 546, B, G). A split tubular structure, or syrinx,
which partially encloses the pedicle, is developed in the delthyrium of some spire-
bearing forms.
The deltidium has its origin in the Cephalula stage of Protremata {Thecidea
mediterranea) contemporaneously with the rudiments of the dorsal
and ventral valves, while the embryo is still in the free swimming
condition. The dorsal valve and incipient deltidium appear first,
being secreted by the rudimentary dorsal mantle and the dorsal sur-
face of the body, the latter subsequently becoming the pedicle. The
ventral valve is formed last, but is widely separated from the dorsal.
Between the two valves is placed the short and thick, but as yet
unattached pedicle, on the dorsal surface of which the third plate,
known as the prodeltidium, still remains. Shortly before the animal
becomes fixed by the pedicle, the jDrodeltidium fuses with the posterior
margin of the ventral valve. The pedicle is at this stage entirely
surrounded by shell, being enclosed on one side by the ventral valve, fl^iseci™ deTudia^
and on the other by the deltidium. The latter plate then continues plates, or pseudo-
, ■ j_ T r ii ■ J. • -I- I.- deltidium.
to grow as one piece, extending irom tlie apex in an anterior direction,
and is secreted entirely by the pedicle (Fig. 541). The deltidium is never punctate
in structure, Imt it may bear spines (Aulosteges), and sometimes exhibits a round or
pedicle perforation {Clitambonites). Tlie deltidium is characteristic of the Protremata,
while a similar plate, the hornccodfdtidium, is developed in some of the Neotremata
and Atremata. This covering of the delthyrium is always present in the young of the
Protremata, but is absent in the Telotremata. In many of the Protremata (Orthidae,
etc.) the deltidium is only present in nepionic stages of the individual, being
resorbed at maturity ; but in the great majority of these forms it remains persistent
throughout life.
Deltidial plates occur only in the order Telotremata, and consist of two pieces
which begin as narrow, linear, calcareous plates, growing medially from the walls of
the delthyrium. They gradually increase in size, and usually come in contact
medially with one another, either below or above the pedicle foramen, and are
secreted by an extension of the ventral mantle lobe. Thus in respect to their origin
they differ from the deltidium of the Protremata, which is secreted by the jiedicle,
and not by the mantle. The deltidial plates are never present in the earliest growth
stages of the shell, the delthyrium being then an open triangular fissure through
which the pedicle is protruded. In the adult stage the deltidial plates may remain
as narrow, linear discrete plates (Fig. 530, i?) ; may meet beneath the pedicle foramen
Fig. 530.
A, Vyclothyris ves2oertilio (Brocchi), with united deltidial plates. B, Terebratella doraata (Lam.), with
discrete deltidial plates. C, Young specimen oi Stringocephalus burtoni (Defr.), with the deltidial plates united
above the foramen.
(Fig. 535, B) ; or they may wholly enclose the pedicle (Fig. 530, A). The deltidial
plates frequently unite by fusion, when they closely resemble a true deltidium, and
are known as a fseudodeltidium {Cyrtia, Cyrtina, Fig. 529).
The chilidium is a convex plate which often covers the cardinal process of the
360
MOLLUSCOIDEA
PHYLUM V
dorsal valve in the Protremata. It is particularly well developed in the families
Clitambonitidae and Strojjhomenidae (Fig. 585, B). The chilidinm is not to be homo-
logised with the deltidium, since it never appears earlier than the adolescent stage,
and is aj)parently a secretion of the dorsal mantle lol^e. Both its origin and phyletic
significance are therefore very different from those of the deltidium.
The listrium is a plate closing the progressive track of the pedicle opening or
pedicle cleft, in some Neotremata, posterior to the apex of the ventral valve.
Internal Characters of the Shell : Articulation. — The two valves are
held in apposition either by muscles only (Atremata and Neotremata), or they
are united by articulation (Protremata and Telotremata). In the latter case
there are to be seen in the ventral valve a pair of cuneate or tooth-shaped
projections, one on either side of the delthyrium, called the hinge-teeth (Fig.
535, B), which fit into the so-called dental sockets of the dorsal valve. Articu-
lation is also aided by the cardinal jyrocess, which is a more or less well-
developed apophysis of the dorsal valve, and is received between the teeth of
the ventral valve. By the contraction of the muscles attached to the
cardinal process, the valves are opened along the anterior and lateral
margins ; but when shut, the test entirely encloses the soft parts of the
animal.
The dental sockets are bounded on the inside by hinge-plates (Fig. 535, A),
which are often supported by vertical or inclined septal plates extending to
Fi(i. 531.
Different forais of brauhidia. A, Hcmithiiriti ; flesliy arms supported by two simply curved crura. B, Theco-
spira- inwardly coiled double spires, or spiralia. C, Nucleospira ; and D, Cyrtina; outwardly coiled spiralia.
h-H, J^oops ot Brachiopods. E, Centronella ; F, Dielasma ; G, TerebraUlla ; H, Megatltyris.
the bottom of the shell. The teeth of the ventral valve are sometimes
supported by lamellae known as the dental plates. In addition to the dental
plates, which frequently attain considerable size, there may be a median
septum of variable proportions. This may begin beneath the beak of the
valve, and may sometimes extend as far as the anterior margin (Fig. 535, A).
Some forms are also provided with lateral septa (Thecidiidae).
CLASS II BEACHIOPODA 361
Brachial supports. — Of special systematic importance are the braMdia, or
intermil skeleton of the fleshy arms (Fig. 531), which occur in the Spiriferacea
and Terebratulacea. The brachidia are, as a rule, prolonged basally from the
crura, and are extremely variable in form. They usually pass through a
more or less complex series of metamorphoses during the growth of the
individual, and do not attain their complete development until the animal has
reached maturity.
The simplest form of brachial supports is found in the Rhynchonellacea and
Pentameracea, whei-e it consists of two short, or only moderately long, curved
processes called the crura when discrete, and cruralium when the plates are
united. The crura are attached to the hinge-plates. The cruralium is
formed by the union 'of the crural plates in the Pentameracea. It serves
for the attachment of muscles, and may either rest upon the bottom of the
valve, or may be supported by a median septum. When the crura remain
sepai'ate, and are therefore not for muscular insertion, they are homologous
with and the equivalent of the crura in the Ehynchonellidae.
In the Spiriferacea, two thin, spirally coiled ribbons, or spiralia, are
given off from the crura ; the coils exhibiting great diversity in form, in the
number of volutions, and in the direction of the hollow cones (Fig. 531,
B, C, D). The spiralia are usually joined by a transverse band or jiigum
(Fig. 531, D). When the latter is discontinuous, the parts are called the
jugal p)i'ocesses. The bifurcations of the jugum may enter between the con-
volutions of the spiralia, and may be continuous with them to their outer
ends, forming what is termed a double spiral or diplospire (Fig. 531, B). In
the Terebratulidae, the brachia are also extensions of the crura, and form free,
shorter, or longer loops, which depend toward the anterior margin (Fig. 531,
E, F). The two descending branches may either unite directly or may be
joined by a transverse band ; or the descending branches may recurve, continue
upward as ascending branches, and be connected posteriorly by a transverse
band. In the Terebratellidae, during all or some portion of the animal's
existence, the loops are attached to a median septum by outgrowths from the
descending lamellae (Fig. 531, G). In the Stringocephalidae and Mega thy rinae
(Fig. 531, j&) the descending branches are parallel to the lateral margins of
the shell, and unite along the median line ; but in some degenerate species
a remnant of the loop is represented by a transverse band situated centrally
on the median septum. The entire form of the brachidia is manifestly
dependent upon the character of the convolutions of the fleshy arms. In
recent Hemithyris (Fig. 531, A) the brachia form hollow spiral cones, and if
we imagine these as supported by a calcareous framework, the result will be
a form of support like that seen in the Atrypidae. The fleshy arms of the
Terebratellidae are continuous with, and have at first the form of the loop,
but later develop a coiled median arm. Here the loops only have calcareous
supports ; but in the Spiriferacea the entire brachia are provided with an
internal calcareous skeleton.
The changes in the form of the brachidia in the Telotremata during the
ontogenetic stages of the individual furnish very important data in regard
to the relationships existing between the different groups. In the Spiri-
feracea, not only does the number of convolutions of the spirals increase with
age, but the brachidia begin with Centronella- and Dielasma-MVe. loops, from
the outer ends of which the spires are developed. Still more striking are
362 MOLLUSCOIDEA phylum v
the metamorphoses which the loops of the Terebratulacea undergo. According
to (Ehlert and Beecher, the loop of the living austral genus Magellania passes
through stages which correspond successively to those of Gwynia, Argyrotheca,
Bonchardia, Magas, Magasella, Terehrafella and Magellania; and Friele has
shown that the metamorphoses of the loop in the boreal form Macandrema
cranium correspond in succession to the genera Platidia, Ismenia, Muehlfeldtia,
Terebratalia and Macandrevia.
A knowledge of the character of the brachidia in the Spiriferacea and
Terebratulacea is almost always requisite for critical generic determinations.
But an examination of the interior of the shell in fossil Brachiopods often
involves great difficulties, owing to the infiltration of calcite, or the filling up
of the shell cavity with sediment. Not infrequently the shell and the
brachidia are secondarily replaced by silica ; and if the interior filling matter
be dissolved away by dilute hydrochloric acid, exquisite preparations may be
obtained, often revealing the minutest details. Sometimes hollow shells are
found, in which the brachidia are well preserved, but these structures
generally are more or less encrusted. It is often necessary to remove the
ventral valve, when the infiltrated material can be cut away by the use of
proper tools. Success in manipulations of this kind requires not only con-
siderable dexterity, but the conditions of preservation must have been very
favourable. The brachidia must be perfectly preserved, and the surround-
ing matrix must admit of being removed without injury to the specimen.
When other expedients fail, recourse can still be had to polishing, the shell
being gradually ground down by abrasion with emery powder on a glass
plate. The beaks are first ground away, until the first traces of the crura
appear; the surface is then cleaned and kept moistened while a careful
drawing is made. Grinding is resumed for a short interval, when the
surface is again cleansed and drawn. This process is repeated until the
sections include the entire brachial support. From the series of transverse
sections thus obtained, the brachidium can be ideally reconstructed.
The spondylium is an internal ventral plate traversing the posterior
portion of the valve (Fig. 585, C). On the superior surface of the plate are
inserted the adductors, diductors and the ventral pedicle muscles. Beneath
the spondylium, which may be supported by a median septum, are situated
the reproductive organs. The plate is homologous with the solid or excavated
platform of the Atremata (Trimerellidae and Lingulasmatidae).
Soft Parts : Mantle. — Lining the entire inner surface of the shell is a
thin, transparent membrane, which appears in the embryonic condition as
two distinct lobes of the thoracic segment in the Cephalula stage. This is
the mantle or pallium, which is primarily concerned in the secretion of the
shell. In Crania it consists of three layers : a middle cartilaginous, an inner
ciliated one, and an outer layer of cells. The layer lying against the surface
of the shell is often studded with minute caeca or blind tubes, which enter
the perforations of the test. The mantle (or certain of its layers) is folded
upon itself at various points, enclosing cavities or pallial sinuses, which contain
the circulating fluids, and frequently portions of the genital organs. Distinct
impressions of these sinuses are often observable in the valves of both recent
and fossil specimens (Fig. 532). In all the greater sinuses of the mantle, in
the perivisceral cavity, and in the cavernous brachia and cirri, occur calcareous
spicules of various shapes. These are especially abundant in the Thecidiidae,
CLASS II
BRACHIOPODA
363
In inarticulate £^^^^4
Fia. 532.
Camiiroplwria, hvmhlctnnetisis
Howse. Permian ; Humbleton,
Bngland. Internal mould showing
pallial sinuses
and form an irregular mass or network. They appear to be absent in
Magellania, Terebratella and Lingula. The outer margins of the mantle are
thickened and set with numerous chitinous, simple
or barbed setae, sometimes of great length.
The shell cavity is divided by a vertical mem-
branous wall, which is an extension of the mantle,
into two regions : a posterior, or visceral cavity, and
an anterior, or brachial cavity. The posterior cavity
contains the principal viscera, the alimentary, cir-
culatory, nervous and muscular systems. The an-
terior chamber is occupied by the arms.
Organs of the Visceral Cavity. — The membranous
partition is pierced centrally by the oval or slit-like
mouth, from which the digestive tube extends back-
wards as a simple or bent canal,
species, the alimentary canal is very long, makes
several convolutions, and terminates in a well-defined anus, situated on one
side of the animal. In the Protremata and Telotremata the digestive tube
is shorter and much simpler than in the Atremata and Neotremata, The
intestine makes a single convolution and terminates blindly in the living
representatives of these orders, being surrounded by large hepatic lobes.
In many Paleozoic species it probably did not terminate blindly, since the
intestine passed through the hinge-plate by a central foramen. There is no
heart, circulation being apparently maintained by the cilia lining the vas-
cular sinuses. These sinuses pass into the perivisceral chambers, and are
developed into vascular dilations at the back of the stomach and elsewhere.
These bodies are not contractile, and their function is unknown. Two
numerously branched vascular trunks diverge from the anterior portion of
the perivisceral chambers, traversing the mantle in either valve to its
margins, and several others pass over the fleshy brachia for their entire
length. The nervous system consists of a circum- oesophageal ring on which
two supra-oesophageal ganglia are inserted. From the swellings of the
oesophageal ring (notably from that on the lower side), nerve fibres are
given off to the bi'achia, muscles, pedicle and the two lobes of the mantle.
In adult Brachiopods sense organs are not known with certainty ; but in
the embryos such are believed to be present. So far as is known the
sexes are always separate. The sexual organs in both male and female
are located essentially alike, and have a paired arrangement. Generally
they occupy the main trunks of the vascular sinuses, but may extend into
the visceral chamber, or, in some of the inarticulate forms, may be restricted
to the latter.
The Brachial Cavity. — The greater part of the anterior or brachial cavity
is occupied by the spirally enrolled labial appendages, the so-called arms, or
brachia. These are two in number, one at each side of the mouth, and are
of extremely delicate constitution (Figs. 533, 534, and 531, A). The tissue
of which they are composed is essentially cartilaginous, and is traversed by
several circulatory canals as well as by a groove. The' outer edges of the
brachia are fringed with long and movable cirri or tentacles, by means of which
currents are set up that conduct small food particles to the mouth. The
arms are frequently supported by a slender calcareous framework called
364
MOLLUSCOIDEA
PHYLUM V
the brachial supports, or brachidia, described above. There are no special
respiratory organs, the blood being oxygenated in the inner surface of the
I, a mantle and in the spiral
Fig. 533.
Liothyrina vitrea
(Linnaeus). Recent.
Fleshy brachia simply
recurved.
: Fig. 534.1,
Magellania flavescens (Val.). Median vertical
section, slightly enlarged, d, Spiral brachia ; h,
Fringed brachial margin ; pr, Cardinal process ;
-, Alimentary canal ; v, Mouth ; ,f.s, Septum ; o,
Adductors ; c, c', Diductors (after Davidson).
arms, where it is
brought into close os-
motic relation with the
water.
Muscular system. —
By means of muscles
Brachiopods are en-
abled to open and close
their valves, and to a
limited extent can pro-
trude and retract the
pedicle. In the articu-
late forms (Protremata
and Telotremata) there are three sets of muscles — namely, the diductors,
which by contraction open the valves ; the adductors, which by contraction
close the valves ; and the pedicle muscles, or adjustors, which also by contrac-
tion withdraw the pedicle. The points of attachment of these muscles leave
more or less distinct impressions in the valves of both recent and fossil
Brachiopoda, and the subject is therefore worthy of careful examination.
The adductors, or closing muscles, are attached on either side of the median line
in the dorsal valve, and leave two elongate scars lying immediately to the right and
left of the median line, enclosed between the diductors (Fig. 535, L', ft). These
muscles e.xtend almost
directly from one vah'^e
to the other, and as each
muscular band is once
divided, their insertions
on the dorsal valve are
quadruple. Their im-
pressions on this valve are
known as the anterior and
posterior adductors (Fig.
535, A, B, a, a').
The principal diduc-
tors, or opening muscles,
originate on the ventral
valve at the anterior edge
of the visceral area, and
on either side of the
lnAr^i^n linp • tlip ^r-iTs; of ^^ooP- P''' Cardinal process ; x, Hinge-plate; z, Hinge-teeth ; a, «', Ini-
meaicUi niic , Lue ^uub ui pr^,ssions of adductors ; d, rf', Diductors ; p, p', Pedicle muscles.
these muscles being usually
the largest and deepest of any in the animal. They taper rapidly in crossing the
interior cavity, and their small extremities are attached to the anterior portion of
the cardinal process of the dorsal valve. There are also inserted on the cardinal
process, behind the principal diductors, two much smaller muscular bands, which
are called tlu; accessory diductors. Their attachment on the ventral valve is repre-
sented by two feelile scars in the posterior part of the muscular region, but these are
rarely observable in fossil specimens (Fig. 535, A, B, d).
Fig. 635.
MaiieUania flaresrcns (\'al.). Recent ; Australia (after Davidson).
Dorsal valve. B, Ventral valve. D, Deltidial plates. F, Foramen.
A,
S,
CLASS II
BRACHIOPODA
365
Wlien a functional pedicle is present, there are found, in addition to the valvular
muscles, two pairs (one to eacli valve), and a single unpaired muscle ; these are
attached to the pedicle, and are called the pedicle muscles (Fig. 535, B,p,p'). The pair
in the ventral valve originates immediately outside of and posterior to the adductors
and diductors ; the pair in the dorsal valve is attached behind the posterior adductors ;
and the unpaired muscle lies at the base of the pedicle in the ventral valve. Only
the latter unpaired band, as a rule, leaves a perceptible scar in fossil specimens.
The entire muscular system in the Protremata and Telotremata works with the
utmost precision. The cardinal process is received
between the teeth of the ventral valve in such a
manner as to allow the dorsal valve to swing freely
in the median vertical plane as on hinges, and at
the same time prevents motion in a lateral direc-
tion. The diductors, being attached to the cardinal
process, act upon a lever arm when they contract,
thus opening the valves, ^hile the contraction of
the adductors serves to close them (Fig. 534).
In the Atremata and Neotremata the miiscles
are arranged differently, and are often more compli-
cated and numerous, as articulation is almost never
j)resent in these orders. The gieatest comj^lexity is
attained in Lingula (Fig. 536), because these animals,
in addition to the absence of articulation, slide their
valves laterally. '
Ontogeny. — The development of Brachio-
pods from the egg to maturity may be divided
into two periods : (a) stages of development from
the egg to that condition in which the animal is ^"t^r'^Z.!'^nr^'^: il
recognisable as possessing some distinctive class interior of ventral vaUe showing mus-
» 1 /7\ P ,1 r. . 1 11 1 ''^'''"'' mipressions ; n, Adductors; c,
characters; and (6) from the nrst shelled con- Protractors; j), Retractors; o, Pedicle
dition, or protegulum, to maturity and old age.
Fig. 536.
muscle.
Our knowledge of the earliest embryonic conditions is restricted to Terebratulina,
Liothyrina, Argyrotheca and Thecidea. After fertilisfition the larvae may remain
attached, and j^ass their early stages within the parent ; or they may develop cilia
before segmentation, and be set free in the pallial chamber or in the sea-water. The
free larvae swim by the aid of cilia with a twirling motion. There are five well-
marked stages of develojiment before the
larvae can be definitely recognised as
Brachiojjods. These are : (1) The prot-
evibryo, which includes the ovum and its
segmented stages preceding the formation
of a blastula, or primary internal cavity
B
D
Fi<}. 537.
Argyrotheca neapoliiana (Schacchi). Recent.
A, Protembryo ; unsegmented ovum. B, Prot-
embryo ; ovum composed of two spheres. (.-',
llesembryo; blastosphere. D, MetemVjryo ; gast-
rula (after Sliipley, from Beecher).
Fig. 538.
Argyrotheca neapoliiana (Schacchi). A, Neo-
embryo; embryo of two segments. i>, Neoembryo ;
cephalula, ventral side, showing cephalic, thoracic
and caudal segments, eye-spots, and bundles of
setae. C, Neoembryo ; lateral view of completed
cephalula stage, showing extent of dorsal (d) and
ventral (v) mantle lobes, and umbrella - like
cephalic segment. (A and B after Kovalevski, C
after Shipley ; all reproduced from drawings by
Beecher.)
366
MOLLUSCOIDEA
PHYLUM V
(Fig. 537, A, B) ; (2) tlie mesemhryo, or blastospliere, a multi-segmented larva with an
internal cavity (Fig. 537, C); (3) the metcmhryo, or gastrula stage (Fig. 537, D); (4)
the neoembryo, or the ciliated Cephalula stage, which consists atj first of a cephalic lobe,
bearing eyes in Argyrotheca, and a caudal lobe, to which is added later a thoracic
segment carrying four bundles of setae, while at the same time the dorsal and ventral
sides of the latter segment become extended over the caudal lobe, and are progres-
sively defined as two lohes (Fig. 538) ; (5) the typemhryo, or larval stage, in which
the dorsal and ventral thoracic lobes, or mantle, fold over and enclose the cephalic
lobe (Fig. 539, B). Upon the mantle lobes, either
before or after turning, there is a corneous integument
which develops into the protegulum before the for-
mation of the true shell. The caudal segment be-
comes the pedicle, and may in this stage serve to
attach the larvae to foreign objects, or the pedicle
Fig. 539.
Arfiyrotheca neapolUana (Scbacchi). A, Neoembryo ; completed
cejihalula stage. B, Typembryo ; transformed larva resulting from
folding upwards of mantle lobes over cephalic segment ; ad, Muscles
from bundles of setae to sides of body cavity ; di, Muscles from dorsal
to ventral sides of body ; rp. Muscles from ventral side of body to
caudal segment or pedicle (after Kovalevski, from Beecher).
Fig. 540.
ArgyrnthecaneapoHtana(Schacchi).
A, Phylembryo ; Brachiopod show-
ing shell (protegulum), beginning of
tentacles of lophophore (1), obsoles-
cence of eye -spots, and formation
of oesophagus ; t, Hinge-teeth ; vp,
Ventral pedicle muscles. B, Nepio-
nic Brachiopod, showing distinct
tentacles of lophojjhore, mouth and
stomach, and transformation of
muscles from typembryo ; ad, Ad-
ductors ; di, Dlvarleators ; vp,
Ventral pedicle muscles (after
Ko\alevski, from Beecher).
may remain undeveloped for a time. A rudimentary digestive tract is present, and
also four pairs of muscles, which later become the adductor, diductor and ventral
pedicle muscles.
In the phylembryo, or sixth stage of development, the embryonic shell, ov protegulum,
is completed ; the tentacular lobes of
the lophophore, or brachia, api^ear ; the
four bundles of setae are dehisced ; ob-
solescence of the eyes occurs, as well as the
agreement of the muscular system with
that in adult forms (Fig. 540).
The protegulum has been observed by
Beecher in many genera, representing
Fio. 541.
Thecidea (iMcazella) mcditerranea (Risso).
Recent. . ^
A, Dorso-ventral longitudinal section of cephalula; nom.iir nil +!-.« l^n,lT„„ e ■^■'' c i.^y
7i, Head; d, Dorsal mantle lobe; ,-, Ventral mantl^ ""^^^^^ ^^^ ^^^ leading families of the
lobe ; rfs, Beginning of dorsal vahe ; del, Shell plate class, and therefore it may be inferred
forming on dorsal side of body ; p, Pedicle. B, Dorso- fi i. ii j. i • ti
ventral longitudinal section of typembryo ; vs, Ventral ^^^''^^ ''"^ protegUlUlll IS Common tO all
valve; /iZ, Hinge-line of dor.sal valve. C, Adult speci- Brachiopods. It is Semicircular or semi-
men seen from the dorsal side, showing ventral area and ,,. . 1 .
deltidium. (.4 and « after Kovalevski; C after Beecher.) eliiptical in outlmo, with a straight or
arcuate hinge-line, and no cardinal area.
The prototype preserving throughout its development the main features of the
CLASS II ■ BRACHIOPODA 36V
protegulum, and showing no sej^arate or distinct stages of growth, is represented Ijy
the genus Paterina (Fig. 543).
So far as observed, the protegnluni, or Paterina stage, in tlie Atreniala and
Telotremata is followed by the Obolella stage of nearly circular outline. After this
stage, specific characters appear, and in the open delthyrium of the Telotremata there
are usually developed the first rudiments of the deltidial plates. In the Protremata,
the Paterina stage is not followed by the Obolella stage, but the wide delthyrium of the
protegulum is at once aftected and modified, and develops into the deltidium. In the
Acrotretacea, belonging to the Neotremata, there is often developed a homccodeltidium,
resulting from secretion by the mantle, and therefore of difl^'erent origin from the triie
deltidium occurring in the Protremata, which is deposited by the pedicle. In the
Discinacea, belonging to the Neotremata, the pedicle opening is an open notch in the
posterior margin of the ventral valve. In derived forms this is progressively closed
posteriorly ; geologically in the phylum, and ontogenetically in the latest derived
genera and species.
Habitat and. Distribution. — Brachiopods are usually gregarious in
habit, often growing in clusters attached to one another. This is not only
true of Recent species, but of Paleozoic forms as well. Brachiopods are
found in all latitudes and at all depths, but are largely shallow-water animals,
for of the living species 71 per cent occur between the strand-line and 100
fathoms. Liothyrina wyvillii was dredged from the enormous depth of 2945
fathoms. Terebratulina caput-serpentis ranges from a few fathoms to a depth
of 1170 fathoms.
Brachiopods are most abundant in warmer seas, the Japanese province having
twenty-nine species. As a rule, those occurring in cold waters are not found
in warm waters. Lingulids and Discinids are almost restricted to the strand-
lines in warmer waters less than 60 feet deep. Of the thirty-three living
genera, at least 60 per cent have fossil representatives. Lingula and Crania
have lived since the Ordovician ; since the Jurassic, six genera have continued,
since the Miocene one, since the Pliocene seven, and since the Pleistocene three.
Of the 158 living species only 16 per cent occur fossil, and but five are as old
as the Eocene and Miocene. Three genera are confined to the deep sea, and
all of the abyssal forms are usually thin-shelled, brittle and translucent.
Migration of Brachiopods is possible only during the early larval stages,
and then to a very limited extent among the articulate forms. Morse observed
that Terebratulina became attached in a few days, but Midler kept Discinisca
in confinement nearly a month before any became sessile.
Colour. — The shells of most living species are of light or neutral tints,
white or horn-colour. A deep orange-red in radiating bands or in solid tints
colours some species {Terebratulina, Kraussina, etc.) ; light yellows, deep and
light shades of green {Lingula), black in bands (Crania), or masses (Iihynchonella)
embellish these shells. Even among the fossil species traces of faded colour-
marks are occasionally observed ; Deslongchamps has described them among
Jurassic species, Davidson among the "Carboniferous, and Kayser has found a
colour-marked PJiynchonella in the Devonian. The large highly ornamented
species of Paleozoic times, with their external sculpture heightened by a
brilliant colouring, must have been objects of exquisite beauty (Hall and
Clarke).
Classification. — The Brachiopoda, since 1858, have been divided by
nearly all systematists into two orders, based on the presence or absence of
368 MOLLUSCOIDEA ■ phylum v
articulating processes. These divisions, " Articules and Libres," were recog-
nised by Deshayes as early as 1835, l)ut not until twenty-three years later
were the names Lyopomata and Arthropomaia given them by Owen. These
terms have been generally adopted by writers, though some prefer Inarticulata
and Articalafa Huxley, or Bronn's Ecardines and Testicardines. Bronn (1862)
and King (1873), while retaining these divisions, considered the presence or
absence of an anal opening more important than articulating processes, and
accordingly proposed the terms Pleuropygia and Apygia, and Tretenterata and
Clistenterata respectively. In many Paleozoic rostrate genera of Clistenterata,
it has been shown that an anal opening was also present, and therefore the
absence or presence of this organ is not of ordinal value.
The first attempt to construct a classification of the Brachiopods was that
of Leopold von Buch, who took for his principal differential characters the
conformation of the umbonal region, the presence or absence of a pedicle, the
nature of the deltidium, and the external form and ornamentation of the shell.
While his classification does not reflect a perfect understanding of the features
in question, it is remai'kable that von Buch, nearly eighty years ago, and
Deslongchamps, twenty-eight years later, recognised some of the principles
upon which the classification of the Brachiopoda is now established, as, for
example, the nature of the pedicle opening.
Up to 1846 the general external characters of the Brachiopods served
the majority of authors as the essential basis for generic differentiation. In
that year, however. King pointed out that more fundamental and constant
characters exist in the interior of the shell, a fact which soon came to be
generally recognised, mainly through the voluminous and admirable contribu-
tions of Thomas Davidson.
AVaagen in 1883 found it "absolutely necessary" to divide Owen's two
orders into seven suborders. The basis for these suborders rests on no
underlying principle of general application, and yet five of these divisions are
of permanent value, for each contains an assemblage of characters not common
to the others.
No classification can be natural and permanent unless based on the history
of the class (chrono genesis) and the ontogeny of the individual. However, as
long as the structure of the early Paleozoic genera remained practically un-
known, and the ontogeny wholly uurevealed, nothing of a permanent nature
could be attempted. In the excellent volume by Hall and Clarke (Palaeontology
of New York, vol. viii., 1892-95), the great majority of the Paleozoic genera
are clearly defined. The ontogenetic study of the Paleozoic species was
initiated in 1891 by Beecher and Clarke, followed by Beecher, and more
recently by Schuchert ; and their results combined with those derived from
the study of the development of some living species, such as have been
published by Kovalevski, Morse, Shipley, Brooks, OEhlert, Beecher and
others, confirm the conclusion reached through chronogenesis. Moreover, the
application by Beecher of the law of morphogenesis, as defined by Hyatt,
and the recognition and establishment of certain primary characters have
resulted in the discovery of a fundamental structure of general application for
the classification of these organisms. It has for its foundation the nature of
the pedicle opening and the stages of shell development. On this basis
Beecher (1891) has divided the class into four orders: the Atremata, Neo-
tremata, Protremata and 2'elotremata.
CLASS II BRACHIOPODA 369
The nature of the pedicle opening being employed for oi'dinal divisions,
persistent internal characters of the shell are, as a rule, used for superfamily
purposes. Such are the presence or absence of a spondylium, brachial supports,
etc. Family divisions are based upon a combination of external and internal
generic characters, such as the outer form, nature and position of muscles,
internal plates, etc.
No division, however, has any value unless the group contains forms of
but one phylum, since a phylum or line of descent cannot originate twice.
However, it happens that the same or nearly the same combination of mature
characters is developed along different lines (homoeomorphy) ; and when this
occurs the ontogeny will show it. It is therefore not correct to group different
stocks under one and the same genus. For instance, the family Terebratellidae
probably divided during early Mesozoic times, one stock drifting into boreal
and another into austral regions. These two stocks agree structurally in the
earliest shelled condition and also at maturity ; but between these two stages
of development, the austral group (Magellaniinae) passes through a different
series of loop metamorphoses from the boreal one (Dallininae)..
It was by the application of the above-mentioned principles that Schuchert,
in 1893, arranged all the genera of Brachiopoda under the four orders
instituted by Beecher. Further attention has since been given to this subject
by the same writer, and the arrangement now oftered combines the brilliant
results obtained by Charles D. Walcott in his studies of the Cambrian forms
of all lands, and the important work of S. S. Buckman, relating to the
Brachiopods of Great Britain.
Order 1. ATREMATA Beecher.
This order includes primitive inarticulate, corneous or calcareophosphatic
Brachiopoda, with the pedicle usually emerging freely between the two valves.
Growth takes place mainly around the anterior and lateral margins.
Delthyrium or pedicle aperture originally unmodified, in later genera modified
by homoeodeltidia and pseudochilidia, or by thickened, striated and more or
less furrowed or even cleft vertical cardinal margins, the ventral cleft in most
specialised forms tending to enclose the pedicle and finally to restrict it to
the ventral valve ; when completely restricted the genera are referred to the
order Neotremata. Specialised forms tend to develop rudimentary articula-
tion or muscle platforms. The three other orders of Brachiopods have
arisen from the Atremata.
Superfamily 1. RUSTELLACEA Walcott.
Primitive, thich-shelled, corneous or calcareo-phosphatic Atremata, developing more
or less of homoeodeltidia and pseudochilidia. Muscle scars and vascular sinuses as a
rule not well defined in the shell. Out of this stock arose the Obolacea and Kutor-
ginacea. Cambrian and Ordovician.
Family 1. Rustellidae Walcott.
Primitive Eustellacea with the pedicle aperture of both valves small, more or less
open, and not much modified hy homoeodeltidia or pseudochilidia. Muscle scars and
vascular' sinuses not well defined in the shell. Lower Cambrian.
VOL. I 2 B
370
MOLLUSCOIDEA
PHYLUM V
Bustella Walcott (Fig. 542). The most primitive known Brachiopod.
Lower Cambrian ; Vermont,
Family 2. Paterinidae Schucliert.
Progressive Eustellacea with the j^edide aperture more or less closed hy
homoeodeltidia and ■pseiidochilidia. Cambrian.
Paterina Beecher (Fig. 543). Surface concentrically ornamented.
Pig. 542.
Rudella edsuni Walcott. Lower Cam-
brian ; Vermont. A, Ventral valve show-
ing pedicle furrow (/))• ^> Cardinal
view showing the open and immodified
pedicle opening, l/j (after Walcott).
Fig. 543.
PaterUm superha Walcott. Middle Cambrian ; Vermont.
A-C, Views of the ventral valve showing the large convex
homoeodeltidinm. D, Exterior of dorsal valve. 2/3 (after
Walcott).
Subgenera : Micromitra Meek; and Iphidella Walcott (Iphidea Billings 1872, non
Baly 1865). Shell in the former more or less ornamented by crenulated
concentric lines, while the latter has diagonally intersecting rows of pits.
Lower and Middle Cambrian ; North America.
Volhorthia von Moller. A globose form of Paterina, with well-developed
pseudodeltidia. Ordovician ; Esthonia.
Mickwitzia Schmidt. Very large round forms with more or less ornate
exteriors. Lower Cambrian ; Esthonia, Sweden, America. Causea Wiman
is regarded by Walcott as probably identical with Mickwitzia. Lower
Cambrian ; Sweden.
Superfamily 2. KUTORGINACEA Walcott and Schuchert.
Progressive, thick-shelled, almost calcareous atrematous-like shells, tending to he
transverse and developing rudimentary articulaiion, more or less rudimentary cardinal
areas, homoeodeltidia and muscle scars prophetic of the Protremata. Derived out of
Eustellacea. Cambrian,
F'amily 1. Schuchertinidae Walcott.
Primitive round Kuforginacea with small cardinal areas. Externally like Obolus,
with an open subtriangular delthyrium which apparently is without a homoeodeltidinm.
Muscle scars and vascular markings prophetic of the Billing sellidae of the Protremata.
Cambrian.
Schuchertina Walcott (Fig. 544). Middle Cambrian ; Montana.
Family 2. Kutorginidae Schuchert.
Progressive transverse Kutorginacea with rudimentary cardinal areas, great
CLASS II
BEACHIOPODA
371
delf hi/rial opening, rudimenfari/ articulation and immature homoeodeUidia. Muscle
scars prophetic of the Strophomenacea of the Protremata. Cambrian.
A , B
"1,
Fig. '544.
Schiichertina cuiuhria Walcott. Middle Cambrian ;
near Neihart, Montana. A, Interior of ventral valve.
B, Interior of dorsal valve (after Walcott).
J
Fig. r,i^,.
KxUorgina r.intjiilata Bill. Lower Cambrian ; Vermont.
.!, Interior of ventral valve. /.', Side view of conjoined
valves. C, Interior of dorsal valve ; h, Central scars ;
j, Anterior lateral scar ; s, Median septum (after Walcott).
Kutorgina Billings (Fig. 545). Lower Cambrian ; North America and
Sardinia.
Superfamily 3. OBOLACEA Schuchert.
Derived in Busfellacea. Progressive, thick-shelled, calcareo-jjhosphatic or corneous
Atremata 'without homoeodeUidia or pseudochilidia. Bounded or linguloid in outline,
more or less lens-shaped, and fixed by a short pedicle throughout life to extraneous
objects. Cambrian to Silurian.
Family 1. Ourticiidae Walcott and Scliucliert,
Primitive Obolacea with well-defined pedicle aperture common to both valves.
Interior characters much as in Obolidae. Middle Cambrian.
Curticia Walcott. Middle Cambrian ; Wisconsin and Minnesota.
Obolidae King.
Family 2.
Derived, progressive Obolacea with thickened, striated, verticcd cardinal areas
traversed by pedicle grooves. Muscles and vascular trunks strongly impressed in the
valves. Cambrian and Ordovician.
Subfamily A. Obolinab Dall.
Primitive Obolidae with the pedicle grooves more or less shallow or deeply rounded,
but never tending to form a sheath or to restrict the pedicle opening entirely to the
ventral valve. The most abundant Brachiopods of the Cambrian, vanishing
with the Ordovician.
Obolus Eichwald ( Ungula Pander ; Ungulites Bronn ; Embolus Mickwitz)
(Fig. 546). More or less rounded Obolids. Widely distributed in Europe
and America. The following subgenera are recognised by Walcott : Broeggeria
Walcott, Upper Cambrian, England; Mickwitzella Walcott (Thysanofus Mickwitz,
non Alt. 1860), Ordovician, Esthonia ; Acritis Volborth {Aidonotreta Kutorga
1848, errore 1847), Ordovician, Esthonisi ; Schmidtia Volborth, Ordovician,
Esthonia ; Palaeobolus Matthew, Cambrian, eastern Canada ; Fordinia Walcott,
Middle Cambrian, Utah ; Lingulobolus Matthew {Sphaerobolus Matthew),
Upper Cambrian, eastern Canada ; Westonia Walcott (has transverse parallel
ornamentation). Middle Cambrian, Wyoming, Utah and Idaho.
372
MOLLUSCOIDEA
PHYLUM V
Helmersenia Pander. Very small Obolids with a pustulose or spiny-
surface. Lower Ordovician ; Esthonia.
Lingulella Salter {Eooholus Matthew) (Fig. 547). More or less elongate
Obolids. Widely distributed throughout the world. The following are
subgenera: Leptemholoii Mickwitz, and Lingulepis
Hall (decidedly elongate Obolids). ""^^^ P
pS fr- -
Fici. 547.
Lingulella acutangulus (Roemer).
Upper Cambrian ; Texas. A, Interior of
ventral valve. B, Interior of dorsal
valve ; ;/, Umbonal scar ; /(, Central scar;
!, Transniedian lateral scar ; j, Anterior
lateral scars ; /, Outside lateral scars ; p,
Pedicle furrow ; ps, Parietal band ; pvs,
Vascular branches ; s, Median septum ;
X, Cordiform cavity ; z, Vascular
branches (after Walcott).
Fig. 546.
Obolus matinalis HelU. Middle Cambrian ; Minnesota. .4, Ex-
terior of ventral valve. B, Interior of same. (', Interior of
dorsal valve ; a, Filling of pedicle furrow ; r, Area of outside lateral
scai-s ; h, Central scars ; i, Transmedian lateral scars ; j, Anterior
lateral scars ; ps, Parietal band ; v, Area of visceral ca\'1ty ; vs,
Vascular sinus with outside and inside vascular branches (after
Walcott).
Delgadella Walcott. Has thickened internal margins. Lower Cambrian
of Portugal.
Leptobolus Hall. Very small Lingulellids of the Ordovician of North
America, in which the interiors are marked by two or three diverging,
slightly elevated septa, which occasionally are somewhat bifurcated terminally.
Paterula Barrande (C?/cZ»s Barrande, non de Koninck 1841). Closely related
to Leptobolus, but the inner margins of the valves are thickened. Ordovician ;
Bohemia and North America.
(?) Spondyloholus M'Coy. Generic characters not well known. Ordovician ;
Ireland.
Subfamily B. Neobolinae Walcott and Schuchert.
Progressive Oholidae with posterior platforms, to which were probably attached the
central, outside and middle lateral muscles. Seems to have arisen in thick-shelled
Middle Cambrian Oboliis, and is transitional to the platform-bearing Trimerellids.
Middle Cambrian.
Neobolus Waagen (Lakhmina OEhlert, and Davidsonella Waagen, non Mun.-
Chalmas 1880). Middle Cambrian of India.
^i B
Jf
Fic.
Elkania destdemta (Bill.). Upper
Cambrian; Quebec. /(, Interior of ven-
tral valve, j:, Interior of dorsal valve ;
h, Central scars ; i, Transmedian lateral
scars ; i, Anterior lateral scars ; v, Pos-
terior lateral scars ; p, Platform with
muscle scars ; x, Vascular areas in front
of platform (after Walcott).
Subfamily C. Elkaniinae Walcott and Schuchert.
Divergent Obolidae with posterior or marginal
platforms, to which were attached the central, outside
and middle lateral muscles. Not in line of develop-
ment to Trimerellids. Cambrian.
Elkania Ford (Billingsia Ford 1886, non de
Koninck 1876) (Fig. 548). Cambrian; North
America.
CLASS II
BRACHIOPODA
373
Siilafamily D. Biciinae Walcott and Schuchert.
Progressive OhoUdae with the pedicle restricted to the ventral valve and more or
less enclosed by a pedicle tube. Articulation rudimentary. Out of this stock have
arisen the Obolellidae of the Neotremata. Cambrian.
Bicia Walcott. Lower Cambrian of Quebec and New York.
Hall. Middle Cambrian of North America.
Dicellomus
Family 3. Trimerellidae Davidson and King.
Large, thick- shelled, inequivalved Obolacea, with the ventral cardinal area usually
very prominent, triangular and transversely striated. Adjustor and anterior adductor
muscles elevated upon solid or excavated platforms. Ordovician and Silurian.
Dinobolus Hall {Conradia Hall ; Obolellina Billings). Cardinal area not so
prominent as in the other genera of this family. Platform small, with abruptly-
conical vaults. Ordovician and Silurian ; North America, Great Britain,
Bohemia, Gotland and Esthonia.
Monomerella Billings. Similar to Trimerella, with well-developed platforms
in both valves ; that of the dorsal valve, however, but slightly excavated.
Silurian ; North America, Gotland and Livonia.
Trimerella Billings '{Gotlandia Dall) (Fig. 549). Platforms long, narrow,
Fig. 549.
Trimerella llndstroemi (Dall). Silurian ; Gotland, 1/2. A, Shell seen from the dorsal side. B, C, Interior
of dorsal and ventral valves respectively. D, Internal mould. (A and B after Davidson ; C and D after
Lindstrijm.)
well developed and doubly vaulted. Dorsal beak often thickened into a
prominent apophysis extending against the cardinal slope of the ventral valve.
Silurian ; North America, Gotland and Faroe.
Ehinobolus Hall. Silurian ; North America.
Superfamily 4. LINGULACEA Waagen.
Elongate, thin-shelled, corneous, burrowing Atremata, derived out of Obolinae,
with a more or less long, worm-like, tubular, flexible pedicle. Ordovician to Recent.
Family 1. Lingulidae Gray.
Attenuate, sub-quadrate or spatulate, almost equivalved Lingulacea, with a more
or less long, tubular, flexible pedicle. Muscles highly differentiated and consisting of
374
MOLLUSCOIDEA
PHYLtTM V
six pairs, two of adductors, and four of sliders or adjustors. Ordovician to
Recent. Maximum development in Ordovician, declining after Devonian time.
a
pair
of
Pseudolingula Mickwitz. Has a ventral pedicle groove and
umbonal muscles. Ordovician and Silurian ; Europe and America.
Lingula Bruguiere (P/iare^ra Bolton ; Lingularius Dumeril); {snhgen. Glossina
Phill.) (Figs. 550, 551). Shell thin, usually
compressed, glistening, generally smooth, or
with fine, concentric, more rarely with both
concentric and radial striae ; broad over the
pallial region, tapering more or less toward the
beaks. Ordovician to Recent. Maximum
development in Silurian and Devonian.
Glottidia Dall. Like the preceding, but
interior of ventral valve with two septal ridges
diverging from the beaks. Dorsal valve with
a single median ridge. Recent; American seas.
Dignomia Hall. Both valves with median
seplal ridges ; that of the
\'\ dorsal valve stronger, and
flanked by two submarginal
diverging ridges, which cor-
respond in position to grooves
in the ventral valve. Middle
Devonian ; North America.
BarroiseUa Hall and Clarke.
Lingulids with rudimentary articulation. Silurian and Devonian ; North
America ; (?) Bohemia.
Thomasina Hall and Clarke. Lingulids with the posterior margin of the
ventral valve notched, and with two conspicuous articulating processes.
Silurian ; France.
Lingulipora Girty.
Linijula anatina Brug. Recent. A, Shell
with pedicle. B, Interior of ventral valve.
Fi(i. 5.Jl.
Lingula lewisii Sow.
Silurian ; Gotland.
Lower Carboniferous ; North America.
Lingulids with a punctate shell. Devonian and
Family 2. Lingulasmatidae Wincliell and Scliuchert.
Platform-hearing Lingulacea derived through Lingulidae. Ordovician and
Silurian.
Lingtilops Hall. Small Lingulids with narrow, depressed, not excavated
platforms. Ordovician and Silurian ; North and South America.
Lingulasma Ulrich (Lingidelasma Miller). Large thick-shelled Lingulids
with very prominent, slightly excavated platforms. Ordovician ; North
America ; (1) England.
Order 2. NEOTREMATA Beecher.
Derived and specialised inarticulate Brachiopoda, probably developed
through Biciinae of the Atremata. Shells as a rule more corneous than
calcareous, more or less cone-shaped, with the pedicle emerging through a
perforation or sheath in the ventral valve, or through a triangular more or
CLASS II
BRACHIOPODA
37;
less open cleft during life, or only so in the youngest shelled stages, after
which the ventral valve may become cemented to foreign objects. Pedicle in
geologically younger forms often modified by a listrium. Homoeodeltidia and
pseudochilidia as a rule not well developed.
Superfamily 1. SIPHONOTRETACEA Walcott and Schuchert.
Primitive, fldck-shelled, calcareous or corneous, obolid-like Neotremata, with the
jyedicle passing through a ventral sheath, the aperture of which may remain apical
and circular in outline and posterior to the protegulum, or may become elongate
through resorption by passing anteriorly through the 'protegulum and umbo of the
shell. A listrium is not developed. Dorsal protegulum margined. Cambrian to
Silurian.
Family 1. Obolellidae Walcott and Schuchert.
Primitive Siphonotretacea with the pedicle emerging through a small circidar
perforation in the apex of the ventral valve posterior to the protegulum. Derived out
of atrematous Biciinae. Cambrian.
Obolella Billings (Fig. 552). Small, oval or round, thick shells resembling
Obolids but with a pedicle tube instead of an open furrow. Lower Cambrian
of North America and Sweden. The subgenus Glyptias Walcott, has trans-
verse parallel surface sculpturing. Lower Cambrian ; Sweden.
Pig. 502.
Obolella atlanilca Walcott. Lower
Cambrian; Canada. ,1, Ventral valve
showing vascular sinuses and filling of
pedicle foramen (p). B, Side view of
same. C, Dorsal interior showing the
striated cardinal area (k) and moulds of
the lateral scars ((') (after Walcott).
Fio. 553.
A-C, Siphonotreta verruoom Vern. Middle Ordovician ;
Bsthonia. D, S. unguindata Bichw., showing the internal
opening of the pedicle aperture (after Walcott).
Botsfordia Matthew (Mobergia Redlich). Like Obolella but with a highly
ornate papillose surface. Cambrian ; North America.
Schizopholis Waagen. Middle Cambrian of India. (?) Quebecia Walcott.
Lower Cambrian of eastern Canada.
Family 2. Siphonotretidae Kutorga.
Progressive Siphonotretacea with the circular or elongate pedicle opening at the
apex or passing by resorption anteriorly through the protegulum and umbo of the
shell. Cambrian.
Siphonotreta de Verneuil (Fig. 553). Large and elongate forms in which
the pedicle sheath is long and well developed, external aperture small and
circular. External surface with hollow spines, though rarely preserved ;
shell substance punctured by radiating and branching tubules. Ordovician
and Silurian ; Europe and (?) North America.
376 MOLLUSCOIDEA phylum v
ScMzamhon Walcott (Schizambonia (Ehlert). Small spiniferous Siphono-
tretids with much of the pedicle sheath open as a cleft on the outside.
Upper Cambrian and Ordovician ; America and Russia.
Trematoholus Matthew {ProtosijjJwn Matthew). With rudimentar}'- articu-
lation and lamellose exterior. Lower and Middle Cambrian ; California and
New Brunswick.
Yorkia Walcott. The oldest form of the family. Concentrically striated
exterior. Lower Cambrian of eastern North America. Dearhornia Walcott.
Middle Cambrian ; Montana.
KeyserUngia Pander. Thick-shelled form with decided muscular impres-
sions and median septa in both valves. Lower Ordovician ; Esthonia.
Superfamily 2. ACROTRETACEA Schuchert.
Progressive Neotremata with corneous or calcareo-corneous shells that are more or
less circular in outline and from highly conical to depressed in form. The pedicle
opening is a simple, circular, more or less consjncuous perforation through the apex
of the ventral valve, and is situated posterior to the protegulum. A listrium is not
developed. A false cardinal area is often present. Dorsal protegulum marginal,
Cambrian to Silurian.
Family 1. Acrotretidae Scliiichert.
Same characters as superfamily. The large and depressed forms are of the
sid)family Acrotheliiiae, tuhile the small forms tuith more or less high ventral valves
are of the Acrotretinae. Cambrian to Silurian.
Subfamily A. Acrothelinae Walcott and Sclincliert.
Acrothele Linnarsson (Fig. 554). Cambrian ; North America and Europe.
Subgenus : liedlichella Walcott.
"^V '^--Jvs B
S^ gl
Middle Cambrian ; Sweden.
/(' -I'll IHscinolepis Waagen. Middle
Cambrian : India.
}
'"■ ^^'*' Subfamily B. Acrotretinae
Acrothele (RedlicheUa) grannhita (Linnarsson). Middle Cam- -.j- . .-i
brian; Sweden. .1, Ventral valve witli its minute pedicle foramen. IViatuiew.
B, Dorsal exterior. (.', Acivthele imUtlwivl (Hartt), showing vas-
wiicott)""'' ^''^' ^''^'"'' ^^'"'''■'''" ' ^^""^ Brunswick (after J false Cardinal area often
present.
A B C D jL E Acrotreta Kutorga (Linnars-
fTl vs ^^^ ''f%s ^ ?«ni s^'^^'^ C. D. Walcott) (Fig. 555).
' ^ N^ ^ W ^ \ \ ' ^ Widely distributed throughout
Fig. 555. "~^ the Cambrian and rarely in
A-C, Acrotreta schnudcn.sii Walcott. Middle Cambrian ; the OrdoviciaU of Europe and
Sweden. A, Three views of the ventral exterior. li, Ventral at ^-V, A "
interior with vascular sinus (rs). C, Dorsal interior. D, E, JN Ortu America.
Acrotreta mhronica V.\\Un-'^a.. Ordovician; Esthonia. Cardinal /I pvnihin-n TV/To ffl-iot.r \T^-^
view and dorsal valve (after Walcott). ^ troiliyi a IViattne W. V eU-
tral valve often excessively
high and oblique or elongate in outline. Middle Cambrian ; New Brunswick.
Conotreta Walcott. Highly conical shells with the ventral interior marked
by a number of radiating ridges. Ordovician and Silurian ; North America.
CLASS II BEACHIOPODA 377
Linnarssonella Walcott. Middle Cambrian ; North America.
Discinopsis Matthew. Has marked ventral vascular sinuses. Middle
Cambrian ; New Brunswick.
(1) Mesotrefa Kutorga. Ventral valve spinose. Basal Ordovician ;
Esthonia.
Superfamily 3. DISCINACEA Waagen.
Sjiecialised Neotremata with phosphatic shells, a Ustrium modifying the pedicle
slit, and witltout piseiidodeltidia and false cardinal areas. Dorsal protegulum
usually subcentral. Ordovician to Recent.
Family 1. Trematidae Scliuchert.
Primitive Discinacea, in which the posterior margin of the ventral valve has a
triangular pedicle notch throughout life. A Ustrium is usually present. Ordovician
to Coal Measures.
Trematis Sharpe (Orhicella d'Orb. 1847, non Dana 1846). Ventral valve
unevenly convex, more or less depressed over the posterior region. Pedicle
fissure large, extending from the apex to the posterior margin. Dorsal valve
evenly convex, and sometimes with incurved beak ; posterior margin much
thickened, and broadly grooved for the passage of the pedicle. Surface of
both valves covered with punctures or small pittings arranged either in
quincunx or in radiating rows. Ordovician and (?) Silurian ; North America
and (?) Europe.
Eunoa Clarke. Very large, depressed, thin shells, with fine concentric
lines. Pedicle notch very large. Ordovician ; New York.
Schizocrania Hall and Whitfield. Ventral valve flat or concave, smaller
than the dorsal, and bearing a deep and very broad triangular pedicle notch,
which extends from just behind the beak to the posterior margin. Apex of
notch occupied by a triangular plate or listrium. Surface marked by
concentric growth lines ; no muscular impressions visible on the interior.
Dorsal valve more or less convex, with beak marginal. External surface
radially striated. On the interior, a low median ridge extends from the apex
to beyond the centre of the valve ; posterior adductor muscles strong ; the
anterior ones faint. Ordovician to Devonian ; North America.
Lingulodiscina Whitfield {Oehlertella Hall and Clarke). Much like Schizo-
crania, but the ventral valve has concentric growth lines, and no radiating
striae. Ventral pedicle area greatly elevated and transected by a narrow
open fissure. Devonian to Lower Carboniferous ; North America.
Schizoholus Ulrich. Devonian ; North America. (?) Monobolina Salter.
May be an Obolid.
Family 2. Discinidae Gray.
Derived Discinacea with an open pedicle notch, in early life, in the posterior
margin of the ventral valve, which is closed posteriorly during neanic growth, leaving
a more or less long, narrotv slit, partially closed by the listrium. Ordovician to
Recent.
Orbiculoidea d'Orbigny (Fig. 556). Shells inequivalved, sub-circular or
sub-elliptical in outline. Apices eccentric. Ventral valve deperssed, convex
378
MOLLUSCOIDEA
PHYLUM V
Fig. 556.
A, Orhiculoifka eircc Bill. Ordovician; Belle-
\'ille, Canada. Ventral valve, i/i (after Billings).
B, 0. nitida Pliill. Lower Carboniferous ; Mis-
souri. X, Dorsal; y, Ventral valve, Vi-
or flattened. Dorsal valve larger, usually depressed conical. Pedicle furrow
E originating behind the apex, extending
over a greater or lesser portion of the
radius of the valve, and produced at the
distal end into a short tubular sipho, emerg-
ing on the interior surface near the posterior
margin. Surface with fine, crowded or dis-
tant, rarely lamellose, concentric lines,
occasionally crossed by radiating lines.
Ordovician to Cretaceous; North and South
America, Europe, and probably elsewhere.
Discina Lamarck. Very much like
OrUculoidea, but the pedicle emerges through
the ventral valve antero- posteriorly, im-
mediately beneath the beak, instead of through a sipho postero-anteriorly as
in that genus. Recent.
Until recently Discina embraced all fossil Discinoid shells, but at present
this genus seems to be restricted to a single species,
D. striata, living off Cape Palmas, West Africa.
Discinisca Dall (Fig. 557). Like Orhiculoidea,
but with a small septum, as in Discina, behind
which is an impressed area, externally concave and
internally elevated. This is perforated by a longi-
tudinal fissure, extending from a short distance
behind the septum nearly to the posterior margin.
Tertiary to Recent ; North America and Europe.
Pelagodiscus Dall. Like Discinisca, but the brachia are without spirals.
Recent ; deep oceans.
ScJiizotreta Kutorga. Ordovician and Silurian ; Russia and North America.
Lindstroemella and Roemerella Hall and Clarke, are genera related to Orhi-
culoidea. Devonian ; North America.
Fig. 557.
Discinisca lamellosa (Brod.). Recent ;
Peru. A, Side-view. B, Interior of
ventral valve. C, Exterior of same.
Superfamily 4. CRANIACEA Waagen.
Specialised, cemented calcareous Neotremata without pedicle or anal openings at
maturity. Pedicle functional prohcddy only during nepionic growth. Ordovician
to Recent.
Family 1. Craniidae King.
Crania Retzius. Shell inequivalve, sub-circular in outline. The interior
of both valves shows two pairs of large adductor scars, the posterior
of which are widely separated and often strongly elevated on a central
callosity. Impressions of the pallial genital canals coarsely digitate. Ordo-
vician to Recent ; maximum development in Ordovician and Cretaceous.
Pseudometoptoma von Huene. Very large thick-shelled forms with high
dorsal valves. Ordovician ; Esthonia.
Philhedra Koken. Ordovician ; Europe and America.
Petrocrania Raymond {Craniella (Ehlert 1888, non Schmidt 1870). Large
Craniids with S-shaped vascular impressions. (?) Ordovician and Devonian ;
North America and Europe.
CLASS II
Eleiitherocrania von Huene
Ordovician ; Esthonia.
BRACHIOPODA 379
Biconvex Craniids related to Petrocrania.
Cranismis reUifns (Quenst.).
Upper Jura ; Oerlinger
Thai, Wurtemberg. Interior
of ventral valve, i/i (after
Quenstedt).
Fig. 559.
Ancistritcrania parhiensis (Defr.). Upper Cretaceon.s ; France.
A, Prolile of dor.sal valve. B, Interior of same. ( ', Interior of ven-
tral valve, i/j.
Craniscus Dall (Fig. 558). Ventral interior divided by septa into three
cavities. Jurassic ; Europe.
Ancistrocrania Dall (Fig. 559). Dorsal valve with two muscular fulcra.
Fig. 560.
Isocrania ignabergt'iisis (Retzius). Uppermost Cretaceous ; Ignaberga, Scania, yl, Profile and dorsal aspect
of shell, i/i- B, C, Interior of ventral valve. D, Interior of dorsal valve, enlarged.
Cretaceous ; Europe. Isocrania Jaekel (Fig. 560). Exterior plicate.
Cretaceous ; Europe.
Pholidops Hall {Craniops Hall). Biconvex and but slightly attached
Craniids. Ordovician to Carboniferous ; North America, England, Gotland.
Pseudocrania M'Coy (Palaeocrania Quenstedt). Eadially striated shells
much like Pholidops. Ordovician ; Europe.
Cardinocrania Waagen. Permian of India.
Order 3. PROTREMATA Beecher.
Specialised (through atrematous Kutorginacea), articulate, calcareous
Brachiopoda, with well-developed cardinal areas. Exterior surface nearly
always either plicate, striate or spinous, and but rarely smooth. Pedicle
aperture restricted to the ventral valve throughout life and more or less
closed by a deltidium ; in some forms the pedicle is functional only in early
life and later the animals cement the ventral valve to foreign bodies. Chilidium,
spondylium and cruralium often present. Brachia unsupported by a calcai'eous
skeleton other than short crura.
Superfamily 1. ORTHACEA Walcott and Schuchert.
Progressive Profremata. The older genera have immature spondylia that are
rarely freely suspended but are commonly cemented directly to the valves ( = pseudo-
spondyUa). In the great majority of the later genera all traces of spondylia are lost.
380 MOLLUSCOIDEA phylum v
In early forms the pedicle aperture is usually covered by deltidia and chilidia, but in most
later forms these plates are lost. Pedicle always functional and in the great majority
of forms emerges freely out of the delthyrium. Cardinal process more or less well
developed except in the most primitive genera. A prolific stock of Brachiopods.
Throughout Paleozoic.
^a"
Family 1. Billingsellidae Schuchert.
Primitive Orthacea with a more or less closed, or an open delthyrium. A
cardinal process arises in this family and is therefore either absent, rudimentary or
well developed. A spondylium is usxially developed ami to its uj)per surface are
attached the muscles of the ventral valve. Cruralia rudimentary. Shell structure
dense, gramdar, lamellar, rarely fibrous, apparently irregularly punctate in some
forms. Cambrian.
Subfamily A. Nisusiinae Walcott and Scliucliert.
Primitive Billing sellidae with more or less well -developed deltidia and with or
without rudimentary chilidia. Spondylia and cruralia rudimentary or small, not
supported by septa. Cardinal process generally absent, but rudimentary ivhen present.
Nisusia Walcott, and subgenus Jamesella Walcott. Distinctly jilicate
Billingsellidae without cardinal process. Deltidium well developed with an
apical pedicle foramen. The genus has a spiniferous exterior while the sub-
genus is devoid of spines. Lower and Middle Cambrian of America and
Europe.
Protorthis Hall and Clarke. Has a spondylium, but the deltidium is widely
open for the protrusion of the pedicle. Shell substance apparently punctate.
Middle and Upper Cambrian of America and Sweden. The subgenus Loperia
Walcott, differs in having the ventral umbo high and convex while the rest
of the shell is concave. Middle Cambrian ; Cape Breton, Nova Scotia.
Subfamily B. Billingsellinae Walcott and Schuchert.
Primitive Billingsellidae very much like the Nisusiinae, but without true spondylia
(i.e. pseudospondylia are often present) and cruralia. There is a more or less tvell-
developed simple cardinal process except in Lower Cambrian forms.
Billingsella Hall and Clarke (Fig. 561). Shells essentially orthoid, plicate,
biconvex or planoconvex, and prob-
ably punctate. Deltidia well de-
veloped, but chilidia only partially
so; the pedicle may emerge be-
tween these plates or pass apically
through the deltidium. Common
and widely distributed throughout
the Cambrian of America, Europe
BUlingsdhi coloradoeiuls (Sh\\xn9.vA). Middle Cambrian ; -i pii • .i j- , ■
Texas. A, Ventral exterior. B, Ventral interior. C, Dorsal ^^'^ Unilia ; tnc genUS QICS OUt 111
interior. cCnual bases; f^ Deltidium; j^ Carclinal pro- ^he LoWCr Ordoviciau. The Sub-
cess ; t, Teeth ; ■i'.«, Vascular sinuses (after Walcott).
genus Otusia Walcott, has small
eared forms without deltidia and with a well-developed cardinal process.
Upjier Cambrian ; North America.
Fiii. 561.
CLASS II
BRACHIOPODA
381
JFimanella Walcott. Like Billingsella but more primitive in that the
exterior is smooth. Lower Cambrian ; North America. IVynnia Walcott.
Middle Cambrian ; India.
Subfamily C. Eoorthinae Walcott.
Derived Billing sellidae in which the ddthyria are nearly always loidely open as
in Orthids ; deltidia and chilidia sometimes retained throughout life, but more often
only in the younger growth stages. Spondylia absent. Cardinal process well
developed. Differ from the Orthidae mainly in that the shell structure is dense,
granidar, and with irregularly punctate lamellae.
Eoorthis Walcott. Very much like Plectorthis, but the shell is thinner
and its structure not fibrous. Middle Cambrian and LoAver Ordovician, but
essentially of Upper Cambrian time ; North America, China, Argentina and
north Europe. Subgenus Orusia Walcott, typified by Orthis lenticularis
Wahlenberg. Upper Cambrian of north-western Europe and New Brunswick.
Subgenus Finkelnburgia Walcott, has thick shells with strongly -marked ventral
vascular trunks. Upper Cambrian ; North America.
Family 2. Orthidae Woodward.
Progressive, divergent and terminal Orthacea, derived out of the Eoorthinae,
nearly always with large open delthyria. Cardinal process well developed. Shell
structure fibrous, impunctate or punctate. Ventral muscle area small, obovate or
obcordate ; adductors extending to anterior margin of area. Ordovician to Permian.
Subfamily A. Orthinae Waagen (emend.).
Orthidae with the shell impunctate.
Orthis Dalman (s. str.) (Orthambonites Pander). Typified by 0. callactis
Dalman, or 0. tricenaria Conrad. Shells plano-convex ; costae strong, few,
generally sharp and but rarely bifurcating. Cardinal process a thin vertical
plate. There may be a flat apical deltidium. Plications often with large
oblique tubules penetrating the external layers. Ordovician and Silurian ;
Europe, North America, etc.
Plectorthis Hall and Clarke. Valves subequally convex. Ventral cardinal
area low. Plications strong, simple or duplicate. Ordovician and Silurian ;
North America and Europe.
The following are Ordo-
vician subgenera : A'ustin-
ella, Eridorthis, and Encu-
clodema Foerste (Cyclocoelia
Foerste, no7i Duj.).
Platystrophia King (Fig.
562). Contour spiriferoid ;
hinge-line long with dorsal
and ventral cardinal areas
Platystrophia lynx (Eichw.).
Fig. 562.
Ordovician ;
Cinciunati, Ohio.
equally developed. Strong, sharp plications with the exterior surface finely
granulose. Ordovician and Silurian ; Europe and America.
Hebertella Hall and Clarke. Shells with convexity of valves reversed.
382
MOLLUSCOIDEA
PHYLUM V
Exterior finely plicate, crossed by lamellose growth lines. Ventral muscular
area short, obcordate. Cardinal process well developed, often crenulate.
Ordovician ; America and Europe.
Orthostrophia Hall. Exterior like Hehertella. Muscular area of both
valves short, deeply excavate, with the vascular and ovarian markings
conspicuous. Silurian and Lower Devonian ; North America. Subgenus :
Schizoramma Foerste (Schizonema Foerste, noii Agardh.).
Silurian ; North America.
Subfamily B. Dalmanellinae, novum.
Orthidae with the shell oMmdantly punctate.
Dalmanella Hall and Clarke (Fig. 563). Widely
distributed in the Ordovician and Silurian, but persist-
ing to the end of the Devonian.
Thiemella Williams. Upper Devonian ; North America.
Fifi. 563.
DuhiMnella elegantula (Dalin.).
Silurian ; Gotland, i/i-
Family 3. Rhipidoraellidae, novum.
Progressive, divergent and terminal Orthacea with the external characters of the
Orthidae. Shell structure fibrous, impunctate or punctate. Ventral muscular area
large, bilobed or elliptical; adductors relatively small, and more or less comptletely
enclosed anteriorly by the fl,abellate diductors. Ordovician to Upper Carboniferous.
Subfamily A. Plaesiomiinae, novum.
Ilhipidomellidae with the shell impunctate.
Plaesiomys Hall and Clarke. Relative convexity of valves reversed.
Surface finely plicate and sometimes tubulose. Cardinal process thickened
and crenulate. Ventral muscular scars large and often bilobed. Ordovician ;
America and Europe. Subgenus : Dvnorthis Hall and Clarke. Surface strongly
plicate ; there may be a small deltidium. Ordovician ; North America.
Subgenus : Valcourea Raymond. Near Plaesiomys but strophomenoid in external
expression. Lower Ordovician ; North America.
Pionodema Foerste (Bathycoelia Foerste, non Am. Serv.). Biconvex Orthids,
finely striate, some of them tubulose. Resemble small Schizophoria but are
impunctate. Lower Ordovician ; North America.
Subfamily B. Rhipidomellinae, novum.
Pihipidomellidae with the shell abundantly punctate and finely striate.
Heterorthis Hall and Clarke. Contour strophomenoid with the
diductor scars very large. Ordovician ; North America -^
and Europe.
Ehipidomella ffihlert {PMpidomys tEhlert, non
Wagner). Biconvex, sub -circular shells with short
hinge-lines. Striae generally hollow and open on the
surface into (?) short tubular spines. Late Ordovician pj,. ^g^
into Pennsvlvanian ; widely distributed throughout the y./M^ite /,;?,.//».« (l
world. A', Interior of dorsal
ventral
inn.). Silu-
Sliell, i/i-
\-alve, -/j.
CLASS II
BEACHIOPODA
383
Bilohites Linn. (Dicoelosia King) (Fig. 564). Silurian and Lower Devonian ;
Europe and North America.
Schizophoria King (Fig. 565). Relative convexity of valves reversed.
Large, very finely striate, with the striae hollow and spinose. Cardinal
Frc. 5»j5.
A-C, Schizophoria strkUida (Schloth.). Devonian ; Gerolstein, Eifel. A, Dorsal aspect. B, Interior of
dorsal valve. C, Interior of ventral valve. D, S. rnlviirin (Schloth.). Spiriferensand.stein (Late Lower
Devonian); Xiederlahnstein, Nassau. Internal mould. (All tigures of the natural size.)
process in mature shells with accessory ridges making it multilobate. Dorsal
interior marked by 4 to 6 deep pallial sinuses. Silurian to Coal Measures ;
widely distributed throughout the world. Subgenus : Orthotkhia Hall and
Clarke. Like Schizophoria externally, but in the ventral valve the dental
lamellae and a median septum are highly developed. Coal Measures ; Brazil
and India.
Subfamily C.
Enteletinae Waageii.
Rhipidomellidae with decidedly convex valves and a few broad plications super-
added to the very fine radial striae. Developed out of Orthotichia.
Enteletes Fischer (Syntrielasma Meek and Worthen). Dorsal valve more
convex than ventral. Hinge-line short with a high ventral cardinal area. In
the ventral valve the dental lamellae are high and convergent, and between
them is a marked median septum ; the crural septa of the dorsal valve are
also well developed. Coal Measures and Permian ; North and South America,
Europe and Asia.
Enteletoides Stuckenberg. Upper Carboniferous ; Russia.
Superfamily 2. STROPHOMENACEA Schuchert.
Progressive, terminal Protremata, derived out of Orthacea (Billing sellidae), with-
out spondylia and cruralia. Deltidia and chilidia nearly always present throughout
life ; cardinal process always tvell developed. Pedicle nearly always small, emerging
through the apex of the valve, or lost when the shells cement to foreign objects or anchor
by means of ventral spines. A prolific stock of Brachiopods. Ordovician to Recent.
Family 1. Strophoraenidae King.
Primitive Strophomenacea with well -developed deltidia and chilidia. Shells
usually flat or concavo-convex and hut rarely biconvex. Pedicle usually functional
but tending to be thin and weak, and often lost when the shells cement to foreign
objects or are otherwise held to the substratum {tisually by spines). Ordovician to
Permian.
384
MOLLUSCOIDEA
PHYLUM V
Intermediate
Pledamhonites.
Subfamily A. Eafinesquininae Scliucliert.
Strophomenids that as a rule throughout life have the ventral valve convex and
the dorsal concave. The relative form of the valves is the reverse of that in the
Orthotctinae.
Eostrophomena Walcott. Primitive, small forms with the cardinal process
filling most of the dorsal delthyrium. Teeth inconspicuous, with the muscular
scars almost absent. Surface finely striate with alternating bundles of fine
lines between single coarser ones. Basal Ordovician ; Sweden and North
America.
Leptella Hall and Clarke. Primitive Plectamhonites. Upper Cambrian
and Lower Ordovician ; North America
and England.
Plectella Lamansky.
between Leptella and
Ordovician ; Esthonia.
(?) LamansJcija Moberg and Seger-
berg. Ordovician ; Sweden.
Plectamhonites Pander {Leptaena
Davidson and auct.) (Fig. 566). Ordo-
vician and Silurian ; North America
PlecUxmhonites transversalis (Dalm.). Silurian ; ■, -p,
Gotland. .4, Dorsal aspect, Vl- i?, Interior of dorsal aUCi liiUrOpe.
Divadcators':'' ^^""^'^^ ™^"'' '^'* ^^' ^'^'^""'"''^ = ^'' Leptacua Dalman {Leptagonia M'Coy)
(Fig. 567). Shells having the characters
of Rafinesquina, but the flatter portions of the valves with corrugations and
wrinkles. Where these cease, ^ ^ n '
the shells are more or less
abruptly and often rect-
angularly deflected. Ordovi-
cian to Lower Carboniferous,
Bafinesquina Hall and
Clarke (Fig. 568). Shells
normally concavo - convex
dorso-ventrally. Striae al-
ternating in size, and crossed
by finer concentric growth
A
Fig. 566.
Fig. 567.
Ltptaena rlwmhoidalif (yfa\i\enh.). Silurian; Gotland. J, B,
Dorsal aspect and prolile. C, Interior of dorsal valve.
Fig. 568.
i, Ilafiiiesqulnaalteni(tta{Com-aa). Ordovician; Cincinnati, Ohio. Vi- 11, E. exjiansa (Sov/eTby).
Interior of ventral valve, showing muscular and vascular Impressions.
CLASS 11 BRACHIOPODA 385
lines. Muscular area of ventral valve consisting of two broad flabellate
diductor scars enclosing an elongate adductor. In the dorsal valve, the
bilobed cardinal process is low ; the posterior arboi-escent adductor scars well
defined. Vascular and ovarian markings often well indicated. Ordovician
and basal Silurian ; North America and Europe.
Stropheodonta Hall. Shells very much like Eafinesquina, but with the
cardinal margins finely denticulate and the deltidium fiat or not discernible.
Silurian and Devonian ; North America and Europe.
Leptostrophia Hall and Clarke ; Douvillina Qilhlert ; and Brachyprion Shaler
are subgenera of Stropheodonta. Silurian and Devonian.
Pholidostrophia Hall and Clarke. Smooth or squamose, nacreous small
Stropheodontas. Devonian ; North America and Europe.
Strophonella Hall (Amphistrophia Hall and Clarke). Resupinate Stropheo-
dontas. Silurian and Devonian ; North America and Europe.
Gaspesia Clarke. Aberrant Strophomenid recalling coarsely plicate Orthids.
May, however, be a Pelecypod. Lower Devonian ; Gaspe, Canada.
Subfamily B. Tropidoleptinae Schuchert.
Aberrant Strophomenidae with two very long slender crura that unite vnth a high
vertical dorsal septum. The family is sometimes regarded as better placed among the
Terebratellids of the Terebratulacea.
Tropidoleptus Hall. Plano-convex, plicated shells with a long, straight and
narrow cardinal area. Teeth and dental sockets corrugated on their outer
surfaces. Devonian ; America, Europe and South Africa.
Subfamily C. Davidsoniinae King.
Small specialised Strophomenids, derived out of Bafinesquininae and devoid of a
pedicle, being cemented by the ventral valve to foreign objects.
Christiania Hall and Clarke. Differs from Leptaenisca in having prominent
longitudinal ridges instead of spiral markings on the dorsal interior. Ordo-
vician ; North America, England and Russia.
Leptaenisca Beecher. Ventrally cemented shells having
some of the characters of Plectambonites. Markings of
the fleshy arms are retained on the dorsal shell. Silurian
and Lower Devonian ; North America.
Davidsonia Bouchard (Fig. 569). Thick Leptaenisca-\ike ^^
shells, with spiral markings of the fleshy arms strongly ^ .'. \ , ,
impressed on both valves. Devonian ; England, Belgium iana cie Kon. Devonian ;
^ -p . ' o o gj^gj_ Ventral valve with
and JXUSSia. spiral markings, 2/j.
Subfamily D. Orthotetinab Waagen.
Strophomenids with the ventral valve convex during early growth, becoming sub-
sequently concave, or the reverse of the order in the Rafinesquininae. In the later
forms both valves tend to be convex.
(f) Orthidium Hall and Clarke. Basal Ordovician ; North America.
VOL. I 2 C
386
MOLLUSCOIDEA
PHYLUM V
Strophomena Blainville. Shells like Eafinesquina, but with the relative con-
vexity of valves reversed, and the ventral muscular area sharply limited by
an elevated margin. Ordovician ; America
and Europe.
Schuchertella Girty (Fig. 570). Much like
Strophomena. Shell plano-convex, concavo-
convex or biconvex. Surface covered with
radiating striae, which are convoluted by
sharp concentric lines. Cardinal area of
ventral valve prominently developed and not
attached by cementation ; dorsal area narrow.
Dental plates rudimentary. Cardinal process
united to crural plates, the whole forming
a vertical subcrescentic process. Muscular
impressions flabelliform. Silurian to Upper
Carboniferous ; North and . South America,
Europe and India.
Hipparionyx Vanuxem.. Like Schuchertella, but with the muscular areas
much larger and no dorsal cardinal area. Lower Devonian ; North America.
Schelhoienella Thomas (Orthothetes Waagen, non Orthotefes Fischer) (Fig. 571).
Fig. 570.
SchuchertelJa umbracuJum (Schloth.).
Devonian ; Gerolstein, Eifel. Natnral size.
Fig. 571.
SchellwieneUa crenif:tria (Pliill.). Lower Carboniferous; Wexford. A, Muscular portion of vential valve.
B, Interior of dorsal valve. A, A', Adductors ; K, Diductors ; j, Cardinal process ; d, Dental sockets (after
Davidson).
Near Schuchertella, but with short diverging dental plates and the cardinal area
either rudimentary or absent. Lower Carboniferous ; Europe.
Kayserella Hall and Clarke. Small Schuchertella-like shells, with a very
high dorsal median septum. Devonian ; Germany.
Orthotefes Fischer. Like Schuchertella, but in the ventral valve there is a
small triangular umbonal chamber formed by the uniting of the dental plates,
in front of which is a well-developed median septum. Ventral cardinal area
usually attached by cementation. Upper Carboniferous and Permian ; North
and South America, Europe, India and Russia.
Derbya Waagen. Like Orthotefes, but without the umbonal chamber.
Lower and Upper Carboniferous ; North and South America, Europe and
India.
Omhonia Caneva. Related to Orthotefes as Geyerella is to MeeJcella. Permian ;
Italy.
CLASS II BRACHIOPODA 387
ScaccJiinella Gemmellaro. Near to Derhya, but with excessively high
ventral cardinal areas. Ventral beak cemented ? Shells resemble EicMlio-
fenia, but have originated in some Orthotetinae and not in the Productinae,
Permian ; Sicily and Austria.
Arctitreta Whitfield. Imperfectly known, but seemingly a member of the
Orthotetinae. Upper Carboniferous ; Arctic America.
Streptorhynchus King. Very much like Schuchertella, Ventral area high,
short, twisted and probably cemented. Carboniferous and Permian ; America,
Europe and India.
Meekella White and St. John. Very biconvex shells, with the teeth of the
ventral valve supported by very long dental plates which are nearly parallel
and reach to the bottom of the umbonal cavity ; no median sej^tum. Surface
of valves with coarse costae and fine, radiating, often plumose striae. Upper
Carboniferous ; North America, Eussia, India and China. Subgenus : Ortlio-
thetina Schellwien. Like Meekella, but without costae. Late Upper Carboni-
ferous and Permian ; Europe.
Geyerella Schellwien. Near to Meekella, but with very high ventral areas ;
very long dental septa converging and uniting in a median septum. Ventral
beak cemented. Upper Carboniferous and Permian ; Europe.
S^ibfamily E. Tripleciinae, novum.
Biconvex Strophomenids with marked fold and sinus.
Triplecia Hall (Dicraniscus Hall). Trilobate, unequally biconvex, short-
hinged shells. Cardinal process long, erect and bifurcate. Surface smooth.
Ordovician and Silurian ; North America, England and Bohemia.
Cliftonia Foerste. Striated Triplecia. Ordovician and Silurian of America
and Europe.
Mimidus Barrande. Like Triplecia, but with the median fold on the
ventral valve. No external evidence of a deltidium. Silurian ; Bohemia and
North America.
Streptis Davidson. Like Triplecia, but biconvex and bilaterally unsym-
metrical. Exterior with lamellar concentric shell expansions, Silurian ;
Europe and North America.
Family 2. Thecidiidae Gray.
Cemented Strophomenacea, in which the interior of the shell is impressed with
variously indented brachial furrows. Carboniferous to Recent.
This family was formerly associated with the Terebratulidae. Beeclier has shown,
however, that brachial supports are wanting, and that a true deltidium is present.
Subfamily A. Leptodinae, novum.
Thecidiidae with the brachial markings common to both valves.
Keyserlingina Tscherny. An early form of Leptodus, with few brachial
ridges. Upper Carboniferous ; European Eussia and Austria.
Leptodus Kayser (Lyttonia Waagen ; JFaagenopora Noetling). Very large,
highly inequivalved, irregular shells, frequently with broad lateral expansions.
388
MOLLUSCOIDEA
PHYI UM V
Numerous, laterally directed, brachial ridges in the ventral valve, with corre-
sponding divergent grooves in
the median region of the dorsal
valve. Permian ; China and India.
Oldhamia Waagen (Fig. 572).
Differs from Leptodiis in that the
ventral valve is sub-hemispherical
i'^S^^Sm^^^:^ with the incurved apex covered
^^^f^^^^n by a callosity, as in BelleropJion.
Fio. 572.
Permian ; India and China.
Loczyella Freeh. Said to be
like Leptodiis, but without the
brachial ridges. May not be a
Oldhamia deoipiens Waagen. Productus Limestone ; Salt -r, t • i *"* tt n t •
Range, East India. A, B, Interior of ventral and dorsal brachiopod. Upper UarbOni
valves, respectively (after Waagen). j ^^^^^ . banking, China.
Subfamily B. Thecidiinae Dall.
Thecidiidae with the brachial markings restricted to the dorsal valves.
Thecidea Defrance (Thecidium Sowerby) (Fig. 573). Dorsal brachial im-
pressions with three pairs of symmetrical lobes, radially directed. Cretaceous.
Thecidea and the following genera of the subfamily Thecidiinae comprise for the
most part small, sometimes extremely minute forms, represented from the Trias to
the present day ; the climax of diversity occurred in the Cretaceous.
Lacazella Munier-Chalmas (Figs, 574, 575). Dorsal brachial impressions
Fig. 573.
Thecidea papiUata Scliloth. Upper
Cretaceous; Ciply, Belgium. J, £, In-
terior of ventral and dorsal valves, re-
spectively, 2/j (after Woodward).
Fir,. 574.
Lacazella vermiciilaris
(Schloth.). Upper Cretaceous ;
Maestriclit. Dorsal valve, 2/j
(after Suess).
Fig. 575.
Lacazella inediter-
■ranca (Risso). Re-
cent. Interior of
dorsal valve showing
braehia, % (after
Woodward).
with two or three unequal pairs of lobes, medially directed. Jurassic to
Recent ; Europe.
Thecidiopsis Munier-Chalmas (Fig. 576). The two large, dorsal, brachial
impressions each have four pairs of lobes
laterally and medially directed. Creta-
ceous ; Europe.
Thecidella Munier-Chalmas. Dorsal
brachial impressions simple, anteriorly
directed. Jurassic; Europe. ,„..,„,„^„ ^ ,.
F.'}idp<iplhi MnniPT- Chalmas Trans- on tiie Rlihie. yi', borsaf aspect. 7j, C, Interior
£juaeseua lVlUniei-l.^naimab. J-I^'/^ of ventral and dorsal valves, respectively, Vi-
verse shells in which the dorsal brachial
impressions have three pairs of simple lobes antero-laterally directed. Jurassic;
Europe.
Fig. 576.
Thecidiopsis digltata{Go\AL). Greensand ; Essen
CLASS II
BRACHIOPODA
389
Pterophloios Giimbel (Badrynium Emmrich) (Fig. 577). Dorsal brachial
impressions with about ten laterally directed lobations. Alpine Khaetic.
Davidsonella Munier-Chalmas. Elongate shells with
the long, narrow, dorsal, brachial impressions simple
and antero-laterally directed. Jurassic ; Europe.
(?) Cadomella Munier-Chalmas. Lias ; Europe.
Family 3. Productidae Gray.
Strophomejiacea with holloio anchoring spines.
Ordovician to Permian,
Fig. 577.
-P Pterophloios emmriohi Gum-
Late bel. Rhaetic; Kossen, Tyrol.
Interior of dorsal valve, i/i.
Subfamily A. Chonetinae Waagen.
Produdids with the few anchoring spines restricted to the ventral cardinal margin.
Chonetes Fischer (Fig. 578). Shell transversely elongate, semicircular in
outline, typically concavo-convex, sometimes plano-convex. Upper margin of
cardinal area in ventral valve bearing a single row of hollow spines ; these are
prolongations of tubes which penetrate obliquely the substance of the shell
along the hinge-line. Teeth strong. Cardinal process of dorsal valve divided
by a narrow median and two broader lateral grooves. Brachial impressions
more or less distinct. External surface usually covered with radiating striae,
rarely smooth or concentrically rugose. Late Ordovician to Permian. Sub-
genus : Eodevonaria Breger. Chonetids with denticulate hinge-lines. Lower
Devonian ; America and Europe.
Anoplia Hall and Clarke. Smooth or squamose shells like Chonetes, sup-
posed to be without cardinal spines. Lower Devonian ; North America.
Chonostrophia Hall and Clarke. Like Chonetes, but with the shell reversed
or concavo-convex. Lower and Middle Devonian ; North and South America.
Chonetella Waagen. Upper
Carboniferous ; Lidia. Chonetina
Krotow. Permian ; Russia.
(?) DaviesieUa "Waagen. Shell
productoid, but without spines
and well-developed cardinal area
and teeth. Upper Carboniferous :
England.
(?) Aulacorhynchus Dittmar {Iso-
gramma Meek and Worthen). Very
large, transverse, thin shells with a
ventral platform. Exterior surface
with numerous, regular, continuous,
concentric ridges. Upper Car-
boniferous ; Europe and North
America.
Pio. 578.
A, Chonetes striatellus (Dalm.). Silurian ; Gotland, i/j.
B, Interior of dorsal valve (after Davidson). C, C. sar-
cmulatus de Kon. Devonian ; Coblenz. i/x.
Subfamily B. Productinae Waagen.
Productids with the anchoring spines more or less abundant over the entire ventral
and sometimes also over the dorsal valve.
Produdella Hall. Shells small, productoid, with narrow cardinal areas in
390
MOLLUSCOIDEA
PHYLUM V
both valves. Ventral valve with small teeth ; dorsal valve with sockets and
crural plates. Brachial impressions distinct. Devonian ; America and Europe.
Produdus Sowerby (Pyxis Chemnitz ; Arlmsculites Murray ; Protonia Linck ;
Produda Sow.) (Figs. 579, 580). Shell without functional pedicle, anchored
-?t£a "V
Fu;. 579.
A,
Same
andE
., Productus semiretiuulatus (^Martm). Lower Carboniferous ; Vise, Belgium, i/,. B, P. 'j/igranieiw (Martin).
e horizon; England. Interior of dorsal valve (after Woodward). C, D, P. horridus Sow. Permian; Prus.sia
England, i/j. C, Interior of dorsal valve. Z), Internal mould of ventral valve. ^1, Adductors ; 7.', Diduetors ;
pr, Cardinal process; h, Hinge-line ; i^ Brachial impressions.
by the ventral spines ; concavo-convex, valves usually produced anteriorly ;
outlines semicircular, sometimes transversely elongate. External surface
spinose, usually with more or less prominent radiating
ribs, which are crossed by concentric lines or wrinkles ;
rarely smooth or finely striated. Cardinal areas, teeth,
sockets and crural plates absent or rudimentary.
Ventral valve convex, sometimes geniculated ; often
Fio. 580. with median sinus. Muscular impressions consisting of
Produrtmhorridus Sowerby. two deudritic adductors and a pair of broadly flabel-
Permian ; Gera, Germany. Va- i . ,., r^ t ^ i
late, striate diductors. Cardinal process strong, curved
or erect, extending far above the hinge-line. Brachial ridges well defined ;
traces of spiral or brachial cavities occasionally present in the pallial region.
Extraordinarily abundant in Carboniferous and Permian. Distribution
general.
P. (jiganteus is the largest Brachiopod known, sometimes attaining a width of nearly
one foot.
Subgenera : Diajjhragmus Girty. Produdus with an internal plate in dorsal valve.
Upper Carboniferous ; North America. ATarginifcra Waagen. Has thickened internal
subniargiual ridges. Upper Carboniferous ; Nortli America, India.
Tschernyschewia Stoyanow. Typified by Produdus humholdti d'Orb. Upper
Carboniferous ; India, Russia.
CLASS II
BRACHIOPODA
391
Froboscidella CEhlert. Valves very unequal ; dorsal valve small, concave,
operculiform ; ventral valve larger, convex, furnished with two lateral expan-
sions which bend downward to meet the margins of the dorsal valve, and an
anterior expansion, which is produced forward into one, or occasionally two,
long cylindrical tubes. Carboniferous ; Europe and North America.
Pig. 581.
Sfrophalosia goldfussi (Miinst.). Permian ; Gera, Germany. A,
Dorsal aspect. P>, Profile. C, Interior of dorsal valve with brachial
impressions. Natural size.
Subfamily C. Strophalosiinae, novum.
Prodxbdids anchored to foreign objects by the spines or by most of the ventral shell.
Chonopectxis Hall and Clarke. Chonetes-\\\iQ shells, but cemented ventrally
to extraneous objects. External surface reticulated by a double, oblique
series of concentric lines and fine radiating striae. Lower Carboniferous ;
North America.
Sfrophalosia King (Orthothrix Geinitz ; Leptaenalosia King) (Fig. 581).
Shell productoid in general 4 b c
form, cemented by the ven- ,^4^^^ ('~"v
tral umbo. Both valves .v<^&J"'~iz-a.. I \
with well-defined area, del-
tidium and chilidium. Ven-
tral valve with two pro-
minent teeth unsupported
by dental plates. Miiscular
impressions small ; brachial
ridges distinct. Surface of
ventral valve covered with
spines ; that of the dorsal
valve either spinous, lamellose or smooth. Middle Devonian to Permian ;
Europe, India, North and South America.
Aulosteges Helmersen. Much like Sfrophalosia, but not cemented by the
ventral umbo ; deltidium covered with small spinules and the surface of both
valves thickly set with spines. Permian ; Russia and India.
Etheridgina CEhlert. Shell very small, nearly as broad as long, and
attached to foreign bodies, notably crinoid stems, by the spines of the ventral
valve. Dorsal valve with a small beak ; surface ornamented
by concentric fiexuous plications bearing a few scattered
spines. Carboniferous; Scotland.
Family 4 Richthofeniidae Waagen.
Strophomenacea developed out of the Froductidae, and
remarkably modified by ventral cementation. The form is that
of cyathophylloid corals with an operculiform dorsal valve.
Shell strihcture cysfose. Upper Carboniferous and Permian.
Tegnlifera Schellwien. A youthful expression of the
highly modified Eichthofenia, in which the productoid
characters are still recognisable. Upper Carboniferous ;
Austria.
Fiichthofenia Kayser (Fig. 582). These most remarkably
Pig. 582.
Richthofenia lawrenci-
ana Waagen. Permo-Car-
boniferoiis ; Salt Range.
Vertical section of ven-
tral valve (after Waagen).
392
MOLLUSCOIDEA
PHYLUM V
modified Brachiopods are found in the Permian of China, India, Sicily and
Texas.
Gemmellaroia Cossman (Megarhynchus Gem., non Lap.). Permian ; Sicily.
Superfamily 3. PENTAMERACEA Schuchert.
Specialised Protremata developed out of Nisusiinae among the Orthacea, with well-
developed, supported or free spondylia, and, as a ride, cruralia. Deltidia and chilidia
present in the more primitive forms and generally absent in the last developed families.
The least prolific stock of the Protremata. Cambrian to Permian.
Family 1. Syntrophiidae Schucliei-t.
Primitive transverse Pentamerids, derived out of Nisusiinae, having as a rule long,
straight cardinal areas that usually are devoid of deltidia and chilidia. Spondylia
and cruralia free or supported by septa. Cambrian and Ordovician.
(?) Swantonia Walcott (Fig. 583). Kostrate, plicate, small and rare shells,
with a free but small spondylium. Lower Cam-
brian ; North America.
/' '
'a B
Fig. .583.
Swimtonia anthjuaUt (Bill.).
Lower Cambrian ; Vermont. A,
Ventral exterior. D, Side view
of same showiDi; .spondylium
(after Walcott).
Fig. 584.
Si/iitropliia laUiaUs (Whitfield). Ordovician ; Fort Cassin,
Vermont. A,.(', D, E, View.s of ventral valve showing cardinal
area and siiondylinm. ]!, Dorsal valve. F, Cardinal view of
both valves ground away to show section of spondylium and
cruralium (after Hall and Clarke).
Syntrophia Hall and Clarke (Fig. 584). Transverse, straight-hinged,
primitive Pentamerids with open delthyria in both valves. Spondylia well
developed and supported by an incipient septum ; cruralia small and supported
by a septum. Middle Cambrian to Lower Ordovician ; North America.
Subgenus : Huenella Walcott. Has a plicate surface. Middle and Upper
Cambrian ; North America, China and Australia.
Clarkella Walcott. Like Syntrophia, but the spond3dium is supported by
three septa. Lower Ordovician ; Montana.
Family 2. Clitambonitidae Winchell and Schuchert.
Divergent transverse Pentamerids, derived oid of Syntrophiidae, with well-developed
cardinal areas, deltidia, chilidia and spondylia. Cruralia not developed. Essenti-
ajly Ordovician but range sparingly into Devonian.
Clitambonites Pander (Orthisina d'Orb. ; Pronites and Gonambonites Pander)
(Fig. 585). Valves convex or sub-pyramidal. Hinge-line straight, forming
CLASS II
BRACHIOPODA
393
Fir;. 585.
A, Clitanibonites adscendens (Pand.). Ordovician ; Pawlowsk, near St. Peters-
burg, i/i. B, C, C. Kquamafus (Pahlen). Ordovician ; Kuckers, Esthonia. B,
Interior of dorsal valve, showing edge of the chiiidinm. C, Interior of ventral
valve, showing spondylium, septum and deltidinm (after Pahlen).
the greatest diameter of the shell. Cardinal area of the ventral valve high ;
delthyrium broad, and covered by a perforate deltidium ; that of the dorsal
valve covered by a
chiiidinm. Dental
lamellae of ventral
valve very strongly
developed, nniting
to form a concave
spatulate plate or
spondylium. This
plate serves for the
attachment of
muscles, and is sup-
ported by a median
septum extending
for about one-half the length of the valve. External surface radially striated
and often lamellose. Shell substance impunctate. Ordovician ; North Europe
and North America.
Subgenus : Remipronites Pander. Biconvex Orthid-like forms with fine non-lamellose
striae. Ordovician ; Esthonia.
Pohjtoechia Hall and Clarke. Like Clitambonites but with the spondylia
supported by three septa, thus dividing the umbonal cavity of the ventral
valve into five chambers. Ordovician ; North America.
Scenidium Hall {Mystrophora Kayser). Small orthisinoid shells with the
delthyrium partially closed by a concave imperforate deltidium. Cardinal
process extending as a median septum throughout the length of the shell.
The septum is sometimes greatly elevated anteriorly in Devonian species.
Ordovician to Devonian ; North America, Europe and the Urals.
Family 3. Porambonitidae Davidson.
Derived {out of Syntrophiidae), progressive, semi-rostrate Pentamerids, with the
deltidia and chilidia vanishing more and more in time. Spondylia and cruralia
present, but the former tends to thicken and unite with the ventral valve. Ordovician
to Lower Devonian.
Subfamily A. Porambonitinae Gill.
Non-plicated Porambonitidae, with the shells externally pitted. Ordovician.
Porambonites Pander {Isorhynchus King) (Fig. 586). Shells similar
to
Fig. 58t;.
PmcMnbonites aequirostris {%<i'i\\ot\i.). Ordovician (Vaginatenkalk) ; St. Petersburg. A-C, Anterior, lateral
and posterior aspects of shell, Vi- -D. Punctate surface, magnified. E, F, Interior of ventral and dorsal valves,
respectively.
Parastrophia in form, but without plications, and with obtusely triangular
394
MOLLUSCOIDEA
PHYLUM V
areas in both valves. Shells thick, variously pitted externally. Ordovician ;
Russia.
Noeilingia Hall and Clarke. Exterior like Porambonites, but with long,
straight hinge-line, prominent cardinal areas, and perforate beaks. Ordovician;
Russia.
Subfamily B. Parastrophiinae, novum.
Plicated Porambonitidae. Ordovician to Lower Devonian.
Camarella Billings. Small, smooth shells with a few low plications and
without cardinal areas. Dorsal valve at maturity most convex. Spondylium
well defined. Cruralium very small, supported by a long septum. Ordovician ;
North America and (?) England.
Parastrophia Hall and Clarke. Much like Camarella, but with a moderately
long, straight cardinal line, and no cardinal area. Dorsal umbo conspicuous,
projecting beyond that of the ventral valve. Ordovician and Silurian ; North
America and England.
Anastrophia Hall (Brachymerus Shaler, noii Dej.). Much like Parastrophia,
but with the dorsal umbo more prominent and the valves with numerous
sharp plications extending to the beaks. Silurian and Lower Devonian;
North America, England and Gotland.
(?) Lycophoria Lahusen. Russia and Scandinavia.
Family 4. Pentameridae M'Coy.
Terminal, usually rostrate Pentamerids, developed out of Porambonitidae.
Spondylia and cruralia well developed. Sometimes there is a concave plate in the
ventral delthyrium that is interpreted as the 'deltidium ; if so, it is a special develop-
ment due to the highly incurved beaks of both valves in the decidedly convex species.
Silurian to Permian.
Conchidium Linn. (Gypidia Dalman ; Antirhynchonella Quenstedt ; Zdimir
Barrande) (Figs. 587 ; 588, D). Shell strongly inequivalve, biconvex, with
Fig. 587.
Conchidium hiloculare, Linn. Silurian ; Gotland. A, Shell of the natural size. B, Beak showing concave
deltidium. (', D, Interior of dorsal and ventral valves, respectively, x, Spondylium ; .S, Median septum of
ventral valve, Fig. 7) ; h, Dental lamellae ; c, Crura ; ,S', Septum-like supports, Fig. C.
highly arched ventral valve. Surface numerously plicated. Spondylium narrow
and deep, and supported by a high vertical septum of variable length. A
small cardinal process present. Silurian and Devonian ; distribution general.
CLASS II
BRACHIOPODA
395
StricMandinia Billings. Similar to Conchidiuni, but with a straight hinge-
line and no prominent arched ventral beak. Spondylium small and short,
supported by a short median septum. Silurian ; North America, England
and Gotland.
Pentamerus Sowerby (Pentastke Blainville). Like Conchidium, but with
smooth shells, or sometimes with a few broad and obscure radiating undula-
tions. Silurian ; distribution probably general.
Orthotropia Hall and Clarke. Similar to small Pentamerus, but with a
short hinge-line. Differs also internally. Silurian ; Wisconsin.
Holorhynchus Kiar. Transverse Pentamerus, with incipient plications.
Spondylium not supported by septum. Silurian ; Norway.
Cajjellinia Hall and Clarke. Like Pentamerus, but with the relative con-
vexity of the valves reversed. Silurian ; North America.
Clorinda Barrande (Barrandella Hall and Clarke). Small Gypidula-like
Pentamerids usually with smooth shells, rarely plicate. Spondylium with-
out a supporting septum. Silurian ; North America and Europe.
Pentamerella Hall. Much like Clorinda, but with strong plications and a
narrow cardinal area. Devonian ; North America.
Sieberella CEhlert ; and Gypidula Hall. (Fig. 588.) Galeatiform Penta-
D
. -' Fig. 5SS.
A-C, Gypidula galmta (Dalm.). Devonian ; Gerolstein, Eifel. A, Dorsal aspect, Vj. B, Anterior aspect.
C, Transverse section below the hinge-line. (Lettering the same as in Fig. 587, f, D.) D, Conchidium Jcniglitii
(Sow.). Silurian ; England, i/.i.
mei'ids,with the median sinus on the dorsal, and the fold on the ventral valve.
In Sieberella there is no cardinal area, but in typical Gypidula there is a well-
defined, cross -striated, cardinal area.
Surface smooth or plicate. Silurian and
Devonian; North America and Europe.
Branconia Gagel. Like Gypidida,
but with sharp and few plications, as
in Pugnax of the Rhynchonellids. Sil-
urian ; Glacial drift of Germany.
Semimda M'Coy {non auct.). Ac-
cording to Buckman the genotype is
Terebratula penfaedra Phillips. Shells
rhynchonelliform with the surface
more or less strongly plicated. Spon-
FiG. 589.
Camarophoria schlotheimi (v. Buch.). Permian ; Gera,
ermany. .4, Shell, Vi- £, Internal mould, f. Interior
dvlium supported by a long median of shell, enlarged, pr, Cardinal process ; c, Crura ;
•' . -p.^^ . , V) ■ T? „^^^ X, Spondylium; g, Dental plates of dorsal valve;
septum. Devonian to Permian ; Europe, ,; ^.^ 'kedian septa.
India and North America. Subgenus
Camarophoria King (Fig. 589) may, according to Buckman, be used for the
more transverse, fully plicate shells.
396 MOLLUSCOIDEA phylum v
Camarophorella Hall and Clarke. Biconvex, sub-circular CamaropJioriae,
but without sinus, fold and plications. Lower Carboniferous ; North America.
Strophomenacea of unknown relationships.
Family 1. Eichwaldiidae Schuchert.
Primitive or aberrant, rostrate Strophomenacea, with narrow lateral grooves and
ridges for articulation. Delthyrium closed hy a concave plate {? deltidiiim). Pedicle
emerging through the ventral umbone and moving with grotvth anteriorly hy resorption
through the shell, as in Siphonotretidae. Ordovician and Silurian.
Eichwaldia Billings. The single species of this genus has a smooth
exterior. Ordovician ; North America.
Dictyonella Hall {Eichwaldia auct.). Exterior surface of valves pitted in
quincunx, resembling Trematis. Silurian ; North America, England, Bohemia
and Gotland.
Order 4. TELOTREMATA Beecher.
Specialised (through Atremata, 1 Obolacea), articulate, calcareous Brachio-
poda, with the pedicle opening shared by both valves in earliest shelled
stages, usually confined to one valve in later stages, and becoming more or less
modified by deltidial plates in advanced growth stages. Brachia supported by
calcareous crura, loops or spiralia.
Superfamily 1. RHYNCHONELLACEA Schuchert.
Rostrate, primitive Telotremata, with or without crura for the support of the
hrachidia. Pedicle foramen nearly always beneath the leak and but rarely through
a truncate ventral apex. Shells almost always impunctate. Ordovician to Eecent.
Family 1. Protorhynchidae Scluieheit.
Primitive Ilhynchonellacea without deltidial plates or crura. Ordovician.
Protorhyncha Hall and Clarke. Biconvex Phynchonellac with the fold
and sinus ill-defined. No cardinal process or dorsal median septum. Surface
with low radial j)lications. Ordovician ; North America.
Family 2. Rhynchonellidae Gray.
Bhynchonellacea with crura of greater or lesser length. Shells usually plicate,
rarely smooth or spinose. Ordovician to Recent.
Sul)family A. Rhynchotreminae, novum.
RhynchoneUids with a cardinal process. Ordovician to Devonian.
Orthorhynchula Hall and Clarke. Ehynchonellae with short, straight hinge-
line and cardinal areas in both valves, bisected mesially by open delthyria.
Teeth unsupported by dental lamellae. A linear cardinal process present.
Ordovician ; North America.
Rhynchotrema Hall (Stenochisma Comad, 1839; and Hall, 1867) (Fig. 590).
CLASS II
BRACHIOPODA
397
Thick-shelled, often gibbous Rhijnchonellae with prominent, thick, concave
deltidial plates. Dorsal valve with a'thick median septum, upon which rests
B
Fio. 500.
Rhynclwtrctna capax (Conrad). Ordovician ; Wisconsin. A, Interioi' of ventral \'alve sliowing concave
deltidial plates {(!p) and teeth (0. B, Dorsal view. C, Dorsal interior showing cardinal process (j), crural
processes (c) and dorsal sockets (Ji). (After Hall and Clarke.)
a linear cardinal process. Crural plates very broad and stout. Ordovician ;
North America.
StegerhyncJms Foerste, Exterior as in Camarotoechia, but with a thin
vertical cardinal process as in Rhynchotrema. Silurian ; North America and
Europe.
Ehynchotreta Hall. Trihedral Bhynchonellae with the ventral beak acu-
minate, produced and truncate. Pedicle foramen apical, the delthyrium
being completely closed by the deltidial plates. Dental lamellae and car-
dinal process present. The prominent dorsal median septum separates
posteriorly, each branch supporting one process of the divided hinge-plate.
Silurian ; North America and Europe.
Eatonia Hall. Bhynchonellae with large, flabellate, deeply excavated
muscular scars in the ventral valve. No dental lamellae. Cardinal process
large, resting upon a short median septum, and bifurcate at its summit.
Devonian ; North America.
Uncinulus Bayle. Like JFilsonia, but with the hinge-plate undivided, and
with a well-developed cardinal process. Devonian ; North America and
Europe.
(?) Cydorhina Hall and Clarke. May be of the Athyridae rather than of
the Rhynchonellidae. Devonian ; North America.
Subfamily B. Rhynchonellinae Gill.
Rhynchonellids without a cardinal process. Silurian to Recent.
Camarotoechia Hall and Clarke (Fig. 591). Sharply plicate Bhynchonellae
A
with the dorsal median
septum bearing pos
a short crural
Cardinal process
dental lamellae
Silurian to
Carboniferous ;
America and
teriorly
cavity.
absent ;
present.
Lower
North
Europe.
Plethorhyncha Hall
and Clarke. Large, ponderous Bhynchonellae, with almost no dental lamellae
and no crural cavity. Lower Devonian ; North America and Europe.
Pio. 591.
Camarotoechia congregata (Conrad). Devonian; New York. A, Dorsal
aspect. B, C, Dorsal interiors showing hinge-plate (hp), rostral chamber
(d), crural processes and dental sockets (h). (After Hall and Clarke.)
398 MOLLUSCOIDEA phylum v
Rhynchotetra Weller, Elongate, coarsely plicate shells nearest to
Camarotoechia. Dental lamellae uniting into a spondylium, which is supported
by a median septum. Lower Carboniferous ; North America.
Tetracamera Weller. Like Camarotoechia, but with rostral dorsal cavity
divided into four chambers by the crural plates and a median septum. A
spondylium present, but practically without septal support. Lower
Carboniferous ; North America.
Paraphorhynchus Weller, Coarsely plicate Ehynchonellae with fine
additional striae. Interior much as in Camarotoechia. Lower Carboniferous ;
North America.
Leiorhynchus Hall. Internally like Camarotoechia, but with the plications
on the lateral slopes usually faint or obsolete. Devonian to Carboniferous.
Subgenus : Moorefieldella Girty. Differs in having a finely plicate surface.
Lower Carboniferous ; North America.
Wilsonia Kayser (Uncinulina Bayle). Sub-cuboidal or sub-pentahedral
Bhynchonellae with the low plications marked anteriorly by fine median lines.
Internally as in Camarotoechia. Silurian to Lower Carboniferous. North
America and Europe.
Hemiplethorhynchus von Peetz. Very similar to Camarotoechia. Crural
cavity with a posterior triangular opening. Upper Carboniferous ; Altai,
Russia.
Hypothyridina Buckman (Hypothyr^ King, non Hubner 1822). Sub-
cuboidal Bhynchonellae with a very rudimentary dorsal median septum.
Plications as in Wilsonia. Vascular sinus frequently strongly impressed in
the ventral valve. Devonian ; North America and Europe.
Pugnax Hall and Clarke. Bhynchonellae with a deep dorsal and shallow
ventral valve, and very prominent fold and sinus. Dental lamellae short ;
no median septa. Devonian to Carboniferous ; North America and Europe.
Subgenus : Allorhynchus Weller. Has decided angular plications as in
Camarotoechia. Lower Carboniferous ; North America.
Pugnoides Weller. Exterior like Pugnax, with the internal characters of
Camarotoechia. Lower Carboniferous ; North America.
Shumardella Weller. Much like Pugnax, but with a short dorsal median
septum that is not connected with the hinge-plate. Lower Carboniferous ;
North America.
Bhynchopora King (Bhynchoporina QEhlert). Plicate Bhynchonellae with
the shell substance punctate. A crural cavity as in Camarotoechia, but roofed
over by the hinge- plate. Dental lamellae well developed. Range from
Lower Carboniferous to Permian ; Europe and North America.
(?) Torynifer Hall and Clarke. May be Bhynchonellae with the crural plates
united into a hinge-plate. Genus not yet defined. Lower Carboniferous ;
North America.
Terebratuloidea Waagen. Bhynchonellae with very large apical truncate
foramen, but without dental plates or median septa. Carboniferous to
Permian ; India.
Bhynchonella Fischer (as restricted by Hall and Clarke) (Fig. 592, A).
Sub-pyramidal pauciplicate shells with the pedicle opening as in Cyclothijris.
Dental lamellae and a dorsal median septum present. Jurassic and
Cretaceous.
Cyclothyris M'Coy (as redefined by Buckman in 1906) (Figs. 592, B,
CLASS II BRACHIOPODA , 399
and 593). Multiplicate Bhynchonellae with the pedicle opening below the
Fi(!. 592.
A, Rhynrhonella loxia Fiscli. Upper Jura ; Moscow. «, /), Profile
and dorsal view, Vi '> o> Internal mould ; d, Anterior view. B,
Cyclothyris quadriplicata (Quenst.). .Middle Jura; Boptingen, Wiir-
temberg.
Fig. 593.
A, Cyclothyris vespertilio
(Brocchi). Upper Cretaceous ;
Villedieu, Touraine. Vl- B, C.
lacunosa (Schloth.). Upper Jura ;
Engelhardsberg, Franconia. In-
terior of dorsal valve.
venti-al beak. Embraces the bulk of Mesozoic Rhynchonellids. Genotype
Terebratula latissima Sdwerby. Distribution general in Mesozoic time.
Upwards of 700 species of Brachiopods have been described under the name of
Rhynchonella, most of which are found in Mesozoic strata and are now to be referred to the
genus Cyclothyris. But few Rhynchonellids agree with the genotype, which is RhyndioncUa
loxia Fischer (Fig. 592) from tlie U]>per Jura of Russia. It is probable that there are no
Rhynchonellas in the Paleozoic. Hall and Clarke and Weller have shown that most of the
American Paleozoic species belong to other genera. Bittner has also removed from
Rhynchonella many Triassic species.
Halorella Bittner. Sharply plicated Bhynchonellae with a median sinus
on both valves. Alpine Trias.
Austriella Bittner. Small triangular, usually smooth-shelled Ehi/nchonellae
without prominent fold and sinus. Alpine Trias.
Novella Bittner. Like Austriella, but with prominent anterior fold and
sinus. Alpine Trias.
Ehynchonellina Gemmellaro. Transverse Bhynchonellae with fine radial
striae. Cardinal margin nearly straight, with a low concave ventral area.
Crura very long, ventrally curved. Median septum of dorsal valve faint.
Jura ; Sicily and the Alps.
Dimerella Zittel. Small plicate shells with a high umbo and a straight
hinge-line. Delthyrium large, with linear deltidial plates. Dorsal valve with
a high median septum extending to the ventral
valve. Alpine Trias.
Peregrinella CEhlert. Large, strongly plicate
Bhynchonellae without fold or sinus. Cardinal
area well developed. Cretaceous ; Europe.
Hemiihyris d'Orb. (Fig. 594). Smooth or
faintly plicate Bhynchonellae with a high ventral
beak and open delthyrium. No dental plates. F'«- ^^'^■
-P, IlemUhyris psittacea (Chem.). Recent:
Kecent. Mediterranean. Vi-
400
MOLLUSCOIDEA
PHYLUM V
Basiliola Dall. Deep-sea forms resembling Ilemithyris, but with the
deltidial plates united into a spondylium-like plate. Recent.
Frieleia Dall. Resembling Heinithyris, but with a small dorsal spondylium.
Recent ; American Pacific.
Atrefia Jeffreys (Cri/ptopora Jeffreys 1869, non Cryptoporus Motoch 1858;
Ncatretia QChlert). Small, smooth shells with an acute and
prominent open venti"al beak. Dental plates and a high,
mesially situated, dorsal septum present. Recent.
Subfamily C. Acanthothyrinae, novum.
Bhynchonellids with a spinose surface.
Acanthothyris d'Orb. (Fig. 595). In general like Hemi-
Pm. 595.
Amnthothyris spinosa ,7., ., ■,■, ^ ^ 11,11,
(Sciiioth.). Middle t/iyns, but With well-developed dental plates
pS.tate!'''"''^^'^" Recent ; Europe and Japanese sea.
Jurassic to
Superfamily 2. TEREBRATULACEA Waagen.
Specialised Telotremata with the brachia supported by calcareous, primitive or
metamorphosed loops. Shell structure always punctate. Devonian to Recent.
Division A. Terebratuloids.
Terehratulacea with the loops unsupported by a median dorsal septum at any stage
of growth. Brachial cirri directed outwards in larval stages.
Family 1. Centronellidae Hall and Clarke.
Primitive Terebratuloids with short loops developing direct and composed of two
descending lamellae, uniting in the mediayi line and forming a broad arched plate.
Shells smooth, faintly striate or rarely plicate. Devonian to Triassic.
This family comprises the simplest of all Terebratuloids, and from it are probably
descended the other loop-bearing families.
Centronella Billings (Fig. 596). Commonly small, smooth, plano-convex
or concavo-convex shells, with the descend-
ing branches of the loop broadening
rapidly anteriorly, and uniting in a tri-
angular, mesially ridged plate. Hinge-
plate perforate. Devonian ; North America.
Amphigenia Hall (Enantimphen Whid-
borne). Elongate-ovate, high -shouldered
shells without median fold or sinus.
Surface with concentric growth varices
and faint radial striae. Dorsal valve with
a large sub-quadrate hinge-plate perforated
by the visceral foramen and without a
North and South America, France and
Fig. 596.
Cent ronelki glansfagea (RM). Devonian; Erie
County, N.Y. .1, B, Profile ;md dorsal aspect, Vi-
C, Loop, enlarged.
cruralium.
Germany.
Bensselaeria
Middle Devonian ;
Hall. Ovate or elongate-ovate striate Terebratuloids. The
descending branches of the loop diverging for a short distance, thence acutely
CLASS II BRACHIOPODA 401
beat, converging, and uniting in an elongate triangular plate, which on the
posterior margin gives off a small, posteriorly directed, rod-like process.
Hinge-plate large and often much thickened. Thick dental plates present.
Lower Devonian ; North America and Germany.
Lissopleiira Whitfield. Strongly plicate Bensselaeriae, with the dental
plates uniting to form a short rostral cavity. Lower Devonian ; North
America.
Beachia Hall and Clarke. Lentiform, finely striated Bensselaeriae with the
lateral margins of the valves inflected, the anterior plate of the brachidium
broader, and the rod-like process longer. Lower Devonian ; North America.
Newherria Hall (Bensselandia Hall). Resembling Bensselaeria externally,
but without the stxdate surface. Interior strongly marked by muscular scars
and vascular sinuses. Devonian ; North America and Europe,
Chascothyris and Denkmannia Holzapfel. Devonian ; Germany.
OrisJcania Hall and Clarke. Large Centronellae with a continuous hinge-
plate bearing a thin vertical spur or cardinal process. Lower Devonian ;
North America.
Selenella Hall and Clarke. Comprises biconvex terebratuliform shells
with a CentroneUa-like loop, but the triangular j^late not mesially thickened.
Devonian ; North America.
Bomingerina Hall and Clarke. Small biconvex Centronellae with the
median ridge on the f^nterior plate of the loop elevated into a high vertical
lamella almost touching the ventral valve and extended both anteriorly
and posteriorly. Devonian to Lower Carboniferous ; North America.
Trigeria (Bayle) Hall and Clarke. Plicated, plano-convex Centronellae.
Devonian ; France, Brazil and North America.
(?) Scaphiocoelia Whitfield. Very large, plicate, piano- or concavo-convex,
Centronella-\ike shells exteriorly. Loop unknown. Shell substance fibrous,
impunctate. (?) Devonian ; South America.
Juvavella Bittner. Small, smooth, biconvex shells, with a very short
Centronella-\ike loop. Alpine Trias.
Juvavellina and Dinarella Bittner. Alpine Trias. Aspidothyris Diener.
Trias of India.
Nudeatula Bittner. Like Juvavella, but having a longer loop with a well-
developed and fimbriated vertical median plate. Alpine Trias.
Family 2. Stringocephalidae King.
Specialised Devonian Terebratuloids with a long loop, following the margin of the
dorsal valve, and not recurved in front. Development direct. Probably no median
coiled arm. Shells smooth. Devonian.
Stringocephalus Defr. (Fig. 597). This, the solitary genus of the family, is
limited to the Devonian of Europe and North America.
Family 3. Terebratulidae Gray.
Terebratuloids developing originally a Centronella-like loop, and thence by a short
series of metamorphoses resulting at maturity in a free loop of varying form
Devonian to Recent.
VOL. I 2 D
402
MOLLUSCOIDEA
PHYLUM V
Subfamily A. Megalanterinae Waagen.
Paleozoic Terehratulidae with a long loop giving off ascending branches. Shell
smooth. Devonian to Carboniferous.
Fig. .097.
Stringocephalus hurtlni Defr. Devonian ; Patfratli, near Cologne. A, Side-view, "/g natural size. B, Greatly
reduced diagram showing brachidium and median septa. ' ', Young specimen with large delthyriuni and deltidial
plates. I), Interior of dorsal vah'e, natural size, partly restored, a, Adductors ; c, Crura ; (', Dental sockets ;
I, Loop ; pr, Cardinal process ; x, Median septum.
Megalanteris (Ehlert {Meganteris Suess). Large, smooth, equally biconvex,
sub-oval shells, with the long convergent jugal processes of the loop extending
beyond the connecting band of the ascending branches. Devonian ; Europe
and North America.
Cryptonella Hall. Elongate oval shells with short jugal processes.
Devonian to Lower Carboniferous ; North America, England and Bohemia.
Harttina Hall and Clarke. Centronella-\\ke shells with a high dorsal
median septum and the descending branches of the loop laterally fringed with
irregularly set spinules. Carboniferous ; North America and Brazil.
(?) CrijptacantUa White and St. John.
Upper Carboniferous ; North America.
Subfamily B. Dielasmatinae, novum.
Derived Paleozoic Terehratulidae with
short loops. Often there are cruralia present.
Shells smooth or coarsely plicate. Devonian
to Permian.
Eunella Hall and Clarke. Like Dielasma
but without a cruralium. Devonian ; North
America.
Dielasma King (Ejnthyris King, non
Phillips) (Fig. 598). Dental lamellae
strong. To the divergent crural plates is attached a shalloAV, often quite long,
free or sessile cruralium. Devonian to Permian ; Europe, India and America.
Fig. 598.
Dielasma elongatnm(Bch\oth.). Permian; Hum-
bleton, England. .1, Dorsal and anterior views,
i/i- B, Interior of conjoined valves, greatly en-
larged (after Davidson).
CLASS TI
BEACHIOPODA
403
Girtyella Weller. Like Dielasma, but the cruralium is supported by a
septum. Lower Carboniferous ; North America.
Bielasmoides Weller. Like Girtyella, but with septal plates instead of
crural lamellae. Lower Carboniferous ; North America.
Cranaena Hall and Clarke. Dental lamellae strong. Socket plates
uniting into a hinge -plate which is posteriorly perforate ; no cruralium.
Devonian and Lower Carboniferous. Subgenera : Hamburgia and Bielasmella
Weller. Lower Carboniferous, North America.
Dielasmina Waagen. Plicated Dielasmids, Carboniferous ; India.
Beecheria Hall and Clarke. Like Dielasma, but without dental lamellae ;
cruralium completely sessile. Carboniferous ; North America and India.
Bowleyella AVeller. Both valves with median septa. Lower Carboniferous ;
North America.
Heterelasma Girty. Smooth Dielasmids with a ventral fold and a dorsal
sinus. Median septa in both valves. Hinge-plate rudimentary. Permian ;
Texas.
Hemiptychina Waagen. Plicated Dielasmids without dental plates. Carboni-
ferous to Permian ; India.
Notothyris Waagen (Bostranteris Gemmellaro). Coarsely plicate biconvex
shells with a perforate hinge-plate as in Centronella. Permian ; India.
Subfamily C. Terebratdlinae Dall.
Post-Paleozoic Terehratulidae tvith a short loop. A median unpaired coiled arm
exists in Eecent genera. Triassic to Recent.
Terebratula Miiller 1^76 (as redefined by Buckman 1907) (Fig. 599).
Genotype Anomia terehra-
tida Linn. Pliocene. Large
biplicate shells of the Ter-
tiary of Europe.
Musculus Quenstedt.
Buckman states that this
term will be useful for the
Cretaceous biplicate species.
Genotype Terebratula acuta
Quenst. Europe.
Epithyris Phillips, non ^'\^^^^ ^^^^^^^^Sd^
King. Buckman uses this
Pig. 599.
Fig. 6UU.
Pygope diph y a (Colonna,). Titlionian ;
Trent, Tyrol. Vi-
genus for a small group
of Jurassic biplicate forms. m^IZ' Mi^l^ j^IrafS
Genotype Terebratula maxil- "ear Aarau, Switzerland, i/i-
lata Sowerby. Europe.
Ehaetina and Ziigmeyeria Waagen. These genera comprise biplicate
forms, Trias ; Europe.
Pygope Link {Diphyites Schroter) (Fig. 600) ; Antinomia Catullo ; and
Pygites de Haan (as redefined by Buckman 1906). Three independent genera,
according to Buckman, with the shells originally bilobed, the two lobes often
uniting anteriorly in adult specimens, but leaving posteriorly a median
hollow space passing through both valves. Developed out of a Glossothyrid-
like form. Jurassic ; Europe.
404
MOLLUSCOIDEA
PHYLUM V
Propygope Bittner. Triassic ; Europe.
Didyothyris Douvill^ (Fig. 601); Glossothyris Boxw'iWq (Fig. 602); Pseuclo-
r/lossothyris Buckman ; (1) Disculina Deslong. All from the European Jura.
Liothyrina CEhlert (LiotJujris Douville) (Fig. 603). Tertiary to Kecent.
Terebratulina d'Orb. (Fig. 604). Jurassic to Recent ; distribution general.
Chlidonophora Dall. Deep-sea Terebratulinae. Recent.
Subfamily D. Dyscoliinae Beecber.
Post-Paleozoic Terebratulidae with the loop short and no coiled median arm.
(?) Cretaceous, Recent.
Glossothyris nttcleata (Schloth.).
Upper Jura ; Bngelhardsberg,
Franconia. i/j.
Fic. 601.
Diclyolhyi-U coarctatu, (Park.). Great Oolite ; Bath, England. A-C, Three
views of the natural size. D, Portion of outer surface, enlarged.
Fi(i. 603.
Liothyrina vitrea (liinn.). Recent ; Mediterranean, i/i-
Fig. 604.
Tereb-ratulina suh-
ftfriata (Schloth.).
Ujiper Jura ; Nat-
theim, Wurtem-
berg. Viv
Dyscolia and Eucalathis Fischer and CEhlert. Recent.
(?) A(julhasia King. Small Terebratulina-\ike shells with the ventral beak
greatly elevated and a triangular false cardinal area. Cretaceous to Recent.
Division B. Terebratelloids.
Terebratulacea with the loop supported by a median dorsal septum throughout
life, or only in the younger stages. Brachial cirri directed inwards during larval
stages. This section has two phyla having a common origin, now geographically
separated in two provinces, one austral, the other boreal.
Family 1. Terebratellidae King (emend. Beecher).
Terebratelloids with the loop in the higher genera composed of two jmmary and
two secondary lamellae, passing through a series of distinct metamorphoses while
attached to a dorsal septum. Devonian to Recent.
CLASS II
BRACHIOPODA
405
Subfamily A. Megathyrinae Dall (emend. Beecher).
Terehratellidae in tvhich the loop is composed of descending branches only, passing
in the highest genus through stages correlative with Gwijnia, Argyrotheca and
Megathyris. The lower genera do not complete the series. The original stock for the
two following subfamilies. Jurassic to Recent.
Gwynia King. Minute, elongate-oval, smooth shells with a short, nearly
straight hinge-line. Neither septa
nor loop. Brachia primitive, consist-
ing of a circlet of cirri. Recent.
Zellania Moore. Minute shells
without a loop, but with a median
septum in each valve. Lias ; Europe.
Argyrotheca Dall (Cistella Gray)
(Fig. 605). Externally like 3Iega-
thyris, but without lateral septa.
Cretaceous to Recent ; Europe.
Megathyris d'Orb. (Argiope Des-
long.) (Fig. 606). Transversely elongate, plicate shells with
straight hinge -line. Dorsal valve with three or five septa, causing
brachidium to have four lobes. Jura to Recent ; Europe.
Fio. 605.
Argyrotheca hilo-
cularls (Desl.).
Cenomanian ; La
Fi(i. 1506.
Megathyris decollata (Chem.). Re-
cent; Medicerranean. Interior of
dorsal valve, ■i/i (after Bavidson).
long
and
the
Subfamily B. Dallininae Beecher.
Terebratellidae with the loop composed of descending and ascending lamellae,
passing in the highest genera through metamorphoses comparable to the adult structure
of Platidia, Ismenia, Muehlfeldtia, Terebratalia, and Dcdlina. The lower genera,
therefore, do not progress to the final stages. Jura to Recent. Recent genera
restricted to boreal seas.
Platidia Costa (Morrisia Davidson). Small, smooth, biconvex shells with
a large pedicle opening common to both valves. In the dorsal valve there
is a high vertical
plate to which are
attached the de-
scending branches;
ascending branches
not represented.
Recent.
Ismenia King.
Coarsely plicate
shells with the loop
consisting of fim-
FiG. 60S.
Fig. 607.
TrlgoneUlna pectuncula (Scliloth.). Upper
Jura ; Engelhardsberg, Frauconla. A-C,
Shell of the natural size. D, E, Two .views
of loop, enlarged.
Mnehlfpldtlxi truncata (Gemm.). . , , .
Recent ; Mediterranean. Interior briate descending
of dorsal valve, c, Crura ; (7, Dental i \i aa a -n c\
sockets ; «, Jugum ; /, ?, Ascending Draucnes anu
and descendiiig branches of loop ; simple aSCeudiug
p. Process attached to median sep- ^ <-'
turn ; pr, Cardinal process ; S, branches. Jura.
Median septum.
Trigonellina Buckman (Fig. 607). Jurassic ; Europe.
Muehlfeldtia Bayle {Megerlea King) (Fig. 608). Jura to Recent.
406
MOLLUSCOIDEA
PHYLUM V
Fremdina Dall. Subgenus of Muehlfeldtia. Recent.
Terehratalia Beecher. Shell when adult like Terehratella, but passing
through a quite different series of metamorphoses. Recent.
Dallina Beecher. Elongate Terehrataliae with a small cardinal process and
a ventral median sinus. Tertiary to Recent.
Macandrevia King. Elongate Terehrataliae with dental plates and no
cardinal process. Recent. A subgenus of Eudesia, according to Dall.
Laqueus Dall (Fremda Dall). Like Terehratalia, but the loop has two
lateral processes connecting the ascending and descending bi'anches. Recent.
Fig. 609.
A, B, Kingena lima (Defr.). Cretaceous ; England. Lateral and frontal aspect of loop, enlarged (after
Davidson). C, Specimen from the Galeritenplriner of Salzgitter, i/,. D, External surface, enlarged. E, F,
Kingena friesensis (Schriifer). Upper Jura ; Gruibingen, Wiirtemberg. Vi- ^'> Crura ; d, Dental sockets ;
e, Jugum ; /, I, Ascending and descending branches of loop ; j. Cardinal process ; r, Point of recurvature of
loop ; S, Median septum.
Kingena Davidson (Kingia Schloenbach) (Fig. 609). Cretaceous ; Europe
and North America.
Pseudokingena Bose and Schlosser. Cretaceous ; Europe.
Lyra Cumberland (Terehrirostra d'Orb.) (Fig. 610). Cretaceous; Europe.
Fto. tilO.
Lyra 7ieocoiniensis (d'Orb.).
Lower Cretaceous ; Morteau,
Doubs. Natural size.
A, Trigonogemus elegans Koenig. White Chalk ;
England.- Interior of dorsal valve, enlarged (aftei-
Davidson). B, T. palissiiiWoodw. Upper Cretace-
ous ; Ciply, Belgium, i/j.
Delthyridea
King)
Trigonosemus Koenig (Fissitrirostra, Fissirostra d'Orb.
(Fig. 611). Cretaceous,- Europe.
ilficro</i?yns Deslongchamps (Fig. 612); Ornithella Deslongchamps, ; Zeilleria
Bayle. Jurassic genera ; Europe.
Aidacoihyris'DonVxWii (¥ig. 613). Trias to Cretaceous ; Europe. Eudesia
King ; Orthotoma and Trigonella Quenst. ; Flahellothyris Deslong. Jura ; Europe.
CLASS II
Fimbr
BRACHIOPODA
407
iotliyris and Epkyrta Deslong. Jura. Camerothyris Bittner. Trias.
Cincta Quenstedt. Jura. Antiptychina
Zittel. Jura. Plesiothyris Douvill6. Jura.
These are all European genera.
1 Hynniphoria Suess; ? Crurahda Bittner;
? Orthoidea Friren.
Microtlu/ris lagenalh (Sohlotli.)- Conibrasli ;
Rushden, England, i/j (after Davidson).
Fifi. 613.
Aitlacothyris resupinafa (Sow.). Middle Lias ; Ilminster,
England (after Deslongchamps).
Subfamily C. Magellaniinae Beecher.
Terebratellidae ivith the loop composed of descending and ascending branches,
passing in the higher genera through metamorphoses comparable to the adult structure
D
Fig. 614.
Magaf: pinailus Sow. White
Chalk; Meudon, near Paris. A,B,
Shell, i/i- '-', Vertical section. D,
Interior of dorsal valve.
Fio. 615.
Coenothyris fultiaris (Schloth.). Muschelkalk ; Wlirzburg. ^4,
Dorsal and anterior views, i/j. B, Loop enlarged and restored
from sections treated with aci<l (partly after Koschinsky).
of Bouchardia, Magas, Magasella, Terehratella and Magellania. The lower genera
become adidt before reaching the terminal stages. Jura to Recent. Recent genera
restricted to austral seas.
Bouchardia Davidson (Fachyrhynchus King). Recent ; South Atlantic.
Magas Sowerby (Fig. 614). Cretaceous; Europe. Pachymagas von
Ihering. Tertiary ; Patagonia. Magasella Dall. Recent. Coenothyris
Douville (Fig. 615). Trias; Europe.
408
MOLLUSCOIDEA
PHYLUM V
Terebratella d'Orb. (Delthyris Menke ; Ismenia King ; Waltonia Davidson)
(Fig. 616). Jura to Recent.
Magellania Bayle {IFaldheimia King; Neothjris Douville) (Figs. 534, 535,
pr 617). Jura to Recent.
Ehynchorina Q^hlert. Cre-
taceous. Megerlina Deslong-
champs. Recent. Kraussina
Davidson (Kraussia Davidson,
non Dana 1852). Recent.
Mannia Dewalque. Miocene.
(?) Bhynchora Dalman. Cretace-
ous.
Fig. 616.
Fio. 617
Superfamily 3.
SPIRIFERACEA Waagen.
Telotremata with the adult
„ , ,, „ . . .,. , X „ brachia supported by calcareous
TerehrateUa aorf^afa Maqellania flaveacens (val.). Re- ■ 7 7 77 ■7- /-\
(Lam.). Recent ; Cliili. cent ; Australia. Interior of dorsal Spiral lamellae Or Spiralia. (jV-
i/i. valve, somewhat enlareetl. j • • j. t
'^ ' " dovician to Jurassic.
Tlie Spiriferacea are ahimdaiitly represented from the Silurian to the Carl^oni-
ferous, during whicli time the jugum undergoes many and often rapid changes. The
brachidia in Zygospira are knowai to begin with a Centronella-like loop, as in the
primitive Terebratulacea.
Family 1. Atrypidae Gill.
Divergent Spiriferacea with the crura directly continuous with the primary
lamellae, which diverge widely and have the spiral cones between them. Jugum
simple, complete, or incomplete. Ordovician to Devonian.
Subfamily A.
Zygospirinae Waagen.
Primitive Atrypidae with a simple jugum, either posteriorly or anteriorly
directed. Spiralia with apices directed toward the median dorsal region. Ordovician
to Devonian,
Zygospira Hall (Anazyga Davidson ; Orthonomaca Hall ; Hallina Winchell
and Schuchert ; Protozyga Hall and Clarke) (Fig.
618). Like Atrypa, but small, and the spirals
composed of fewer coils. Jugum a simple con-
necting band, situated rather anteriorly. Sur-
face sharply plicate, never lamellose. Ordovician
and Silurian ; North America.
Catazyga Hall and Clarke. More rotund and
finely striated than Zygospira, with the complete
jugum decidedly posterior in position. Ordo-
vician and Silurian ; North America.
Atrypina Hall and Clarke. Primitive Atrypae
with few plications, and but three or four
volutions in each spiral. Jugum as in Atrypa,
Fic. 618.
Zyifosplra wodcMa Hall. Orilovician ;
Cincinnati, Ohio, ^/i (after Hall).
CLASS II
BRACHIOPODA
Late Ordovician to Devonian ;
409
North America and
but continuous.
Europe.
Glassia Davidson (Fig. G19). Small, smooth shells, with the apices of the
laterally compressed spirals situated at the centre of
the brachial cavity. Jugum similar to that of Atrypina.
Ordovician to Devonian ; Europe and America.
Subfamily B.
Atrypinae Waagen.
Terminal Atrypidae with the jugum situated extremely
posteriorly, complete in young stages, hat at maturity dis-
continuous. Spiralia dorso-medially directed. Late Ordo-
vician to Devonian.
Atrypa Dalman (Spirigerina d'Orb.) (Fig. 620).
Shell radially plicated, usually with lamellar expansions
or hollow spines. Spirals introverted, dorso-medially
directed. Jugum extremely posterior in position, and complete in young
Pic. 619.
Glassia obuvata (Sowerby).
Silurian ; Wenlock, England.
Interior of dorsal valve. '^/^
(after Davidson).
Fio. 620.
Atry2^a reticularis (Liim.). Middle Devonian; Gerolstein. Eifel. ^1, Umlional aspect of adult specimen. B,
Ventral aspect and profile of youny shell. C, Interior of dorsal valve, showing spiralia, crura, and jugum.
D, Ventral valve, showing muscular and vascular impressions, a, Adductors ; c, Diductors ; (/, Deltidial plates ;
o, Ovaries ; p, Pedicle muscle.
stages ; but mesially absorbed at maturity. Widely distributed in the late
Ordovician, Silurian and Devonian.
Grueneivaldtia Tschernyschew. Atrypa-like shells, but with the relative
convexity of the valves reversed. Devonian ; Russia.
(?) Karpinshya Tschernyschew. Elongate, Atryjpa-\\\iQ shells, with a median
dorsal septum. Devonian ; Russia.
(1) Clintonella Hall and Clarke. Silurian ; North America.
Subfamily C.
Dayiinae Waagen.
Fir;. 621.
Dayia iiarirula(iiov/.). Silurian; Lud-
low, Shropshire, s/o (after Davidson).
Derived Atrypidae with the jugum drawn out
posteriorly into a simple short process. Spiralia
laterally directed.
Dayia Davidson (Fig. 621). Small smooth
shells, with the jugum situated anteriorly, and
drawn out posteriorly into a simple short process.
Spiralia laterally directed. Silurian ; Europe.
410 MOLLUSCOIDEA phylum v
Family 2. Oyclospiridae, novum.
Primitive Spiriferacea with the crura directly continuous with the bases of the
primary lamellae, which are closely set and nearly parallel. Spiralia very slightly
introverted and of but three or less volutions ; no jugum present. Middle Ordovician.
Cyclospira Hall and Clarke. Small, smooth, rostrate shells, with a deep
ventral and a shallow dorsal valve. Dorsal hinge-plate supported by a median
septum. Middle Ordovician ; North America.
Family 3. Spiriferidae King.
Derived Spiriferacea with the crura directUj continuous with the bases of the
primary lamellae, which are situcded between the laterally directed spiralia. Jugum
simple, complete, or incomplete. Silurian to Jurassic.
Subfamily A. Spiriferinae, novum.
Sjjiriferidae with the jugum discontinuous at maturity, represented by two short
jugal pjrocesses, one attached to each primary lamella. Shell structure with scattering
perforations, but never regularly punctate. Silurian to Permian.
Spirifer Sowerby. This name has been made to cover a vast number of
Paleozoic Brachiopods having a more or less alate form, a multiplicate surface,
and terminally directed spiralia. Various attempts have been made to group
the species into phyletic series, but as there is present more or less of homoeo-
morphic development a completely satisfactory arrangement is not yet at
hand. The following scheme is of tentative character.
Spirifer Sowerby sensn sfricto {Fusella M'Coy) (Fig. 622, A). Transverse,
usually alate Spirifers with the entire shells more or less closely plicate ;
plications simple or dichotomous. Short dental plates developed, but no high
median septa in either valve. Genot3'-pe Anomites striatus Martin. Section
Aperturati Hall and Clarke. Devonian to Permian ; distribution general.
Section Spiriferella Tschernyschew. A group of subquadrate Spirifers
suggesting S. cameratus, but with the surface finely papillose. Ventral shells
very thick, with strong dental plates. Upper Carboniferous ; Urals, Alaska
and North America.
Section Trigonotreta Koenig. Early, coarsely plicate Spirifers in which
the plications are simple and not dichotomous. Genotype S. aperturatus
Schlotheim. Devonian ; Europe and America.
Section Choristites Fischer (Fig. 622, D). Quadrate Spirifers that are
decidedly multiplicate and have long dental plates. Genotype S. mosquensis
Vern. Carboniferous ; Europe and America.
Section Dzieduszychia Siemiradz. Large short-hinged Spirifers with a
plicate sinus in either valve. Genotype Terebr. kielcensis Roemer. Middle
Devonian ; Europe.
Section Brachyfhyris M'Coy. Rounded, tumid, short-hinged Spirifers, with
broad and depressed plications tending to be absent on fold and sinus.
Genotype *S^. ovcdis Phillips. Carboniferous ; Europe and America.
Subgenus Adoljia Giirich (Fig. 622, ^, C). Quadrate to alate, multiplicate
but not dichotomously plicate Spirifers, that have no plications on fold or
sinus (rarely, the fold is bilobed and then there may be a plication in the
sinus). Surface pustulose or finely pustulo-striate. Dental plates short ; no
ventral median septum. Genotype S. deflexus Roemer. Section Ostiolati
CLASS II
BEACHIOPODA
411
Hall and Clarke. Essentially Devonian but persisting into Carboniferous ;
distribution general.
Subgenus Syringothyris Winchell {Syringopleura Schuchert). Like Adolfia,
but usually with large and erect ventral cardinal areas, and always with an
internal tube or syrinx, situated in the delthyriura. Upper Devonian and
Lower Carboniferous ; widely distributed.
A D
Fio. 622.
A, Spirifer striatus (Martin). Lower Carboniferous ; Ireland. Portion of dorsal valve removed, showing
spiralia, •V4 (aifter Davidson). B, S. (Adolfia?) speciosus (Scliloth.). Devonian; Eifel. i/j. C, S. (Adolfia?)
macropterus (Goldf.). Devonian ; Coblenz. Mould, i/j. D, S. (Choristites) mosquensis Vern. Middle Carboni-
ferous ; Moscow. E, Same, interior of ventral valve, i/j. p, Pseudodeltidium ; x, Dental plates.
Subgenus Syringospira Kindle. Like Syringothyris, but with a striate fold
and sinus. Upper Devonian ; New Mexico.
Subgenus Delthyris Dalman. Small early Spirifers that are coarsely plicate
except on the fold and sinus. Surface lamellose ; the imbricating lamellae
marked with very fine radiating striae which do not terminate in spines.
Short dental lamellae present along with a more or less high ventral median
septum. Resemble Spiriferhia, but the shell structure is not finely and
regularly punctate. Genotype D. elevata Dalman. Section Lamellosi-Septati
Hall and Clarke. Silurian and Devonian ; distribution general.
Subgenus Eospirifer, novum. Quadrate or alate early Spirifers that are
either smooth, radially undulate, or plicate, but without plications on fold and
sinus. Surface with additional fine, filiform, radiating striae which may be
minutely crenulate or granulose. Dental lamellae present. Genotype Spirifer
radiatus Sowerby. Section Eadiati Hall and Clarke. Essentially Silurian
but persisting into Lower Devonian ; distribution general.
412 MOLLUSCOIDEA phylum v
Cyrtia Dalman (Fig. 623). Distinguished from Spirifer by having an
unusually high ventral area, with its narrow delthyrium closed by a perforated
pseudodeltidium, resulting from fused deltidial plates.
Silurian to Devonian ; Europe and North America.
Subfamily B. Reticdlariinae Waagen.
Pio. 623.
Spiriferidae with a spinose surface. Spiralia prohahly
as in Triqonotretinae. Late Silurian to Permian.
Cyrtia exporrecta (Walil-
Naturai size. ' ' Reticularia M'Coy. Spirifers without alations, and
generally without radial undulations. Surface with
imbricating lamellae that terminate in spines. Dental plates present.
Genotype R. reticulata M'Coy. Section Fimhriati {pars) Hall and Clarke.
Devonian to Lower Carboniferous ; widely distributed.
Subgenus Prosserella Grabau. Small early Eeticulariae with well-developed
parallel and closely set dental lamellae. Late Silurian ; North America.
Subgenus Squamularia Gemmellaro. Like Eeticularia, but without dental
or septal plates. Carboniferous and Permian ; widely distributed.
Subfamily C. Martiniixae Waagen.
Spiriferidae with a smooth surface. Spiralia prohahly as in the Trigonotretinae.
Devonian to Permian.
Amhocoelia Hall. Small, concave, or plano-convex, usually smooth Spirifer-
like shells. Four well-defined adductor scars near the anterior margin in the
dorsal shell. Devonian to Carboniferous ; North America and Europe.
Martinia M'Coy. Short-hinged Spirifers that in general have smooth or
concentrically marked exteriors, and rarely may be somewhat radially un-
dulate. No dental plates or median septa; Genotype Anomites glaber Martin.
Section Glabrati-Aseptati Hall and Clarke. Lower Carboniferous to Permian ;
distribution general.
Subgenus Martiniopsis Waagen. Like Martinia, but with well-developed
diverging dental and septal plates. Permian ; India.
Subgenus Mentzelia Quenstedt. Like Martinia, but with a prominent
ventral median septum. Triassic ; Europe.
Metaplasia Hall and Clarke. Smooth Spirifer-Yike. shells, with a median
fold on the ventral valve and a sinus on the dorsal valve. Lower Devonian ;
North America.
Verneuilia Hall and Clarke. Small, smooth Spirifers, with a deep median
sinus and two pronounced angular divergent ridges on each valve. Devonian
to Carboniferous ; Europe.
Family 4. Suessiidae Waagen.
Spiriferacea with the crura directly continuous with the bases of the primary
lamellae. Spiralia laterally directed. Jugum continuous and more or less V-shaped.
Shell structure highly punctate. Silurian to Jurassic.
Cyrtina Davidson (Fig. 624). Cyrtia-like shells, with the dental lamellae
CLASS II
BRACHIOPODA
413
converging and united with the median seiDtum. Silurian to Lower Carboni-
ferous. Distribution general.
(?) Cyrtinopsis Scupin. Like Ci/rtina, but shell structure is not punctate.
Devonian ; Germany.
Thecocyrtella Bittner. Very small, ventrally cemented, smooth-shelled
Cyrtinae. Alpine Trias. Cyrtotheca Bittner. Alpine Trias.
Bittnerula Hall and Clarke. Like Thecocyrtella, but with the abbreviated
Fk;. 625.
Spiel ferina rostrata (Sowerby).
Middle Lias ; Ilminster. i/i (after
Davidson),
Fig. 624.
. A,Cyrtinahcteroclyta(DeiT.). Devonian ; Eifel. Vi- B, Shell witli
dorsal valve mostly removed, showing spiralia, % (after Davidson).
C, Cyrtina carhonaria M'Coy. Lower Carboniferous ; Kendal, Ireland,
i/i. Interior of ventral valve. The pseudodeltidium is removed to
show the dental plates and median ^ptum.
dental plates uniting with the very high median septum, forming a transverse
platform beneath the united deltidial plates. Alpine Trias.
Spiriferina d'Orb. (Fig. 625). Like Spirifer, but with the shell substance
punctate, and a prominent ventral median septum. Loop simple, complete.
Carboniferous to Jura.
Suessia Deslongchamps. Similar to Spiriferina, but the dental plates not
extending to the bottom of the valve. Jugum with a median process. Jura ;
Europe.
Family 5.
Uncitidae Waagen.
Deltidial plates
Spiriferacea with the crura directly continuous with the bases of the primary
lamellae. Spiralia laterally directed. Jugum as in Suessiidae. Just within the
posterior margin of the dorsal valve are concave pouch-lihe plates,
united and deeply concave. Shell structure impunctate.
Family anomalous. Devonian and Permian.
Uncites Def ranee (Fig. 626). Shells rostrate, striate,
with the ventral beak long, frequently distorted and
arched. No cardinal area. Deltidial plates united,
forming a concave plate. Pouch-like plates just within
the margins of the dorsal valve. Devonian ; Germany.
Uncinella Waagen. Permian ; India.
Family 6. Rhynchospiridae Hall and Clarke.
Derived Spiriferacea with the bases of the primary
lamellae situated betiveen the spiralia and sharply recurved
dorsally at their junction with the crura. Spiralia laterally
directed. Jugum usually with a single process that is Cologne.'^ 'vi
Fig. 620.
Uncites gryphus (Schloth.).
Devonian ; Benzberg, neajc
414
MOLLUSCOIDEA
PHYLUM V
commonly recurved, hut is sometimes bifurcated. Shells plicate and their structure
abundantly punctate. Silurian to Permian.
Rhynchospira Hall (Fig. 627, C, D). Eostrate, radially plicate shells with
a short curved hinge-line ; apex truncated by a circular pedicle opening.
Dorsal hinge-plate like
that of Trematospira.
Spirals with from six
to nine volutions.
Jugum V-shaped, ex-
panding apically and
terminating pos-
teriorly in an oblique
edge. Shell structure
punctate. Devonian
and Lower Carboni-
ferous; North Amei'ica
and Europe.
Homoeospira Hall
a linear cardinal process
Pig. 027.
.-1, B, Pti/chospira ferita (von Buch). Devonian ; Gerolstein, Eifel. i/j.
C, D, Rhynckospira salteri (David.). Silurian ; Wenlock, Shropshire. C, In-
terior of dorsal valve. D, Median vertical section through both valves, 3/j
(after Davidson).
and Clarke. Like the last,
separating the crural plates,
in an acute stem. Silurian ;
having
but differs in
Jugum not apically expanded, but terminating
North America.
Ptychospira Hall and Clarke (Fig. 627, ^, B). Like Rhynchospira, but with
a few angular plications. The jugum has a long, simple process passing
outward between the coils to near the inner surface of the ventral valve.
Devonian to Lower Carboniferous ; North America and Germany.
Retzia King {Trigeria Bayle). Resembling Rhynchospira externally. The
ventral umbonal cavity has a split tube. The single process of the jugum
terminally forked. This genus formerly contained all shells having a retzioid
exterior. At present, however, but a single species is admitted. Devonian ;
Europe.
Hustedia Hall and Clarke. Externally like Eumetria,
but with coarse plications, and internally with a split
tube, as in Retzia. Spirals and jugum similar to those
of Eumetria, but with fimbria and spinules respectively.
Upper Carboniferous and Permian ; America, Europe,
India and China.
Trematospira Hall. Transverse Rhynchospirae. Silu-
rian and Devonian ; North America.
Para2;?/5ra Hall and Clarke (Fig. 628). Like Trematospira,
but with the fine, simple ribs covered with very delicate,
short, hair-like spines. Devonian ; North America.
Eumetria Hall. Elongate terebratuliform shells with
numerous fine radiating striae. Hinge - line short.
Dorsal hinge-plate very complicated. Jugum similar
to that of Retzia, but the terminally bifurcated process
is extended backward at an abrupt angle, and termi-
nates just in front of the apices of the primary lamellae.
Shell structure punctate. Lower Carboniferous ; North
America and Europe.
Acambona White. Carboniferous ; North America.
Fig. 628.
Parazyija hirsvta (Hall).
Devonian ; Louisville, Ken-
tucky. ^, Shell of the natural
size. B, Same with dorsal
valve partly broken open,
showing spiralia. (.', hinge-
line of ventral valve, enlarged
after Hall).
CLASS II
BEACHIOPODA
415
Family 7. Meristellidae Hall and Clarke.
Derived Spiriferacea, with the bases of the primary lamellae situated between the
spiralia and sharply recurved dorsally at their junction with the crura. Spiralia
laterally directed. The jugum has a single process that may remain simple or may
bifurcate ; the bifurcations, however, do not enter bettveen the lamellae of the sjnralia,
but recurve and join the jugal process near their origin. Shell usually smooth, but
sometimes finely hirsute, and the structure impunctate. Late Ordovician to
Devonian.
Sulifamily A. Hindellinae Schuchert.
Primitive Meristellidae in which the jugum has a single process that is 'usually
simple and rarely is sharply recurved terminally.
Hindella Davidson. Ovate or elongate, sub-equally convex, smooth,
meristelloid shells. The V-shaped jugum has a short, acute process. A
dorsal median septum present. Late Ordovician ; North America. Sub-
genus Greenfieldia Grabau. Has no median dorsal septum. Late Silurian ;
North America.
JFhitJieldia Hall and Clarke. Externally sometimes like Hindella, but
usually the shells have a fold and sinus,
the spirals have more volutions, and the
jugal process is longer and curved.
Genotype JF. nitida H.,and C. Silurian
and Lower Devonian ; North America
and Europe.
Hyattidina, nom. nov. {Hyattella Hall
and Clarke, non F6r. 1821). Similar
to Hindella, but compactly sub-penta-
hedral, and without the dorsal median
septum. Late Ordovician and early
Silurian ; North America.
Nucleospira Hall (Fig, 629). Sub-circular, biconvex shells with numerous
Fig. 029.
Nucleospira pisum (Sow.). Silurian ; Wenlock,
England. A, Interior of dorsal valve. B, Vertical
section through both calves, -^/^ (after Davidson).
fine, short spinules. Jugum with a long, straight, simple process,
to Lower Carboniferous ; North America and Europe.
Silurian
Subfamily B. Meristellinae Waagen.
Specialised Meristellidae, in which the jugal process bifurcates and may remain
so or may continue to grow, forming two loops as in the handles of scissors.
Meristina Hall (IVhitfieldia Davidson) (Fig. 630). Biconvex, smooth-
shelled. Jugal stem with a short bifurcation. Silurian ; North America
and Europe.
Glassina Hall and Clarke. Like Meristina, but with the bifurcations of
the jugum originating directly from its apex. Silurian ; England.
Meristella Hall. Externally like Merista, but without spondylia. Apex
of jugum with two annular processes. Devonian ; North and South America
and Europe.
Meristospira Grabau. Like Meristella, but with strong dental lamellae.
Hinge-plate perforated by a visceral foramen and the dorsal septum not united
with the hinge-plate. Late Silutian ; North America.
416
MOLLUSCOIDEA
PHYLUM V
CharioneUa Billings. Similar to the last, but with a greatly modified
hinge-plate. Devonian ; North America.
Pentagonia Cozzens {Goniocoelia Hall). Meristellids with a broad, angular,
Fig. eSO.
Meristina tumida (Dalm.). Silurian ; Gotland. A, Shell of the natural size. B, Interior of ventral valve.
C, Hinge-line and median septum of dorsal valve.
sharply limited, ventral sinus and abrupt lateral slopes. Dorsal valve with
a wide, rounded fold, divided by a narrow sinus and umbo-laterally with two
short flanges. Devonian ; North America.
Merista Suess (Camarium Hall) (Fig. 631). Like Meristella, but with a
spondylium. Silurian (?) and Devonian ; Europe and North Amei'ica.
D
Fin. 631.
Merista harculea (Barrande). Devonian (P"-) ; Konieprus, Bohemia. A, External aspect of ventral valve,
broken away near the apex so as to show the " shoe-lifter process," i/j. i>, Fractured shell showing median
septum ; spiralia destroyed (after Barrande). C, D, Frontal and lateral views of spiralia, slightly enlarged
(after Davidson).
Dicaniara Hall and Clarke. Meristellids with a spondylium (" shoe-lifter
process ") and brachidium. Devonian ; Europe.
Dioristella Bittner. Similar to Meristella. Alpine Trias.
Camarospira Hall and Clarke. Like Meristella, but with a small spon-
dylium supported by a median septum, to which is attached only the pedicle
muscle. Devonian ; North America.
Family 8. Ooelospiridae Hall and Clarke.
Specialised Spiriferacea, with the primary lamellae as in the Meristellidae ; the
jiigum has a single process which may remain simple and free, or articulate in a
ventral septal socket. Shells plicate, often lainellose, and the strncttire impunctate.
Silurian and Devonian.
Anoplotheca Sandb. (Bifida Davidson). Concavo-convex small shells with
CLASS II
BRACHIOPODA
417
few plications, crossed by fine, often imbricating growth lines. Jugum
originating near the mid-length of the primary lamellae, uniting and forming
a simple upright stem articulating in a cavity in the ventral valve. Dorsal
valve with a high median septum. Devonian ; Germany and France.
Coelospira Hall. Shells externally much like Atrypina, but with laterally
directed spirals. Jugum similar to that of Anoplotheca. Silurian and
Devonian ; America and Europe. Subgenus : Leptocoelia Hall. Larger shells
with coarser plications. Silurian and Devonian ; widely distributed.
Anabaia Clarke. Similar to Coelospira, but with a highly convex dorsal
valve. Silurian ; Brazil and North America.
Vitulina Hall. Like Coelospira, bv;t with few plications and a long
hinge-line. Plications covered with fine radiating lines or rows of pustules.
Devonian ; America and South Africa.
Family 9. Athyridae Phillips.
Specialised Spiriferacea, with the bases of the primary lamellae situated between
the spiralia and sharply recurved dorsally at their junction with the crura. Spiralia
laterally directed. Jugum complete, V-shaped, with the apex drawn out into a simple
process which bifurcates ; this elongates and enters more or less extensively between the
lamellae of the spiralia. Shells smooth, lamellose, or spinose ; structure impunctate.
Devonian to Triassic.
Subfamily A. Athyrinae Waagen.
Primitive Athyridae, in which the single process of the jugum bifurcates. The
branches usually terminate between the first and second volutions of the spiralia.
Shells lamellose or spinose.
Fio. 632.
Athyris concentrica (von Bnch). A, Shell with dorsal valve partly removed. B, Interior of dorsal valve,
i/i- C, D, Frontal and lateral aspect of spiralia (after Davidson).
Athyris M'Coy {Cleiothyris Phillips, non King ; Spirigera d'Orb. ; Euihyris
Quenstedt) (Fig. 632).
Sub-equally biconvex shells with concentric growth lines extended into
lamellae. Ventral umbo not prominent, incurved, usually concealing the
pedicle opening and deltidial plates. Teeth supi:)orted by dental lamellae.
Hinge-plate of the dorsal valve perforated by a "visceral foramen." The
peculiar jugum of this genus is illustrated in Fig. 632, C, D. Devonian and
Carboniferous ; distribution general.
Anathyris von Peetz. Athyrids with straight hinge-lines and a hidden
ventral area. Devonian ; Europe.
VOL. I 2 E
418 MOLLUSCOIDEA phylum v
Adinoconchus M'Coy. Athyrids with very wide, radially striate, concentric
lamellae. Carboniferous ; Europe.
Cleiofhyridina Buckman (Cleiothyris King, non Phillips). Athyrids with con-
centric rows of flat spinules. Carboniferous and Permian ; distribution
general.
Composita Bronn {Seminula Hall and Clarke, non M'Coy). Genotype Spirifer
amhiguus Sowerby. Smooth-shelled Athyrids. Dorsal hinge-plate very pro-
minent. Carboniferous ; distribution general.
Comelicania Freeh. Large, decidedly alate Athyrids with angulated sinuses
in both valves. Alpine Upper Permian.
Janiceps Freeh. Small, sharply triangular Athyrids with angulated sinuses
in both valves. Alpine Upper Permian.
Spirigerella AVaagen. Permian ; South America and India.
Amphitomella Bittner. Smooth - shelled
Athyrids with a double cardinal process and
median septa in each valve. Alpine Trias.
Tetraetinella Bittner (Plicigera Bittner)
(Fig. 633). Athyrids with four correspond-
ing ribs on each valve. Alpine Trias. Sub-
genus : Stolzenhurgiella Bittner. Alpine Trias.
Pentadinella Bittner. Athyrids with five
TdmHlnella trigondln (8c]^\ott\eim). ,. ., , , ^-^
Muscheikaik ; Recoaro, Italy. Vi- corrcsponduig nos On each valve. Occurs in
the Alpine Trias.
Anomadindla Bittner. Athyrids with a number of angular alternating
ribs towards the anterior margins. Alpine Trias.
PomatospireUa Bittner. Small smooth shells having the contour of Dayia
or Cydospira. Alpine Trias.
Subfamily B. Diplospireltjnae Schucliert.
Specialised Athyridae (out of the Athyrinae), with the jugal bifurcations very
long, lying between the volutions of the spiralia, and continuing toith these to their
outer ends. Sometimes there is an additional jugal process which articulates with the
ventral valve, or recurves and joins the jugum. Devonian to Triassic.
Kayseria Davidson. Lenticular, plicated shells with a median plicated
sinus on both valves. Jugum with a ventral articulating process and the
bifurcations continued between the spiral ribbons to their outer ends.
Devonian ; Germany.
Diplospirella Bittner. Athyrids with the jugal processes coextensive
with the principal spiral coils. Alpine Trias.
Pexidella Bittner. Athyrids difiering from Diplospirella in that the
jugum is much reduced and situated^ in the umbonal region. Valves much
thickened in the apical region. Alpine Trias.
Euradinella Bittner. Diplospirellids with short corresponding ribs.
Alj)ine Trias. Didymospira. Salomon. Alpine Trias.
AnisadineUa Bittner. Diplospirellids with alternating ribs. The
secondary spiral coils give oft' a process which returns and joins the jugum.
Alpine Trias.
CLASS II
BRACHIOPODA
419
Subfamily C. Koninckininae Waageii.
Highly specialised Athyridae with jugmn and spiralia essentially as in Diplo-
spirellinae. The spiralia, however, are not laterally directed as in the former group,
but point ventrally, this being due to the concave form of the dorsal valve. Triassic
and Jurassic.
Koninchina Suess (Fig. 634). Shell sub-orbicular, concavo-convex, smooth,
with a straight hinge-line, or strophomenoid in external appearance. Car-
dinal area obsolete at maturity. The accessory spirals take their origin
Fio. 634.
Konincldna leonhardi (Wis.sm.). Upper
Trias ; St. Cassian, Tyrol. A, Shell show-
ing spiralia, enlarged. B, Ventral and
dorsal aspects, i/j. ,
Fig. 635.
Amphicliwi, with re-
stored brachidia (after
Bittner).
Fic. 636.
Thecospira haidingeri (Suess).
Rhaetic ; Starhemberg, Austria.
A, Ventral valve, i/i. B, C,
Brachidia, enlarged (after Zug-
meyer).
from the upper surface of the jugum, and are coextensive with the primary
spirals. Trias ; Europe.
Amphiclina Laube (Fig. 635). Like Koninckina, but sub-trigonal in out-
line, and with well-developed cardinal area and deltidial plates. Trias and
Jura ; Europe.
Koninckella Munier-Chalmas. Similar to Amphiclina, but with well-
developed cardinal process. Trias and Jura ; Europe.
Amphiclinodonta Bittner. Like Amphiclina, but with interlocking denti-
culate ridges and tubercles within the margins of the valves. Alpine Trias.
Koninckodonta Bittner. Like Koninckina, but with prominent cardinal
areas and a row of sub-marginal thickened tubercles on the interior of the
ventral valve, which interlock with similar callosities on the dorsal valve.
Alpine Trias.
Thecospira Zugmeyer (Fig. 636). Ventrally cemented Koninckininae with
well-developed cardinal area and cardinal process. Alpine Trias.
Range and Distribution of the Brachiopoda.
Owing to their great abundance, world-wide distribution and remote
antiquity, as well as their excellent state of preservation, Brachiopods occupy
a very conspicuous rank among extinct Invertebrates, and furnish us besides
with a large number of important stratigraphic index fossils. The composi-
tion of their shells, usually of calcite, enables them to resist the destructive
action of the fossilisation process more successfully than the shells of Mollusks,
many of which are composed wholly or in part of aragonite. Their value
as index fossils, however, is somewhat lessened owing to the difficulty of
identifying numerous genera, without a knowledge of their internal structure,
and this is often difficult to ascertain.
420 MOLLUSCOIDEA phylum v
Three of the four orders into which the class is divided are represented in
the lowest Cambrian, or Olenellus zone, indicating that Brachiopods had their
origin in pre-Cambrian times. In the Lower and Middle Cambrian, the
Atremata and Neotremata predominate ; and although the Protremata are known
in the Lower Cambrian by very typical species, it is not until the Upjjer
Cambrian that the order becomes conspicuous. They are particularly char-
acteristic of the Paleozoic. The Telotremata do not appear until the Middle
Ordovician and since Silurian times have always been prolific, but are
especially characteristic since early Mesozoic times.
In the Lower Cambrian (Olenellus beds), 22 genera of Brachiopods are
represented, occui'ring both in North America and in Europe. A marked
increase is apparent in the Middle Cambrian, for here Walcott records 37
genera, and in the Ordovician and Silurian, where the climax of their diversity
is reached, upwards of 3000 species are known. These are distributed chiefly
in North America and in Europe (Great Britain, Scandinavia, Bohemia,
Russia and Portugal) ; but numerous forms are also found in South America,
Australia, China and eastern Siberia.
In the Devonian, Brachiopods are scarcely less plentiful than in the Silurian,
although a considerable number of genera, especially those belonging to the
Atremata and Neotremata, have now disappeared. The most noted European
localities where Brachiopods abound are the Eifel, Ehineland, Westphalia, the
Hartz, Belgium, Devonshire, Boulogne -sur-Mer, Cabrieres in the Cevennes,
the Asturias and the Urals. North America also yields great quantities of
Devonian Brachiopods.
The Carboniferous of North America and its equivalent horizons in Europe
and Eastern Asia, together with the Permian of the Mediterranean countries,
India and Armenia, are very rich in Brachiopod remains, especially those
belonging to the Prodaciidae, Sirophomenidae, Spiriferidae and Rhj nchonellidae.
In the North European Permian, the number of species of Brachiopods is
reduced to about 30, but in the Salt Range of India far greater numbers
occur. In the Alpine Trias, the Terebratididae, BhynchoneUidae and Koninck-
ininae attain a great development.
The Jurassic and Cretaceous Brachiopods belong almost exclusively to
the Terebratididae, BhynchoneUidae and Thecidiidae ; the first two families in
particular being represented by an astonishing number of species. The
Spiriferacea become extinct in the Lias.
With the beginning of the Cenozoic era, Brachiopods are no longer a con-
spicuous group of fossils. The species occurring in the Tertiary are almost
without exception generically identical with those now living, and scarcely
exceed them in number. On this account they are devoid of practical interest
or importance to the geologist.
Phylum VI. MOLLUSC A.'
(Malacozoa Blainville ; Saccata Hyatt.)
The Mollusca form a well -characterised, and, on the whole, remarkably
homogeneous group of Invertebrates, which have existed since the earliest
recognised advent of life upon the globe. Their progressive modifications
afford us a most important guide to the successive stages of the evolution of
organic life as preserved in the various geological horizons.
The Mollusca are characterised as a group by passing through a Trocho-
1 Literature : Adams, H. and A., The Genera of Recent Mollusca, 2 vols. London, 1853-58. —
PhiUppi, R. A., Handbuch' der Conchyliologie. Halle, l^^Z.—Keferstein, W., Die Malacozoa.
Bronn's Classen und Ordnungen des Tluerreichs, vol. iii., 1862-66.— Tryow, G. IF., ahA Pilsbry,
H. A., Manual of Conchology, 16 vols. Philadelphia, 1879-96.— T^isc/ter, P., Manuel de Con-
chyliologie et de Paleoutologie conchyliologique, 1880-87. — Woodward, S. P., Manual of the
Mollusca. 4th Edition, with' Appendix by R. Tate, mO.—Tnjon, G. W., Structural and Syste-
matic Conchology, 3 vols. Philadelphia, 1882-84.— //^ermp-, H. von, Le Systeme naturel des
Mollusques. Bull. Sci. France, 1891, vol. xxiii. — PeZseneer, P., Introduction a Tetude des
Mollusques. Brussels, 1894.
Sovxrby, J., Mineral Conchology of Great Britain, 7 vols. London, 1812-30.— ^rocc/w, G. B.,
Conchiologia fossils subappenina, 2 vols. Milan, ISU.—Deshayes, G. P., Coquilles fossiles des
environs de Paris, 3 vols., 1824-37. — Goldfuss, A., Petrefacta Germaniae, 1826-40.— CowrarZ, T. A.,
Fossil Shells of the Tertiary Formations "of North America (1832-33) ; and Fossils of the Medial
Tertiary of the United States (1838-61). Reprints by G. D. Harris, l^°iZ.^ Morton, S. G., Synopsis
of the Organic Remains of the Cretaceous Group of the United States, ISBi.—Philipjn, E. A.,
Enumeratio Molluscorum Siciliae, 2 vols., l83Q-U.—Grateloup, J. P. S., Catalogue zoologique du
Bassin de Gironde. Bordeaux, lSSS-40.— Hall, J., Palaeontology of New York, vols, i.-viii.
Albany, 1847-95. — IFoof^, S., Monograph of the Crag Mollusca. Palaeont. Soc, 1848-56, vols, i.,
ii. — Sandberger, G. and F., Die Versteinerungen des rheinischen Schichtensystems in Nassau,
1850-56. — Af orris and Lycett, Monograph of the Mollusca of the Great Oolite. Palaeont. Soc,
1850-63.— il/'Coy, F., British Palaeozoic Fossils. London, 1851-55.— Picfei, F. J., and Campiche,
G., Description des fossiles du terrain cretace de Sainte-Croix. Paleont. Suisse, ser. 5, vols, i.-iv.,
1858-72.— Quenstedt, F. A., Der Jura. Tiibingen, \8h8.— Sandberger, F., Die Conchylien des
Mainzer Beckens. Wiesbaden, 1860-63.— Des/;ayes, G. P., Description des animau.\ sans vertebres
decouverts dans le Bassin de Paris, 5 vols. Paris, 1860-66.— ZoHo/, P. de. Monographs of the
. Fauna of the Upper Jura of Switzerland, Haute-Marne, Yonne, Boulogne-sur-Mer, Valtin, Tonnerre ;
of the Neocomian of Mt. Saleve ; the Urgonian of Landeron ; the Gault of Cosne, etc., 1861-75. —
Cossmann, M., Essais de paleoconchologie comparce. Paris, 18^5.— Gabb, W. M., Palaeontology of
California, vols. i. and ii., 1864, 1869. — Idem, Topography and Geology of Santo Domingo. Trans.
Am. Phil. Soc, 1873, vol. xv.— Geuiiiz, H. B., Die Dyas. Leipzic, 1864. — Koninck, L. G. de,
Faune du calcaire carbonifere de la Belgique. Ann. Mus. d'Hist. Nat. Belg., 1886, vol. vi. — M'Coy,
F., Synopsis of the Characters of the Carboniferous Limestone Fossils of Ireland, 1862. — Meek,
F. B., Report on the Invertebrate Cretaceous and Tertiary Fossils of the Upper Missouri Country.
U.S. Geol. Surv. Terr., 1876, vol. ix. — Waagen, W., Salt Range Fossils. Mem. Geol. Surv. India.
Palaeont. Indica, ser. 13, \88Q-87 . — White, C. A., Non-marine fossil Mollusca of North America.
3rd Ann. Rept. U.S. Geol. Survey, 1883.— TFa^co^, C. I)., Fauna of the Lower Cambrian or
Olenellus Zone. 10th Ann. Rept. U.S. Geol. Surv., \8'^<^. — Whidborne, G. F, Monograph of the
Devonian Fauna of the South of England. Palaeontogr. Soc, 1889-1907.— il/ec^-, /''• B., and
WortJien, A. H., Palaeontology of Illinois, 1866-75, vols, i.-vi.
421
422 MOLLUSCA phylum vi
sphere and a Veliger larval stage ; by possessing bilaterally symmetrical,
unsegmented bodies ; a larval shell gland, from which a harder exoskeleton
or shell is secreted, though not always permanently retained ; a mouth,
intestinal canal and anus ; a closed, but partly lacunary circulation, assisted
by a heart with one or more auricles, and containing a usually colourless
body fluid or haemolymph ; a nervous system with at least three pairs of
ganglia connected by commissures ; sexual reproduction by ova and sper-
matozoa ; audition and equilibration provided for by otocysts ; respiration
by ctenidial or secondary gills, or by the tegumentary surface, which may be
invaginated to form a pulmonary sac ; locomotion by a muscular organ called
the foot, or by special parapodial structures, or by swimming ; the organs
typically paired, and protected by a sac-like integument called the mantle ;
and the visceral sac having a tendency toward torsion, so as to become usually
asymmetrical. Sexually Mollusks are usually dioecious ; or, if monoecious,
are incapable of self-fertilisation.
Owing to the homogeneity of the group, its division into classes has been
attended with some differences of opinion, depending upon the point of view,
the anatomist laying more stress upon certain groups of characters, and the
morphologist upon others. From a general standpoint, the Mollusca are
readily divisible into five classes, as follows : Pelecypods, Scaphopods,
Amphineura, Gastropods and Cephalopods. The first of these is well marked
off from the rest by the presence of a bivalved shell and the absence of a
distinct head and of a radula, and the two groups have been contrasted as
Aglossa (or Lipocephala) and Glossophora (or Cephalophora).
Class 1. PELECYPODA Goldfuss.^
(LamelUbranchiata Blainville ; Conchifera Lamarck ; Bivalvia (Bonanni) Linn6 ;
Lipocephala Lankester.)
Aquatic, Ulaterally symmetrical, acephalous Mollusks, protected by a pair of
shelly valves, which are secreted by the lateral portions of the mardle, connected by an
1 Literature : Neumayr, M., Zur Morphologie des Bivalveusclilosses. Sitzungsber. Akad.
Wiss. Wieii, 1883, vol. Ixxxiii., and Deukschr. 1891, vol. Iviii. — Ueber die Herkuiift der Unioiiideii.
Sitzungsber. Akad. Wiss. 1889, vol. xcviii. — Beitrage zu einer morphologischeu Eintlieilung der
Bivalven ; init Vorwort von E. Suess. Denksehr. Akad. Wiss. Wien, 1891, vol. Iviii. — JTAiYf,
C. A., Review of the fossil Ostreidae of North America, 4th Ann. Re]iort U.S. Geol. Survey
(1883), 1884. — Jackson, R. T., Phylogeny of the Pelecypoda. The Avieulidae and their Allies.
Mem. Boston Soc. Nat. Hist., 1890, vol. iv. no. 8. — Men&gaux, A., Recherches sur la circulation
des Lamellibranches marines, 1890. — Hyatt, A., Remarks on the Pinuidae, Proc. Boston Soc.
Nat. Hist., 1892, vol. xxv. — -Moynier de Villepoix, R., Recherches sur la formation et I'accroisse-
ment de la coquille des mollnsques, 1893. — Bernard, F., Serie de notes sur le developpement et la
morphologie de la coquille chez les Lamellibranches. Bull. Soc. Gt-ol. France [3], 1895-97, vols.
xxiii.-xxv. — Dull, W. H., Anew Classification of the Pelecypoda. Trans. Wagner Inst. Sci. Phila-
delphia, 1895, vol. iii. pt. 3. Also Proc. U.S. Nat. Mus., 1895, vol. xvii. no. 1032.— Hyatt, A.
Terminology proposed for the Description of the Shell in Pelecypoda. Proc. Am. Assoc. Adv.
Sci., 1895, vol. xliv. — Fischer, //., Resume des travaux de M. F. Bernard sur le developpement
de la coquille des Pelecypodes. Journ. de Conch., 1897, vol. xlv., no. 4. — March, M. C, (General
Classification of the Pelecypoda. Ann. Mag. Nat. Hist., [8] 1912, vol. x.
A. On Paleozoic Forms : Barrandc, ./., Systeme Silurien du centre de la Boheme. Acephales,
i.-iv., 1882. — Becde, J. W., Carlioniferous Invertebrates. Kansas Univ. Geol. Surv. , 1900, vol. vi.
—Clarke J. M., Naples Fauna in western New York. Mem. N.Y. State Mus., vi., 1900.— Hcdl, J.,
Geol. Surv. New York. Palaeont., vol. v., 188i~85.— Idem, Whitjield, R. P., Meek, F. B., and
Vlrich, E. 0., Description of Palaeozoic Fossils. Palaeont. Ohio, 1873-75, vols, i., ii. , and Geol.
Ohio, 1893, vol. vii. — Hind, IF., Monograph of the British Carboniferous LamelUbranchiata.
CLASS I
PELECYPODA 423
elastic ligament, and closed by the contraction of muscles attached to the inner faces of
the valves ; feeding hj ciliary action and destitute of a radida or jaw ; breathing by
lateral gills ; imperfectly sensible to light and rarely provided with peripheral visual
organs ; possessing olfactory organs (osphradia), auditory and equilibrating organs
(otocysts), tactile papillae, and a nervous system composed of ganglia united by nerves,
but without a pedovisceral commissure; provided with an extensile, tactile or loco-
motor organ (foot) ; a circulatory system containing haemolympth, and operated by a
single or faired cardial ventricle and two auricles ; a more or less convoluted intestinal
canal, ivith its oral and anal extremities at opposite ends of the body ; a stomach ;
paired nephridia, connected with the pericardium, and discharging independently of
the rectum ; reproducing without copulation, by ova and spermatozoa ; monoecious or
dioecious ; development external to the ovary ; the post-larval stage protected by a
prodissoconch, and sometimes exhibiting specicd nepionic stages.
External Characters. The Shell. — The embryonic Pelecypod is provided
Palaeont. Soc, 1896-1905. — Ulrich, E. 0., Lower Silurian Lauiellibraiicliiata of Minnesota. Rept.
Geo!. Surv. Minn., 1897, vol. iii.
B. On Mesozoic Forms : Benccke, E. W., Die Versteineruugen der Eisenerzformation von
Deutsch - Lotliringen unci Luxemburg. Abh. GeoL Spezialkarte Elsass - Lotliring., 1905, n.s.,
vol. V. — Bittncr, A., Revision der Lamellibrancliiaten von St. Cassian. Abh. Geol. Reichsanst.
Wieu, 1895, vol. xviii. — Bulim, U., Die Bivalven der Stramberger Schichten. Palaont. Mittlieil.
Mus. Bayer. Staates, 1883, vol. u.—Borrissyak, A., Die Pelecypoden der Jura-Alilageruugen im
europaisclien Russland. Mem. du cours geol., nouv. ser., 1904-9. — Broili, F., Die Fauna der
Pacbycardientuffe der Seiser Alp. Palaeontogr., 1903-7, vols. 1., liv. — Coquand, W., Monographie
du genre Ostrea des terraips cretaces, 1869. — Healcy, M., The Fauna of the Napening beds
(Rhaetic) of Upper Burma. Palaeont. Indica, 1908, n.s., vol. ii., no. 4. — Ilolzapfel, E., Die
Molhisken der Aachener Kreide. Palaeontogr., 1887, vol. xxxiv. — Kitchin, F. L., The Jurassic
Fauna of Cutch. Laniellibranchiata. Palaeont. Indica, 1903, ser. ix., vol. iii., pt. 2. — Lcmbe, G.,
Die Fauna von St. Cassian. Denkschr. Akad. Wiss. Wien, 1866, vol. xxv.—Pavlow, A., Enchaine-
ments des Aucelles et Aucellines du Cretace Russe. Nouv. Mem. Soc. Impi'r. Nat. Moscou, 1009,
vol. xvii. — Pompeckj, J. F., Uber Aucellen und Aucellen-ahnliche Formen. Neues Jahrb. f.
Min., 1901, Supi^lem. vol. xiv. — Quaas, A., Beitrag zur Kenntniss der Fauna der obersten
Kreidebilduug in der Lybischen Wtiste. Palaeontogr., 1902, vol. xxx. pt. 2 — StoUczka, F.,
Cretaceous Fauna of Southern India. The Pelecypoda. Mem. Geol. Surv. East India, 1871, vol.
iii. — Waagen, L., Die Lamellibrancliiaten der Pachycardientuffe der Seiser Alp. Abh. Geol.
Reichsanst. Wien, 1907, vol. xviii. pt. 2. — Wood, H., Monograph of the Cretaceous Lanielli-
branchiata of England. Palaeont. Soc, 1899, vol. \m. — Zittcl, K. A, von. Die Bivalven der
Gosaugebilde. Denkschr. Akad. Wiss. Wien, 1865-66, vol. xxv.
C. On Tertiary Forms : Androussov, N., Fossile und lebende Dreissensidae Eurasiens. Trav.
Soc. Imp. Sci. Nat. St-Petersb., sect, geol., 1897, 1903, vols, xx., xx\x.— Arnold, R., The
Tertiary and Quaternary Pectens of California. U.S. Geol. Surv. Profess. Papers, no. 47, 1906. —
BeUardi, L., and Sacco, F., I Molluschi terziari del Piemoute e della Liguria. Torino, 1872-1901. —
Chssnumn, M. , Catalogue illustre des coquilles fossiles de I'Eocene des environs de Paris. Fasc.
Ann. Soc. Malacol. de Belgique, 1888-89, vols, xxiii., xxiv.—Idem, and Fissaro, G., Iconographie
complete des coquilles fossiles de I'^^ocene des environs de Paris. Fasc. 1, Pelecypodes, 1904. —
DaU, W. H., Contributions to the Tertiary Fauna of Florida, i.-vi. Trans. Wagner Inst. Sci.,
1890-1903, vol. ni.—Deperet, C, and Roman, F., Monographie des Pectinides neogenes de I'Europe
et des regions voisiues. Mem. Soc. Geol. France, 1902, vol. x.—Fontaniies, F., Les Molhisques
pliocenes de la Vallee de Rhone et du Roussillon. Lyons, 1879-83. — Gregorio, A., Monographie
de la faune eocenique de I'Alabama. Palermo, 1890. —^«m5, G. D., Bull. Amer. Palaeont.,
1895-97, vols, i.-iv. — Hoernes, M., Die fossilen MoUusken des Tertiiirbeckens von Wien. Abhandl.
Geol. Reichsanst. Wien, 1870, vol. iv. — Koencn, A. von, Das norddeutsche Unter-Oligocan und
seine Mollusken-Fauna. Abhandl. Geol. Spezialkarte Preussen, 1889-93, vol. x. — 02)penheim,
P., Zur Kenntnis alttertiiirer Fauuen in Agyjiten. Palaeontogr., 1903-6, vol. xxx. pt. 3. —
Ortmann, A. E., Families and Genera of the Najades. Ann. Carnegie Mus., 1912, vol. viii. no.
x. — Sandberger, F., Die Conchylien des Mainzer Beckens, 1860-63. — Idem, Die Land- und
Siisswasser - Conchylien der Vorwelt. Wiesbaden, 1875. — Schafer, F. X., Die Bivalven der
Miocanbildungen von Eggenburg. Abh. Geol. Reichsanst. Wien, i910, vol. xxii. — Simpson, 0. J.,
Synopsis of the Naiades or Pearly Fresh-water Mussels. Proc. U.S. Nat. Mus., 1900, vol. xxii., no.
1205. — Ugolini, R., Monografia dei Pettinidi neogenici della Sardegna. Palaeont. Ital. 1906-7,
vols, xii., xiii. — Wood, S., Monograph of the Eocene Bivalves of England. Palaeontogr. Soc,
1861-71.
424
MOLLUSCA
PHYLUM VI
with a saddle-shaped, single shell gland, which secretes a pellicle of the same
form, upon which, at two points corresponding to the valves, calcification sets
in independently. These rudiments remain con-
nected across the dorsum for a time, by the uncal-
cified portion of the original pellicle, which develops
into the ligament of the adult. The paired em-
bryonic shell, corresponding to the protoconch of
Cephalopods, has been named by Jackson the fro-
dissoconch (Figs. 637, 638). In general these valves
are very uniform in character, as seen on the tips
Completed of the uucroded valves in the adult. They are
usually rounded or slightly pointed at the umbonal
end, and have in their earliest stages a straight,
rather long hinge line. In Solemya the prodissoconch
is elongate, rounded at the ends, with the ventral and dorsal margins nearly
parallel, much as in the adult shell. In Pinna the prodissoconch is globular,
as in most bivalves. In Unio, Avodon and Philohnja, a second or nepionic
Fig. 637.
Ostrea virginiana.
prodissoconcii stage, vie\ved from
the anterior end (.1), and from
the right upper side (B). s7/j
(after Jacl^son).
Fig. G38.
A, Avicula sterna. Young specimen, viewed from the left («) and right (b) sides, the latter sliowiiig byssal
sinus, li'/i- B, Area pexata. Very young, showing prodissoconch (p), succeeded by early dissoconch growth.
^^/i (after Jackson).
stage is traceable, owing to a semi-parasitic habit of the young, which leave
the mother and become encysted on the fins or gills of fishes ; during this
period the shell remains stationary, though some development of the contained
soft parts is in progress.
The bivalve shell reduced to its lowest terms comprises two convex pieces
(the valves), attached to one another dorsally (1) by an elastic ligament usually
external to the cavity of the two valves ; and (2) by muscles and connective
tissues which pass from the inner surface of one valve to the inner surface of
the opposite valve. The contraction of the muscles brings the margins of the
valves into close contact, thereby forming a hollow receptacle in which the
soft parts of the animal are enclosed, and from which all obnoxious foreign
matters may be excluded. The elasticity of the ligament, acting on the
principle of the C-spring, tends to separate the valves when the tension of
the internal adductor muscles is relaxed. The extension of the substance
of the valve is secreted by marginal glands around the edge of the investing
tissue or mantle, and is subsequently reinforced by material supplied by
secretion from the general surface of the mantle. As the animal grows and
the original prodissoconch becomes too small to cover the soft parts, the valves
are enlarged around the margins, so that each of them represents, fundament-
ally, a hollow cone. Since growth progresses more rapidly along some
portions of the mantle than at others, the cones necessarily become oblique.
iS^if^r
CLASS I PELECYPODA 425
arched or cycloidally curved. The apex of the cone is formed by the beak
or umbo of the valve, the base is the entire margin of the valve.
The shell of most Pelecypods is composed of several layers of distinct
structure. The external layer is usually thin, flexible and dark-coloured,
chiefly composed of a horny substance termed conchiolin. This layer is
known as the epidermis, or more properly the periostracum ; it is not easily
corroded, and hence serves as a protection to the underlying calcareous
layers. The outer calcareous layer is composed of prisms of calcite arranged
more or less perpendicular to the external surface ; the inner layer is made
up of thin, more or less parallel lamellae of porcellanous or pearly texture,
disposed at right angles to the general direction of the prismatic layer,
and exhibiting the mineralogical characters of aragonite (Fig. 639). Besides
the lamellar or prismatic
structure, many forms show
under the microscope
minute, sometimes branched
tubulation.
The variations in shell
substance are somewhat
characteristic of diff"erent
groups. The prisms diff'er p^^^ g39_
greatly in size, the Ifirger Veitical section of the shell of Unio. e, b, a, a', the outer pris-
nr>f>ni'vit.rr in Tnnpm-nmiKi Qnrl matic layer, showing successive increments of shell growth; c, c',
ULUUlllug ill lliUU.iailtWb anu the inner lamellar strata. Highly magnitied (after Carpenter).
Pinna, the smaller in the
Anatinidae and Myacidae. The prismatic layer is wholly absent in the
Chamidae and many other Teleodesmacea ; in the Pectinidae and Limidae
the prismatic layer is feebly developed and often recognisable only in young
shells. In the Rudistae the prisms run nearly parallel with the outer surface.
As aragonite is more soluble than calcite, it frequently happens in fossil
shells that the layers composed of the former minei'al have entirely dis-
appeared, leaving only the calcitic layers. Pearls are merely loose portions
of the inner layer secreted by the mantle surface, usually around foreign
bodies which have reached the interior of the shell and set up irritation there.
In the majority of Pelecypods the valves form a nearly complete defence ;
in borers, burrowers and a few degenerate types, the valves cover less and
less surface in proportion to that which is bare ; in a few the mantle is re-
flected so as to envelop more or less of the outer surface of the valves ; and
finally, in Chlamydoconcha, the valves are permanently internal, separately
encysted, with the ligament isolated and encysted between them. No
example is known of a Pelecypod absolutely destitute of valves in the adult
state.
The valves of the shell are in general substantially equal ; but sometimes
they are unequal, especially in sessile or sedentary forms ; and rarely they
are spirally twisted, as in Stavelia and Spirodomns. The hinge or articulus
comprises the whole articulating apparatus — hinge plate, teeth, ligament, etc. :
the primitive hinge, which is coextensive with the ligament, is distinguished
by Hyatt as the cardo. The cardinal axis, or right line forming the axis of
revolution of the hinge, is parallel with the antero-posterior axis of the
animal (as determined by a line drawn through the mouth and posterior
adductor) in the ordinary Teleodesmacea ; but in the winged Prionodesmacea,
426 MOLLUSCA phylum vi
such as Ostrea, Pedalion, etc., the two axes are at a considerable angle with each
other.
The dental armature is usually situated on the dorsal margin, which for
this reason is called the cardinal margin. It comprises the teeth, or project-
ing processes and sockets, usually alternating in the single valve, and opposite
with respect to both valves. In the more modern and perfected types, the
cardinal margin is reinforced by a vertical deposit of shell in the form of a
lamina called the hinge plate, upon which the teeth are set. Above the hinge
plate in each valve rise the beaks or umbones, which are usually curved
toward the antei'ior end of the shell (prosogyrate), but are sometimes directed
backward (opisthogyrate) or outward (spirogyrate).
According to the ordinary terminology, the height of a Pelecypod is
measured on a vertical line from the beaks to the ventral margin ; the length
corresponds to the greatest distance between the margins parallel with the
antero-posterior axis above defined ; and the thickness, or diameter, is measured
by a line at right angles to the vertical plane descending from the cardinal
axis (Fig. 641). AVhen the shell is placed with the oral end anterior, the
valves are termed right and left respectively, as viewed from above the
articulus. The portion of the shell anterior to the beaks is usually shorter
than that behind them, except in such forms as Donax or Niicula.
Viewed laterally, most Pelecypod valves may be divided into regions,
corresponding in the main to the disposition of the internal organs. The oral
area extends from the anterior end of the cardinal line to the anterior side of
the pedal area. The latter is often marked by a swelling of the valves, and
sometimes by a sinus (Pholas) ; it extends backward to a point where the
branchial crest, radiating from the beaks, forms the anterior boundary of the
si-phonal area. The dorsal or posterior limit of the siphonal area is marked by
an angle in the incremental lines ; and above this, extending to the posterior
end of the cardinal line, is the intestinal area. In the alate forms, like Pteria,
the wings usually called anterior and posterior are really, with reference to
the antero-posterior axis of the animal, dorsal and ventral.
In certain borers, the siphons are greatly produced beyond the valves, and
a calcareous tube is secreted, lining the burrow ; the valves, situated at the
anterior end of the boring, either lie free, or are partially or wholly fused
with the tube. In the Pholadidae the naked portions of the animal between
the edges of the valves are often protected by additional shelly pieces, which
are organically separate from the valves ; and some burrowers have the free
ends of the siphons protected by leathery or calcareous shields. In the
Teredinidae these shields are specially modified to protect the entrance of the
burrow, and are called " pallets."
Ornamentation. — The external ornamentation of the valves is always a
conspicuous character. It comprises (beside the concentric or .incremental
lines which indicate the successive additions to the shell margin, and are
believed to coincide with resting stages during the process of growth) radial
or concentric striae, ridges, ribs, folds, nodes, spines or foliaceous processes.
These are supposed to arise from temporary or permanent modifications of
the mantle margins, such as papillae, minute tentacular or proliferate
processes.
Above the hinge line, in archaic types, is an area often set off" by an
impressed line and called the cardinal area. In the more perfected modern
GLASS I PELECYPODA 427
forms this area is commonly divided ; a heart-shaped space in front of the
beaks, and bounded by a ridge or groove, being known as the lunule ; and a
more elongated space extending backward from the beaks being designated the
escutcheon. Both areas often have a special sculpture, differing from that of
the remainder of the shell.
Another form of ornamentation is sometimes found on the opposed inner
margins of the valves, away from the hinge line, as in Digitaria (Fig. 756),
or Transennella ; it probably aids in preventing a lateral displacement of the
valves. In general, all ornamentation may be confidently ascribed to a
dynamic origin.
Internal Characters. Soft Parts. — The Pelecypod body is enclosed
within two thin, partly fleshy mantle lobes, which are united or continuous
below the cardinal margin, and open or partially united at other points on
their periphery. Within the mantle lobes are the visceral mass including
the internal organs, the gills or ctenidia, the foot and the palpi. When the
mantle edges are united so as to form tubes for the entrance and discharge of
Avater, such tubes are called siphons. These organs, all of which have been
utilised in classification, will be considered separately.
The mantle is closely applied to the surface of the valves, and is usually
attached to them along a line near its periphery. This line is indicated by a
continuous scar or impression upon the inner surface of the valves, termed
the pallial line. Outside the pallial line a portion of the margin is free and
usually thickened. In it are contained the glands which secrete the shell,
and also pigment glands ; it is ornamented by papillae, tentacular processes,
etc., and is sometimes furnished with visual organs of a primitive sort.
Certain archaic forms had no distinct pallial line, the mantle being organi-
cally attached over a more or less irregular area. The ends of the pallial
line are commonly continuous with the scars of the adductor muscles.
The majority of Pelecypods have two adductor muscles, and are distinguished
accordingly as Dimyarian, or Homomyarian ; in some the anterior muscle is
absent or degenerate {Monomyaria) ; and in. others an intermediate condition
obtains (Ileteromyaria or Anisomyaria). The number and position of the
adductors was formerly accepted as a fundamental feature in classification,
although many difficulties were presented by exceptional cases. Recent
researches have shown that an absolute foundation for classification cannot
be afforded by the number of adductors ; but still, if allowance be made for
degeneration caused by inequilaterality, torsion and other causes, the general
myarian types harmonise fairly well with the larger divisions based on the
totality of characters.
The visceral mass, as a rule, occupies the upper portion of the shell,
and contains the heart, intestinal canal, generative organs, renal and other
glands. The rectum usually lies above the posterior adductor, and dis-
charges into the anal siphon, when present. The mouth is placed at the
forward end of the visceral mass below the anterior adductor, and is commonly
furnished on each side with a pair of leaf-like expansions of the integument
called palpi, which are ciliate internally, and serve to conduct alimentary
matter from the gills to the mouth. Palpi are seldom wanting, and their
form and character remains fairly constant throughout a number of groups.
The mouth itself is unarmed, and the alimentary canal is more or less bent,
usually exhibiting a dilation which is regarded as the stomach.
428 MOLLUSCA phylum vi
The Foot. — From the ventral surface of the visceral mass projects an
extensile muscular organ, known as the foot, which is capable of being pro-
truded beyond the margins of the valves, or entirely retracted within the
mantle lobes. The muscles serving to move this organ are inserted upon the
shell near the adductor scars, leaving small accessory impressions. In a
large majority of bivalves, the foot has the familiar hatchet-shape from which
the class name is derived, but as an organ of locomotion, tactile use, and
possibly prehension, it is modified for special uses in many forms. A few
Pelecypods, such as Ostrea, have the foot altogether aborted, though remnants of
its retractor muscles exist and are attached to the valves ; and in some cases
{Pholadomya, Halicardia) an accessory foot- like organ, or " opisthopodium,"
is developed at the posterior end of the visceral mass.
In many Pelecypods the foot is provided with a gland secreting horny
matter which solidifies in threads after extrusion, forming a fixative tuft or
cable called the hijssus, by which the animal adheres to extraneous objects.
Some sessile genera have the byssus more or less calcified, when it forms a
shelly phig closing a sinus or foramen in one of the valves through which it
passes. Many of the Pectinidae have a comb-like series of denticles (denoliutn)
on the edge of the byssal sinus, in which the byssal threads rest. In perma-
nently sessile forms, the byssus is usually absent.
Gills. — On either side of the visceral mass above the foot and usually
extending from the palpi to the posterior adductors are the gills or denidia.
In a general way the ctenidium is composed of a stem carrying a nerve and
blood-vessel, from which on each side leaflets or slender filaments are given
out laterally. In the more archaic types (Nucula, Yoldia, Solemya) these gills
are plate-like, not organically united except by the stem, though in some
cases attaining a solidarity as a mass, by the interlocking of very large cilia,
distributed in bands or patches on the opposed surfaces of individual plates.
These plate - like gills are termed foliobranchiate or protobranchiate.
According to their structure, other types of gills are intermediate between
these and the so-called " filibranchiate," in which the plates are elongated and
strap-like, and the " reticulate," in which the filaments are united by cross
conduits in a net-like manner. Attempts have been made to employ the
various types of gills as fundamental characters in classification, but experience
has shown that they cannot be depended upon as the exclusive basis of any
systematic arrangement.
Siphons. — When the mantle lobes are united, two posterior openings, more
or less tubular, are always present
(Fig. 640). The dorsal tube, called
the dorsal or anal siphon, serves for
the discharge of water which has
been inhaled through the ventral
pjf. p,4o ^ or branchial siphon, carried to the
Saxicava arcfica Lam. Animal with closed mantle giUs, deprived of its OXygen and
edges, shnwins foot (p), protrudiii,;,' from the pedal open- p^KUlp mrtiVlpc! and ihpn pynpllpd
InK, and anal (,v) and Inanchial (.s') siphons. Natural size. eCUDie partlCieb, anu tlieu expeiieu.
The anal siphon also carries eff"ete
matters from the rectum, and sometimes ova are discharged in the same
way. The tubes are sometimes adherent or enclosed in the same envelope,
and sometimes separate to their base ; in general, however, a septum or
partition exists between the two passages, thus avoiding the mixture of the
CLASS I
PELECYPODA
429
two currents. The siphonal septum is frequently carried forward internally,
or supplemented by a junction of the gills in such manner as to form a
practically continuous partition between the anal and branchial regions
within the mantle. The siphons are always contractile, and, except in
sedentary burrowers, usually retractile wathin the shell.
The siphons, being a local modification of the mantle margin, receive their
musculation from the same source. In general, the muscles have spread
inward, fari passu with the increase in length of the organ to be retracted,
and their insertion on the valve leaves an angular scar called the pallial sinus,
which is an important aid in classification of the minor groups. It has some-
times been assumed that the absence of this sinus was evidence of the
asiphonate character of the species, but the example of Lucina, Cuspidaria,
and several other siphonate forms which have no pallial sinus show that this
is not necessarily true. Formerly, when the character of the pallial line was
Ftg. 641.
Fig. 642.
Lutraria elUptica Roissy. Interior of left valve show- C'rassatellitesplumheus{Chem.). Interior of left
ing pallial line (p) ; pallial sinus (s) ; anterior (a) and pos- valve showing entire pallial line (m) ; anterior (a)
terior (»') adductor scars; and resiliifer (/). hv, Length; and posterior (a) adductor scars; and resiliifer
lit, Height of the sliell. -/-^ natural size. (I). 2/^ natural size.
regarded as of prime importance, the Pelecypods with a sinus were called
Sinupalliafa (Fig. 641), and those without, TntegripaUiafa (Fig. 642).
The Hinge. — The origin both of the hinge structure and the ornamentation
of the shell can be perhaps best understood by a consideration of what is
known regarding the archetype of the class, and by noticing the changes that
have since been introduced. The original protopelecypod was small, thin,
symmetrical, sub-circular or oval, with a short external ligament equally dis-
posed on each side of the beak along the hinge line. The mantle was not
uniformly attached to the shell along a pallial line, as in modern Pelecypods,
but adhered more or less irregularly and was not provided with extrusile
siphonal tubes. The adductor muscles were sub-equal, symmetrical, and
situated high up in the valves. The surface of the valves was smooth, or
(probably in connection with the development of tactile papillae on the mantle
edge) radiately ribbed. These conclusions are justified not only by inference
and by recent investigations on the morphology of the prodissoconch, but by
the characters of the most archaic Pelecypods, summarised by Neumayr under
the name of Palaeoconcha.
Since the general form of the Pelecypod depends upon its principal
anatomical characters (the size, number and position of the muscles, the
presence, size and character of siphons, byssus, etc.), then, to a certain
limited extent, especially in the modification of the primitive simple Palaeo-
430 MOLLUSCA phylum vi
conchs, it is plain that the differences of form would march with the respective
anatomical differences. For example, those forms which retained the simple
open mantle and sub-equal adductors would continue to be of a rounded and
symmetrical shape ; while those which tended to produce elongate siphons, or
in which marked inequality of the adductors was developed, would probably
present more elongate or triangular outlines. The differences of form would
necessarily react upon the developing hinge, from the inevitable operation of
physical laws, and thus tend to produce in connection with particular lines of
evolution of form, particular types of hinge.
The recent researches of Bernard and Simroth have developed the fact
that in some Pelecypoda the ctenidium originates as a lateral plate, which
becomes transversely folded, and in which the reticulate form results from
subsequent perforations between the folds, and not from the concrescence of
originally separate filaments, as has been hitherto supposed to be the invari-
able mode.
Neumayr has shown that, among the Palaeoconcha, ribbing existed in
various species along the dorsal as well as the other margin, and that it pro-
duced denticulations there ; and that when these denticulations had become
a fixed specific character, the ribbing disappeared from the area above the
hinge margin.
In this way (as analogically in the Recent Crenella, etc.) the initiation of
the processes called hinge teeth began. Such projections, interlocking at a
time when the serrations of the other margin of the open valves could be of
little assistance in securing rigidity, offered a means of defence of the greatest
importance when fully developed by natural selection, one which would be
useful at every stage of development, but would increase in usefulness with
increase in size. In fact, this was just such a feature as would lend itself to
the fullest operation of natural selection. Once well initiated, its progress
was inevitable, and its variety and complexity only a question of time.
From recent studies by Bernard of the development of hinge teeth in
nepionic Pelecypods of many groups, it appears that in most if not all Priono-
desmacea and some Teleodesmacea there is first developed on each side of the
ligament (or behind it in Ostrea) a series of transverse denticulations or
minute taxodont teeth, forming what has been called a provinculimi or primi-
tive hinge, independent (so far as yet observed) of the permanent dentition.
The latter begins subsequently by the development of distinct laminae on
the hinge plate. In the Teleodesmacea, toward the ends of the hinge plate
the primitive lamellae originate below the provinculum or in its absence, and
grow proximally. The inner ends of the anterior lamellae become hooked,
and these hooks separate from the distal portions which remain to form the
anterior laterals, while the hooks develop into the cardinals, and the posterior
lamellae into the posterior lateral teeth. The facts point, of course, to the
provinculuni as representative of the primitive hinge as observed in many
Palaeoconchs ; but the gap between the provinculum and the beginnings of
the permanent dentition, indicates a suppression of certain developmental
stages which only further researches can supply.
The dynamical origin of the shelly processes of the hinge, which we call
teeth, has only recently attracted attention. In this work Neumayr led the
way, and his contributions have been most valuable ; yet, as often happens
with pioneer work, he failed to grasp fully all the details of the subject, and
CLASS I
PELECYPODA
431
the nomenclature he proposed has required revision. Several groups or
kinds of teeth can easily be distinguished. These are not necessarily funda-
mental, since the teeth, being largely moulded by the dynamics of their
situation, change with the influences- to which their form is due, and in course
of time may become obsolete from disuse {Anodon), or modified so as to
simulate the teeth of groups with widely different pedigree (Nucula, Mutela,
Plicatula, Trigonia). In general, however, at any given time, the types of
teeth are good evidence of the relationship of forms to which they are
common, especially if the development from the younger stages of the species
under comparison proceeds along similar lines.
The modifications of the hinge now generally recognised are as follows : —
In the Taxodonta the hinge is composed of alternating teeth and sockets,
mostly similar, and frequently forming a long series, as in Area (Fig. 643, A)
A
Fig. 643.
Taxodont hinges. A, Area, with external ligament. B, Leda,
with internal resilium.
Fir;. 044.
Schizodont liinge.
Trigonia pectinata
Lam. Recent ; Aus-
tralia.
or Leda (Fig. 643, B). The Schizodonta have heavy, amorphous, variable
teeth, often obscurely divided into sub-umbonal (pseudocardinal) and lateral
(posterior) elements, as in Trigonia (Fig. 644), Unio (Fig. 645), and Schizodus.
In the Isodonta the original taxodont
provinculum is often replaced in the adult
by a hinge structure derived from two
ridges (the "auricular crura") originally
diverging below the beaks. This becomes,
in the most specialised forms, an elaborate
interlocking arrangement of two concentric ^'
pairs of teeth and sockets, which cannot
be separated without fracture, as in Spon-
dylus (Fig. 718). In less sj^ecialised forms,
such as Pccten, the provinculum becomes
obsolete, and the crura only partially de- fS^^^^
velop.
The Dysodonta of Neumayr was originally a heterogeneous group, and the
term is now restricted to that division having a feeble hinge structure, whose
origin is more or less palpably derived from external sculpture impinging
upon the hinge line, as in Myoconcha (Fig. 646), Pachymytilus (Fig. 647), and
Crenella.
The preceding groups, together with the edentulous Solemyacea, constitute
the order Prionodesmacea, which is knit together by community of descent
still traceable in their anatomy.
Fig. G45.
Schizodont hinge of Unio stnchei NenmajT,
showing pseudocardinal and lateral teeth.
432
MOLLUSCA
PHYLUM VI
nor the latter
one gi'oup.
Dysoflont hinge of
Mi/ocoiich(.i striiUula
Goldf. LowerOolite;
Bayeux, Calvados.
Vi.
d'Orb. Coral Rag; Coulange - sur ■
France. '■^/■.
■.i-
The Pantodonta are a small group of Paleozoic forms whose dentition
partakes of the synthetic character of the more archaic forms, while fore-
shadowing the future teleo-
dont types. In this group
the laterals may exceed a
pair in a single group, which
is never the case in the
modern types. Orthodontiscus
and Allodesma are examples.
The Diogenodonta are the
modern and perfected forms
in which there are differen-
tiated lateral and true car-
dinal teeth upon a hinge
plate, the former never ex-
ceeding two,
three in any
Fir:. 646,
pjj. g^^ Astarte (Fig. 754), Crassatel-
Bysodont hipge of Paehymytilu!< petaM.s UteS (Fig. 642) and Corbicula
i-Yonne, (Fig. 76 1 ) are examples.
The Cydodonta exhibit
extreme torsion in their dentition, which curves out from under the beaks
and is not set upon a flat hinge plate. Isocardia (Fig. 806), Tridacna and
Cardium (Fig. 801) are examples.
In the Teleodonta are found the most highly perfected types of hinge.
The characters of the less specialised forms hardly differ from those of the
Diogenodonta, but they are placed here on account of their obvious affinities
as shown by other characters. The most sjjecialised forms add to the ordinary
cardinal series of the Teleodesmacea (10101 ) either a roughened area, as in
Venus ; a series of extra cardinals, as in Tivela ; or accessory lamellae, as in
Macfra, making the hinge more complicated or efficient. Cytherea (Fig. 809),
Madra (Fig. 824), Venus mercenaria and Tivela are examples.
Several of these forms were included by Neumayr in a group called Des-
modonfa, which he founded on such types as Madra under a misapprehension
as to the character of the hinge ; almost all of the others were included in
his Heterodonta, which, construed strictly, would take in all dentiferous
Pelecypods, since the alternation forming its essential character is inseparable
from the possession of functional teeth.
The Astlienodonta comprise borers and burrowers in which the teeth have
become obsolete from disuse. Corhula (Fig. 828), Mya (Fig. 827) and Pholas
(Fig. 833) are illustrative types. In the last-named a remarkable develop-
ment of the sub-umbonal attachment of the mantle has produced a myophore
which is sometimes wrongly interpreted as a tooth. The exceptional develop-
ment of this featvu'e is explained by the dynamics of Pholad existence.
The above groups form the orderTeleodesmacea, and dentally are intimately
related. Recent studies by Bernard ^ as to the genesis of individual teeth
^ Bernard, F., Sur le developpement et la morphologie de la coqiiille chez les lamellibrancbes.
Bull. Soc. Geol, France [3], 1895-97, vols, xxiii., xxiv. — Vest, W. von, tlber die Bilduiis uiid
Entwicklnng des
Dull, W. 11., On t
xxxviii. — Rcis, O.
Bivalveiisclilo.sses. Verh. Sieheiib. Vereins Naturw., 1895-96, vol. xlviii.- —
he hinge of tlie Pelecypods and its development. Ainer. Journ. Sci., 1S89 [?>], vol.
Das Ligament der Bivalven. Jahresh. Ver. Vaterl. Naturk. Wiirtt., 1902, vol. Iviii.
CLASS I PELECYPODA 433
among members of this order show great uniformity in the early stages.
But inasmuch as these observations are dependent upon the mode of growth
in highly specialised Pelecypods, in which the development of teeth is largely
secondary, care must be taken not to confound these processes with those by
which hinge teeth were originally initiated in edentulous Protopelecypods.
Finally, in the Anomalodesmacea we have a tribe of burrowers which have
preserved to the present day some of the features which characterised the
edentulous Protopelecypods of ancient geological time. The small teeth of
the nearly edentulous hinge may sometimes be associated with the submersion
of the resilium and the development of a chondrophore, but in other cases
they may be the remnants of hinge teeth acquired in the ordinary way early
in the geological history of the group.
Dental Formulae. — For the purpose of recording compactly the number
and character of the teeth in adult Pelecypods, a formula has been suggested
by Steinmann, which, somewhat amplified, is as follows : —
Let L represent the left and R the right valve, and the teeth be repre-
sented by units ; the sockets into which teeth of the opposite valve fit by
zeros ; the resilium or chondrophore by C ; the laterals by 1 ; the clasping
laminae which receive the laterals by m, if single ; if double, by m2. Where
two taxodont rows meet on one hinge margin and are not separated by a
resilium, as in Glycimeris, let their junction be marked by a period. Obsolete
or feeble teeth may be represented by the italicised symbol for normal teeth.
For amorphous, interlocking masses, which cannot be classified as teeth, and
are of varied origin, the symbol x is adopted. The enumeration begins at the
posterior end, and the right-hand end of the formula is always anterior.
Thus, types of teleodont dentition may be represented as follows : —
Astarte horealis, -rrrTii-n^r- ; Crassatellites antillarum, v, . „,„ ; Venus mercenaria,
L -01010 R^iOlOZ??!^ ' K/cOlOm' '
R" ioToT (^^^ ^^^^ ^^^® ^ represents the rough area below the ligament).
In investigating the genesis of the individual hinge teeth in various
genera of the Teleodesmacea, Munier-Chalmas and Bernard have adopted the
following formula, which expresses at once the origin and position on the
hinge of the several teeth. In the majority of cases the teeth appear to be
derived from two primitive pairs of lamellae in each valve, one pair anterior
and one posterior. Each adult tooth is designated by an Arabic numeral
corresponding to the primitive lamella from which it is derived, with a for
the anterior and h for the posterior tooth Avhen a single primitive lamella
gives rise to two teeth. The laterals are counted from below upward in
Roman numerals, the odd numbers belonging in every case to the right, and
the even numbers to the left valve. If it is necessary to name a socket it
receives the designation of the tooth which occupies it, supplemented by an
accent ('). A and P stand for anterior and posterior, L for lateral, and CA
for cardinal teeth. Finally, if a tooth disappears, its place is indicated by
a zero with an index showing which particular tooth it was. The numeration
of the cardinals always begins with the right median cardinal tooth. Thus,
CAl = median cardinal of the right valve, CA25 = left median cardinal derived
from the posterior part of primitive lamella number two ; LA I = ventral
anterior lateral, LP III = dorsal posterior lateral, etc.
Ligament. — The ligament wh-ich unites the two valves, as stated above, is
primitively continuous with them as the uncalcified part of the primitive
VOL. I 2 F
434 MOLLUSCA phylum vi
pellicle secreted by the original shell gland ; it is therefore neither external
nor internal. With its subsequent dift'erentiation, and the thickening of the
valves by calcification deposited about it, it occupies a depression in the
cardinal margin which Bernard has regarded as internal. In a sense it is
internal, but its position at this stage is not significant, and there is no
fundamental difference between the cases. The differentiation in function
and structure which we find in the adult between the ligament, properly
so-called, and the " internal ligament " or resilium, is a later development.
The ligament may be regarded as a 'fundamental character of Pelecypods,
and is universally present, though in some cases as a mere degraded rudiment
(Pholadacea) ; it may be separated from the valves and functionless (Chlamydo-
concha), or present only in the young stages and lost through specialisation
due to the sessile habit (Rudistids).
As the most important factor in the mechanism of the valves, the liga-
ment has undoubtedly developed with the evolution of the class, and its
chief modifications date from the earliest period in the life-history of the
group. The function of the original ligament was that of an external link
between the valves having the essential nature of a C-spring. That is, the
insertion of the ligament edges on the cardinal margins, or, at a later period,
on thickened ridges or nymphae by which these margins are reinforced to bear
strains, resulted in the following conditions : — The valves being held together
and, in closing, approximated by the contraction of the adductor muscles, the
preservation of their precise apposition, marginally, is due to a rotary motion,
exerted along the axis of the ligament, which pulls the attached edges of the
ligament nearer to each other and exerts a strain on its cylindrical exterior.
This operation, with a thin ligament, involves a tensile strain on the Avhole
cylinder ; with a thick ligament the external layers are strained and the
internal layers compressed, so that to the tensile elasticity of the external
layers is added the compressional elasticity of the internal portion. The
result of the differing strains to which the several layers of the ligament are
subjected brings about a difference of structure, and, whenever the ligament
becomes deep-seated, there is a tendency for the respective parts to separate
along the line where the two sets of strains approximate. We then have two
elastic bodies, operating reciprocally in opposite directions, the outer or liga-
ment proper tending to pull the valves open to a certain distance correspond-
ing to its range of tensional elasticity ; and the other or resilium (for which
the objectionable terms "cartilage" and "internal ligament" have been used)
tending to push them open to an extent corresponding to its range of expansion.
The ligament proper is of a more or less corneous nature, tough and semi-
translucent beneath its external surface. When dry it has a vitreous fracture,
and often shows hardly any fibrous texture.
The resilium is distinctly lamellar or composed of horny fibres, which are
apt to give a pearly sheen to its broken surface. There is often a more or
less extensive intermixture of lime in its substance, which may be diffused, or
may be especially concentrated along the median plane. As may be seen by
examining the unbroken resilium (as in Madra), this organ in such cases has
something of an hour-glass shape ; the ends which fit into the " cartilage pits "
or resiliifers being more expanded than the centre between them. The deposit
of lime in the form of an accessory shelly piece, usually termed the ossiculum
or lithodesma, serves for the reinforcement of the resilium.
cr^Ass I
PELECYPODA
435
'Mm
Fig. 648.
Hmnoraya'calciformis Ag. Lower Oolite ; near Bayeux.
With well-preserved external, opisthodetic ligament. 2/3.
For the type of ligament which extends on both sides of the beaks,
Neumayr adopts the designation amiihidetic ; and for the more perfected type
which has been withdrawn wholly behind the beaks, he employs the term
opisthodetic (Fig. 648). Glycimeris offers a conspicuous type of the amphidetic
ligament : Tellina and Venus ex-
emplify the opisthodetic arrange-
ment. In many bivalves a
lozenge-shaped cardinal area ex-
tends amphidetically between the
beaks, while the ligament is wholly
posterior, being visible as an
oblique triangular space, with its
apex at the umbonal point and
its base at the hinge line, as in
Fteria. Nearly every stage in
the recession of the ligament can
be observed, from truly central to
posterior, in Lima and its allies.
The most perfected type of ligament is that which may be compared to a
cylinder split on one side, and attached by the severed edges, one edge to
each valve. This type is known as parivincMlar (Tellina, Cardium) ; its long
axis corresponds with the axis of motion or vertical plane between the valves,
and in position it is iisually opisthodetic. Another form is like a more or
less flattened cord extending from one umbo to the other (Spondi/lus, Lima),
with its long axis transverse to the plane of the valve margins and the axis
of motion. This is called alivincular ; it may be central or posterior to the
beaks, but, unless veiy short, is usually associated with an amphidetic area.
Lastly, a third form must be noted which consists of a reduplication of the
alivincular type at intervals upon the area (Perna, Area, Fossula), either
amphidetically or upon the posterior limb of the cardinal margin. This is
designated as multivincular, and is developed out of the alivincular type.
In some forms with a rigid hinge and internal resilium, the ligament may
degenerate into its archaic epidermic character, as in some species of Spondylus.
It is impossible to draw a sharp line between these and similar forms in which
the ligament is not quite reduced to the state of epidermis, as in some species
of Ostrea. The cardinal area above referred to is in part the morphological
equivalent of the lunule of teleodont Pelecypods. In general, when the
ligament has become opisthodetic, the remnant of the area in front of the
beaks forms the lunule and may be called prosodetic. The amphidetic area
is an archaic feature which has been lost by the more specialised types of
modern bivalves, and its gradual disappearance may be traced in various
Prionodont genera.
The separation of the ligament and resilium has been described as due to
mechanical causes. In those cases where the resilium becomes submerged
between the valves, the area of attachment of its ends in thin-shelled forms is
more or less thickened and assumes a spoon-like form projecting from the
hinge-plate, termed the cJiondrophore or resiliifer ; this is often reinforced by a
special prop or buttress called the clavicle. It has been suggested by Neumayr
that part of the armature of the hinge, in the shape of teeth, is due to deposits
made parallel to or induced by the presence of the chondrophore and resilium.
436 MOLLUSCA phylum vi
There is some reason to think that the presence of the resilium in Peden
and Sjpondylus may be connected with those changes of the anricular crura
which lead to the assumption of dental functions by the latter. But it is well
known that submergence of the resilium occurs independently in many unre-
lated groups of bivalves ; and it is probable most of them were previously
dentiferous and still retain their teeth, although more or less modified or
displaced, while the edentulous genera seldom show any teeth which appear
to owe their existence solely to the presence of a chondrophore. The nearest
approach to a hinge composed of dental laminae of such an origin is found in
Placuna, Placenta and Placunanomia, together with the Spondylidae already
mentioned.
Classification. — The class Pelecypoda, which comprises about 5000 recent
and twice as many fossil species, appears to be divisible into three ordinal
groups : Prionoclesmacea, Anomalodesmacea and Teleodesmacea ; of which the
third represents the most perfected and developed (though not always the
most specialised) modern type of bivalve. There seems little reason to doubt
that all these orders are descended from a Prionodesmatic radical or prototype,
and that for various reasons the first and second retain more evident traces of
this origin than the third.
For convenience of comparison, the characteristics of these orders will be
stated here.
Prionodesmacea. — Pelecypods having the lobes of the mantle generally separated, or,
when caught together, with imperfectly developed siphons ; the soft parts in general
diversely specialised for particular environments ; the shell structure nacreous and prismatic,
rarely porcellanous ; the dorsal area amphidetic or obscure, rarely divided into lunule and
escutcheon, and wlien so divided, having an amphidetic ligament ; ligament variable, rarely
opisthodetic ; nepionic stage usually with a taxodont provinculura ; permanent armature of
the hinge characterised by a repetition of similar teeth upon the hinge line, or by amorphous
schizodont dentition ; habits active, sessile or nestling, not burrowing ; monoecious or
dioecious.
This group, originating with the earliest forms, has retained many arcliaic
features through immense periods of geological time, although occasionally developing
remarkable and persistent specialisations. Notwithstanding most of its subdivisions
have arrived at a notable degree of distinctiveness, intermediate forms of ancient date
connect them all, more or less effectively, with the parent stem.
Anomalodesmacea. — Pelecypods having the mantle lobes more or less completelj' united,
leaving two siphonal, a pedal, and sometimes a fourth opening between them ; siphons well
developed, always at the posterior end of the body ; two subequal adductor muscles ; the
shell structure nacreous and cellulo- crystalline, rarely with a prismatic layer; the area
amphidetic or obscure, rarely distinctly divided ; the ligament usually opisthodetic, generally
associated with a separate resilium, chondrophores and lithodesma ; valves generally un-
equal, the dorsal margin without a distinct hinge plate, armature of the hinge feeble, often
obsolete or absent ; rarely with lateral laminae or well-developed dental processes ; usually
burrowing, hermaphrodite, and marine.
This group is intimately related to many of the Palaeoconcha, except as regards
the presence of a pallial sinus. • It retains many archaic features, and includes several
of the most specialised modern forms. Through the Anatinacea it aj^proxiuiates the
Myacean Teleodesmacea. It is peculiar in the possession of a litliodesma, and in the
structure of its gills and hinge. The forms with a reticulate gill have it of a different
type from the reticulate gills of the other orders ; those which retain a modified
foliobraiu'h gill have it diffei'cnt from the fbliobrancli gill of Prion odesmacean groups.
There ai'e no forms with a filibranchiate gill, or with a typically fully develoj^ed
reticulate gill.
CLASS I PELECYPODA 437
Teleodesmacea. — Pelecypods with reticulate gills, the ventricle of the heart embracing
the r^'ctiun ; having the mantle lobes more or less connected and usually possessing developed
siphons ; the adductors practically ecjual ; the shell structure cellulo-crystalline(porce]lanous)
or obscurely prismatic, never nacreous ; the dorsal area, when present, always prosodetic or
divided into lunule and escutcheon ; ligament opisthodetic, with or without separate
resilium ; without a lithodesma, rarely with external accessory shelly pieces ; nepionic stage
usually without a taxodont provinculum ; pei'manent armatm-e of the hinge characterised by
the separation of the hinge teeth into distinct cardinals and laterals ; the posterior laterals,
when present, placed behind the ligament ; the animals active or nestling, sometimes sessile,
but rarely sedentary burrowers, rarely inequivalve, usually possessing a hinge plate and a
pallial sinus ; sexes usually separate.
It is doubtful if this group is represented in the Paleozoic rocks, especially below
the Carboniferous, though genera belonging to it are foreshadowed by some of the
Palaeoconclis. Although most of the Teleodonts live embedded in the surface of the
sea-bottom, they retain their ability to migrate, and only a few extremely specialised
forms inhabit permanent burrows of their ow^n construction. They are sometimes
commensal in the burrows of other animals. Similarly, few of them fix themselves
Ijermanently by a byssus, although often byssifei'ous, especially when young. With
the exception of a few specialised forms they possess a pair of direct and reflected
branchial laminae on each side of the body, frequently united behind the foot, forming
an anal chamber ; the two sets on one side usually of unequal size, and of the reticulate
tyj^e. None are known with typically foliobranch or filibrancli gills, although some
abyssal forms have archaic sub-foliobranchiate ctenidia.
There remains a small group of fossils, difficult to refer to a place in the system,
yet characterised by several features in common ; these have been named by Neumayr
Palaeoconcha, and are defined by him as follows :—
Palaeoconcha. — Prototypic Pelecypods, Mith thin shells, a simple or obscure pallial line,
sub-equal adductor scars placed high in the valves ; dorsal area absent or amphidetic ; liga-
ment externa], vaiiable ; hinge margin edentulous or with polymorphous teeth formed by
modifications of the margin and not set upon a hinge plate.
While the forms included here are not always actually tlie most ancient, yet in
their modifications they indicate clearly the origin of many subsequently developed
structures found in Pelecyj)ods of a more modern type ; and owing to their undifferen-
tiated polymorphic character are difficult to assign a place in any classification based
on more highly developed forms. There is little doubt that some of these show taxo-
dont affinities, and others recall Pholadomya ; but the final discussion of these puzzling
forms awaits greater knowledge of them and other early bivalves. It is to be under-
stood that the places assigned them in the present systematic arrangement must be
more or less provisional. Neumayr included in this group the following families ; —
Vlastidae. Fraeeardiidae, Solenopsidae.
Gardiolidac. Silurinidae. Grammysiidac.
AntipleiD-'idae. Protomyidac (including possibly Posidonoviyidae.
Lunulicardiidac. the Recent Solemya). Daoncllidae.
The pelagic Planktomya henseni, recently described by Simroth, presents many of
the characteristics of the Palaeoconchs. The posterior cardinal margin is denticulate,
the ligament internal, and the gills are rejjresented by a single lateral plate parallel
with the longer axis of the shell on each side ; a type elsewhere only knowar in con-
nection with the younger stages of Scioheretia.
438
MOLLUSCA
PHYLUM VI
Order 1. PRIONODESMACEA Ball.
Section A. Palaeoconcha p.p. Neumayr.^
Family 1. Solemyacidae.
Shell soleniform, equivalve, low-beaked, edentulous, gaping, with the anterior end
longer and the epidermis conspicuous, exceeding the valves ; area obscure or none ; ligament
amphidetic, parivincular, usually internal posteriorly ; mantle lobes united ventrally,
attached in front to the periostracum and valves by a broad surface, leaving no distinct
pallial line ; a single posterior siphonal and anterior pedal foramen in the mantle ;
adductors s^ib-equal, with a thickened ray in front of the posterior sear ; animojl dioecious,
marine, burrowing. Devonian to Kecent.
Solemya Lam. Carboniferous to Eecent, rare in all horizons. Janeia King,
shorter and less inequi valve, may include most of the Paleozoic species hitherto
referred to Solemya. Glinopistha Meek and Worthen, from the Carboniferous, is also'
allied, and Dystactella Hall, is united with it by Zittel. Phthonia Hall, from the
Devonian, is placed here by Ulrich. Acharax Dall, Mesozoic to Recent, has a purely
external ligament and no clavicle.
Family 2. Solenopsidae Neumayr,
Shell thin, elongate, equivalve, with very anterior beaks ; the hinge edentulous, ligamient
parivincular, external ; pallial line not sinuated ; a ridge or groove radiating from the
beak to the lower posterior angle of the valves. Marine. Devonian to Trias.
Sanguinolites M'Coy. Elongate, obliquely truncate behind ; beaks low, sculp-
ture of concentric or broken lines, an-
terior adductor scar buttressed by a
Carboniferous.
Promacrus and Prothyris Meek.
Carboniferous.
Arcomyopsis Sandb. Somewhat
curved, with prominent beaks; obliquely
truncate behind; posterior area radially, the rest of the surface concentrically
sculjitured. Devonian.
Solenopsis M'Coy (Fig. 649). Very long, scabbard-shaped, smooth ; anteriorly
short and rounded, gaping behind. Devonian to Trias.
' ridge.
Fig. 649.
Solenopsis pelagica Goldf. Devonian ; Eifel District.
Family 3. Vlastidae Neumayr.
Shell thin, very inequivalve, beaks elevated, hinge line edentulous, arched, meeting at an
obtuse angle beneath the beaks, leaving a dorsal opening ; surface smooth or concentrically
striate.
The two genera Vlasta and Dux (Vevoda) Barrande, from the Silurian of Bohemia
(Etage E 2), constitute this family.
Family 4. Grammysiidae Fischer.
Shell thin, equivalve, oval or elongate, with the beaks sub-central to anterior ; hinge
edentulous, sometimes thickened. Ligament parivincular, external ; 'pallial line not
simiate ; surface smooth or concentrically sculptured. Silurian to Carboniferous.
' [The terms Palaeoconcha, Taxodonta, Schizodonta, etc., preceded liy Roiiiau numerals, are
retained here merely as convenient descriptive ajipellations, and are in nowise to be regarded as
possessing systematic values.]
CLASS I
PELECYPODA
439
Grammysia Vern. (Sphenomya Hall) (Fig. 650). Shell elongate-ovate, concen-
trically sculptured, with a deei^ lunule ; cardinal margin thickened, edentulous ;
surface with several radial
grooves. Silurian and De-
vonian. Protomya Hall is
similar but without the AmXil/i£K^i\\\lll]\ Xfl/I'i'J' '■
Leptodormis M'Coy, Sil-
urian ; Elymella, Glossites,
Euthydesma, Paleanafina
and (?) Tellinopsis Hall ;
Devonian.
Gardiomorpha Koninck,
Fig. 650.
n,^Ql i,^flof,irI K^oVc oi„.^c<- Grammysia hamiltcnensis Vern. Spirifer Sandstone (Lower Devonian) ;
uvai, mnaiea, oeakS almost Lahnstein, Nassau (after Santlberger).
anterior, consj^icuous, ad-
jacent, jjrosogyrous ; hinge line thin, arched. Silurian and Carboniferous.
Isoculia M'Coy. Like the preceding, but with coarse concentric sculpture.
Carboniferous.
Other Carboniferous genera are Broeckia Koninck ; Ghaenomya Meek ; Sedgwickia
M'Coy ; and Edmondia Koninck. The last is like Gardiomorpha but gapes in front,
with a narrow ridge below the beaks.
The Cambrian Fordilla Barrande, earliest of bivalves if a Mollusc, very likely belongs
to the bivalved Crustaceans near Estheria. It is minute, oval, somewhat arcuate, and con-
centrically striated. Lo^Ver Cambrian ; New York and Massachusetts.
Another bivalved shell, regarded by some authors as a Pelecypod, Modioloides priscus
Walcott, from the Lower Cambrian of eastern New York, is probably also of Crustacean
affinities. Pizzaroa, Timaria and Bistramia Hoek, from' the Silurian of Bolivia, are probably
byssal bivalves.
Family 5. Cardiolidae Neumayr.
Shell equivalve, inflated, obliquely ovate, with prominent beaks, and edentulous hinge ;
sculpture often radial, or sometimes of concentric ridges which may be confined to the
beaks. Silurian and Devonian.
Gardiola Bred. (Fig. 651); Gloria Barrande; Eopteria
(? Euchasma) Billings ; from the Ordovician, may also belong here.
Family 6. Antipleuridae Neumayr.
Shell very inequivalve without gape below the beaks; hinge
obscurely taxodont, with an amphidetic area and predominantly
radial sculpture. Silurian.
Antipleura, Dualina and Dalila of Barrande.
Family 7. Praecardiidae Neumayr.
Shell equivalve with taxodont dentition and usually strong
radial sculpture. Silurian and Devonian.
This family contains the following genera of Barrande from the Silurian of
Bohemia : Praecardium, Paracardium, Puella, Pentata, Buchiola {Glyptocardia Hall),
Praelucina, Regina, Praelima ; to which Neumayr adds Pleurodonta Conrath, and
Pararca Hall. It is possiljle that Silurina Barrande, regarded by Neumayr as the
type of a distinct family, may also be included. It is distinguished by its feelder
structure and a dorsal radial groove near the cardinal border.
Fio. 651.
Canliola mrnucopiac
Goldf. Devonian ; Ebers-
reuth, Piclitelgebirge. ^/j.
440
MOLLUSCA
PHYLUM VI
Pig. 652.
Section B. Taxodonta Neumayr (emend.).
Superfamily 1. NUCULACEA.
Shell of variable form, closed ventrally, equivalve, loith a smooth epidermis ; nacreous
or porcellanous iviih tubuliferous external prismatic layer ; area obscure, or none, when
present divided into lunule and escutcheon ; ligament variable, amphidetic ; gills folio-
branchiate ; both adductors present and sub- equal ; foot grooved and reptary, not
byssiferous ; marine.
Family 8. Ctenodontidae Dall.
Shell nuculiform, with the teeth in a continuous arched series ; no area ; ligament
external, alivincular, icithout an external resilimn ; pallial line simple. Ordovician
and Silurian.
Ctenodonta Salter (Tellinomya Hall p.p.) (Fig. 652). Oval, smootli or con-
centrically striate, iii^ the later horizons sometimes with Leda-like
ornamentation. Ordovician and Silurian.
Gucullella (M'Coy) Fischer. Ovate, thin-shelled, with a straighter
hinge Hue and a radial buttress to the anterior adductor. Silurian.
Family 9. Nuculidae Adams.^
ctenodonta pectim- Shell compact, closed, with the teeth in two series meeting below the
culoidcs HaXl. Ordo- , ,77777 .71, j,
vician; Cincinnati, umbones, separated by a chondrophore ; area represented by an obscure
H^m ^'^ ^^^^^^ lunule and escutcheon ; no ligament, but a wholly internal, amphidetic,
alivincular resilium ; internal layer of shell nacreous; mantle lobes
free, without siphons ; pallial line simple. Silurian to Eecent.
Nucula Lam. {Nuculana Link) (Fig. 653). Oval or triangular, concentrically or
reticulately sculptured. Silurian to Eecent. Re- a
presented by over 200 fossil and half as many Recent , r!^^Z"~^. c
sj)ecies.
Acila Adams. With divaricate sculpture. Lower
Cretaceous to Recent.
Family 10. Ledidae Adauis.i
Shell as in the Nuculidae, but clungated icith the /^"".,V ^ ,,. 7,
... ,. . 7 A, Nucula stngilata Goldf. Upper
ligament variable, the resihum sometimes external or Trias ; St. Cassian, Tyrol. Vi- f-, n.
absent, the internal shell layer sub-nacreous or por- ^J^^^^l Linn. Mioceno; Gru.ssbaeh, near
cellanous, the ends of the shell iiartly gaping; the
mantle lobes more or less united ; with complete, sometimes
elongate siphons ; pallial line usually satiated. Ordovician
to Recent.
Gleidophorus Hall (Adranaria Muu. -Chalm.) (Fig.
654). Shell rostrate, the anterior side shorter, with an
internal radial buttress. Ordovician and Devonian.
^"■- 654. Gytherodon Hall. Silurian and Devonian. (?) Bedonia
Ckidirplwrus ruUrat^ s,u„ll>. Rouault ; Cadomia Tromelin; Palaeoneilo Hall; Anuscula
Internal iiKinkl iroHi Lower Devon- . '
ian ; Nieiieriahnstoin, Nassau. V,. Barr. ; and AlyojAusia Neiimayr. Sihuiau.
^ Vemll, A. E., and BksIi, K. ,/., Revision of the genera of Ledidae and Ninulidae. Anier.
Jouni. Sci. [4], 1897, vol. iii.
CLASS I
PELECYPODA
441
Leda Sclium. (Figs. 655, 656). Shell rostrate, elongate, often keeled, concentri-
cally striate ; hinge as in Nucula ; pallial sinus small. Silurian to Recent.
o
.Fin. (555.
Lrda rostral a
(Lam.). MiiWle Jura;
Milhaud, Aveyron.
Vi-
Fig. fibii.
Leda deshayesiana Ducli.
Oligocene ; Rupelmonde,
Belgium. '^|■^.
Fig. 657.
Yoldia arctica Gray.
Pleistocene ; Bohus-
lan, Sweden. Vi-
Fl(i. 6.58.
Nucnllna oinlis
(Wood). Miocene;
Forchtenau, near
Vienna.
Yoldia Moller (Fig. 657). Shell thin, wide, and more or less gaping behind,
hinge as in Nucula. Cretaceous to Recent.
Nuculina d'Orl). (Fig. 658). Nuculiform, hinge teeth few and discrepant; with
large lateral tooth and external ligament. Tertiary and Recent.
Malletia Desm. and Tindaria Bell. Yoldiform and nuculiform respectively, but
without internal chondrophore. Tertiary and Recent.
Superfamily 2. ARC ACE A Deshayes.
Shell of varied fornij usually 'with a pilose epidermis, porccllanous, with tubuliferous
non-prismatic external layer ; area typically comphidetic, ligament external, ali- or
multivincular ; gills filihranchiate, with the filaments ustially reflected ; mantle lobes
free, without siphons, the pallial line simple ; foot variable, deeply grooved, byssogenous ;
marine or fluviatile.
Family 11. Parallelodontidae DalL
Shell arciform., ivith the posterior hinge teeth elongated, tending to he parallel to the
hinge mtirgin ; ligament m,ultivincular. Carboniferous to Recent.
The ancient forms of this group appear to connect
with tlie Pteriacea through Ptcrinea, and with Area
through CucuUaea. The Recent forms, which from
their shell characters have been referred to Macrodon,
are all small and probably .sliould be referred to the
Arcidae. The relationship of this family to the
Arcidae is very intimate but not exclusive.
Parallelodon Meek (Macrodon Lycett) (Fig.
659). Shell elongate, sul)- quadrate, with am-
phidetic area, and
j)rominent, rather
anterior beaks.
Anterior teeth
transverse or flex-
uous, posterior long
and parallel to the
hinge line. Devon-
ian to Tertiary ;
maximum in Coal Fig. 659.
Measures. Parallelodon hirsonensis Morri.s and ■^'"' ^^^'
n^rint^r^^ntr^^^,,-, ^^^^ C^reat Oolite ; Minclilnlianipton, CmulUuaTierMlia iVOrh. Oxfonlian ; Vieil
IrrammatOdon England. Vi- St. Remy, Ardennes. Vi-
442 MOLLUSC A phylum vi
Meek and Wortlien, and Nemodon Conrad, are allied. Carbonarca Meek and Wortlien.
Beaks inflated, curved, angular behind ; hinge margin curved, with two oblique
teeth. Carboniferous.
Cucullaea Lam. (Fig. 660). Shell inflated, trapezoidal ; hinge teeth in the centre
of the hinge short, transverse or oblique, the terminal teeth on each side longer, sub-
parallel to the hinge line ; posterior adductor usually supported by a radial elevated
lamina or buttress. Jura to Recent ; maximum in Mesozoic.
GucuUaria Desh., of the Eocene, and Idonearca Conrad, are closely allied.
Family 12. Cyrtodontidae Ulrich.
Shell equivalve, short, usually heavy, convex and earthy, loithout persistent epidermis,
area small, ligament parivincular (?) ; hinge teeth transitional between the Parallelodon
and Dysodont type; adductor scars sihb-equal, the posterior larger but less impressed.
Ordovician and Silurian.
These forms are evidently intermediate in character. They recall Liinopsis among later
types, are nearly related to the Parallelodontidae, but have not the multivincular ligament ;
the hinge has Dysodont elements, but the difference of texture and epidermis stand in the
way of assimilating them with Mytilacea.
Cyrtodonta Bill. (Cypricardites p.p. Conrad ; Palearca Hall). Shell rounded,
moderately ventricose, with rather tumid, incurved, anterior beaks ; area narrow and
obscure ; cardinal teeth two to four, obliquely curved or horizontal ; lateral teeth near
the posterior end of the hinge elongate, strong, curved or oblique ; pallial line simple.
Anterior adductor set on the wall of the valve. Ordovician and Silurian.
Vanuxemia Bill. Beaks more nearly terminal, anterior adductor scar excavated
out of the liinge plate. Ordovician.
TVIiitella and Tschyrodonta Ulrich ; Matheria Billings. Ordovician and Silurian.
Family 13. Limopsidae Dall.
Shell pectunculoid, equivalve or nearly so ; the ligament alivincular, partly
immersed, its socket approaching a chondrophore ; area small ; foot long, narrow, grooved,
byssiferous ; otherwise as in Arcidae. Trias to Recent.
These forms precede the typical Area and have a special facies of their own. The two
dental series of the hinge are often discrepant in character or direction, recalling the
Parallelodontidae.
Limopsis Sasso (Fig. 661). Small, rounded or oval, recalling Glycimeris, except
for the alivincular ligament. Trias to Recent.
Trinacria Mayer {Trigonocoelia Nyst). Like Limopsis, but tri-
angular, with the posterior slope keeled. Eocene. Gnisma Mayer,
from the Eocene, appears to be related.
Family 14. Arcidae Dall.
Shell' trapezoidal or rounded, with the posterior side longer; ligament
usually multivincular ; hinge typicodly taxodont, with the teeth in two
Limopsis aurita similar series, meeting below the beaks, and approximately vertical to
Brocchi. Pliocene; the margin of the valve ; foot stout, short, deeply grooved. Jura to
Piacenza. i/.. -r, ^
Recent.
Most of the Paleozoic ^rc«dike forms are probably Parallelodontidae, and the typical
Areas are preceded by Pectunculoid forms. The convergence of the types of Arcacea as we
recede in geological time is very marked, and their relations to the Nuculacea are evident in
spite of the later developed differences.
Fig. 661.
CLASS I
PELECYPODA
443
Area Lain, (type A. noae Linn.). Shell trapezoid, equivalve, with a wide amphi-
detic area, distant conspicuous beaks, and radial sculptiu'e ; a wide byssal gape ; a
long, straight, transversely dentate hinge line, with many small similar teeth.
Tertiary and Recent. Used in the wider sense to include all the groups of Arcidae,
there are some 200 living and 300 to 400 fossil species.
Subgenera : Barbatia Gray (Fig. 662) ; Scapharca, Noetia, Anadara (Fig. 663) and
Argina Gray ; Scaphula Benson (fresh-water), etc.
Isoarca Mlinst. (Fig. 664). Shell smooth, inflated ; beaks full, incurved ; hinge
line with rather amorphous dentition. Upper Jura and Lower Cretaceous.
Fig. 662.
Area {Larhatia) harbata Linn. Miocene ;
Gruiid, near Vienna, i/i-
Fifi. 603.
Area (Anadara) diluvii Lain.
Pliocene ; Siena.
Fig. 664.
Area (Isoarca) cordi-
fonnis Ziet. Upper Jura ;
Nattheim, WUrtemberg.
Glycimeris Da Costa (Pectunculus Lam. ; Axinea Poli) (Fig. 665). Rounded and
almost symmetrical. Basal margin dentate ; area as in Area, liut shorter ; ligament
Fio. 665.
Glycimeris dbovatus (Lam.). Oligocene ; Weinheim, near Alzey, Hesse, i/i.
multivincular ; teeth ol)lique, in an arched series, interrupted during growth by the
subsidence of the areal margin. Cretaceous to Recent ; maximum in Miocene.
Section C. Schizodonta Steinmann (emend.).
Superfamily 3. PTERIACEA DalL
Shells of varied form, frequently alate, with a nacreous or sub-nacreous inner and
prismatic on.ter layer ; the epidermis seldom conspicuous ; area amphidetic ; ligament
variable, usually not parivincular ; gills filibranchiate or reticulate, usually reflected;
mantle lobes free, without siphons ; pallial line simple ; the anterior addtictor smaller.
444
MOLLUSCA
PHYLUM VI
or frequently obsolete in the adult, though j^rescnt in the young; generally Ossiferous ;
hinge schizodont or edentulous. The young sometimes showing a distinct neinonic stage.
Marine.
Family 15. Pterineidae Dall.
Shell fteriiform, bialate, dimijarian, the anterior adductor smaller ; inequivalve, very
inequilateral; dentition obscure; ligament amfliidetic, external, multivincular (?) ; the
hyssus passing through a notch in the smaller valve. Ordovician to Devonian.
In Plerinea and its allies Ave have the first indications of divergence of what ultimately
became taxodont and schizodont dentition. • From this assemblage, as indicated by Jackson,
a large ijrojjortion of the Prionodesmacea have diverged in various directions. It is probable
that from tliis source the filibranchiate Taxodonts have sprung, rather than directly from the
foliobranchs.
Rhombopteria Jackson (Fig. 666). Posterior wing sej)arated from the body of the
A B
Fifi. 666.
Rliomliopteria mira
(BaiT.). Silurian (B);
Prague, Bohemia (after
Jackson).
Fig. 667.
A, Pterinca laci'is Goldf. Devonian ; Niederlahnstein, Nassau. Interior of left
valve, i/i- B, P- lineata Goldf. Same locality ; external view.
valve by a shallow sinus ; anterior wing short ; teeth obscure, the posterior elongated.
Silurian.
Pterinea Goldf. (Fig. 667). Left valve convex, right valve flat ; hinge plate long,
broad, auriculate before and behind ; area amphidetic, grooved ; ligament j)arivin-
cular (?) ; anterior teeth obscure, transverse ; the posterior elongate, nearly parallel to
the cardinal margin, depressed behind. Posterior adductor scar large, the anterior
small but strong, inserted below the anterior wing. Ordovician to (carboniferous ;
particularly abundant in the Devonian of Europe and America.
Actinodesma Saitdb. (Glyptoclesma, Ectenodesma Hall ; Dolichoptcron Maurer).
Like Pterinea, Ijut with tlie wings elongated and pointed. Devonian.
Leptodesma, Hall ; Kochia Freeh (Onychia, Sandb.; Loxopiteria Fi'ecli). Devonian.
Family 16. Lunulicardiidae Fischer.
Usually equivalve, triangular shells %oith terminal beetles, from which a sharp ridge
runs toward the lower margin, bounding a, flattened area. Hinge margin straight, long.
Internal characters unhioivn. Silurian and Devonian.
Lunulicardium Miinst. Anterior side with a byssal sinus. Silurian and
Devonian. L. semistriatum Miinst.
Patrocardium Fischer (Hemicardium Barr., non Cuvier). Without byssal sinus.
Silurian.
Additional genei-a : Amita (Spanila, Tetinhi), Mila, TenJca, Babinlca (Matercula)
Barrande. Silurian.
CLASS I
PELECYPODA
445
Fjuuily 17. Ambonychiidae Milkr.
Shell mytiliform, with no anterior wing, the anterior addAictor obsolete ; equivalve,
very inequilateral; dentition obsolete or schizo-
dont ; ligament external,, multivincular (?) ;
byssus passing through a narroiv gape between
the valves which are otherwise closed. Ordo-
vician to Devonian.
The typical Ambonychia, according to Uliich,
is edentulous ; the forms ordinarily passing under ,
that name being now rel'erred to Bijssonychia. In /
this group the byssus does not pass tlirough a {i
group the byss
notch in one of the valves
The Ambonychiidae include the typical mem-
bers of Ambonychia, Byssoptcria and Amphicoelia
Hall ; Ojristhoptcra {Mcgaptcra) Meek ; Anomalo-
donta Miller ; Byssonychia and AUonychia Ulrich,
and their allies.
Pig. 60S.
A, Byssonychia sp. Cincinnati Group; Cin-
cinnati, Ohio. Interior of right valve. Vj (after
Miller). B, B. radiata (Hall). Same locality.
Byssonychia Ulrich (Fig. 668). Hinge
with several small cardinal and two or three slender lateral teeth ; area striated ;
byssal opening present in the upper half of the anterior face ; otherwise as in
Ambonychia.
Paleocardia Hall. Silurian. Mytilarca and Plethomytilus Hall. Devonian.
Gosseletia, Barrois {Gyrtodontopsis Freeh.). Thicker shelled, with heavier and
more numerous teeth. , Devonian.
Glionychia Ulrich. Edentulous, concentrically sculptured, Ordovician.
Fig. G69.
Pinna pyramidalis Miinst.
Quader Sandstein ; Schan-
dau, near Dresden. 1/3.
Fig. 670.
Pinnigena sechaclil Bohm. Upper Jura ; Kelheim, Bavaria.
External and internal views, 1/3 natural size.
446
MOLLUSCA
PHYLUM VI
Family 18. Pinnidae Meek.
Shell mytiliform, not alate, dimyarian, the anterior adductor smaller ; equivalve,
truncate and wholly open behind; edentulotis ; area linear; ligament imrivincular,
internal ; shell structure coarsely frismatic, with a thin, partial, nacreous lining ;
byssiferous. Devonian to Recent.
Palaeopinna Hall. Devonian ; North America.
Aviculopinna Meek. A very small wing in front of the beaks. Carboniferoiis
and Permian.
Pinna Linn. (Fig. 669). Shell thin, with a long hinge line and emarginate
nacreous layer ; valves carinate, the carina sulcate, section triangular. Jura to
Recent.
Pinnigena Sauss. {Trichites Plott) (Fig. 670). Muscular impression very large;
prismatic layer extremely thick ; sculpture divaricate. Jura and Cretaceous.
Atrina Gray. Shell with broad adductor scars ; short hinge line, no sulcus or
carina, the nacreous layer entire. Carboniferous to Recent.
Cyrtopinna Morch. Jura to Recent.
Family 19. Conocardiidae Neumayr.
Shell sub-trigonal, anteriorly truncate and gaping, the margins of the gape frequently
produced into a tube-like rostrum and sharply serrate below, the posterior end usually
alate, the wing divided internally by a longitudinal ridge;
dimyarian, the anterior adductor scars smaller ; equivalve
more or less gaping behind ; schizodont, with a single
anterior lateral, and an obscure or obsolete cardinal
tubercle ; area ill-defined, amphidetic ; ligament external,
parivincular ; shell structure cancellate, or btdlt up of
holloio prisms resembling those of Pinna, but not solid ;
valves thick, internally marginate ; byssifeous (?) ; marine.
Conocardium alaeforme Sowerby. Ordovician to Carboniferous.
Lower Carboniferous ; Tournay, Bel-
gium, i/i. This group includes Conocardium Bronn [Pleurorhynchiis
Phill.) (Fig. 671), and lihipidocanlium Fischer. It is ex-
tremely isolated, and comprises some fifty species. These remarkable shells have been
referred by most paleontologists to tlie Cardiacea, with wliich they have no connection what-
ever except analogy of form with a few aberrant Cardiidae.
Fl(i. 071.
Family 20. Pernidae Zittel.
Shell sub-mytiliform, with a broad posterior wing ; monomyarian, the anterior adductor
Fir.. 672.
A, Gervillia aviculoiden Sow. Oxfordian ; Dives, Calvados. li, G. /mea/i.s- Bouvijjiiier.
Hinfre.
absent in the adult ; inequivalve, teeth irregular or absent, with a serial muUivincular
ligament ; byssiferous, with a moderate gape, or none. Permian to Recent.
CLASS I
PELECYPODA
447
Tliis family diflers from the Pteriidae cliiefly by its multivincular ligament in the adult
state. It linds its maximum development in the Jura and Cretaceous.
Bakewellia King. Small, obliquely elongated, alate behind, three to four den-
ticulations under the beaks. Permian.
Gervillia Defr. (Fig. 672). Posterior wing obscure, hinge plate thick, beaks
terminal, pointed, with obscure dental ridges sub-jiarallel
to the long axis of the valve. Trias to Eocene.
Subgenus Roernesia Laube (Fig. 673). With a strong tooth
under the beak and subtaxodont denticulations on the pos-
terior cardinal liorder. Trias.
Odontoperna Freeh. Quadrate with two to three
oblique dental folds below the beaks. Trias.
Pedal-ion Solander (Jsognoinon Klein ; Perna Brug. ;
MuUetia Fisch.) (Fig. 674). Equivalve, subquadrate, . . ,. ,^ ,,, „ ^
. , . , ° . . ,1 ,1 J . 1 Hoernesia sociahs (Schlotli.).
With terminal beaks, an anterior byssal notch, edentulous Muscheikalk ; wtirzburg, Bavaria,
hinge, and numerous ligamentary grooves. Trias to Recent.
Edentula Waag. Alpine Trias. Pernostrea Munier-Chalmas. Jura.
Inoceramus Sowerby {Catillus
Brong. ; Haploscapha Conr. ; Neo-
catillus Fisch.) (Fig. 675). Rounded
Pig. 673.
Fig. 674
Pedalion soldanii (Desh.). Oligocene ; Waldbockellieim,
near Krenznach, Prussia, i/.i.
Inoceramus cripsi Mant. Upper Cretaceous
Gosau, Austria. 1/2 natural size.
with concentric sculpture ; prominent, rather anterior beaks,
and edentulous hinge bearing numerous small ligamentary pits.
Jura, and especially the upper and middle Cretaceous.
Subgenera : Adinoccramus Meek (Fig. 676), with radial sculp-
ture ; Volviceramus Stol. ; Anoimea Eichw. ; Haenleinia Biihm.
Grenatula Lam. Thin-shelled, elongate, smooth. Jura (?),
Pliocene and Recent.
Family 21. Pteriidae Meek.
Shell avicnloid, bialate, monomyarian, mequivalve, with an
alivincular ligament ; the byssus issuing by a notch in the smaller
valve ; the young dimyarian, the anterior adductor disappearing
with age. Silurian to Recent.
Pteria Scopoli {Avicula Brug.) (Fig. 677). Cardinal
border in the young with pseudocardinal and lateral teeth, becoming more or less
obscure with growth ; shell thin, oblique. Devonian to Recent.
Fig. 676.
Actinoceraimis sulcatus
Park. Gault ; Perte dii
Rhone, Ain. l/j.
448
MOLLUSCA
PHYLUM VI
Subf'enera: AcHnopteria, Lciopteria, Vertumnia Hall. Devonian. Ptcrondes M'Coy.
Devonian and Carboniferous. ? rMtotia de Kon. Carboniferous. Oxytoma Meek (Fig. 678).
Trias to Cretaceous. Mclcagrina Lam. Jura to Recent.
Lmwptera Hall {Monopteria Meek ; Myalinodonta, Paropsis (Elilert). Anterior
wing reduced, posterior large. Devonian and Carboniferous.
Fio. 677.
Pleria contort a
(Portl.)- Rliae-
t i c ; K (i s s e n,
Tyrol.
Fig. G7S.
Fleria {Oxytoma) costata Sow. Great Oolite ;
Luc, Calvados.
Fig. 079.
I'seudomonotis ecliinata Sow. Corn brash
(Oolite) ; Sutton, England.
Pteroperna Morris and Lycett. Middle Jura.
Pseudomonotis Beyr. {Eumicrotis Meek) (Fig. 679). Left valve flat, anterior wing
not developed or minute. Devonian to Cretaceous.
Gassianella Beyr. (Fig. 680). Left valve inflated with prominent incurved beak ;
Fi(i. 680.
Cassianella gryphacata (Munst.). Upper Trias ;
St. Cassian, Tyrol.
Fig. 681.
Monotis salinaria (Schloth.). Red
Alpenkalk (Norian) ; Berchtesgaden,
Bavaria. 2/3.
tlie liglit flat or concave, without byssal sinus ; teeth small as in Pteria, but more
numerous ; area amphidetic, wide. Trias.
Monotis Bronn (Fig. 681). Equivalve, compressed, radially striate, with low, sub-
central beaks ; anterior wing indistinct, rounded ; posterior wing short, truncate or
oblique. Trias.
HaloUa Bronn (Daonella Mojs.) (Fig. 682). 'Equivalve like Monotis, but the
Fig. 082.
Fig. 083.
Hdluhia (^Daunella) lommrll Wissm. Lower Keuper (Norian) ; Posidonomya hecheri Bronn. Culm Measures;
Wengen, South Tyrol. Herborn, Nassau, i/i-
anterior wing only represented by a smooth non-projecting area (Halobia), or both
wings absent {Daonella). Abundairt in the Trias.
CLASS I
PELECYPODA
449
Fosidonomya Bronn {Ahlacomya Steiiim.) (Fig. 683). Eqiiivalve, tliin, compressed,
concentrically waved ; hinge margin straight, edentulous ; valves not auriculate ; beaks
sub-central, not conspicuous. Silurian to Jurassic. Over fifty species are known ;
very profuse in the Jura-Trias, sometimes forming massive beds.
Malleus Lam. ; (?) Philobrya Carpenter ; (?) Hochstetteria Velain. Recent.
Family 22. Myalinidae Freeh.
Shell obliquely ovate, widened behind, sometimes with a small anterior ear ; bealcs
anterior or terminal ; hinge edentulous, straight ; area
amfhidctic, longitudinally grooved; ligament parivin- ^^fi^^^^'^TJ^
cular (?) Adductor scars sub-eqiud ; byssal notch distinct.
Silurian to Jura.
Fig. 684.
Aucella mosrjuensis Keys. Upper
■Jura; Moscow, Russia.
; anterior auricle distinct,
Trias of Asia Minor.
Aucelkt Keys,
waved, sometimes
Myalina de Kon. Shell thick, oljlique, with deep
adductor scars anteriorly under the terminal beaks.
Silurian and Devonian.
Hoplomytilus Sandb.; Myalinoptera Freeh ; Ptycho-
desma, Mytilops and Modiella Hall. Devonian. Leio-
myalina Freeh ; Aplianaia, Posidoniella de Kon. ; Liebea
Waagen ; Atomodesma Beyr. Carboniferous.
Pergamidea Bitt. Thick-shelled, equivalve, inflated
sharply truncated ; hinge margin notched below the beak.
Mysidia Bitt. Anterior ear reduced. Trias.
(Fig. 684). Thin, inequivalve, inflated, small, concentrically
with radial striae. Left valve larger, arcuate, with very small
anterior ear ; right valve flatter and smaller. Area short,
striated, with a ligamental sulcus below the beak. Upper Jura
and Cretaceous ; distribution world wide.
Family 23. Vulsellidae Adams.^
Shell Ostreiform, not alate, monomyarian, edentulous, inequi-
valve, tvith an alivincular ligament ; byssus wanting ; otherwise
as in the Pteriidae. Tertiary to Recent, A degraded type
which has become specialised through commensalism with
Sponges.
Vulsella Lam. (Fig. 685). Shell vertically produced,
irregular, edentulous, with a triangular chondrophore for the
ligament. Eocene to Recent.
Vulsellina de Rainc. Eocene. (?) Ghalmasia Stol. Creta-
ceous. (? sxhb Ostreidae.)
Superfamily 4. OSTRACEA Goldfuss.
Shell degenerate, sessile, inequivalve, generally edentulous,
Pjp^ ggg loings obsolete ; tvith a sub-nacreous or porcellanous inner and
Vulsella caillaudi zitt prismatic outer layer ; epidermis inconspicuous ; area amphidetic,
Lower Eocene ; Miiiich, ligament alivinculav ; foot and byssus absent ; valves usually
close-fitting ; mantle lobes free, without siphons.
' Family 24. Ostreidae Lamarck.
Shell distorted by ea,rly adherence to other objects ; monomyarian, the anterior
^ Douvllle, II.., Etudes sur les Vulsellidt'S. Ann. Pak'out., 1907, vol. ii.
VOL. I
2 G
450
MOLLUSCA
PHYLUM VI
adductor ahsent ; edentulous, or with obscure schizodont dentition; dimyarian when
young ; the foot obsolete or absent in the adult. Carboniferous to Eeceiit.
Ostrea Linn. (Fig. 686). Shell irregular, inequivalve, and witli terminal beaks,
Fiii. CSO.
Ostrea digitalina Dubois. Miocene ; Vienna Bnsin.
Fig. 687.
Alectryonia grrgaria
(Sow.). Oxfordian ;
Dives, Calvados.
with radial or foliaceous sculpture, usually disci-epant on tlie two valves. Some species
(0. virfiinica, titan, giyantea, etc.) attain a very large size. Carboniferous to Kecent.
Alectryonia Fischer {Dendrostrea Swains ; Actinostreon Bayle) (Fig. 687). Left
valve attached to roots or branches by clasping shelly processes ; both valves with
strong, often divaricate folds and undulate margins. Trias to Recent ; maximum in
Jura and Cretaceous.
Gryfhaea Lam. {Pycnodonta Fisch. ; Gryphaeostrea Conr.) (Figs. 688, 689). Left
Pio. GSS.
Gryphaea areuata Lam.
Lower Lias ; Pfoliren, near
Donaueseliinfren, Baden.
Pio. 089.
Grypluwa ivsicvlarls Lam. White ClialU ;
Isle of Rugen.
valve strongly arched, ^\■ith incurved l)calv, sessile wlien young, later free ; right valve
fiat and opercular. Lias to Tertiary ; cliiefly Mesozoic.
Exogyra Say [Am^thidonta Fischer ; Geratostreon, Aetostrem, Bhynchostreon Bayle)
(Figs. 690, 691). Eesembliug Gry^ihaea, Ijut the valves more equal, hinge Avith an
obscure tooth, beaks of both valves more or less spiral, the pit for the ligament uarrow.
Upper Juj'a and Cretaceous.
CLASS I
PELECYPODA
451
Terquemia Tate {Garpenteria Desl.). Shell with a marginal ridge, sessile by the
right valve
left valve flatter, free. Trias and Lias.
Fig. 690.
Exogyra columha Lam. Greensand (Ceno-
manian) ; Regensbnrg, Bavaria.
Pio. 691.
Exngym fiahcUatoi (Goldfuss). Cenonianian
Saint Pan! Cloister, Egypt.
Family 25. Eligmidae Gill.
Shell thick, suh-equivalve, free when adult, resembling Chalnuma in form,, anteriorly
with an irregular pedal gape ; edentulous, monomyarian, ivith the adductor seated on the
free extremity of a myophore projecting from the umbonal cavity, otherwise like the
Ostreidae. Upper Jura.
Eligmus Desl. If the characters of this genus have been correctly interpreted, it
can hardly be retained in the Ostreidae
desiraljle.
Further investigation of the genus is
Superfamily 5. NAIADACEA Menke.
Shell of varied form, normally equivalve and dimyarian ; rarely alate ; shell
substance nacreous and prismatic, with a conspicuous epidermis; area obscure or
amphidetic ; ligament parivincular, usually opisthodetic and external ; pallial lobes
usually free, except for an anal siphon, the pallial line simple; foot normally long,
compressed, keeled ; byssus obsolete ; young usually with a distinct nepionic stage ; station
usually fiuviatile or lacustrine.
Family 26. Oardiniidae Zittel.
Shell equivalve, closed, with feeble concentric sculpture or smooth ; dentition schizodont
or obscure ; ligament opisthodetic, external ; dimyarian, adductor scars sub-equal, pedal
scar feeble or invisible ; station marine or brackish water. Devonian to Trias.
Amnigenia Hall. Devonian (Catskill) of North America, and Khenish Prussia.
Garbonicola M'Coy {Anthracosia King) (Fig. 692). Shell thin, oblong ; hinge
with a blunt elongated cardinal, and a feeble posterior lateral tooth upon a thickened
hinge plate. Common in the Coar Measures and estuarine Permian of Russia, also
America and Africa.
Naiadites Dawson {Anthracoftera Salter). Shell modioliform, obliquely triangular,
with almost terminal beaks, straight hinge-line, striated hinge-plate, and superficially
marked with flat concentric lamellae. Coal Measures ; North America and Europe.
452
MOLLUSCA
PHYLUM VI
Anthracomya Salter ; Asthenodonta Wliiteaves. Coal Measures. Palaeomutela
(Obligodon) and Palaeanodonta Anializky. Brackisli Permian marls of Eurojie.
Anoplophora Sandb., emend, von Koenen (JJniona Pohlig) (Fig. 693). Eiglit valve
witli a blunt thick cardinal tootli fitting into a socket in the opposite valve. Left
valve beside the socket has a long posterior lateral tooth. Trias (Lettenkohle). A.
donacina Schloth. ; A. leltica (Quenst.).
1 -»>-sCT*'^ r™ -' ' -""•'
Fio. 693.
Anoplo'phora lettica (Quenstedt).
Trias ; Friedrichshall (after Al-
berti).
A
Fio. 692.
A, Carhonicola carhonaria (Goldfuss).
Permian ; Niederstaiifenbach, near Kusel,
Rhenish Bavaria. B, C. Vittncrl (Ludw.).
Coal Measures ; Ilannibalzeche, near
Bochum, Westphalia (after Ludwig).
Fi<;. Gy-t.
Trigonodus sandbergeri Albert! .
Trias (Lettenkohle) ; Zinimern,
Wiirtemberg. ^4, Hinge, from a
gutta-percha cast taken from a
natural mould. B, Natural mould.
V:.
■Trigonodus Sandb. (Fig. 694). Cardinal tooth strong, triangular, .sometimes
divided, short, oblique, anterior ; two elongate laterals in the left valve, and one
lateral in the right valve. Trias ; especially common in the Lettenkohle dolomite
and the Eaibl beds.
Heminajas Neumayr. Trias. H. {Myo])horia) fissidentata Wohrmann.
Pachycardia Haner. Oblong or trigonal, concentrically striate or smooth ; beaks
nearly terminal, curved, adjacent, with a lumule ; anterior end inflated, blunt ;
posterior compressed ; two strong divergent cardinal teeth in each valve, the anterior
on the right being weaker and nearly marginal ; each valve has also a long posterior
lateral tooth. Alpine Trias.
Gardinia Agassiz {TJialassites Quenst.) (Fig. 695). 01>long, thick, short anteriorly,
Fig. 695.
Cardinia hybrida Sow. Lower Lias ; Ohrsleben, near Halberstadt, Saxony.
rounded. Cardinal teeth weak or obsolete, posterior lateral strong. Lower Lias, and
reported also from the Dogger.
(?) Nyassa Hall. Devonian. (?) Guerangeria (Davousti) ffihlert. Lower Devonian.
CLASS I
PELECYPODA
453
Family 27. Megalodontidae Zittcl.^
Shells equivalve, sub-mytiliform, closed, with feeble concentric sculpture or none ; di-
myarian, loith amphidetic area, and external opisthodetic ligament, frequently supported
by nympha^e ; cardinal teeth strong, usually tivo or three, with a posterior lateral, all
Pio. 696.
Megalodon (Ewinegalodon) cncullatus Goldf.
near Cologne, i/j.
Devonian ; Paft'rath,
Pig. 69T.
Megalodon(Neomegalodon)
triqurU'r (Wulfeii). Internal
mould. Trias dolomite ;
Bleiberg, Carinthia.
Fk.;. G9S.
Megalodon (Neomegalodon) griimfteHiStoppani.'^Rhaetic Blbigenalp, Tyrol (after Giimbel).
heavy and amorphous ; anterior adductor scars distinct, loith a well-marhed myophoric
ridge and pedal scar, the posterior adductor scars frequently bordered by an elevated
crest. Marine. Silurian to Upper Jura.
These shells, which are often very ponderous, sometimes bear a remarkable resemblance
to some Recent American Uniones. The myophoric ridge is common to very distinct bivalves
of many unrelated groups. The true position of these forms cannot be regarded as positively
fixed as yet. Pachyrisma is thought by Bohm to be genetically related to Cardium, and the
genus Megalodon may have been ancestral to primitive Chamacea.
Megalodon Sow. (TcMiroceras and Lycodes Schafli. ; Conchodon Stopp.) (Figs. 696-698).
1 Gllmbel, C. W., Die Daehstelnbivalveu. Sitzungsber. Akad. Wiss. Wien, 1862, vol. xlv. —
Hoernes, ii., Materialen zu einer Monographic der Gattung Megalodns. Denkschr. Akad. Wiss.
Wien, 1880, vol. xl. — Buhm, O. Megalodon, Pachyrisma und Diceras. Ber. Natiirforsch.
Gesellsch. Freiburg, 1891, vol. vi.
454
MOLLUSCA
PHYLUM V
Beaks prosogyrous ; hinge plate very broad and massive, without laterals ; the two
cardinal teeth separated by a deep socket ; anterior adductor scar small, semilunar,
in front of the anterior cardinal ; posterior scar longer, less distinct, situated on an
elevated or thickened radial ridge. The oldest Devonian species {M. cucuUatus Goldf.)
has amorphous cardinals and a smooth rounded shell (Euviegalodon). The Triassic
species sometimes attain a large size, have a radial posterior ridge, smooth teeth, and
divided right posterior cardinal teeth {Neomegalodon Gilmb.). They are extraordinarily
aljundant in the Dachstein limestone and Hauptdolomite of the Northern Alps, and
are also plentiful in the Raibl and Rhaetic beds of the Southern Alps.^
Pachyrisma Morr. and Lye. {Pachyme.galodon Giimb.). Like Megalodon, but with
a larger anterior adductor scar, a rounded anterior tooth before the cardinals, and a
strong posterior lateral. Trias to Upper Jura.
Durga Bohm. Like Pachyrisma, but without an elevated area at the posterior
adductor. Lias.
Protodiceras Bohm. Lias. Dicerocardium Stoppani. Rhaetic.
Megalomus Hall. Silurian ; North America.
Family 28. Unionidae Fleming.
Shell equivalve, dimyarian, typically schizodont, ivith pseudocardinals and laterals
if dentiferous ; consjncuously nacreous ; beaks usually sculptured ; ligament opisthodetic,
external; lobes of the mantle generally united to form an anal sipjhon, but the functional
branchial siphon ahoays incomplete below; foot compressed, keeled, large, rarely with a
feeble byssus ; usually dioecious; the young having a specialised prodissoconch
(glochidium) and a distinct nepionic stage. Fluviatile. Trias to Recent.
Typical Uniones make their appearance in the Trias of Texas, but are not abundant until
the Cretaceous and Tertiary. The origin of the family has been sought in the Trigoniidae,^
which have a very similar ontogeny as a group ; in Trir/onodus ^ and related forms ; and by
Pohlig in the Triassic Uniona. An older view recognises the Carboniferous Anthracosia and
other Cardiniidae as probable ancestors. The weiglit of evidence is in favour of the latter,
though there is mucli probability that each of tliese groups bears a certain amount of relation-
ship to the present family, Avhich will be better realised when more evidence is obtainable.
Recent studies by Simpson and Ortmann of the anatomy of living genera of Unionidae
have shown that considerable differences exist as regards the soft parts, more especially the
Fio. 699.
Unio stachei Neumayr. Pliocene (Congerian stage) ; Sibinj, Slavonia. ;;>, Adductor ; x. Pedal scar.
marsupial apparatus (that part of the gills which contains the glochidia) and the shape of
the glochidia. These differences permit of an improved system of classification for the
modern forms, but as the shape of the shell is not at all correlated with the natural divisions
indicated by the structure of the soft parts, it is impossible to apply this system with
certainty to fossil Unionidae.
Unio Retzius (Fig. 699). This, the typical genus, originally included also the pearl
1 Tausch, L. vq)i,_ tJber Coiiohodus, etc. Abhandl. geol. Reichsanstalt, 1892, vol. xvi.
2 Neumayr, M., Uber die Herkunft der Unioniden. Sitzber. Akad. Wiss. Wien, 1889, xcviii.
3 Wiihrmann, S. von, Uber die systematische Stclluiig der Trigoniden uud die Abstamniung
der Nayadeu. Jahrb. geol. Reichsanst., 1893, vol. xliii.
CLASS I PELECYPODA 455
mussel {Mya margaritifem Linn.), iu which the iDosterior laminae of the hinge are
obsolete. It shows in the majority of species amor^^hous, heavy, radial, pseudocardinal
and lateral teeth on the hinge ; the shell is variable in form and ornamentation, some
species having strongly marked sexual differences in the shell. Most of the species
are pearly, with a conspicuous Ijrown or greenish periostracum ; the anterior adductor
scars are high, and the j^edal scars conspicuous.
Anodonta Cuv. Valves thin, and armature of the hinge obsolete ; lives in still,
muddy water. Tertiary and Recent.
Margaritana Schum. The pearl mussel, formerly associated with Mya and Unio, is
anatomically intermediate between the Unionidae and Mutelidae. Tertiary and Recent.
Family 29. Mutelidae Gray.
Shell resemhling that of the Unionidae, itrithout pseudocardinals and laterals ;
having, tohen dentiferous, an irregularly taxodont hinge armature ; beaks unsculptured ;
mantle lobes generally partly closed ; siphons more complete. Nepionic stage {knoivn
only in a fev) South American forms) said to be represented by a Lasidium. Cretaceous
to Recent.
Spatha Lea. Elongated, inequilateral, with a short edentulous hinge. Living in
Africa, and doulitfully j^resent also in the Upper Cretaceous of Provence.
Anodontites Bruguiere {Glabaris Gray) ; Leila Gray ; Monocondylaea and Mycetopoda
d'Orb.; Mutela Scopoli (Tridina Lam.); and Pleiodon Conrad. Recent. Two
subfamilies,' Mutelinae and Hyriinae, are recognised by Ortmann on the basis of
structural differences in the soft parts.
Family 30. Etheriidae Lamarck.
Shell sessile, irregularly modified by adherence to other bodies, nacreous, ivith a
tendency to cellularity of structure; edentulous; ligament amphidetic, parivincular,
deeply sunken, with a large internal resilium, modified by the distortion of the valves ;
young regular, equivalve, dimyarian ; the adult irregular, inequivalve, and either (1)
monomyarian, or (2) with a very degenerate anterior adductor, or (3) with sub-equal
adductors. Mantle lobes united only for the anal siphon ; foot degenerate or absent in
the adult ; young byssiferous ; station fluviatile. Pleistocene and Recent.
The young shell of Bartlctlia has well-marked nympliae and internal resilium. The
relationship of the Naiadacea to Ptcria renders the remarkable resemblance of the adult
Muellcria to Ostrea less surprising, since Ostrca is now known also to be derived from the
Pteriidae.
Etheria Lam. Ostreiform, attached to rocks in African rivers. Also Pleistocene
of West Africa.
Muelleria Ferussac ; Bartlettia Adams. Recent ; South American rivers.
Superfamily 6. TRIGONIACEA Bronn.
Shell equivalve, inequilateral, closed, dimyarian, not alate ; shell substance nacreous
and prismaAic ; hinge teeth few, sub-umbonal, typically schizodont ; area obscure or none ;
ligament parivincular, opisthodetic, external ; gills filibranchiate ; mantle lobes usually
free, but modified on the posterior edges to form functional siphons without conjunctive
partitions ; pallial line usually simple ; non-byssiferous, though possessing an obsolete
byssal apparatus ; young without a distinct nepionic stage ; dioecious; marine.
Family 31. Lyrodesmidae Ulrich.
Shell with the hinge armature radiating fan-like from below the umbones ; teeth five
to nine; pallial line feebly sinuate or simple. Ordovician and Silurian.
Lyrodesma Conr. (? Actinodonta Phil). Shell oval, cardinal border narrow, with-
out ligamentary area. Ordovician and Silurian ; America and Europe.
456
MOLLUSCA
PHYLUM vr
Family 32. Trigoniidae Lamarck.
Shell with few hinge teeth (5), the mantle lubes wholly free, but so applied to each
other in life as to form functional siphons ; pallial line simple. Devonian to Eecent.
Schizodus King (Fig. 700). Ovate or quadrate, sniootli ; lateral teetli not fluted ;
anterior adductor scar witli a small radial buttress. Abundant m the Permian.
Myojjhoria Bvonn {Neoschizodus . Gieb.) (Figs. 701, 702),
Smootb or radially sculptured, ^^^J^ ^J usually witli a strong
radial ridge extending from the
downward to the basal margin ;
uml)ones backward and
the sculpture on the areas
Schizodus ohscuriis Sow. Zechstein; Nieder-
rodeDbach, near Hanau. .4. Internal mould,
i/i- TJ, Hinge, Vl (=ifter King).
Fig. 701.
Myophirria laevigata
(All)erti). Schaumkalk ;
Riidersdorf, near Ber-
lin. ■ i/i.
Ftci. 702.
Myoplioria dccussnta Miin.st.
Upper Trias ; St. Ca.ssian, Tyrol.
A, Exterior of right valve, Vi-
li, Enlarged view of liinge.
Fig. 703.
Trigonia navis Lam. Lower Brown Jura ;'
Gunder.sliofen, Alsace. i/i.|
Fig. 704.
Trigonia daudala Park. Middle Cretaceous
(Hervien); Meule de Bracquegnies, Belgium. Vi-
Fig. 705. .
Trigonia costata Sow.
Middle Jura ; Wiirtembeig.
Fig. 706.
.Trigonia cf. aliformis Park. Senoiiian ;
Vaels, near Aix-Ia-Chapelle. i/i.
Trigonia jicctinata
Lamarck. Becent; Au.s-
tralia. Hinge, i/i.
CLASS I
PELECYPODA
457
thus sejiarated usually discrepant. Beaks mesogyrate, lateral te(jtli fluted, muscular
scars buttressed by feel>le ridges. Abundant in the Trias.
Subgenus : Myo'plwriofsis Wiihrm. {Astartopsis Wohr.). Trias.
Tric/onia Brug. (Figs. 703-707). Surface sculptured with nodulose riljs or rows of
l)ustules, the posterior dorsal area usually discrepant with the rest. Beaks opistho-
gyrous, nearly terminal ; teeth striated ; adductor scars strong, with buttressing ridges.
Lias to Recent ; abundant in Jura and Cretaceous, very sparse in later horizons.
Section D. Isodonta Fischer.
Superfamily 7. PECTINACEA Reeve.
Shell usually inequivalve, flabelKform, more or less auriculate, and monomyarian ;
shell structure sub-nacreous, corrugated, and rarely prismatic, occasionally tabular ; area,
lohen present, amphidetic ; ligament amphidetic, alivincular ; gills filibranchiate, free, the
filaments with or without a reflected limb ; mantle lobes free, loithout siphons, usually with
■ ocelli, papillae, or other tactile prominences along the margin, and with an inner pro-
jecting lamina {curtain) near the margin, at right angles to the plane of the valves ; pallial
line simple ; foot small, usually sub-cylindrical, grooved, and byssiferous ; usually mon-
FlG. 708.
Avieulopecten "papyxaceus Sow.
Coal Measure.s ; Werden, West-
plialia.
Family 33. Pectinidae Lamarck.
Shell inequivalve, inequilateral, auriculate, usually closed, monomyarian, usually
free; area amphidetic or obscure; ligament obsolete extern-
ally, the immersed portion forming an internal resilium,
provinculum taxodont in the very yo^tng, obsolete later, the
crural teeth feeble or not developed. Silurian to Recent.
Aviculopecten M'Coy (Fig. 708). Shell pectiniform,
radially sculptured. Hinge margin long, feeljly auriculate;
ligament in numerous shallow grooves radiating to the
amphidetic margin of the area. Silurian to Carboniferous.
Subgenera : Pterineopecte^i Hall ; Orhipecten Freeh {Lyrio-
2)ccten Hall). Devonian.
Grenipecten Hall (Pernopecten Winch.). Like Aviculo-
pecten, but with a taxodont hinge. Carboniferous.
The preceding genera lead up -to the prototypes of Pteriidae
as a radical for the present family.
Pecten Miiller (Vola Morch ; Janira Schum. ; Neithea
Drouet) (Fig. 709). Shell nearly equilateral, very inequi-
valve, sub -symmetrical, with well -developed, sub -equal
ears ; one valve (usually the right) more convex than the
other ; interior of the valves not lirate ; hinge with a
strong medial internal resilium, on each side of which
interlocking crural ridges and grooves radiate in the
adult ; byssal notch inconspicuous. Cretaceous to Recent,
The above diagnosis is of the subgenus Pecten s. s. In a
wide sense all the species of Pecten are free and auriculate, and
without internal lirae. They have been divided into an ex-
cessive number of sections according to the superficial shell characters, but these rarely
march with anatomical differences, and cannot properly be regarded as of generic value. The
most familiar of the groups thus named are as follows : — ■
Ciilamys Bolten {Pallium Schum.; Decadopecten Riipp.) (Figs. 710, 711). Shell radially
. Fro. 709.
Pecten quinquecodata Sow. Ceuo-
manian ; Rouen, i/l-
458
MOLLUSCA
PHYLUM VI
sculptured, nearly equi valve, with small, unequal ears, and deep byssal notch with well-
developed ctenolium. Trias to Recent.
Camptoncctcs Ag. (Fig. 712). Shell small, thin, nearly smooth, with fine divergent
striation radiating from a median line. Jura to Recent.
Fio. 710.
Pecten (Chlamys) suhtcxtorius
Goldf. Coral-Rag; Nattheim.
Fig. ril.
Pcctcn {Chlamys) varius Linn.
Pliocene ; Rhodes.
Fk;. 71-2.
Pecten (Ento-
lium) cornutus
Pecten (Cam2)tonectes) lens Qneniit. Upper
Sow. Middle Jura ; Balin, Jura ; Hohen-
near Cracow, i/^. zoUeiu. i/i.
IhitoUum Meek (Fig. 713). Smooth, thin, witli sub-equal ears diverging at a sharp angle
above the beaks ; byssal notch obsolete. Carboniferous to Cretaceous.
Pseudaiimsium Adams. Shell small, thin, glassy ; the posterior ear obsolete, byssal notch
distinct. Cretaceous to Recent. Syncydonema Meek is scarcely different.
Amusium Bolten (Fig. 714). Shell with raised radial riblets internally; ex-
Atibu
Fii;. 714.
ii„ u, „i,taUis (Broun). Miocene ; Baden, near Vienna. !/!•
Fig. 715.
Hlnnitcs ahjectuK (Pliill.).
Middle Jura ; Balin, near
Cracow, i/i.
ternally smootli or delicately sculptured ; valves large, flattisli, with sulj-e(pal ears ;
byssal notch inconspicuous or absent. Lias to Eecent.
Subgenus : Propcamusiuvi Greg. Small, thin, abyssal ; often with relatively conspicuous
sculpture, usually discrepant on the valves. Tertiary and Recent.
Hinnites Defr. (Fig. 715). Shell free and Pectinifurni wlien young, later adherent
to other objects and more or less distorted. Trias to Recent.
Pedum Brug. Shell w^itli an alivincular ligament in an open groove and area like
that of Spondylus in the adult ; the young like Chlaviys. Eecent ; sessile on corals.
Family 34. Spondylidae Fleming.
Shell inequivalve, nearly equilateral, closed, pecfiniform, obscurely auriculate, mono-
myarian; sessile; area am.i)liidetic,inucli larger on the attached valve; ligament alivincular,
resiliuvi more or less submerged ; byssus obsolete ; hinge tvith a taxodont provinculum,
CLASS I
PELECYPODA
459
becoming obsolete in the adult and replaced by the typically isodont development of the
crura ; otherivise as in the Pectinidae. Trias to Recent.
Plicatula Lain. {Harpax Park.) (Fig. 716). Shell
compressed, with coarse radial, often divaricate
ribbing, a small area, and long shallow crenulate
crural teeth, diverging at a sharp angle. Trias to
Recent ; maximum in Jura and Cretaceous.
Spondylus Linn. (Figs. 717, 718). Shell inflated,
with radial, often spiny or foliaceous sculiature ;
Fig. 716.
Plicatula pcctlnoldes Lam. Middle Lias ;
Nancy, France.
^^^
Fig. 717.
Sjmndylus sjrinosus (Sow.). Planerkalk ;
Strehlen, near Dresden. 2/3.
Fig. 718.
Spondylus tenuispina Sandb. Oligoceno ; Waldbiickellieim, near
Kreuznach, Prussia. Vi-
attached valve with a consjiicuous area ; crural teetli heavy, short, smooth. Jura,
to Recent ; maximum from the Tertiary onward.
(?) Pachypteria de Koninck. Carboniferous. P. nobilissiina (<Ie Koninck). Pro-
spondylus Zimmerm. Permian and Trias. Philippiella Waagen. Alpine Trias.
Family 35. Dimyidae Dall.
Shell inequivalve, irregular, closed, auricles not differentiated, Ostreiform, dimyarian,
sessile ; shell substance sub-nacreous and
fibrous ; area amphidetic, obscure ; liga-
ment obsolete, resilium alivincular, in-
ternal; hinge armature taxodont, obsolete;
crural development feeble ; gills fili-
branchiate, the direct filaments not
reflected ; foot and byssus absent ; an-
terior adductor distinct, small ; posterior
duplex, larger. Trias to Recent.
- Dimya Rouault {Dimyodon Mun.-
Chalm.) (Fig. 719). The Recent forms inhabit deep water
Fig. 719.
Dimya deshayesiana Rouault. Eocene ; Pyrenees. Inner
and outer views of riglit valve, ^2 (after Rouault).
Family 36. Limidae d'Orliigny.
Shell equivalve, a^mculate, gaping, Pectiniform, monomyarian ; shell substance
fibrous, ivith minute tubules, not nacreous or prismatic ; hinge edentulous, or vjith traces
of taxodont armature; area amphidetic, equal in both valves; ligament alivincular,
460
MOLLUSCA
PHYLUM VI
resilium sub-internal ; gills Jilibranchiate with direct and reflected limbs ; foot small
digifiform, usually byssiferous, the byssiis i^assing through the gape of the valves.
Carboniferous to Eecent.
Lima Brug. Shell inflated, witli radial sculpture ; beaks pointed, and separated
by a lozenge - shaped area ; edentulous.
Carboniferous to Recent ; maximum in
Mesozoic (over 300 species).
Subgenera : Lima s. s. {Radida
auct., non Gray) (Fig. 720). Shell with
strong radial ribs.
Fig. 722.
Lima (Limatula)
II Ibhosa So w.
Lower Oolite ;
Bayeux, Calvados.
Fk:. 720.
Lima pectinoidcs Sow.
Lower Lias ; Balingen,
Wurteinberg. i/i.
Fio. 721.
Lima (Flagiostoma) gigantea Sow. Lower Lias ;
Goppingen, Wurtemberg. 2/.,.
Fio. 723.
Limaca dnpli-
cata Goldf. Great
Oolite ; Langrune,
Noriuaudy.
Fig. 724.
Ctenostreon prohoscidea Sow. Oxfoidiaii ; Dives, Calvados.
Plagiostoma Sow. (Fig. 721). Smooth or finely striated.
Limatula Wood (Fig. 722). Medially ribbed, laterally smooth, valves not gaping.
Limaea Bronn (Fig. 723). Small, with taxodont armature at the angles of the
hinge. Lias and Recent.
Ctenostreon Eichw. (Fig. 724). Compressed, irregular, thick-shelled, with coarse
radial ribs. Upper Jura. Badiotella Bittner. Alpine Trias.
CLASS I PELECYPODA 461
Siiperfamily 8. ANOMIACEA Herrmannsen.
SJiell monomy avian, not alate ; edentulous or isodont, usually sessile; shell substance
nacreous, tuhuUferous, with traces of a prismatic layer; area obscure, usually small,
amphidetic ; ligament obscure, with an alivincular internal rcsilium; (jills filihranchiate,
mantle lobes free ; foot small, grooved, digitiform ; dioecious; marine.
Family 37. Anomiidae Gray.
^liell variable, irregular and inequivalve lohen sessile, byssiferous lohen young ; in
most genera the byssus becomes modified to a calcified or horny plug passing through
a foramen in the right valve, and fastened to other objects, a condition which may be
permanent or transient-; area small, amphidetic; ligament amphidetic, more or less
internal, supplemented by an internal resilium, for which the crura serve as chondrophores,
ali- or multivincular ; hinge usually edentulous, rarely rugose, with amorphous inter-
locking rugosities ; posterior adductor small, sub-central, in the sessile forms reinforced by
the pedo-byssal muscles, which are modified for service as addtictors. (?) Devonian. Jura
to Recent.
Anomia Miill. Shell thin, sessile by the calcified byssus
or perforation in the right valve, conforming to the subjacent
more convex, with four muscular scars on
a central area ; a chondroishore in the
lower valve. Jm-a to Recent.
(?) Limanomia Boych. Devonian.
Hypotrema d'Orb. Jura and Cretaceous.
Placunanomia Brod. Miocene to Recent.
Garolia Cantraine. (Fig. 725). Shell
orbicular, compressed, radially striated ;
right valve with a byssal foramen nearly
closed in the adult ; resilium much as in
Anomia ; adductor scar single. Eocene ;
Egypt.
passing
sur&ce
throiigh a sinus
; the left valve
Subgenus : JVakuUina Dall. Smooth ;
byssal foramen obsolete ; the resilium received
on diverging crura on the upper valve. Oligo-
cene ; Florida.
Brug. :
Fig. 725.
CaroUa placunoides Caiitr. Eocene ; Wadi el Till, near
Cairo, Egypt. Interior of both valves, 2/3.
Placenta Retzius [Placuna
Placunema Stol. ; Pseudoplacuna Mayer)
Shell free, orbicular, thin, very compressed ;
the resilium with long, unequal crura.
Tertiary and Recent.
Ephippium Bolten. Like Placenta,
but the shell radially waved ; yoiuig with a small byssal perforation, which becomes
closed and obsolete in the adult. Tertiary and Recent.
Placunopsis Morr. and Lye. Shell rounded, imperfoi-ate, free, or sessile. Jura.
Hemiplicatala Desh. {Semiplicatula Fisch.) ; Saintia Rainc. Eocene. Paranomia
Conrad. Ripley Group. Monia Gray. Miocene to Recent ; California.
Section E. Dysodonta Neumayr (emend.).
Superfamily 9. MYTILACEA Fdrussac.
Shell anisomyarian, usually equivalve, not alate or notched for a byssus, edentulous or
dysodont ; shell substance sub-nacreous, rarely more or less prismatic, with a conspicuous
462
MOLLUSCA
PHYLUM VI
epidermis; area amphidetic or obscure; ligament iHirivincular, usually opisthodetic and
external; gills usually filihranchiate ; mantle lobes without ocelli, more or less free,
generally with the anal siphon complete and the branchial incomplete ; foot small, digiti-
form., grooved, byssiferous ; monoecious ; mostly marine.
Family 38. Modiolopsidae Fischer (emend.).
Shell modioliform, usually equivalve, free, thin, with sub-equal adductor scars;
ligament deep-seated ; hinge edentulous or dysodont ; sometimes byssiferous. Ordovician
to Cretaceous.
The heavier forms show an obtuse ridge or two extending from the beaks toward tlie basal
margin. The pedal scars are separate from and behind the anterior adductors. The forms
included here appear to be
the prototypes of the Myti-
lidae, from which they differ
chiefly in those characters
that are common to most of
the ancient types, such as the
sub-equality of the adductor
scars and their more dorsal
situation. The recent Idas is
very similar.
Modiolopsis Hall (Fig.
726). Valves elongate-
oval, closed, ' with nearly
terminal beaks, narrow
hinge plate, and edentulous
hinge. Ordovician and
Silurian.
Modiomorpha Hall.
Similar, but with a wider
hinge j^late, and single,
oblique, elongate, posterior
ridge - like tooth. De-
vonian.
Myoconcha Sow. (Fig.
727). Hinge usually with an elongate cardinal, and a long, Aveak, lateral tooth in
the right valve ; otherwise resembling Modiolopsis. Carboni-
ferous to Cretaceous.
(?) Hippopodium Sow. Thick, inflated ovate, concentric-
ally waved. Hinge with a long, blunt, oblique, cardinal
tooth, or edentulous ; adductor scars strong. Jura.
Modiolodon, JVJiiteavesia, Eurymya, Aristerella, and Prolo-
bella Ulrich ; Ordovician ; North America. Goniophora
Phillips. Silurian and Devonian. Orthonota Conrad. De-
vonian. Orthodesma Hall and AVhitf. Ordovician ; North
America.
Family 39. Mytilidae Fleming.
Shell equivalve, very ineriuilateral, heteromyarian, slightly
gaping, typically dysodont ; area amp)hidetic or none ; ligament
usually external, deep-seated ; rarely with an alivincular ^^^^ -og
internal resilium ; pallial line simple; mantle lobes united MytHusstMacvhSow. Great
below the anal siphon, otherwise free; generally byssiferous. Oolite; Minchiiihampton,Eiig-
Devoiiian to Recent. ' ' ''
Modiolopsis inoilwlnris " '"''
(Conrad). Ordovician ; Cin- Myoconclm striatula Goldf. Lower Oolite
cinnati, Ohio. Vl- Bayeux, Calvados, l/l-
CLASS I
PELECYPODA
463
Mytilus Linn. (Fig. 728). Shell elongated, tliin, with terminal pointed beaks ;
valves wider and rounded behind, gaping a little for the byssus, smooth or radially
sculptured, with smooth margins, conspicuous epidermis, and a thin nacreous layer ;'
hinge with a few small teeth under the beaks, or edentulous. Trias to Recent.
Pachymytilus Zitt. (Fig. 729). Shell thick, trigonal; the front margin deeply
imj^ressed. Upj)er Jura.
Modiolus Lam. (Figs. 730, 731). Like Mytilus, ■
Pachymytilus petasus d'Orb. Coral-Rag ;
Coulange-sur-Yonne. 8/3.
Modiolus as-
Ijerus Sow.
Great OolitR ;
Langrune, Cal-
vados. 1/1.
Modiolns imbrl-
cntus Sow. Middle
Jura ; Balin, near
Cracow, Austria.i/i.
Lithopliagus inclusus (Phill. ).
Great Oolite ; Miiichinhamp-
ton, England. A, D, Shell,
l/l- t', Mould of the buiTOw.
but the beaks not terminal, edentate, anteriorly rounded and wider. Devonian to Eecent.
Subgenera : Modiolaria Loven. Small, radially sculptured toward the ends, usually
smooth toward the middle, modioliform. Tertiary and Recent. Crcnella Brown. Small,
rounded, radially sculptured all over. Tertiary and Recent.
Stavelia Gray. Recent. Valves spirally twisted.
Litlioplmgus Meg. {Lithodomus Cuv.) (Fig. 732). Sul) -cylindrical, with rounded
ends ; perforating coral, limestone and other substances, in which the animal forms
flask-shaped excavations ; moulds of the latter are often found in the fossil state.
Carboniferous to Recent.
Family 40. Dreissensiidae Gray.
Shell mytiliform, equivalve, of prevailingly jJrismatic substance ; area linear, amrphi-
detic ; ligament suh-infernal ; anterior adductor and pedal protractors inserted on a
myophoric septum ; mantle lobes united to form anal and branchial sijjhons, and also
ventrally ivith a pedal opening ; pallial line usually simple; gills reticulate ; otherwise
as in Mytilus. Tertiary to Recent. The relations of this family are in question.
Dreissensia Van Ben. (Tichogonia Rossm.) (Fig. 733). Smooth, without a pearly
layer, w^ith a single apical septum ; fluviatile and estuarine. Eocene
to Recent ; Europe.
Mytilopsis Conr. Mytiliform, small, thin ; myophore for the
pedal protractor distinct from that which supports the anterior
adductor. Tertiary and Recent ; America.
Gongeria Partsch (Fig. 734). Sub-quadrate, heavy, large ;
myophores as in Mrjtilopsis. Very profuse in the Neocene of Eastern
Europe (Gongeria lieds).
Dreissensiomya Fuchs. Notable for being the only example of the Mayeiice'"' Vi
Mytilacea with a distinct pallial sinus. Miocene ; Eastern Europe.
Septifer Recluz. Valves -with strong radial or divaricate sculpture. Marine
Tertiary and Recent.
Pig. 733.
Drcisseiisia brardi
Faujas. Miocene ;
Weissenau, near
464 MOLLUSCA phylum vi
The Eecent .families, Jiiliidae and Modiolarcidae, if their validity be confirmed,
Fio. 734.
Congeria siibglohusa (Partsch). Upper Miocene ; Inzersdorf, near Vienna.
may find a place in this vicinity. Julia Gould (Prclsina Desh.), and Berthelinia are
reported from the Tertiary, the former in the Oligocene of Florida.
Order 2. ANOMALODESMACEA Dall.
Superfamily 1. ANATINACEA Dall.
Anomalodesmacea with \/ -shaped reticulate gills not secretimj a calcareous tube exterior
to the shell.
This group is divisible into sections as follows : — (a) Eusiphonia, with long siphons, and
the lithodesma, when present, at the anterior end of the internal resilium, and external to
the mass of the resilium ; and {h) Adelosiploonia, with sliort siphons, the lithodesma dividing
the mass of the resilium niesially.
Section A. Eusiphonia.
Family 1. Pleuromyacidae Zittel.
Shell slightly inequivalve, hinge ivith an obscure projection or edentulous, the cardinal
border of one valve covering that of the other valve, which is swpplcmented by a sort of
A laminar nympih, the ligament sub-internal between
them ; area inconstant or obscure ; pallial sinus
present ; valves closed or slightly gaping. Trias to
Lower Cretaceous.
Pleuromya Ag. {Myacites auct.) (Figs. 735, 736).
Posterior side longer, somewhat gaj^ing, hinge
margin with a thin horizontal lamina in each
valve, the left inferior, the margin with a feeble
notch behind the lamina ; ligament parivincular.
Trias to Lower Cretaceous ; abundant, but seldom
well preserved.
Gresslya Ag. (Fig. 737). Like Pleuromya, but
the right hinge margin projecting over the left,
anterior side sliort, wide ; ligament parivincular,
almost internal, attached to an internal nymjih-
like callosity in the right -valve, which appears as a groove on internal moulds.
Abundant in thci Jura, especially in the Lias.
Flii. 735.
Pleuromya peregrina d'Orh. Upper .hira ;
ChorostUi'iw, near Moscow. A, Internal
mould, i/i- i'l Hinge.
CLASS I
PELECYPODA
465
Ceromya Ag. (Fig. 738). Curdate, inflated, with ratliui' auteiidr, prosogyrous
beaks ; hinge margin of the right valve
superior, edentulous, hut with a blunt
Flc. 730.
Fleuromya tenuistriata
Ag. Middle Jura, Za-
jaczki, Poland, i/j.
Fu:. 737.
Gresslya latiroxtris
Ag. Lower Oolite ;
Tannie, Sartlie. '/l-
Fio. 73S.
Ceromyacf. adhnsls Queiist. IMiddlt; .Jura ;
Kiieuttingeri, Lorraine. Hinge, i/.j.
elongated process in front of an internal callosity. Chiefly occurring as moulds. Jura.
Family 2. Pholadellidae Miller (eiuL-nd.).
Shells obovate, usually attenuated behind and slightly gajnng^ hinge margin thin,
edentulous, ligament parivincular, external ; posterior adductor scar large. Paleozoic.
Allorisma King. Elongate, arcuate, the jjallial line sinuated, anterior side
shorter, sometimes with a lunule ; sculpture strongest mesially. Carljoniferous and
Permian.
Rhytimya Uhich. Elongate, sub-quadrate, concentrically waved, the waves
stronger anteriorly ; sculj)tured on the posterior half with
radiating series of granules ; lunule very narrow. Silurian.
Pholadella and Gimitaria Hall. Devonian ; North
America.
Family 3. Pholadomyacidae Gray.
Shell substance nacreous and cellulo - crystalline ; gills
Plioladomya murchitioni Sow.
Middle Jura ; Piezclinow, Poland.
I'lioladomya deUoidcu Ag.
Middle Jura ; England, l/o.
Pig. 741.
Plioladomya pusch i Goldf. Oligocene ;
Tolz, Bavaria. 2/3.
completely united, behind, forming a septum belotv the anal chamber ; foot small, with an
o'pisthop odium ; siphons long, united to their tips, not ivholly retractile, naked; ventral
commissure of the m.antle ivith a pedal and an opisthopodial foramen. Shell thin, equi-
VOL. I 2 H
466
MOLLUSGA
PHYIAIM VI
valve, (japing, edentulous, or with an obscure subumhonal tubercle; ligament, and
resilium external, opisthodetic, seated on nymphae ; area obsolete or obscure, not amphi-
detic ; beaks entire ; pallial sinus loell viarked ; marine. Trias to Recent.
Pholadomya Sow. (Figs. 739-741). Sliell thin, sub-ovate, with radial and con-
centric sculpture, inflated, and with rather prominent beaks ; hinge edentulous, or
with an ol)scure thickening ; scars feeble, pallial sinus moderately deep. In the
Gonimnya duboisi Ag. Inferior Oolite ; Bayeux,
Calvados. A, Shell, l/j. B, Surface showing puncta-
tions, magnified.
Fig. 743.
Ilinnomyd (Arcomya) calreifortiii.i Ag. Inferior Oolite ;
Les Moutieux, near Bayeux, Calvados, -/s.
posterior dorsal region the radial sculptui'e is usually feeble or absent. Lower Lias to
Recent ; formerly very abundant, but now represented by a single species from the
Antilles, P. Candida Ag., and another from Japan.
Procardia Meek. Includes those forms with an escutcheon. Jura.
Goniomya Ag. (Fig. 742). With V-shaped sculpture. Lias to Cretaceous ; very
plentiful in Middle and UiJper Jura.
Homomya Ag. {Arcomya, Myopsis Ag. p.p.) (Fig. 743). Distinguished from the
typical Pholadomyas by its smooth or very finely sculptured shell, without rilts.
Trias to Cretaceous.
(?) Machomya, Plectomya Loriol ; Mactromya Ag. Jura and Cretaceous.
Family 4. Anatinidae Dall.
Soft pchHs like Pholadomya, the foot small and grooved, ventral foramina small, and
the siphons with a horny integument, not entirely retractile. Shell sub-equivalve, truncate,
or gaping behind, edentulous, the resilium internal between
two spoon-like chondrophores vertically directed and often
supported by buttresses ; ligament obsolete or absent ; area
obsolete; beaks transversely fissured; pallial sinus well
marked ; monoecious ; marine. Jura to Recent.
Anatina Lam. (Plafymya, Ccrcomya Ag.; Plicomya
Stol.) (Fig. 744). Shell thin, nearly equivalve, con-
centrically but feebly sculptured, posterior side shorter
than the anterior. Jura to Recent. Laternula Bolten, is a prior name.
Periplomya and Anatimya Conrad ; Rhynchomya Agassiz. Cretaceous.
Fig. 744.
Anatina prmhicta Zittel. Upper
Cretaceous ; Gosau Valley, Austria.
Family 5. Periplomatida,e Dall.
Shell sub-nacreous, conspicuously inequivalve, nearly closed, edentulous; the resilium
internal, between two anteriorly or vertically directed chondrophores, often buttressed, the
lithodesma rarely wanting ; ligament and area, absent ; beaks fissured ; pallial sinus
broad and shallow; siphons separated to their bases, naked and ivholly retractile; mono-
ecious; marine. Tertiary and Recent.
CLASS I
PELECYPODA
467
Periploma Scliuin. Shell oval oi' rounded, smootli or with i'aint concentric striae ;
lithodesma present. Tertiary and Recent.
Gochlodesma Couth. Buttress of the chondrophore posteriorly directed ; no litho-
desnia. Pliocene and Recent.
Bontaea Leach {Ligula p.jj. Mont.) ; Tyleria Adams. Recent.
Family 6. Thraciidae Dall.
Shell earthy and cellulo-crystalline, not nacreous ; ineqioivalve, thin, edentidous, often
with a granular sihrface ; ligament and resilium ^PM
chiefly external, opisthodetic, parivincular, seated
on posteriorly directed nymphae ; area absent,
beaks usiudly entire ; valves nearly closed, with .^^!ft^\IJi0?!MK^S: //
pallial sinus ; mantle openings small ; siphons
long, sepjarated to their tips, naked ; monoecious : HfHiMPX " ^^^SS^^r^- ///
marine. Jura to Recent.
Thracia Leach {Gorimya Ag.) (Fig. 745).
Shell smooth or concentrically striated, with
granular surface, usually more or less rostrate.
Trias to Recent.
Gyathodonta Conr. Shell witli oblique or
angular waves of sculjiture, otherwise like the
preceding. Tertiary and Recent.
Fid. 745.
Thracia liuxrta Ag. Upptu- Jura ; Pruntiut,
SwitzerUuicl. i/j.
B'ushia Dall ; Asthenothaerus Carpenter. Recent.
Family 7. Myochamidae Dall.
Shell very inequivalve, free or sessile, solid, sub-nacreous, edentulous, the dorsal
margins of one valve overlapfing those of the other, which fit into corresponding dc])res-
sions in the shell loall ; ligament amphidetic, external or absent ; resilium internal,
alivincular ; area amphidetic or obsolete, a false area formed on each side of the beaks by
the flattened cardinal margin of the valves ; shell closed ; pallial sinus small. Tertiary
and Recent.
The gills and siphons of Myochama Stutchbury, which lives sessile on shells, are
more like those of Thracia than of the Pandoridae, with which it has usually been
associated. The anatomy of Myodora is unknown. Its minute area curiously recalls
that of Spondylus, and it is free.
Section B. Adelosiphonia.
Family 8. Pandoridae Gray.
Shell compressed, inequivalve, free, solid, with nacreous and prismatic layers ; the
dorsal edges of the valves overlapping, but not socketed, ivith dentiform crural ridges on
either side of the resilium, but no true teeth; ligament amphidetic, external, obsolete;
resilium internal, opisthodetic, usually reinforced on its anterior surface by a mesial
elongate lithodesma ; area none; valves closed, beaks entire, pallial line simple; marine.
Cretaceous to Recent.
Pandora Brug. Diverging crura without connecting lamellae ; buttress and
lithodesma absent. The subgenus Kennerleya has a lithodesma. Tertiary and Recent.
Goelodon Carp. Crura of the left valve united by a transverse lamella. Glidio-
phora Carp, has the hinge plate buttressed and a lithodesma. Tertiary and Recent.
468
MOLLUSCA
PHYLUM VI
Family 9. Lyonsiidae Dall.
Shell inequivalve, thin, suh-nacreous, edentulous; ligament obsolete, the resilium
internal, uniting the edges of a long, mesial lithodesma to a narroiv chondrophoric sub-
marginal ridge on each valve; beaks entire, valves nearly closed, pallial sinus distinct;
marine. Tertiary and Recent.
Lyonsia Tiirton. Small, thin, posteriorly elongate with delicate radiating sculp-
ture. Tertiary and Recent.
Entodesma Philippi. Recent. Actinomya Mayer. Eocene ; North America.
Family 10. Lyonsiellidae Dall.
SIbell nearly cquivalve, sub-nacreous, with a more or less distinct tubercle in front of
the resilium on the dorsal margin ; ligament obsolete, cartilage internal with a, large
lithodesma ; area, obscure or absent ; beaks entire ; valves almost closed ; fallial sinus
obsolete. Tertiary and Recent.
Halicardia Dall ; Lyonsiella Sars. Chiefly Recent.
Superfamily 2. ENSIPHONACEA Dall.
Dijf'ering from Anatinacea by the formation of a calcareous tube, which may include
one or both of the valves, and is usually furnished with a perforated anterior
disk surrounded by a more or less complete fringe of small calcareous tubules.
Family 11. Olavagellidae d'Orbigny (emend.).
Shell degenerate, extremely specialised for a burrowing life; valves
nacreous, free when young ; ivhen adult, one or both merged in a calcareous
tube anteriorly discoid and fringed, ivith a narrow pedal foramen in the
middle of the disk ; free valves edentulous, the ligament external, opisthodetic,
sup'ported by nymphs ; pallial line sinuate ; tube frequently encrusted with
extraneous material ; marine. Cretaceous to Recent.
Clavagella Lam. {Bryopa Gray ; Stirpulina Hoi.) (Fig. 746). One
of the valves not attached to the tube and adductor muscles persistent.
Cretaceous to Recent.
Brechites Guett. {Aspergillum Lam.). Both valves merged in the
tube, anterior adductor reduced, and the posterior obsolete. Pliocene
and Recent.
Superfamily 3. POROMYACEA Dall.
Fio. 746.
Clavagella
caillati Uesh.
Eocene ; Grig-
non. i/o (after
Deshayes).
Anomalodesmacea having modified foliobranch or lamellar gills, slightly
or not at all reticulated, and frequently degenerate or even absent; valves
free, witliout a calcareous tube external to them ; mantle lobes united, until siphons and
a pedal, but no opisthopodial foramen ; the cartilage reinforced beloio by a lithodesma.
Family 12. Euciroidae Dall.
Shell sub-equivalve, nacreous and cellulo-crystalline, externally granulose ; hinge
with a strong tubercle in the right valve before the resilium, and the dorsal margins
modified to overlie and underlie each other; ligament obsolete; resilitim opisthodetic,
internal, ivith a strong lithodesma ventrally ; area obscure or absent ; a depressed false
CLASS I
PELECYPODA
469
lunule before the beaks ; valves closed, pallial sinus shallow, obscure ; sii^hons short,
separate ; marine. Tertiary to Recent.
Pecchiolia Meuegli. Shell heavy ; beaks spirogyrate, distant ; sculpture radial.
Eocene ; Alabama. Miocene ; Europe.
Euciroa Dall. Recent, abyssal.
The genera Verticordia Wood ; Tri(jonulvna d'Orl). ; Haliris Uall ; and (?) Allo-
pagus Stol. {Hippagus Desh., non Lea) are included under the family Verticordiidae.
Tertiary and Recent.
Equivalve, oval, thin, in-
Family 13. Poromyacidae Dall.
Shell rounded, nacreous and cellulo -crystalline, granular or smooth externally ; hinge
with obscure tubercles in front of the resilimn ; ligament external, opistliodetic ; resilium
sub-internal beloiv the ligament, with a small lithodesma ; area obscure or absent ; a
depressed false lunule in front of the beaks; valves nearly or entirely closed; pallial
sinus small or obsolete; marine. Cretaceous to Recent.
Liopistha Meek {Oymella, Psilomya Meek) (Fig. 747).
flated, concentrically or
radially striated, gaping
and compressed behind ;
beaks prominent, in-
curved ; hinge with a
nymph and projecting
process on each side ;
ligament sunken, partly
external. Cretaceous.
(?) Basterotia Mayer
{Eucharis Recluz, non
Peron). Valves sub-equal, closed, with a strong tooth in the right and two in the
left ; surface granular ; form trapezoid. Miocene and Recent.
Poromya Forbes {Embla Loven). Ovate, plump, surface granular ; pallial line
irregularly widened, not sinuate. Eocene and Recent.
Dermatomya Dall. Surface smooth, with a conspicuous periostracum ; pallial
line sinuate. Recent, abyssal.
Cetomya, Getoconcha Dall {Silenia Smith). Recent, aby.ssal.
Fit.. 747.
Lio^nstha freqiiens Zitt. Upper Cretaceous ; Gosau, Austria. Vi-
Family 14. Ouspidariidae Dall.
Shell sub-equivalve, rostrate, earthy or cellulo-crystalline, rarely with surface granula-
tions; hinge edentulous or 'with sub-umbonal tubercula-
tion, sometimes bicttressed ; ligament sub-internal, anterior
to the beaks or obsolete; resilium internal, with a mesial
or ventral lithodesma ; area amphidetic or obscure ; valves
closed except at the tip of the rostrum ; pallial line simple ;
siphons united ; marine. Jura to Recent.
Guspidaria Nardo (Neaera Gray ; Ryderia Wilton)
(Fig. 748). Shell concentrically sculptured ; hinge
with a small posteriorly inclined chondrophore in each
valve, and an elongated ridge behind it ; ligament always anterior to the beaks
when present. Jura to Recent.
Subgenera : Cardiomya Adams ; with radial sculpture and a posterior lateral tooth in
the right valve. Leiomyn Adams ; smooth, with an anterior cardinal in each valve, and
Fir;. 748.
Cuspulnria cuspidata Olivi
Miocene ; Baden, near Vienna.
Vi-
470 MOLLUSCA phylum vi
anterior and posterior Laterals in the right valve only. Plcctodon Carp. ; surface granulated.
Rhinoclama 1). and S. ; like Plcctodon, but without cardinal teeth. I'rojndomya D. and
S. ; hinge with a buttress, one anterior cardinal, but no lateral in either valve. Halonympha
D. and S. ; right valve with a single cardinal, no other teeth in either valve, a conspicuous
posterior laminar buttress in each valve. Luzonia Dall. Tertiary and Recent.
Myonera Dall and Smith. Shell thin with concentric waves and sparse radial
ribs ; hinge edentulous ; rostrum short, rounded. Kecent, abyssal.
(?) Corburella Lycett. Middle Jura. Siihenio-psis Sandl^erger. Tertiary.
Order 3. TELEODESMACEA Dall.
A. Pantodonta.
Laterals exceeding two in any one group.
Family 1. Allodesnaidae Dall (CtjcloconcJiidae Ulrich).
Shell rounded; valves equal, free, closed, with feeble concentric sculpture; area
linear, am^^hidetic ; ligament sub-external, 2>arivincular, opisthodetic ; adductor scours
sub-equal, pedal scars above and distinct from the adductors ; pallial line entire ; hinge
ivith one or two lateral laminae on each side of the beak, the posterior below the ligament,
received into corresponding grooves on the right valve; cardinal teeth radially grooved;
one or two in each valve, those in the right valve stronger. Ordovician and Silurian.
This family, as suggested by Neumayr, probably exemplifies the first step in the develop-
ment of the Teleodesmacean hinge. But it must be admitted that its amphidetic though
linear area, the occasional multiplicatiou to three of the lateral laminae, and the sub-ligament-
ary location of the hinder laminae, are very reminiscent of the prevalent Silurian Schizodont
type, and the family can be admitted to the Teleodesmacea only as a probable ancestor, ratiier
than a perfectly developed type of the modern assemblage.
Orthodontiscus Meek {Gycloconcha Miller ; (?) Anodontopsis M'Coy). Ordovician
and Silurian.
Allodesma Ulrich. Like Orthodontiscus, but more elongate, the beaks more
anterior, the anterior adductor scar l)uttressed by a radial ridge, and the anterior
lateral teeth short or absent. Ordovician
B. DiOGENODONTA.
Laterals normally one or two, and cardinals three or less, in any one group.
Superfamily 1. CYPRICARDIACEA Dall.
Lobes of the mantle partly closed ventrally ; anterior lateral laminae absent, or
grouped with the cardinal teeth, short and obscure.
Family 2. Pleurophoridae Dall.^
Shell substance cellulo-crystalline ; valves equal, free, closed ; adductor scars sub-equal,
free from the pedal scars; imllial line entire, or feebly sinuated ; area obscure; liga-
ment external or seated in a groove, parivincular ; margins of the valves usually plain ;
hinge with one left and two right posterior laminae, the anterior laminae absent or con-
fused with the cardinals ; two or three cardinal teeth in each valve, of which the posterior
in both valves is sub-parallel to the dorsal shell margin, and in the right valve is usually
bifid. Mantle with a moderate pedal and two siphonal openings, the latter usually not
produced into tubes, l^evonian to Recent.
•' Cyprinidae p.p. of authors, but this name cannot be used.
CLASS I
PELECYPODA
471
This family, so well known under the i)reoccupied name Cyprinidae, probably shared the
same origin as the Astartidae, and tlie two do not definitely separate until the Jura. The
position of the Paleozoic ancestors is necessarily doubtful, and they are placed ditferently
by different authors. The group is divided into two subfamilies, Plcurophorinae and
Veniellinae.
PleuropJiorus King (Fig. 749). Elongated, sul)-rectangnlar ; beaks sub-terminal ;
surface smooth or with radial sculjiture ; hinge with two cardinal teeth in each valve ;
Fui. 749.
Pleiirophonis eostatus King. Per-
mian ; layers Quarry, England. A,
Shell, Vi (iifter King). B, Internal
monld Ironi Gera, Thnringia (after
Geinitz).
Fiii. 750.
Anisoc/irdia elegans Mun.-Chalm. Kimmeridgian ;
Cap de la Heve, near Havre, i/i-
anterior adductor scars deep, with a buttress-like ridge liehind it. Devonian to
Trias ; esiiecially abundt'int in the Permian.
Gypricardella Hall [Microdon Hall); Mecynodon Keferst. ; Gypricardinia Hall.
Devonian. Astartella Hall. Carboniferous.
Anisocardia Mun.-Chalm. (Fig. 750).
Rounded or trapezoid, plump, smooth or
radially striate ; posterior slope some-
times keeled ; hinge with a strong
sometimes bifid right cardinal behind,
and an anteriorly directed front cardinal;
Arctlca islandicit (Linn). Pleis-
tocene ; Boliusliin, Sweden.
Venilicardia cordiformts, d'Orb.
Gault ; Seignelay, Yonne.
Fic. 753.
Veniella tumida Nyst. Crag ; Antwerp.
left valve with a forwardly directed anterior and a posterior cardinal tooth. Jura to
Tertiary.
Roudairia Munier-Chalm. Like Trapeeium, but with a sharp keel and smooth
area behind, anteriorly with concentric ridges ; right posterior cardinal bifid. Upper
Cretaceous.
472 MOLLUSCA phylum vi
Trajpezimn Huinpli. emend. Megeiie {Lihitina Scliiiiu . ; Cypricardia Lam.). Shell
elongate, trai)ezoidal, concentrically, or more rarely radially sculptured, often with a
posterior keel ; three cardinal teeth in each valve, the posterior in the right valve
often bifid. Jura to Recent.
Plesiocyprina Munier-Chalm. Jura. Cicatrea Stol. Cretaceous. Goralliofhaga
Blainv. Tertiary and Recent.
Arctica Schum. {Cyclas Brug. ; Cyprina Lam.) (Fig. 751). Oval or rounded, in-
flated, concentrically striated ; beaks prominent, curved, cardinals three in each valve,
the left posterior often Infid, the middle left cardinal largest, and the posterior ridge-like.
Abundant in the Jura and Cretaceous, and represented by one or two living species.
Venilicardia Stol. (Fig. 752). Cretaceous. Pygocardia Mun.-Chalm. Tertiary.
Veniclla Stol. {Venilia Morton; (?) Goniosoma Conr.) (Fig. 753). Left valve with
the anterior cardinal strong, sub-triangular. Cretaceous and Tertiary.
Superfamily 2. ASTARTACEA Dall.
Lohes of the mantle free ventrally ; lateral laminae obscure, when present distant
from the cardinals.
Family 3. Curtonotidae Dall.
Bhell short and heavy, ivith sub-terminal beaks ; valves free, equal, closed ; area
obscure; ligament as in the Astartidae ; adductor scars, especially the anterior, deep;
pallial line simple ; hinge plate broad, without lateral laminae ; the formula of the
cardinals ^-.-z-^.,-:, or ^ftttt^. Devonian and Carboniferous.
KlOlO KlUl
This group is inserted conformably with the opinion of Neumayr, who regards it as the
radical of the Astartidae.
Curtonotus Salter. Oval, cardinal border thick, with one very strong tooth in the
left, and a strong anterior and thin posterior tooth in the right valve. Scars of the
adductors strong, especially the anterior. Devonian ; England.
Prosocoelus Keferst. Devonian. Protoschizod us de Kon. Carboniferous.
Family 4. Astartidae d'Orbigny (emend.).
I>]idl substance cellulo-crystalline, with a pronounced epidermis; shell rounded or
sub-triangular, usually with concentric or not radial sculpture ; valves equal or sub-equal,
free, closed; area distinct; ligament and resilium external, parivincular, opistkodet'ic;
beaks prosocoelous ; adductor scars sub-equal, loith a distinct anterior pedal scar ; pallial
line simple; hinge plate distinct, hinge with anterior and posterior
lateral teeth and their respective sockets, usually more or less obsolete ;
cardinal teeth not bifid at the summit, the terminal teeth frequently
obsolete. Lobes of the mantle free ventrally, not produced into siphons.
Pig. 754. Trias to Recent.
mM\llmt-f\nt Astarte SfAv. (Crassina Lam.) (Fig. 754). Roundly triangular or
('icrslioion, "aIsiicc. oval, rather compressed, thick ; smooth or concentrically sculptured ;
'•■ lunule impressed ; right anterioi' cardinal strong.
A nmnher of genera have been associated with Astarte which prolialily belong elsewhere.
The following subgenera, however, are wortliy of reeogiiilioii ; Coehistarle Bohin, Prcconia
Stol. ; Crass iii.rlhCv>-i.j\e, nnn Guppy (Fig. 755); Promh-ia Bi)liiii. Jura. Erlphyla Gabb.
Cretaceous. Grotriania Speyer ; GoodaUia Turtou (Fig. 757) ; Rhcdocyma Dall ; Digitaria
Wood (Fig. 75G). Tertiary and Recent.
CLASS I PELECYPODA 473
Opis Dcfr. (Fig. 758). Ti-igoiial, cordate, sinootli or concentrically striate ; Ijeaks
Fio. 757.
Astartc (GoodalUa)
miliaris Defr. Eocene ;
Grignon, • near Paris
(after Desliayes).
Fig. 755.
Astartc obliqua Desh. Interior
Oolite ; Bayeux, Calvados.
Fig. 750.
Digitari profunda De.sh.
(as Woodia). Eocene ; Aizy,
near Laon. A, Hinge, en-
larged. 75, Shell.
prominent, prosocoelous ,; lunnle very deep, bordered by a keel;
cardinal teeth long, narrow (2 : 1). Trias to Cretaceous.
Opisoma Stol. Jura. Seebachia Neuniayr. Cretaceous.
Fig. 758.
Opis goldfuasiana
d'Orb. Upper Jura ; Nat-
theim. Wiirtemberg.
m
Family 5. Crassatellitidae Dall.
Shell as in the Astartidae, hut the valves always somewhat unequal, and usually
ore or less rostrate, the beaks compressed, erect or opisthocoelous ; Ivjament infernal,
Fig. 75P.
Crassatellites i^lumhca (Chem.). Eocene (Calcaire Grossier) ; Damery, near Bpernay. 2/^.
more or less obsolete, resilium large, wholly internal, attached at each end to a chondro-
phoric pit in the hinge plate behind the cardinal teeth ; lateral teeth and sockets usually
alternated in the valves, the hinge plate heavy, flat ; the posterior cardinal in the right
valve very small or obsolete, ivith no distinct socket in the opposite valve ; f^dl cardinal
, , L 1010
Lower Cretaceous to Recent.
Tlie earlier forms of this family have a small resilium close to the nearly marginal liga-
ment. With time, later ones show a gradual descent of tliese organs, until in some of tlie
more specialised modern representatives there is no ajtpreciable ligament remaining, and the
474
MOLLUSCA
PHYLUM YI
resilium has become large and deeply immersed. The parallelism between this group and
the Mactridae, in the gradual immersion of the ligament, could hardly be
more com})lete.
Crassatellites Kruger {Crassatella Lam. 1819, non Lam. 1799)
(Figs. 759, 760). Cretaceous to Eeceiit ; represented by about seventy
fossil and forty living species.
Trioclonta Koenen. Oligocene. Scavibula Conrad ; Remondia
Gabb {Stearnsia White) ; Antlwnyia Gabli ; Grassatellina ISIeek.
Cretaceous.
(?) Ptychomya Ag. Like Crassatellites, but with radial sculpture
"" ''^^' and three cardinals in each valve. Cretaceous.
hronni ' Merlm Grassinella Guppy, non Bayle {Gouldia auct., non Adams ;
Oligocene; Wein- Pseiideripliyla Fisch.). Small, sub-triangular, very compressed, con-
nfjiiiij iiGtir Aiz(*y. * ti •tit m • i t\
i/j. centrically ribl:)ed. Tertiary and Kecent.
Superfamily 3. CYRENACEA Tryon.
Cyjiricardians which have become specialised^ for fresh or brackish water conditions,
and, as usual in such cases, have developed great variability of character ; tisually vivi-
parous.
Family 6. Oyrenidae Gray.
Shell iiorcellanous, with a conspicuous epidermis, usually with concentric sculpture;
valves equal, free, closed, usxially with plain margins; area obscure or none; ligament
and resilium external, parivincular, opisthodetic ; adductor scars sub-egual, separate
from the pedal ; pallial line simple or ivith a small simis ; hinge with anterior and
posterior laterals usually double in the right, single in the left valve, distinctly separated
from the cardinals; cardinal teeth bifid, at the summit, three in each valve when none
are obsolete. Mantle open ventrally, the siphons distinctly developed, short, more or less
united. Lias to Recent.
Many of these forms merge with one another as we recede in time. The Recent American
forms and many fossils show a pallial sinus ; oriental s}>ecies are generally without it. In
some fossils the laterals of the right valve are not double.
Cyrena Lam. Rounded, sub-equilateral, plump, concentrically sculptured, with
smooth margins ; cardinals three, the laterals smootli. Lias to Eecent (300 species) ;
maximum in the Cre-
taceous and onwards.
Subgenera : Corbieula
Megerle (Figs. 761, 762).
Smaller than Cyrena, and
the laterals sharply cross-
striated. Ecjcta Adams.
Compressed, elongated,
thin ; almost rostrate.
Recent ; marine.
Like
Fic. 761.
right
Corhicula fluminalis
(MiilL). Pleistocene ;
Teutschentlial, near
Halle, Saxony.
Corhicula semistriata Desh. Oligocene
(Cyrena marls) ; Flonheini, near Alzey. Vi-
Batissa Gray.
Cyrena, but the
anterior and left posterior cardinals feelile or obsolete ; anterior laterals very short,
posterior ones elongated. Upper Cretaceous of Oregon, and living in Indo-Pacilic
region.
Veloritina, Leptesthes Meek. Laramie Group. Villorita Gray {Velorifa Gray, 1 847).
Oligotiene to Recent. The relations of the Recent Egeria Roissy, and Proflscheria Dall
{Galatea Lmg., non Fabr. ; Fischeria Bernai'di, non Desv.) are not positively fixed.
CLASS I
PELECYPODA
475
Family 7. Sphaeriidae Dall.
Shell as in the Gyrenidae, but small, with a feeble, short ligament, a simple fallial
line, and no hinge plate ; cardinal teeth usually two i^i each valve, variable, very thin,
often nearly parallel to the hinge margin or defective in part of the series ; laterals as in
the Gyrenidae, distinct. Upper Cretaceous to Eecent.
Sphaerium Scop. {Gyclas Lam., non Brug.). Branchial siphon complete ; shell
equilateral, inflated, rounded. Upper Cretaceous to Recent.
Subgenus EujJera Bgt. Shell compressed, trapezoid. Tertiary and Recent ; sub-tro])ical.
Gorncocyclas Ferussac {Pisiditim Pfeilf.). i Shell inequilateral ; branchial siphon
merged with the pedal opening. Eocene to Recent.
Superfamily 4. CAEDITACEA Menke.
This group appears to have branched off from the Astartoid radical in the early
Mesozoic, forming in one sense a sort of parallel series loitli the Astartidae, with tvhich it
is contrasted most obviously by its prevailing radial sculpture and prolonged posterior
cardinal tooth.
Family 8. Oarditidae Gill.
Shell as in the Astartidae, but usually with radial scihlpture, the pedal adjacent to
the anterior adductor scar ; ligament external, parivincular ; resilium usually included
in the ligament, rarely , internal ; hinge fidly developed, with the Icominae as in the
Astartidae, and usually obsolete ; the anterior cardinal often obsolete, the posterior pro-
longed parallel with the dorsal margin even beloiv the ligament. Full cardinal formula
p • M&rine ; dioecious, frequently viviparous. Trias to Recent.
The earlier forms approach the Astartidae and Pleurophoridae so closely that they can
hardly be discriminated.
Gardita Brug. Elongate, quadrate, with prominent, very anterior beaks ; sculji-
Pio. 763.
Palaeocardita cre.nnta
(Munst.). Upper
Trias ; St. Cassian,
Tyrol.
Fic. 704.
Venericardia imhricata Lam. Eocene ; Grignon, near Paris.
ture radial and usually imbricated, commonly with a lunule ; inner margins dentate ;
cardinals long and oblique. Trias to Recent.
Palaeocardita Conr. (Fig. 763). Like Carditct, but with a posterior lateial
tooth. Trias and Cretaceous.
Venericardia Lam. (Fig. 764). Rounded or cordate ; lateral teeth al)sent or
obsolete. Cretaceous to Recent.
476
MOLLUSCA
PHYLUM VI
Garditamera Conr. Elongated, siili-mytilifonn. Pleuromeris Conrad. Small,
equilateral, trigonal. Galyptogena Dall. Ovoid, smooth externally. Garditella
Smith. Small, with internal ligament. All Tertiary and Recent. Tlicadia Adams ;
Milneria Dall. Females with a shelly marsupium. Recent.
Superfamily 5. CHAMACEA Geinitz.
Garditian forms specialised for a sessile habit, usually with exceptionally spiral
groivth, and very unequal valves. Marine.
Family 9. Diceratidae Dall.^
Resembling Ghama, but with the adductors usually borne on myophoric laminae, or
projections which a^re prolonged into the umbonal cavity below the hinge plate ; valves
grotesquely distorted, sub-equal, with p)i'olongcd and tim'stcd umhones, or the free valve is
reduced to an opercular form, spira.l, and even concave; the teeth often reversed relatively
to their situation in Ghama. Jura and Cretaceous.
This family has possibly been derived from the Megalodontidae of the Paleozoic and early
Mesozoic, and in .turn has given rise to a branch that has survived to the present day
Dlccras arictinwni Lam. Coral-Raa; ;
St. Mihiel, Meu.se. s/.,.
A, Diceras arietinum hum. Coral-Rag; St. Mihiel, Meuse.
Fixed left valve, 2/3. B, D. zittcli., Mun. - Chalm. Tithonian ;
Stramberg. Right valve, 2/3. a, a', Anterior and posterior
adductor .sear.s ; c, Ma.ior cardinal ; d, Socket for left anterior
cardinal ; I, Ligamentary groove ; s, Buttres.s ridge before
po.sterior adductor scar.
(Chamidae), as Avell as to others that became extinct at the close of the Mesozoic. _ In all cases
the forms in which the umbo of the free valve is coiled have preceded more specialised forms
1 For the Chamacea and Rudistae, NeumajT proposed the term Pachydonta. For special litera-
ture see : Zittel, K. A. von. Die Bivalven der GosaugebiMe. Deukschr. Akad. Wis.s. Wien,
1864, voh xxiv.—Oemmellaro, G. G., Caprinellidi della Ciaca dei dintorni di Palermo, 1865.—
Munier-Ghalmas, E. , Prodrome d'une classification des Paidistes. Journ. deConchyl., 1873, vol. xxi.
— White, a. A., Bull. U.S. Geol. Surv., No. 4, 1884 ; No. 22, X'i^b.—DouvilU, H., Several papers in
Bull. Soc. Geol. France [3], xiv. p. 389 ; xv. p. 756 ; xvi. p. 699 ; xvii. p. 627 ; xviii. p. 324 ;
1886-90.— (Zi Stefano, G., Studii stratigrafici e paleontologici sul systema cretaceo di Sicilia.
I. Gli Strati con Caprotina. Palermo, 1888. II. Calcari con Polyconites di Termini-Imerese.
Palaeout. Ital., 1898, vol. \v. — Fuiterer, K., Die Obereu Kreidebildungen der Umgebung des Lago
di Santa Croce. Palaeont. Abh., 1892, n.s. vol. M.—Bohm, G., Beitriige zur Kenntnis der Kreide in
den Siidalpen. Palaeontogr., 1894, vol. xU.—Douville, JT., Eltudes sur les Eudistes. Mem. Soc.
Geol. France. Palrontologie, i. iii., 1890-96.— Paro/(a, 0. F., Sopra alcune Rudiste Senonianc
dell' Appeniuo ineridiouale." Mem. Accad. Torino, 1900, ser. 2, vol. l.—Paqider, V., Les Rudistcs
urgoniens. Mem. Soc. Geol. France, Paleont., 1903, vol. xi.—Toucas, B., Etudes sur la classifica-
tion et revolution des Hippuiites. torn, cii., 1903, and vol. xxi. p. 506, 1891.
CLASS I
PELECYPODA
477
with an operculiform free valve. The highly modified Hippuritidae evidently indicate the
last stage of the evolutionary series.
Diceras Lam. (Heterodiceras, Plesiodiceras Mun.-Chalia. ; Pseudodiceras Gemiu.)
(Figs. 765, 766). Shell smooth, inequivalve, with Ijotli valves convex, the attached
valve larger, dentition normal or inverse ; beaks prominent, j)rosocoelous ; ligament as
in Chama, supported on nympliae ; right valve with a small anterior and large
elongated curved posterior tooth almost parallel with the hinge margin ; left valve
Fk;. 767.
A, liequienia atiimomaifioldt'.). Urgouiaii ; Orgon, Boiu;heH-du-Rliiine. i/s- /'', f. Small individual of
11. (ToHCJxaia) lonxihde! (Sow.), fioin same locality. B, Left ; <', Kiglit valve, i/j.
with a single, large, ear-shajjed tooth in front of the elongated socket for the principal
tooth of the right valve ; posterior addnctor scar on a projecting Inittress. Upper Jura.
Apricardia Gueranger. Cenomanian and Turonian. A. carinata Guer.
Requienia Matheron (Fig. 767, A). Smooth, very inequivalve, attached by the
spirally twisted beak of the left valve ; right valve opercular, spiral, flat ; teeth
feeble ; posterior adductor scar buttressed. Lower Cretaceous, especially the Urgonian
of southern Europe, the Alps and Texas.
Subgenus Toucasia Mun.-Chalm. (Fig. 767, B, C). Ditfers from Requienia in having
both valves keeled. Urgonian and Cenomanian.
Matheronia Mun.-Chalm. Urgonian and Cenomanian, M. virginae (Gras.).
Family 10. Chamidae Lamarck.
Shell substance threefold, the inner layers imrcellanous and tubnlar, the middle
obscurely prismatic, the external cell lolo -crystalline ivith reticulated tubules and an incon-
spicuous epidermis; valves unequal, irregular, one of them sessile; closed, usually
rounded in form with conspicuous sculpture, often differing in the opposite voJves ;
adductor scars sub-eqiial, elongate, pedal scars minute, distant; ligament and resilium
external in a deep groove, parivincular, opisthodetic ; area distinct, prosodetic ; beaks
more or less spiral, prosogyrous ; pallial line simple ; hinge plate heavy, arcuate ; hinge
frequently ivith a minute or obsolete posterior lamina, chiefly in the fixed valve;
cardinals one or two in the free valve, tioo loith an intennediate socket in the fixed valve ;
the anterior cardinal broad, usually deeply grooved or multifid, the posterior simple, long
and curved parallel ivith the dorsal border ; siphoned orifices not produced into tubes;
adductors each composed of txoo elements. Cretaceous to Recent.
Either of the valves of Chama may be the attached one, but the teeth in the fixed valve,
whether right or left, are always the same, and similarly with the free valve. The fixation
is generally by the left valve.
Chama Linn. (Fig. 768). Nepionic shell roimded. Ligament sometimes continiied
to the point of the beaks, as in other bivalves with gyrate umbones ; form rounded.
478
MOLLUSCA
PHYLUM VI
attached valve deeper and larger, the free valve flatter ; margins usually cross-striated,
surface lamellar or spinose ; adductor scars large, not elevated. Cretaceous to Recent;
maximum in Eocene.
Fifi. 768.
Cliwma squamosa Lam. Eocene ; Hamp-sliire. i/i.
Echtnochama Fiscli. Nepionic shell elongated, liaving the form, hinge and other
characters of Cardita ; attached when adolescent, free in the young and adult stages.
Valves sub-equal and similar; surface vermiculate, sj)inose, with radial ribs. Oligocene
and Recent.
Family 11. Monopleuridae Fischer.
Shell substance ivithout canals; shell sessile, closed, very inequivalve ; free valve with
the cardinal formula 101, opcrculiform or slightly spiral; fixed valve with the formula
010, conical, unrolled or spiral; area loanting ; ligament external, parivincular,
opisthodctic. Cretaceous.
Monopleura Math. (? Dipilidia Math.) (Figs. 769, 770). Very inequivalve, smooth
or ribbed ; dentition always inverse ; attached by the right valve, which may be either
Fio. 769.
Fig. 770.
Monopleura trilohita d'Orb. Neocomian (Schiiittenkalk) ; Orson, Monopleura varians Matli. Ur-
Bouches-du-Rhone. l/j. A, B, Anterior and posterior views. C, Interior gonian ; Orgon, Bouclies-du-Uli6ne.
attached valve. Interior of both valves, i/j.
twisted or coniform ; left valve conical or flat ; ligament as in Chama ; posterior
adductor scar buttressed. Lower Cretaceous ; Southern Europe and Texas.
Valletia Mun.-Clialm. Neocomian. Gyropdeihra Douvilk'. Cenomanian to
Senonian. Baylcia Mun.-Chalm. Turonian. B. pouechi Mun.-Chalm,
Family 12. Oaprinidae d'Orbigny.
Shell substance internally furnished ivith large parallel canals, th.e external layer
prismatic ; valves heavy, irregular, unequal, closed ; free valve spiral, cardinal formula
CLASS I
PELECYPODA
479
101, ^vith a posterior myophoric crest for the adihictor ; fixed valve conical or spiral,
cardinal formula 010; ligament in a deep groove, almost internal, parivincular,
opisthodetic. Cretaceous.
G aprina ^'Orh. {Gemmellaria Muii.-Clialm. ; Cornucaprina Futt.) (Figs. 771, 772).
Fig. 771.
Loiif^dtudinal seetion of
the fixed valve of ('aprina
advcnu, showing cavitie.s in
tlie inner .shell layer.
Fig. 772.
Cross-section
of the free valve
of Caprina cam-
munis Qemmeh,
.showing parallel
canals in the
middle layer.
Fig. 773.
riwjidjityclius aiiuiUoni d'Orb. Upper Cretaceous ;
Gosau, Austria. 2/^.
Very inequivalve, attached by the apex of the coniform right valve. Left valve large,
s]3irally twisted ; inner layer of lower valve made up of concentric lamellae between
which cavities are sometimes left. The middle layer of the free valve traversed by
numerous simple, wide, parallel canals, extending from the margin to the apex; tooth
of the attached valve Well developed, a series of depressions between the posterior
adductor scar and the margin. Cenomanian. The typical species, G. adversa d'Orb.,
is of large size.
Schiosia Buhm. Like Gaprina, but the fixed valve somewhat gyrate and the
canal system present in both valves. Cenomanian ; Upper Italy.
Plagioptychus Math. (Sphaerocaprina Gemm. ; Orthoptychus Futt.) (Figs. 773,
Fig. 774.
Flaijioptychus ofjuiUoni (d'Orb.) (P. paradoxus Math.). Upper Cretaceous (Hippurites Limestone); Le
Beausset, Var, France. A, Right. B, Left valve of the same individual, seen from within, 2/3. a, Anterior;
a' Posterior adductor scar ; I, Ligamentary groove ; c, Anterior tooth ; c'. Posterior tooth of left valve ;
f?,' Socket; », Buttress. C, Section of the small valve near the margin, showing canals (y) of tlie middle layer.
JIagnified.
774). Right valve conical or twisted, attached ; left valve convex, with incurved
480
MOLLUSCA
PHYLUM VI
l)eak ; ligament as in Ghama. Shell structni-o like Caprina, but the free valve with
canals in the middle layer ; the walls of tlie canals bifurcate ontward, forming in
section a fringe of peripheral minor channels (Fig. 774, G). Cenomanian and Tiironian ;
Europe.
Cajjrinula d'Orb. (Chaperia Mun.-Chalm.) (Figs. 775, 776). Right valve elongated,
A attached, conical or incurved ;
left smaller, gyrate ; both with
canal system, the periplieral
III i?P~7H/ Fc 'W^-x calials smaller ; hinge as in
Caprina.
Turonian
gal, Sicily and Texas.
IclbthtjosarcolitltusDcg-
marest {Gaprinclla d'Orl).)
Caprmula haylei Gemm.
Upper Cretaceous ; Ad-
dauran, near Palermo, i/.,
(after Gemmellaro).
Cenomanian and
especially in Portu-
Pio. 770.
Caprlmda boissyi d'Orb. Cross-
section of the lower (.4) and upper
(_C) valves, c, Teeth ; s, Septum ; .
u, Body ca\'ity ; x, Sockets. 2/3
(after Woodward).
Vir.. 777.
Mass consisting of Caprotina
semiMriatd and C. stiiata
d'Orb., and a smooth Sphaeru-
lites. Greensand ; Le Mans,
Sarthe (after d'Orbigny).
Cretaceous. Gaiirotina d'Orb. (Fig. 777). Canals obsolete, replaced in some species
by cavities. Neocomian to Turonian.
Goralliochama White. Right valve conical, elongated, attached ; left smaller, with
incurved beak ; anterior cardinal tooth buttressed, strong ; posterior cardinal weak ;
canals as in Plagiop)tychus, bounded within by a coarsely cellular layer ; lower valve
with a prismatic outer and laminar inner layer, separated by an intermediate cellular
stratum. Cretaceous ; Califoinia.
Superfamily 6. RUDISTACAE (Rudistae, Lamarck).
Ghamacea in which the spirality of the valves has been lost, the area and ligament
vertically submerged, and the dorsal margins recurved over them so as to bring the ligament
into a sub-central position above the teeth but far below the dorsal margin, where it finally
becomes obsolete. The teeth, no longer forming a hinge but rather a clithrum, specially
modified for the vertical motion of the operculiform. left valve, in which rotation is prevented
by the projection of the modified teeth into deep sockets in the fixed valve ; the latter conical,
thick ; pallial line simple, enclosing the whole cavity ; shell structure specialised in tioo
very different layers; sessile, marine.
The prisms of tlie outer shell layer are parallel to the long axis of the valve, and are cut
at right angles by numerous tabulae, which, together with the upper margin, often bear
impressions of radial vessels. The laminae of which the inner layer is composed are often
separated by cavities which recall the septa of Cyathopliylloid Corals, or those cavities found
in some oyster shells. In Ilippurites the outer layer is traversed by a complex of canals.
The Rudistacae are the most peculiarly modified of all Pelecypods. Their relationship to
the Chamidae through Monopleura and Ca'protina was first recognised by Quenstedt, and
afterwards confirmed by Woodward, Bayle, Zittel, Munier-Chalmas, Douville and others.
CLASS I
PELECYPODA
481
Formerly the group was referred to the most diverse connections, such as Brachiopods, Corals,
Cirripedes, etc., or placed in a special class by itself.
Tlie majority of Rudislids occur gregariously in large numbers, sometimes filling entire
beds ; they are often found in their natural position, standing vertically on the apex of the
attached valve. Notwithstanding their abundance, it is extremely difficult aud often impos-
sible to separate the two valves and expose the interior, hence the hinge of many species is
still only imj^erfectly knoAvn.
Family 13. Radiolitidae Gray (emend.).
Shell sabstance with the exteriud layer thick, prismatic; the internal thin, cellulo-
crystalline {frequently destroyed in fossilisation) ; valves very unequal, the ligamentary
subsidence usually marked ; free valves with tivo projections and two somewhat irreyular
myophores ; fixed valve with one myopihore and two sockets ; summit of the valves sub-
maryinal in the young, subcentral in the adult. Cretaceous.
a, i, Radiolites (BiradioUtes) cornu-pastoris d'Orb. Middle Cre-
taceous (Garentoniaii) ; Pyles, near Perigeux. a, Shell with closed
\-alves. B, C, The two more finely ribbed vertical band.s. b, Interior
of larger valve, viewed from above, a, a', Adductor .scars ; m, Pallial
line ; u, Space occupied by soft jiarts ; x, Empty space between the
sockets. 1/2 (after Bayle). c, Opercular valve of iJ. hournoni (Desm.).
Upper Cretaceous (Dordonian) ; St. Mametz, Dordogne. a, Anterior ;
a', Posterior myophore ; c, c', Anterior and posterior processes of
clithrum. 1/3 (after Bayle).
Spliaendites angeiodes Lam. Ujiper
Cretaceous ; Gosau, Austria, a, Shell
with closed valves, 1/1. h, Opercular
valve, Vi- -*!) Sinus of hinge; a, a',
Jlyophores ; c, c', Processes of clithrum.
Radiolites (Lam.) Bayle [BiradioUtes d'Orb.) (Fig. 778). Lower valve conical,
erect, elongated, vertically ribbed, or made up of successive layers ; usually with two
somewhat smooth bands extending from the apex to the upper margin, which are
supposed by Douville to indicate the position of siphonal orifices ; outer layer very
thick, composed of large polygonal cells or hollow prisms (Fig. 780). Upper valve
operculate, flat or conical, with, central or eccentric umbo. The clithrum is formed by
two vertically projecting striated processes (Fig. 778, c, c) fitting into sockets near
the outer wall of the fixed valve ; next to and outside of tlie sockets are two large,
VOL. I 2 I
482
MOLLUSCA
PHYLUM VI
unequal, slightly excavated adductor scars, correspouding to two broad niyophores in
the upper valve. Middle and Upper Cretace-
ous ; Europe and Texas.
Subgenera : LcqKirousia Bayle. The smooth
bands correspond internally to two prominent
tubercles. Synodontitcs Pirona. Has the two
teeth of the upper valve fused.
Sphaerulites Delam. {RacUolites, Birostrites
Lam. ; Jodamia Defr. ; Bipilidia. 1 Agria
Math.) (Figs. 779-
781). Externally
like Radiolites, but
without the two
bands; valves with
a re-entrant sinus
between the teeth,
which fit into sepa-
rate pits {d, d'),
usually joined by a
y^ith the
Fic. 780.
Pifi. 781.
Sphaemlites foliaeeiis Lam. Carentonian ; lie
d'Aix, Charente. ^-1, Sinus of the liin^e. a, a'.
riclge
Portion of the outer shell layer Anterior and posterior adductor scans ; (/, d',
of the lower valve of a Sjihacru- Anterior and posterior grooved sockets for the
lites or Iladiolites showing the processes of the upper valve ; ;c, x', Empty spaces
of the ligament pits ; y, Cavity at the inner end
of the sinus. 2/3 (after Goldfuss).
innor imro-hi of '^'S® hollow prisms. Cretace-
mnei margin 01 ^^^^ . ^^^^^ Oargano, Italy, i/j.
the sinus ; the two
dej)ressions (Fig. 781, x, x) next the sinus were shown by Petho to have been the
seat of a ligamentary connection lietween the valves ; the adductor scars («, a) resemble
those of Radiolites. Widely distributed in the Middle and Upper Cretaceous.
The supposed genera Dipilidia, Birostrites and Jodamia are based on internal
moulds of Radiolites. The visible submersion of the ligament in some Radiolites
enables us to understand how the stages shown by Hifinmtes have arisen.
Family 14. Hippuritidae Gray.
Shell substance of two layers, the external j^orous, grooved and punctate; the inner
lacunary and ■prismatic ; exterior with sutures corresponding to an " anal " and
'' branchial " inflection, and sometimes with a, ligamentary suture ; clithrum formed of
tiw processes in the free valve, the adductors attached to myophores ; fixed valve with one
thin laminar process ; the adductor scars excavated, the anterior adductor duplex, forming
distinct scars. Cretaceous.
Hippxhrites Lam. (Figs. 782-786). Lower valve cylindro-conic, sometimes a metre
in length, attached by the apex, smooth or longitudinally ribbed, with three furrows
bounding two " columns," or columnar areas, extending from the ajjex to the upper
margin {A, B, G). Upper valve depressed, conic, with sub-central umbo, usually with
two round or oval foramina ; outer surface showing pores, the apertures of short canals
which join larger canals radiating from the beak. The thick outer layer of the lower
valve is usually brown -coloured and made up of thin horizontal strata, which are in
turn composed of small vertical prisms. The white inner layer is porcellanous, and
sometimes contains vacant spaces in the lower part of the shell. Three prominent
folds are present, on the inner side of the shell, formed l;)y the inbending of both
layers of shell, and corresponding to the external grooves {A, B, (J). Of these the
anterior {A) i§ longer and thinner than the others, which are thickened at the internal
end and carry a small tubercle above. In the two subgenera, Orbignyia Woodward
{H. biloculus Lam.), and Batolites Montibrt {H. organisans Lap.), the anterior sinus
disappears entirely. In Pironaea Menegh., a number of accessory folds apj^ear behind
the two columns. According to Douville, the two posterior columns are homologous
CLASS I
PELECYPODA
483
with tlie smooth Ijaiuls of Badiolites, and indicate the position of the siphons.
Woodward supposes that the pit (;/;) contained the internal ligament ; but so far,
Hipiiwrites dosavknsis
Douv. Upper Cretace-
ous ; Gosaii Valley,
Austria, i/o.
HippurUes opiidl Douville. Nefgraben, near Russ-
bacii, Salzburg. A, B, C, Impressed lines bounding
convex vertical areas (columns) corresponding to the
region of the hinge. 1/2.
HippurUes orf/anisans
Montf. Vertical section
of a valve below tlie
living chamber, show-
ing the septa and inter-
septal cavities of the
middle layer, i/j.
remains of the ligament have only been found in the l)ottom of the outer anterior
sulcus, where it seemed to form a vertical band. The second adductor scar is small,
and located between the sulcus and the anterior column {B). The clithrum of the
Fin. 785.
Hiiiinirites radiosus T>e&m. Upper Cretaceous (Dordonian) ; Royan, Charente. a, Upper valve (.1, Sinus of
the hinge ; B, .C, Grooves corresponding to anterior and posterior columns of the lower valve ; c, Anterior, and
c', c", Posterior processes of the clithrum). b, Interior of lower valve seen from above (A, Sinus ; B, C, Posi-
tion of anterior and posterior columns ; a, a', Adductor scars ; d, Socket of anterior, and d', d", of posterior
processes of clithriuu ; u. Body chamber of shell ; x, Vacant cavity near the sinus). 2/^ (after liayle).
upper valve is extremely difficult to prepare, and is known in only a few species.
The anterior process shows near its base two tubercles {a, a'), which correspond to
484
MOLLUSCA
PHYLUM VI
tlie divided adductor scar of the lower valve. Behind the anterior there are two
supplemental processes, which are received into the
sockets d' and d" of the lower valve. The species are
aliundant in the Middle and Upper Cretaceous, and occur
chiefly in littoral sliallow water deposits. The most
noted localities are the Alps and Pyrenees, Provence,
Charente, Istria, Dalmatia, Greece, Sicily, Asia Minor,
Persia and Algiers.
Barrettia
Guatemala.
Woodward. Cretaceous ; Jamaica and
Superfamily 7. LUCINACEA Anton (emend.).
Fir YSti
^ ,,^ Shell v-ith. the anterior adductor scar narrower, 'pro-
Hippuntes cornu-vaccinumGolai. , , , 77 • 7
Ui)perCretaceous;G()san, Austria, duced ventrally ; imsterior scar sliorter, rounded; imuiab
Srsho:'inru.e"int?;;ocS U^^^ si^nple; M ehngcUe, sub-dacate ; hincje feehle, teeth
ciithruiu and rt-iation of tho slieii- radial, often obsolete.
layers. 1/2
Fio. 7S8.
Tancredia {I'alaco-
mya) coraUina Zitt.
Ta?icr('f?i(is«'Kri/o/-7HJs (Danker), Lower Lias ; and Goub. Coral-
Hettingen, Lorraine. 1/1 (after Terqneni). Rag ; Glos, Calvados.
Fi(i.
Family 15. Tancrediidae Fischer.
Shell donaciform, equivalve, with an external lirjament ; the margin of the valves
entire; hinge with posterior
and anterior laterals, the latter
inconstant ; cardinals one in
the left and two in the right
valve, or two in each valve.
Trias to Cretaceous, (?) Eecent.
Tancredia Lycett (Het-
tangia Terq.; Palaeomya Zitt.
and Gouh.) (Figs. 787, 788).
Shell sub -arcuate, attenuated
before the beaks, wider and
shorter behind them ; obli-
quely truncate and somewhat
o-aping posteriorly ; a cardinal tooth on eacli side, and also an elongated posterior
lateral. Trias to Cretaceous ; maximum in Lias.
(?) Meekia Gablj. Cretaceous ; California. (?) Hemidonax Mcirch {Donacicardium
Vest). Recent.
Family 16. Unicardiidae Fischer.
Shell cord.iforni, equivalve, closed, concentrically striated; adductor scars cUi'ptical,
the anterior longer ; fallial line simple ; margin of the
valve smooth ; ligament external, parivincular, seated in a
groove ; with a grooved hinge-plate bearing a single obsolete
cardinal in each valve, or none. Carboniferous to Cre-
taceous.
Unicardium d'Orl). (Fig. 789). Rounded, inflated,
with incurved l)eaks ; hinge margin thin, with a weak
cardinal tooth ; ligament deep seated. Trias to Cretaceous.
Scaldia Ryckholt. Carboniferous.
Pscudedmondia Fischer. Ligament completely external.
Fio. -8i".
Unicardium cxceiitricum d'Orb.
Kiranieridgian ; Cap de la Heve, ( ^,.l,miifeTous
near Havre. Vi- UailJOniieiOUS.
CLASS I
PELECYPODA
485
Family 17. Lucinidae Fleming.
Shell substance porcellanous or chalky, usually ivitli inconspicuous or dehiscent
epidermis, rounded, variably sculptured ; valves equal, free, closed, with low, prosocoelous
Fig. 790.
Luuina ( Milthd) gigantea Desli. Eocene (Calcaire Grossier) ; Grigiion, near Paris. 2/3.
beaks ; adductor and pedal scars adjacent or distinct, the latter small ; anterior adductor
elongated, largely within the pallial line, which is not sinuate ; area tvithin the pallial
line often granular or iiimctate ; cardinal area small, often deeply impressed; ligament
and resilium sub-internal, set in a deep groove, but usually more or less visible externally ;
hinge-plate distinct ; lateral laminae distant from the cardinals, anterior and posterior
in the right, vnth corresponding sockets in the left valve ; cardinal teeth radial, formula
=^^ — , the posterior tooth larger and often bifid, but any or all of the teeth may be obsolete
or absent. Silurian to Eeceut.
Paracyclas Hall. Rounded, tliin-slielled, concentrically striated ; no lunule ; hinge
unlvno^\^l. Devonian.
Lucina Brug. (Figs. 790-793). Rounded, convex or lenticular, usually with a
Fio. 791.
Liwina {My rim) columbclla Lam. Miocene ;
Steinabrunn, near Vienna.
Fig. 792.
Lucina {Prolucina) prisca His. Silurian ; Gotland.
Internal mould (after Roemer).
lunule ; with delicate, concentric, or more rarely radial sculpture ; dentition usually
normal, the laterals developed. Represented Ijy upwards of 300 fossil and 100 recent
species. (?) Silurian, Trias to Recent.
486
MOLLUSCA
PHYLUM VI
Subgenera : Lucina s.s. Lam. 1799 {Loripes aiict. )• Shell smooth. Adult wjth the teeth
and posterior radial plication of the valves obsolete.
Tertiary and Recent.
Prolucina Dall (Fig. 792). Compressed, yrcnate,
almost rostrate ; the anterior side larger. Silurian.
Mijrtca Turton (Fig. 791). Rounded, sub-equi-
lateral ; teeth and posterior fold present. Tertiary
and Recent.
Codakia Scopoli. Compressed, reticulately sculj)-
tured. Tertiary and Recent.
Miltha Adams (Fig. 790). Compressed, nearly
smooth ; laterals absent, cardinals long, feeble (3 : 2).
Tertiary and Recent.
Divaricella Martens. Rounded, inflated, valves
ornamented with angular divergent grooving. Ter-
tiary and Recent.
Tertiary and Recent.
Fio. 7f)3.
Phacoidcs imlchra (Zitt. and Goub.).
Coral-Rag ; Glos, Calvados. 2/^.
Phacoidcs Blainville (Fig. 793).
Family 18. Oorbidae Dall.
' Shell differing from the Lucinidae in being transversely oval, thick, with a heavy
hinge plate, and tisually well-developed laterals; two or three strong cardinals in each
Fic. 794.
Gonodiin wfUingi Hauer. Upper Trias ; Sarize am Predil, near Raibl, Tyrol, i/j.
valve ; the margin of the valves denticulate, and the exterior strongly sculptured ; ligament
external, the adductor scctrs oval, and not projecting into the pallial area. Trias to
Recent.
This family is an off"shoot of the Lucinidae, with which it is commonly united.
> Oonodon Scliafli. {Gorhis p. p. auct.) (Fig. 794). Rounded, plump, concentrically
LlOl
striated. Cardinals
sometimes a weak
ROlO '
posterior lateral present. Trias and Jura.
Gorhis Cuv. {Fimbria Megerle, nan Boh.) (Fig.
795). Tliick-shelled, oval, inflated, reticulately
sculptured ; each valve with two short cardinals,
and anterior and posterior laterals ; adductor scars
similai', sub-equal. Jura to Recent.
Fic. T!)5.
('oW)j.s ImnoUmttt Ijam. Eocene (Calcaire
Grossier) ; Griynon, near Paris, i/i-
Fic. 700.
MjiticUn coarclata Zitt. Tiironian : Oosaii, Austria, i/i-
CLASS I
PELECYPODA
487
Sphaera Sow. {Palacocorhis Cour.). Lower Cretaceous. Sphaeriola Stol. Trias
to Cretaceous. Finibriella Stol. Chalk of Britain. Corbicella Mor. and Lye. Jura.
Mutiella Stol. (Fig. 796). Anterior cardinal Ijorder corrugated, upturned ;
posterior rectilinear, horizontal, with a feeble lateral tooth. Upper Cretaceous.
Family 19. Diplodontidae Dall.
Shell suh-circular in outline, rarely nestling and irregular ; hinge with the laterals
obscure or absent, and the valve margins plain ; the adductor scars continuous peripher-
ally with the pallial line ; soft parts like the Lucinidae, but with the external limb of the
gills developed, and, the anal foramen not tubular. (?) Jura, Cretaceous to Eecent.
Diplodonta Bronn (Fig. 797). Thin-shelled, orbicular, convex, concentrically
striate or pustulose ; cardinals 2 : 2, the left anterior and right posterior Infid ;
laterals obscure or absent. Tertiary and Recent.
Ungulina Daudin. Nestling and often ir-
regular. Felania Recluz. Shell compressed ;
feeble laterals present. Axinopsis Sars ; Sphae-
rella and Tenea Conrad. Cretaceous to Recent.
Family 20. Cyrenellidae Fischer.
Fio. 797.
Dlplodo7ita dilatata Pliill. Pliocene ;
Rhodes. Vi-
Shell as in Diplodonta, but with a con-
spicuous epidermis ; ijallial area smooth ; pallial
line not sinuate ; hing'e without lateral laminae ; the cardinals like Diplodonta, or
with two cardinals in each valve soldered to each other dorsally ; cardinal formula
RTivimn' ^^^'^ anterior left cardinal usually obsolete. Pliocene to Recent, in fresh and
brackish water.
Cyrenoida Joannis {Gyrenella Desli.). Pliocene of Florida, Recent in the Antilles
and West Africa.
Joannisiella Dall. Hinge as in Diplodonta, resilixtm immersed, the larger cardinal
bifid, the teeth not soldered above. Cardinal formula ^^^^-^^ ■ Recent ; Philippines.
Shell
A
Family 21. Thyasiridae Dall.
substance earthy, with inconspicuous epidermis and prosocoelous beaks ; valves
n equal, free, closed, ivith plain margins, smooth, or with feeble
concentric striae, and usually with a radial posterior flexure ;
adductors Lttcinoid, pallial area often punctate ; ligament and
resilium parivincular, opisthodetic, sub - external, seated in a
groove ; area impressed ; hinge feeble vnthout lateral laminae,
edentulous, or with an obsolete cctrdinal tooth in the right valve.
Cretaceous to Recent.
Fic. 70S.
A, Thj/asira Hnuosa (Don.).
Miocene; Grand, near Vienna,
i/x. B, T. unicarlnata Nyst.
Oligocene (Septaria - clay) ;
Preienwalde, near Berlin.
Thyasira Leach (Gryptodon Turton ; Axinus Sow.; Gon-
chocele Gabb) (Fig. 798). Smooth, thin-shelled, living in
deep water. Cretaceous to Recent.
Philis Fisch. Lunule deeply indented, projecting spoon-
like into the cavity of the valves. Recent.
Superfamily 8. LEPTONACEA Dall.
Tlie inc7irrent and excurrent openings between the mantle lobes at opposite ends of the
body, the former a.nterior.
488
MOLLUSCA
PHYLUM VI
This gi-oup contains a great many commensal, nestling or parasitic forms ; if indepen-
dent usually very active, crawling like Gastropods on a sub-rejitary foot, and with the mantle
edges more or less reflected over the valves.
o
Family 22. Leptonidae Gray.
Shell celhdo-crystalline with a 'periostramm ; vcdves equal, free, smooth-edged, often
gaping, variably sculptured ; adductor scars pieripheral, sub-equal ; pallial line simjde ;
area obscure or none ; ligament parivincular, opisthodetic, exter-
nal, often obsolete; resilium visually internal, sub-ximhonal or
oblique ; hinge-plate narroto, channelled to receive the resilium ;
hinge variable, typically consisting of one or two radiating
cardinals and a pair of lateral laminae in each valve, the
anterior laminae often absent, and the posterior frequently
closely adjacent to the resilium, simulating cardinals. One
Cretaceous, and a number of Tertiary and Recent species.
Erycina (Lam.) Fisclier (Fig. 799) ; Kellia Turtou ;
Pythina Hinds ; Lasaea Leach ; Lepton Turton ; Erycinella,
Conrad; Spaniodon Reuss; Fabella Conrad, etc. Tertiary
and Recent.
Pin. 709.
A, Erycinn pelluclda Lam.
Calcaire Grossier ; Parnes. B,
Hinge of E. foucanli Desli.
Lower Eocene ; Herouval.
Greatly enlarged (after De-
sliayes).
Family 23. Galeommatidae Gray.
Shell %dtliout a perceptible epidermis ; valves equal, free, widely gaping ventrally,
smooth or variably sculptured ; adductor scars distant, oval, reduced ; pallial line
simple ; ligament usually obsolete, resilium internal, sub-umbonal or oblique, attached
to an excavated chondrophore in each valve; hinge -p)late hardly
developed ; laterals obscure or absent ; one or two cardinal teeth in
each valve or none. Tertiary and Recent.
Scintilla Desli. (Fig. 800) ; Galeomma Turton ; Passyia and
Sportella Desh. ; Hindsiella Stol. ; Ephip>podonta Tate ; Solecardia
Conrad, etc. Tertiary and Recent.
Family 24. Ohlamydoconchidae Dall.
Fig. SOO.
ScintiUa parisiensis
Desh. Upper Eocene ;
Shell cellulo- crystalline without an epidermis, comprising the (^"te^peshayes)!""^"
prodissoconch with narrow, long, laminar accretions, very small ;
valves ivholly internal, not connected, contained in latcrodorsal separate capsules, without
hinge or hinge-plate, not attached to muscles or ligament ; ligament absent, resilium
separately encapsuled between the obsolete valves, functionless. Recent ; California.
The genus Ghlamydoconcha Dall is evidently the last term in a series beginning
with forms like Lepton, and continued liy Galeomma and Efhippodonta, but the
specialisation has been carried so fer that it may well be regarded as the type of
a distinct family.
Family 25. Kelliellidae Fischer.
Shell with a periostracum ; valves equal, free, closed, smooth externally with plain
margins; pallial line simple; area obscure or none; ligament external, parivincular ;
resilium external or slightly sunken ; hinge plate narroio, entire, with one or tivo
cardinals, and a single anterior lateral placed above the anterior cardinal teeth. Tertiary
and Recent.
CLASS I
PELECYPODA
489
Kelliella Sars ; Lutetia Desli. ; (?) Allopagus Stol. ; Turtonia Alder. Eocene to
Eecent.
C Cyclodonta.
Teeth arched, springing from below the hinge margin, with the hinge-plate obscure or
absent.
Superfamily 9. CARDIACEA Lamarck,
Lobes of the mantle free behind the sij)hons, foot elongate, geniculate; sculpture of
the shell chiefly radial ; cardinal teeth conical, the lateral laminae short, distant from the
cardinals.
Family 26. Cardiidae Fischer.
Shell substance cellulo-crystalline, ivith the external layer more or less tubular ; valves
equal, free, gaping slightly behind, the beaks prosocoelous, the margins usually serrate or
radially striated ; adductor scars sub-equal, the pedal distinct and usually distant ;
ligam.ent and resilium parivincular, external, short, set in a groove ; area obscure ; com-
plete hinge armature consisting of an anterior and posterior lateral in the left, and tmo
A ■ B
Pio. SOI.
CarcUum product um Sow. Turonian ; St. Gilgeii, Salzburg, i/i-
anterior and one posterior lateral in the right valve, any or all of which may be absent ;
cardinal formula ^oTyfrnj ^he teeth simple, smooth, never bifid, one cardinal in each valve
usually persistent, the others inconstant. Trias to Recent.
Gardium Linn. (Figs. 801-803). Cordate, inflated, radiately ribljed or striated,
Fio. SO'2.
Protoeu rdia hifrons
Reuss. Turonian;
Strobl- Weissenbach am
Wolfgangsee, Austria.
Fki. 803.
Cardium {DUcors) diacrepans Bast. Miocene
Dax, near BordeaT'x. Vl-
490
MOLLUSCA
PHYLUM VI
with prominent beaks. Represented by about 200 recent and over 100 fossil species.
Trias to Recent.
A very large number of subgenera and sections have been proposed, based chiefly on the
external sculpture. Some of the more conspicuous groups are the following : —
Prntocardia Beyr. (Fig. 802). Cretaceous. Discors Desh. (Fig. 803) ; Laevicardiuvi
Swains. ; Scrripcs Beck ; Fragum Bolten ; Pa2)yridca Swains. Tertiary and Recent.
Didacna Eichwald, estuarine, leads toward the next family.
Family 27. Limnocardiidae Stoliczka.
Like the Gardiidae, but thin-shelled, witli long united siphons, a short compressed
foot, a pallial sinus and obsolete
hinge armature, living in
brackish or fresh water. Ter-
tiary and Recent.
Adacna Eiclnv. Slicll
elongate oval, truncate behind,
gaping at both extremities ;
siphons very long, pallial
sinus deep. Miocene, and
Recent in Caspian Sea.
Limnocardium Stol. (Fig. 804). Cardinals weak, laterals strong, distant, pallial
sinus moderate, shell closed anteriorly. In brackish Miocene beds, especially the
Sarmatic and Pontic horizons of Eastern Europe, and in estuaries of the Aral, Black
and Caspian Seas.
Fic. 804.
Limnocnrdium conjungens Partsch. Pliocene (Congeria Stage) ;
Brunn, near Vienna. Vi-
Subgenera : Prosodacna Tourn. {Psilodon Cob.) ; Monodacna Eichw.
Arcicnrdiuin Fischer.
Uniocardiu7)i Capell. ;
Superfamily 10. TRIDACNACEA Menke.
Soft parts rotated forward nearly 90° with relation to the valres as compared with
typical dimyarian Pelecypods, the anterior adductor wanting, and the posterior nearly
central in the shell ; cardinal teeth lamellar, oblique.
Family 28. Tridacnidae Cuvier.
Shell very densely porcellanous, with no visible epidermis; valves equal, free, witli
a byssal gape, radially sculptured, with serrate margins and prosocoelous beaks ; ligament
and resilium as in the Gardiidae ; hinge with a single oblique cardinal in each valve, a
single posterior lateral in the left, and tivo in the right valve. Eocene to Recent.
Byssocardium Mun.-Chalni. and Lithoccordium Woodw., of the Eocene, are
])er]iaps precursors of the Recent Tridacna Brug. and Hippopus Lamarck.
Superfamily 11. ISOCARDIACEA Ball.
Lobes of the mantle closed, except for the pedal and siphonal openings, smooth, double-
edged ; foot short, compressed ; sculpture of the shell faint or concentric ; cardinal teeth
lamellar, parallel with the hinge margin.
Family 29. Isocardiidae Gray.
Shell substance cellulo-crystalline, the external layer not tubuJate, with a marked
epidermis; valves equal, free, rotund, completely closed, with, plain, margins and jiro-
CLASS I
PELECYPODA
491
minent prosogyrous beaks ; adductor scars suh-equal ; pedal scar adjacent; area not dis-
tinctly limited ; ligament and resilium external, parivincular, set in a deep groove, con-
tinuous to the heaJcs ; complete armature of the hinge ivith an, inconstant posterior lateral
in each valve, and rarely, an conterior lateral close to the cardinals ; cardinal formula
PQ,„.., the teeth lamelliform, and very variable in details of form. Jura to Recent.
Many species have been referred to this group solely on account of their having gyrate
beaks. Tlie Paleozoic and many Mesozoic species so referred must be separated from
Isocardia.
Isocardia Lam. (Figs. 805, 806). Inflated, smooth oi' concentrically striated ;
beaks distant, much produced, prosogyrate. Jura to Recent.
B
Viv,. S(».5.
IsocariUu striata d'Orb. Portlancliaii ; Cirey, Haute-Mame (after Loriol).
Meiocardia Adams. Keeled, concentrically ribbed. Tertiary and Recent.
? Glisocohos Galjli. Cretaceous ; North America.
Fig. S06.
Hinge of Isocardia lunulata Nyst. Crag ; Antwerp.
Family 30. Vesicomyacidae Dall.
Shell as tn the Isocardiidae, hut with low and inconspiciwus beaks, the valves more
elongated, and the lunule delimited by a sharp groove; cardinal formula ^pTaTqTa"
Tertiary and Recent.
Gallogonia Dall. Pallial line deeply sinuated, and a distinct anterior lateral close
to the cardinal teeth. Recent ; abyssal.
Vesicomya Dall. {Gallocardia auct., non Adams). Rounded or Tapetiform, com-
pressed, or not inflated, with low, inconspicuous, non-gyrate beaks. Eocene and Recent.
D. Teleodonta.
The most perfected type of modern teeth, to ivhich, in addition to the typical (10101)
cardinal series of the ordinary Teleodesmacea, there is added in the most specialised types
{Veneridae, Mactridae) either a roughened area [Venus), a series of extra cardinals
(Tivela), or accessory lamellae (Mactra), rendering the hinge more efficient, or complicated.
492
MOLLUSCA
PHYLUM VI
The hinge characters of the less specialised forms hardly differ from the Diogenodonta,
but they are grouped here on account of their obvious affinities, as shoivn by other
characters.
Superfamily 12. VENERACEA Menke.
Teleodonts with normal gills united to form a complete anal chamber, the mantle
lobes free behind the siphonal region, sub-equcU adductors, an external parivincular liga-
ment seated in a groove, and the shell substance densely cellulo-crystalline with incon-
spicuous epidermis. Complete hinge formula T-^r ~7j — ^i^,^', ^p of which a large
part is usually deficient.
Family 31. Veneridae Leach.
Valves equal, free, closed, with prosogyrous beaks, variably sculptured, with the
margins more or less dentate, except in the smooth species ; adductor scars peripheral,
pedal distant ; pallial sinus more or less sinuated, area very distinct ; resilium usually
external, embraced by the ligament ; hinge-plate developed ; formula of the cardinals
-jTT-r-rY^:^, with (t siugU obsolete lateral in one valve; the cardinals frequently bifid,
usually radially disposed and sub-equal in size, except the posterior left one, which is often
obsolete or obscure; supplementary cardinals or
rugosities are piresent in sfecialised forms. Jura
to Recent ; niaxiniuin in Tertiary and latei'.
The family must be divided into at least four
subfamilies, as follows : —
a. Vcnerinae : typical, with produced siphons,
not byssiferous, the young not retained within the
mother after leaving the egg.
b. Circinac : with separate short siphons, cor-
relative nearly simple pallial line, sub - internal,
partially amphidetic resilium, and compressed beaks.
c. Tapctinac : with long but partly separated
siphons, a byssus present at least in the young ;
hinge with no lateral teeth, otherwise like the
Venerinae.
d. Gemminae : minute shells, with more or less
separated siphons, no byssus, obsolete lateral laminae,
and sheltering the nepionic young within the cavity
of the mother.
Fio. 807.
Cyprimrria discus CMnth.). Upper
Cretaceous ; Gosau Valley, Austria.
Gyprimeria Conr. (Fig. 807).
a. Pronoella Fisch. {Pronoe Ag., non Guer.
Men.). Compressed, pallial sinus very shallow ;
a posterior lateral and three cardinals in each
valve. Jura.
Like the preceding, Imt the right A^alve with only
two cardinals, the hinder one bifid ; pallial sinus very shallow. Cretaceous.
Dosinia Scop. {Artemis auct.). Orbicular, lentiform, concentrically sculptured,
with a deep, well-marked lunule : cardinals 3:3; pallial sinus deep, ascending,
pointed. Cretaceous to Recent.
Eocijclina Dall. (Cyclina Desh.). Cretaceous to Recent. Sunetta Link [Meroe
Schum.) ; Grateloupia Desm. Tertiary and Recent, dementia Gray. Oligocene to
Recent.
Vemis Linn. (Fig. 808). Oval or rounded, plump, cordate, thick ; concentrically
or radially sculptured, with denticulate margins ; hinge-plate lu-oad, with three
cardinals in each valve and no lateral teeth ; pallial sinus short, angular. Jura to
CLASS I
PELECYPODA
493
Recent ; represented by about 200 fossil and as many recent species. Very numerous
sub-divisions have been proposed ; Venus s.s. is typified by V. mercenaria Lam.
FiQ. SOS.
Venus eincta Eichw. Miocene ; Gainfahrn, near Vienna.
Fia. 809.
Meretrix semisulcaia Lam.
Eocene ; Grignon, near Paris.
Meretrix Lam. (Gytherea auct.) (Figs. 809, 810). Hinge witli lateral teetli.
Macrocallista Meek ; Callocardia Adams ; Saxidomus Conrad. Tertiary and Recent.
Fig. 810.
Meretrix incrassata Sow. Oligocene ; Weinheim, near Alzey.
Pig. 811.
C i r c e e x i ?« i a
Hoernes. Miocene ;
Enzesfeld, near
Vienna.
Tivela Link. Hinge witli supplementary cardinals. Miocene to Recent.
b. Girce Scliiim. (Fig. 811). Gafrarium Bolten. Umbones compressed, sculj^ture
often divaricate, ligament immersed. Tertiary and Recent.
Subgenus Gouldia Adams.
Eocene to Recent.
raphia
Sarniatian
Vienna.
Fig. srJ
gregar '
Stage ;
ia Partsch.
Wiesen, near
Small, concentrically striated.
Ptychoniya Agassiz.
Cretaceous,
c. Paphia Bolten
Pul-
se-
less
with
813.
Paphia (Baroda) fmgilis (d'Orb.).
Upper Cretaceous ; Gosau, Austria.
(Tapes Megerle ;
lastra Sow.) (Figs.
814). More or
elongate, oval,
hinge - plate,
and often
bifid cardinals, no la-
terals, and deep pallial
sinus. Cretaceous to
Recent; about 150
living species.
narrow
divergent
494 MOLLUSCA phylum vi
Of the numerous subgenera, Baroda {Fig. 813) and Itscanotia (Fig. 814) Stol., from the
Cretaceous, are remarkable for their elonga-
tion and the riilge-like form of the posterior
cardinal.
Onco'phora Rzehak. Differs from Ta2:)es
in having a very short pallial sinus, and
the anterior adductor scar bounded by a
ridge. Miocene brackish-water beds.
Fio- SI-*- Venenipis Lam. Cardinal teetli 2 :
Papilla {Iscanotia) impar Zitt. Upper Cretaceous ; 9-3 stron"- • a borer or nestler, often de-
Gosau. ' n m' - T Ti
formed. Tertiary and Recent.
(I. Gemma Desh. ; Parastarte Conr. ; Psephidia Dall. Minute shells. Eocene
to Recent.
Family 32. Petricolidae d'Orbigny.
Valves, when not distorted, equal, free, somewhat gaping behind, radiately sculptured
with plain margins and inconsp>icuous beaks ; posterior adductor scar larger than the
anterior, pedal narroio, elongctted, distinct ; ligament and resilium external ; area
obscure or not defined ; hinge without lateral laminae, with tivo or three small, usually
bifid, radial cardinal teeth in each valve. Cretaceous to Recent.
Petricola Lam. (Choristodon Jonas; Naranaio Gray) ; Petricolaria Stol.
The family Glaucomtacidae, of estuarine or fluviatile habit, appears to be related
to Petricola, and includes the Recent Glaucomya (Bronn) Woodward, and Tanysiphon
Benson.
Superfamily 13. TELLINACEA Blainville.
Siphons distinct to their bases, usually long ; pallial line sinuate ; ligament external,
seated on nymphs ; hinge typically with an anterior and posterior lateral in each valve,
tvjo radicd cardinals, of which the anterior is commonly bifid and somewhat pedunculated,
and the posterior, as well as the laterals, often obsolete.
Family 33. Tellinidae Deshayes.
Shell substance cellulo-crystalline, with an inconspicuous epidermis; valves sliglitUj
unequal, free, rounded in front, more or less rostrate, oblique, and gaping behind, com-
pressed, usually with smooth margins, low beaks, and variable, chiefly concentric sculpture ;
anterior adductor scar larger, frequenily irregular ; pedal distinct ; resiliu,m embraced in
the ligament, sub-external; area narroio, small, covered with a dark epiidermis, or
frequently obsolete ; hinge-plate narrow, anterior laterals approximate, posterior more
distant from the cardinals, when present ; cardinal teeth small ; pallial sinus deep,
discrepant in the opposite valves. Jura to Recent.
Tellina Linn. Elongated, the rostrum more or less twisted ; two lateral teeth in
each valve ; shell porcellanous. Jura to Recent.
Subgenera: Tellina s.s. (Figs. 815, 816); Tellidora Morch ; SlrUjilla Turton ; Lincaria
Conrad {Arcopagia d'Orb.) (Fig. 817), etc.
Macoma Leach. Anal siphon long, branchial very short, hinge without laterals ;
shell smooth, earthy, less elongated than in Tellina. Tertiary and Recent.
Gastrana Schum. (Fragilia Desh.). Miocene and Recent.
Quenstedtia Mor. and Lye. Long, oval, obliquely truncate behind ; beaks low,
pallial sinus shallow, only a single cardinal tootli present. Jura.
CLASS I
PELECYPODA
495
Fir.. 815.
TelUna planata Lum. Miocene; Putzleinsdorf,
near Vienna.
Fig. 810.
Tcllina rostralina Desh. Eocene ; Damery,
near Epernay.
Fig. 817.
Tcllina (Linearia) hiradiata Zittel. Upi)(;r
Cretaceous ; Gosau, Austria.
Family 34. Semelidae Dal].
Resembling the Tellinidae, but with the resilium internal, often on a distinct chondro-
■phore, and with the laterals, when present, stronger and less distant. Tertiary to Eecent.
Semele Sclium. (Amphidesma Lam.). Shells large, rounded, thick, often conspicu-
ously sculptured; 100 species. Tertiary and
Recent.
Gumingia Sow. Small, thin, with a spoon- ^
like chondrojihore ; habit nestling. Tertiary
and Eecent.
Scrobicularia Schum. Differs from Semele in
having no lateral teeth. Tertiary and Recent.
Abra Leach {Syndosmya Recluz) (Fig. 818).
Smooth, small, thin ; cardinals 2:2, an anterior and posterior lateral present ;
chondrophore narrow, oltlique, not separated from the hinge line. Tertiary and
Recent ; chiefly in deep water.
Family 35. Psammobiidae DaU.
Shell as in the Tellinidae, but usually more
equivalve and less twisted, with more conspicuous
epidermis and nymphs, broader hinge-plate, and
a ivider posterior gape; lateral laminae on the
Fig. 818.
Abra ajielina {Jim\.). Miocene; Grund,
near Vienna.
Fig. 819.
Psammohia effiisa Desh. Eocene (Calcaire
Grossier) ; Parnes.
Fi<;. 820.
Psammosolen (Mcwha) deshayesii (Desm.). Calcaire
Grossier ; Grignon, near Paris, i/j.
496 MOLLUSCA phylum vi
Jdnge wantiiuj, and the cardiiiaU sometimes three in uiie valve; ligament external and
conspicuous ; no defined area. Tertiary and Eecent.
Psammobia Laiaarck (Gari Sclium.) (Fig. 819). (?) Cretaceous. Tertiary and
Eecent.
Pliorhytis Conrad ; Asaphis Modeer ; Sangninolaria Lam. ; Tayclus Gray ; Nova-
culina Benson ; Ampliichacna Pliil. ; Psammosolen EisKo, with subgenus Macha Oken
(Fig. 820) ; Azor Leacli ; and Heterodonax Morcli. Cretaceous to Eecent.
Family 3G. Donacidae Deshayes.
Valves equal, free, sub-triyonal, tisually closed, solid ; outer surface and inner margins
smooth or radially sculptured, the posterior end usually shorter and obliquely sub-trimcate ;
pallial sinus similar in both valves ; resilium sub-internal, sometimes amphidetic ;
ligament short, external, seated in a deep groove, episthodetic ; hinge-plate moderately
developed, usually with a posterior and anterior lateral in the right, a.nd corresponding
sockets in the opposite valve; cardinal formula daiaii ''''^' strongest cardinal tooth often
bifid. Lias to Eecent.
The resiliuiu is chiefly opisthodetic and sub-internal, but some of the large species have a
small segment of the resilium separate from the rest,
wholly internal, and in front of the beaks.
Isodonta Buv. (Sowerbya d'Orb.) Suh-symniet-
rical, convex, laterals strong, pallial sinus deep. Jura.
Donax Linn. (Fig. 821). Anterior side longer,
laterals weak. Ujiper Eocene and Eecent ; about
Fii;. S21. 100 species. Subgenus Iphigenia Sclium. Eecent.
Donax lucida Eichw. Miocene (Sarmatian Egeria Lea. Lower Eocene.
Stage); Wiesen, near Vienna. ^^^ Hemidonax Morch (Donacicardium Vest).
Superfamily 14. SOLENACEA Lamarck (emend.).
Dwellers in soft sea-bottom, narrow, elongated, modified for burrowing, gaping at
both ends; foot elongated, distally modified to serve as a jnston or stilt toithin the
burrow ; siphons short ; hinge without lateral laminae.
Family 37. Solenidae Leach.
Shell substance as in Tellina, but the external layer shoiving its cellular structure
more clearly ; with a pronounced epidermis ; valves equal, free, usually truncoAe at both
ends, and more or less inequilateral, with low beaks, smooth margins, not rostrate, smooth
or feebly sculptured ; adductor scars narroiv, elongate, dorsally distributed, pedal distinct ;
pallial sinus small in species with anterior umbones, and vice versa ; ligament and re-
silium external, parivincular, seated on nymphs ; area obscure or none ; hinge-plate
hardly developed ; hinge often with a thickened ray crossing the valves and serving as a
buttress; cardinals varying from one to four in each valve, usually a single slender
radial laminar cardinal in the right, and. ttvo in the left valve, with or ivithout one or
two placed parallel with tlie hinge margin, simulating laterals; radial teeth usually
more or less pedunculated, rarely bifid. Devonian to Eecent.
The Silurian forms heretofore referred to this family do not seem to belong to it, but
Palacosolcn Hall is scarcely distinguishable externally from some modern forms ; its hinge,
however, is unknown. The species of this family are mostly much modified for a special
mode of life, hence the variability in certain features, such as the siphons, foot and ferma-
ture of the mantle lobes.
Bolen Linn. (Fig. 822). Scabbard-sliaped, straight, with terminal beaks. Among
the numerous subgenera are : Ensis Sclium. ; Pharella Gray ; Geratisolcn Forbes ;
Siliqua Megerle ; Cultellus Schuni. (Fig. 823). Tertiary and Eecent.
CLASS I PELECYPODA
Palaeosolen Hall. Devonian. Leptosolen Conrad. Cretaceous.
497
Fi... 822.
Solcn suhfraglKs Eichw. Miocene (Sarma-
tian Stage) ; Pullendorf, Hungary.
Fic. S-23.
CuUellus grignonensis Desh. Calcairo
Grossier ; Grignon, near Paris.
Superfamily 15. MACTRACEA Gray.
Resiliuvi internal, seated on chondrophores, left cardinal tooth bifid, fitting below the
two right cardinals, lohich are more or less joined together dorsally. Inner wall of the
mantle behind the siphons exhibiting a laminar sense organ.
Family 38. Mactridae Gray.
Shell 'porccllanous, xvith an obvious epidermis, usually rounded-triangular, with
smooth or concentrically sculptured surface, smooth margins, ctnd prominent frosogyrous
beaks ; valves equal, free, usually with a slight posterior gape ; area not limited ; liga-
ment variably external or internal; resilium connecting sub-triangulnr chondrophores
usucdly excavated out of the hinge-plate, rarely with a pro}) or buttress ; hinge-plate locll
developed, with typically an anterior and posterior lateral in the left, received into soclcets
or paired laminae in the right valve, or obsolete ; cardincds in the right valve two, with
their dorsal edges usually soldered together, and one bifid or deltoid cardinal in the
left, fitting below the former, a delicate accessory lamella often present in either valve, or
all may be more or less obsolete ; siphons toell developed, united, and usually with an
epidermal tunic ; adductors peripheral, sub-equal. Cretaceous to Eecent.
This groui) is so large and its extremes so variable, that
it is best divided into subfamilies, as follows : ^ Mactrinae,
Pteropsidinae, Lutrariinac, Zcnatiinac and ? AnatincUinae.
Mactra Linn. (Fig. 824). Ligament and resilium
separated by a slielly se])tum. Tertiary and Recent.
Subgenera : Mactra s.s., Coelomactra, Mactroderma,
Mactrotoma Dall ; Mactrella Gray.
Fio. 8-'4.
Mactra podolica Eicliw. Miocene
(Sarmatian Stage) ; Wiesen, near
Vienna.
Fio. 825.
Lutraria dliptica Roissy. Pliocene ; Rhode.s. ^/•j.
Spisula Gray. Ligament and resilium not separated, the former more or less
external. Cretaceous to Recent.
^ Dalt, W. IT., Synopsis of a Review of the Genera of Recent and Teitiary Mactridae and
Mesodesmatidae. Proc. Mai. Soc, 1895, vol. i.
VOL. I 2 K
498
MOLLUSCA
PHYLUM VI
Subgenera : Hemimaetra Swains. ; Leptospisula Dall ; Cymbophora Gabb ; ScJdzodcsma Gray.
Mulinia Gray. Ligament and resilium immer8ecl in the same socket. Miocene
and Recent.
•Rangia Desm. (Gnathodon Gray, non Goldfuss). Like Mulinia, Init witli
elongated laterals, and the anterior lateral hooked at the umbonal end. Estuarine.
Pteropsis Conrad. Eocene. Lahiosa (Schmidt) Moller. Miocene and Recent.
Ltotraria Lam. (Fig. 825). Soleniform, hinge Mactroid. Tertiary and Recent.
Schizothacrus Conr. {Tresus Gray) ; Eastonia Gray ; Heferocardia Desh. Tertiary
and Recent. Zenatia Gray ; Anatinella Sow. Recent.
Family 39. Cardiliidae Dall.
Shell cordiform, with prominent prosogyrous heahs, small, thin, radially sculptured ;
posterior adductor scar impressed upon a radial myoplioric lamina, the anterior scar
elongated, pallial line not sinuated ; ligament external, seated on nymphs ; resilium
internal connecting projecting chondrophores ; hinge without laterals, hut the cardinal
teeth as in Mactra. Tertiary to Recent.
Cardilia Deshayes. Eocene and Recent.
Family 40. Mesodesmatidae Deshayes.
Shell solid and heavy, usually Donaciform, with
erect or opisthogyrate beaks, otherwise as in the Mactridae;
siphons naked, not united. Tertiary to Recent.
Mesodesma Desh. Tertiary and Recent. Mac-
tropsis Conr. Eocene. Atactodea Dall {Paphia
Lam. ; Eryx Swains.) ; Davila Gray ; Anapella Dall.
Recent. Ervilia Tnrton (Fig. 826). Tertiary and
Recent. Gaecella Gray. Recent, fluviatile.
Pig. 820.
Ervilia podolica Eicli w. Miocene (Sar-
matian Stage) ; Wicseii, near Vienna. Vl-
E. ASTHENODONTA.
Hinge often essentially Mactroid, hut usually degenerate or obsolete, owing to modi-
fications induced by the burrowing habit.
Superfamily 16. MYACEA Menke (emend.).
Burrotving, long siphoned, frequently inequivalve Pelccijpods, visually with the mantle
lobes largely united below, more or less united siphons, and degenerate hinge apparatus.
Family 41. Myacidae Woodward.
Shell substance cellulo-crystalline, earthy, with a conspicuous epidermis ; valves un-
equal, more or less elongate, rounded in front
and gaping behind ; adductor scars suh-
equal ; pallial line sinuated ; shell margins
plain ; area obsolete or none ; ligament and
resilium internal, opisthodetic, attached in
the left valve to a projecting chondrophore
merging with the dorsal margin behind, and
in the right valve to an inconspicuous,
usually sub-umboncd chondrophore; hinge
edentulous ; siphons united, with a horny
tunic, not wJluIIu retractile. Tertiary and ,_ ... „, ., /r^i • i r, ■. %
' -^ - Mya arcnaria Linn. Pleistocene (Glacial Deposits)
Recent. Bohuslim, Sweden.
CLASS I
PELECYPODA
499
Mya Liun. (Fig. 827). Smooth externally. Tertiary and Recent.
Subgenera
Platyodon Com-ad. Surface decussated, siphon with horny appendages.
Cryptomya Conrad. Small, the ]iallial line discrepant in the two valves. Siihenia Turton.
Minute, byssiferous, nestling. Tugonia Gray. Tertiary and Recent.
Family 42. Corbulidae Fleming.
Shell small, mxich as in Mya, hit the pallial line feeble or obsolete, the ligament
usually sub-external, separated from the resilium, xvhich is internal, alivincular and
amphidetic ; the chondrophore
is received into a socket of the
opposite valve, not merged with
the valve margin ; hinge ivith
one or two sub-umbonal pro-
jecting teeth, and rarely obscure
traces of laterals ; the posterior
gape inconspicuous ; siphons
short, united, naked, tvholly
retractile. Trias to Recent.
Corhula (Bicorhula) gallica Lam.
Calcaire Glossier; Damery, near
Epernay, France. Hinge, i/i.
A,
Fio. 829.
Corhula carinata Duj.
Miocene ; Potzleinsdorf, near
Vienna. B, C. angiv^tata Sow.
Upper Cretaceous ; Gosau.
Corbula Lam. (Figs. 828,
829). Small, ovate, rostrate, very inequivalve, tlie right valve convex, larger, with a
prominent tooth in front of the pit for the resilium, left valve with a flattened
chondrophore, and usually a posterior tooth. Trias to Recent.
Subgenera: Erodona Daudin {Azara d'Orb. ; Potamnniya Sow.). Pallial sinus obsolete,
fluviatile. Pleistocene and Recent. Bothrocorhula Gabb. With a lunule deeply indented
into the cavity of the valves. Tertiary and Recent.
Fl<:. .S30.
Pannpc menardi Desli. Miocene; Vienna Basin. A, Dorsil view
of valves. B, Internal mould. C, Hinge-plate seen from above, 1/2.
Corhulamclla Meek. "With an anterior
myophore. Cretaceous. Aniso-
thyris Conr. {Fachydon Gabb).
Pliocene. Paramya Conr. ; Cor-
hiclomya Nyst. Tertiary and
Recent.
Family 43. Saxicavidae
Gray.
Shell substance as in Mya ;
epidermis conspicuo^is ; valves
equal, free, rude and often
irregular, more or less elon-
gated and gaping, not fully
covering the animal ; adductor
.^cars often irregular, the pallial
line discontinuous or irregular,
the sinus distinct; shell raar-
gins smooth ; area obsolete ;
ligament and resilium external,
parivincular, seated on strong
nymfhs, sometimes tcidely ex-
tended ; hinge without laterals,
ivith few feeble or obsolete sub-
umbonal cardinals. Creta-
ceous to Recent.
Saxicava Fleuriau {Glycimeris Schum. ; Hiatella Daudin ; Byssomya Cuvier ;
Agina Tiirton). Hinge edentulous in the adult, with one or two cardinals in the
500
MOLLUSCA
Tertiary and Recent.
PHYLUM VI
Subgenus Pavomya Gray
young, l^oring in the softer rocks.
{Chaenopea INIayer).
Panope Menard ^ {Ghjcimeris Lam. 1799, non Da Costa) (Fig. 830). Large, gaping
widely behind and slightly in front ; surface concentrically, or feebly sculptured ; an
obscure tooth in each A'^alve. Cretaceous to Recent.
Cyrtodaria Daudin (Ghjcimeris Lam. 1801, non. Schum.). Solenoid with strong
epidermis. Pliocene and Recent.
Family 44. Gastrochaenidae Gray.
Shell substance as in Saxicava ; valves equal, widely gaping in front ; adductor scars
unequal, the anterior smaller ; pallial sinus deep, margins simple; area none; ligament
and resilium external, pjarivincular ; hinge loith a single obsolete cardinal or uliolbj
edentulous; animal frerpbently forming
an external protective tube to sup)plcment
its burrow, but to tvhich it is in no way
attached. (?) Permian. Trias to Recent.
This group stands between the Myacea
and Adesmacea, verging on the latter. Many
of its characters are adaptive, and are re-
peated in the Ensiplionacea, but morpho-
logically its relations to the Saxicavidae
seem close.
Flc. 831
Gastrochacna angusUi Desh.
Eocene (Sables moyens) ;
Valmandois, near Paiis.
Fio. 832.
Gastrochaena deshmg-
ehmnpsii Laube. Middle
Jura; Balin, near Cracow.
Internal mould of burrow
including one of the
valves, i/i.
Gastrochaena Spengler ( Ghaena
Retzius; Bocellaria Blainv.) (Figs. 831,
832). Bores cylindrical or pear-shaped cavities in rock, shell, or coral. ^ Trias to Recent.
Fistulana Brug. Secretes calcareous tubes which stand upright in the sand or
mud. Recent.
Superfamily 17. ADESMACEA Blainville.
Gills with direct and reflected laminae, long, united, extended into the branchial
siphon ; posterior adductor usually 'in front of the visceral ganglion, anterior adductor
external to the cavity of the valves, exerted in a contrary sense to the posterior muscle ;
hinge margin reflected, edentulous; ligament obsolete; a myophoric process extending
■freely into the valve from the sub-unibonal cavity.
Family 45. Pholadidae Fischer.
Shell cellulo-crystalline, with a thin epidermis ; valves more or less gaping in front
and behind,, with inconspicumis beaks and reticulate, often spinose sculpture; m the
A r.
Fin. 833.
I'holas Uvcsqun Watelet. Eocene ; Cuise de la Mothe.
adult supplemented by accessory shelly pieces, ahoays attached to the valves, hit rarely by
an exterior shelly tube like that of the Gastrochaenidae ; the antero-dorsal margins more
or less extensively reflected, the postero-venfral approximated; p)allial line sinuated, area
1 Erroneously written Pnivypea by many authors.
CLASS I
PELECYPODA
501
none; lujament and resilium usually absent, an obsolete remnant of the resilium and
chondro])hore sometimes present in the left valve. (?) Carboniferous, Jura to Recent.
Pholas Linn. (Fig. 833). Surface divided Ijy grooves into area.s whicli often Lave
diverse sculpture ; the adult often provided with accessory shelly plates, each of which
when seated in front of the beaks has been named
a " jirotoplax " ; when above the beaks, " mesoplax" ;
when behind the beaks between the valves, " nieta-
plax " ; and when between the valves ventrally
(Alartesia), " hypoplax." A calcareous septum,
secreted after the completion of tlie burrow, and
occujiying the pedal gape of the valves, is called
the "callum." The addition of these plates and
appendages during growth so changes the appear-
ance of the shell that old and young stages have
frequently been described as specifically or even
generically distinct. Typical Pholads date from
the Jura. Many subgenei'a have been named.
Turnus Gabb (Fig. 834). Cretaceous. Martesia Leach (Fig. 835).
to Recent. Jouannetia Desm. Tertiary and Recent. Teredina Lam.
adult stage soldered together and to a thick adventive calcareous tube.
Fig. 834.
Turnus {Xylopha-
gella) elegantulus
Menk. Upper Cre-
taceous ; Idaho.
Enlarged (after
Meek).
Fig. 835.
Martesia ccmoidea
De.shayes. Eocene ;
Auvers, near Paris.
Vi-
Carboniferous
Valves in the
Eocene.
Shell
831-1.
.1, Valves of the recent Teredo
norveglca Spengl ; inner and ontei-
views. B, Pallet of Xylotrya sp.
C, Pallet of Teredo sp. D, Casts
of boiings of Teredo tournali Leym.
Eocene ; Kressenberg, Bavaria.
Family 46. Teredinidae Scjicchi.
educed, equivalve, auriculate, widely galling, the valves a-pposited
ventrally only on the surface of a parietal tubercle ; adductor
scars unequal, the anterior marginal very small; pallial
line coincident loith the valve margins ; a styloid myophore
projecting from the cavity of the beaks; mantle secreting a
calcareous lining to the burrow; ixdlets variable in form, the
valves ivithout attached accessory shelly plates; area none;
hinge margin reflected, edentulous; ligament absent or
obsolete ; anterior adductor degenerate, attached on the
anterior edges of the valves, and covered only by the mantle ;
animal boring, chiefly in wood. Carboniferous (?) ; Jura to
Recent.
Teredo Linn. (Fig. 836, A, C). Pallets simple, spatuli-
form. Juia to Recent.
Xylotrya Leach (Fig. 836, B). Pallets articulated,
bipinnate. Tertiary and Recent.
The name Teredolites Leymerie, has been projaosed for
the casts of borings of fossil Teredos (Fig. 836, D). The
problematical genus Polorthus Gabb, from the American
Cretaceous, has been referred to this family. The
Paleozoic species are known only by burrows, which are
of
;omewhat doubtful origin.
Vertical Range of the Pelecypoda.
Two small forms of bivalve shells, Fordilla and Modioloides, occurring in the
Lower Cambrian of New York State, have been doulitfuUy referred to Pelecypods,
but are more probably to Ije regarded as Branchiopod Crustaceans. Aside from these
fossils, whose moUuscan affinities must be considered as highly problematical, Pelecypods
502 MOLLUSCA phylum vi
are vmknown from strata geologically older than the St. Peter sandstone, which is of
early Ordovician age. Here appear suddenly several genera of the Modiolopsidae, and
this family, together with the Ambonychiidae, Cyrtodontidae, and Ctenodontidae,
attain the acme of their development dm-ing the Middle and Ui^per Ordovician. In
the Sihirian a considerable number of bivalves is observable, as many as eighty
species having been distinguished in the fauna of the small island of Gotland alone.
A very marked difference in geological range is perceptible among the three orders
into which the class is divided. The Prionodesmacea, including most of Neumayr's
Palaeoconcha, are pre-eminently characteristic of the Paleozoic faunas. Of the forty-
two families referred to this order, no less than seven occur in the Ordovician, and
eighteen in the Silurian, to which seven are added during the Devonian, only three in
the Carboniferous, and one in the Permian. From these ancient stocks only seven
Prionodesmacean families are evolved during the whole of the Mesozoic, and but two
in the Tertiary, while three are Recent.
The order Anomalodesmacea is represented in the Paleozoic solely by its radical,
the Pholadellidae ; eight of its sixteen families originate in the Mesozoic and Tertiary,
and, with the exception of the Pholadellidae and Pleuromyacidae, all have endured
until the present time. Only one faniily appears to be exclusively Recent.
The Teleodesmacca are distinctively modern, although foreshadowed in the Paleo-
zoic by Cypricardian, Lucinoid and Allodesmid radicals (the Solenoid radical is still
questionable). Of forty-seven families thirty can be first definitely recognised in the
Mesozoic, twelve originate in the Tertiary, two are exclusively recent, and only a single
one can be traced continuously from the Paleozoic to the recent fauna.
Of the Prionodesmacean families, 10-5 per cent survive ; of the Teleodesmacean 71
per cent ; and of the Anomalodesniacean 88 per cent. If it were not for the mortality
among the Chamacea and Rudistacae, the ratio of survival among the Teleodesmacean
families would be 95 per cent. Of 105 families which have been discriminated during
the whole history of the class, 76, or about 72-3 per cent, are represented in the
existing fauna. Families have originated in the various geological epochs as follows :
Ordovician 9, Silurian 11, Devonian 9, Carboniferous 3, Permian 1, Trias 13, Jura 14,
Cretaceous 18, Eocene 15, Miocene and Pliocene 3, Pleistocene and Recent 6. From
this it appears that the development of the grovip, judged by the increase of families,
was most intense during the Silurian, thereafter rapidly decreasing until the Trias,
then gradually increasing until the Cretaceous, after which the rate of diff'erentiation
again rapidly declined. It is noted that in the Paleozoic the Pelecypods form about
one-quarter of all the mollusks known from this era ; in the Jura and Cretaceous
about one-half, and in the Tertiary about one-third of this number.
The Ordovician and Silurian are especially characterised by the presence of
Taxodont, Palaeoconch, and the older forms of Schizodont Pelecypods. The Cardio-
lidae, Pterineidae, Amlionychiidae and Modiolopsidae are common to both the Silurian
and the Devonian.
The Devonian has no families solely characteristic, but the brackish-water Car-
diniidae, the Megalodontidae, Trigoniidae, Pinnidae, Pectinidae and Mytilidae first
take rise in this period, and the sinupalliate Allorisma is the first Pelecypod showing
clear evidence of retractile siphons.
The Carboniferous is marked by the appearance of Parallelodon and its allies,
the Limidae and Ostreidae, and some precursors of the Lucinacea and Pholadacea.
The Pernidae and Gastrochaenidae make their advent in the Permian; but, on the
whole, the Carboniferous fauna persists throughout this period. In the Trias, however,
important changes take place ; many old genera disappear, and such forms as the Limop-
sidae, the true Uniones, Spondylus, Dimya, the Pleuromyacidae, Pholadomyacidae,
Astartidae, Lucinacea, Cardiidae and Corbulidae enter upon the scene.
During the Jura, genuine Arcidae, Anomia, Eligmus, various Anatinacea, Cyrcna,
Diceras, Isocardia, and the Teleodont Veneridae, Tellinidae, Donacidae and Pholadacea
CLASS I PELECYPODA 503
are initiated. The character of the Cretaceous is strongly influenced by the aberrant
and short-lived Chamacea and Rudistids. The Mutelidae, Pandoridae, Clavagellidae,
Poromyacidae, Crassatellitidae, Cryptodontidae, Petricolidae, true Solens, the Mac-
tridae and Saxicavidae, also take their origin during this period.
With the beginning of the Tertiary a gradual approximation to present conditions
takes place. The Rudistae have disappeared, the Dysodonts are on the decline, and
the Teleodesniacean types on the increase. Numerous Anatinacea, Leptonacea, Tridac-
nidae, Callocardiidae, Senielidae, Mesodesmatidae and Myacidae appear. At the close
of the Eocene, the wide distribution of many types now characteristic of warm-
temperate, or tropical waters begins to be restricted ; and during the Miocene the
faunal boundaries of mollusks depending upon temperature conditions are laid down
nearly on existing lines.
The following table indicates more exactly the geological range of the families of
Pelecypods according to our present information : —
[Table
504
MOLLUSCA
PHYLUM VI
Families.
.2
'3
o
O
i
3
p
Q
2
<£
'S
o
o
i j
1
.s
5
CO
o
1
5
CD
i
m
c
o
-i-i
C
CD
O
Order 1. Prionodesmacea
A. Palaeoconcha
1. Solemyacidae .
2. Soleiiopsidae .
3. Vlastidae
4. Grammysiidae
5. Cardiolidae .
6. AntipleuridaL'
7. Praecai'diidae .
B. Taxodonta
Superfamily 1. Numlacm
8. Ctenodontidae
9. Nuculidae
10. Ledidae .
Superfamily 2. Arcacca
11. Parallelodontidae .
12. Cyrtodontidae
13. Limopsidae
14. Arcidae .
C. SCHIZOnONTA
Superfamily 3. Ptcriacca
15. Pterineidae .
16. Lunulicardiidae
17. Ambonycliiidae
18. Piiinidae
19. Coiiocardiidae
20. Pernidae
21. Pteriidae
22. Myalinidae .
23. Vulsellidae .
Superfamily 4. Ostraeca
24. Ostreidae
25. Eligmidae
Superfamily 5. Naiadaeea
26. Cardiniidae .
27. Mcgalodontidae
28. Unionidae
29. Mutelidae
30. Etheriidae
Superfamily 6. 2'rigoniacea
31. Lyrodesmidae
32. Trigoniidae .
1
1
^
■
•
—
—
—
—
1
—
^M
i
1
1
CLASS I
RANGE OF THE PELECYPODA
505
Families.
o
o
'>
o
o
.3
3
S
>
Q
P
'3
o
O
C3
ca
a
CM
.3
►-3
CO
1
Eocene.
Neocene.
a
D. ISODONTA
Superfamily 7. Pectinacea
33. Pectinidae
34. Spondylidae .
35. Dimyidae
36. Limidae .
Superfamily 8. Anomiacea
37. Auoniiidae
E. Dysodonta
Superfamily 9. Mytilacea
38. Modiolopsidae
39. Mytilidae
40. Dveissensiidae
Order 2. Anomalodesmacea
Superfamily 1. Anatinacea
A. EUSIPHONIA
1. Pleuromyacidae
2. Pholadellidae .
3. Pholadomyacidae .
4. Anatinidae
5. Peviplomatidae
6. Thraciidae
7. Myochamidae.
B. Adelosii'honia
8. Pandoridae
9. Lyonsiidae
10. Lyonsiellidae .
Superfamily 2. Ensi2)lumacea
11. Clavagcllidae .
12. Euciroidae
Superfamily 3. Poromyacea
13. Poromyacidae
14. Cuspidariidae
?..
■
1
1
506
MOLLUSCA
PHYLUM VI
Families.
a
o
.a
CM
H
;3
o
Order 3. Teleodesmacea
A. Pantodonta
1. Allodesmidae .
B. DiOGENODONTA
Superfamily 1. Cypricardiacca
2. Pleurophoridae
Superfamily 2. Astartacea
3. Curtonotidae .
4. Astartidae
5. Crassatellitidae
Superfamily 3. Cyrenacca
6. Gyreuidae
7. Spliaeriidae .
Superfamily 4. Carditacea
8. Carditidae
Superfamily 5. Chamacea
9. Diceratidae
10. Chamidae
11. Monopleuridae
12. Caprinidae
Superfamily 6. Eudistacca
13. Radiolitidae .
14. Hippuritidae .
Superfamily 7. Lucmacea
15. Tancrediidae .
16. Unicardiidae .
17. Lucinidae
18. Corbidae
19. Diplodontidae
20. Cyrenellidae .
21. Tliyasiridae .
Superfamily 8. Leptonacca
22. Leptonidae
23. Galeommatidae
24. Chlamydoconcliidae
25. Kelliellidae .
C. Cyolodonta
Superfamily 9. Cardiacea
26. Cardiidae
27. Limnocai'diidae
Superfamily 10. Tridacnacea
28. Tridacnidae .
CLASS I
RANGE OF THE PELECYPODA
507
Families.
o
a
o
X:
u
O
M
3
a
C8
o
a:!
a3
a;
a
■S
g
O
o
o
0^
Ph
H
1-5
O
Cx;
'^
Superfamily 11. Isocardiacca
29. IsocarJiidae .
30. Vesicomyaciidae
D. Teleodonta
Superfamily 12. Veneracea
31. Veneridae
32. Petricolidae .
Superfamily 13. Tellinacea
33. Tellinidae
84. Seiiielidae
35. Psammobiidae
36. Donacidae
Superfamily 14. Solenacca
37. Solenidae
Superfamily 15. Mactracea
38. Mactridae , .
39. Cardiliidae .
40. Mesodesmatidae
E. A.STHENODONTA
Superfamily 16. Myacea
41. Myacidae
42. Corbulidae
43. Saxicavidae
44. Gastrocliaenidae
Superfamily 17. Adesmacca
45. Pholadidae
4G. Tcredinidae .
tf
2.
[The text for the preceding chapter on Pelecypods was revised for the first edition of this
work by Dr. William H. Dall, of the United States National Museum, and is here reproduced
with comparatively few changes proposed by himself and Dr. R. S. Bassler. — Editok.]
508 MOLLUSCA phylum vi
Class 2. SCAPHOPODA Bronn.i
(Cirrhobranchiata Blainville ; Solenoconchia Lacaze-Duthiers •
Prosopocephala Stoliczka.)
Aquatic, marine, bilaterally symmetrical onollnsks, protected by an external,
tubular, somewhat curved and tapering shell, open at both ends, the concave side
of tvhich is dorsal ; the shell secreted by a mantle of the same shape, the larger,
anterior opening of which is provided with a circular muscular thickening, the smuller
opening serving as outlet for organic waste and genital products. Mouth furnished
with a radula, borne on a cylindrical snout, and surrounded by a rosette of leaf-like
appendages ; a cluster of numerous exsertile filaments (captacula) springing from, its
base. Otocysts present, but no eyes or tentacles. Foot rather long, conical, with
lateral lobes, and adjacent to the snout ventrally.
Gills are wanting, the general surface assuming respiratory functions. Liver
large, bilateral ; intestine strongly folded, the emus ventral and rather anterior,
genital and kidney orifices adjacent to it. Heart rudimentary, vjith a single chamber.
Nervous system with well-developed ganglia united by commissures. Beproduction
without copulation, the sexual products voided through the right kidney.
Scaphopods are without* exception marine, and for the most part inhabit
deep water. There are few littoral species. They live embedded in mud or
sand, with only the smaller end of the shell projecting above the surface.
Their food consists chiefly of Foraminifera and similar organisms, captured
by the filamentary captacula.
The tubular, curved shell, open at both ends, is characteristic of the class,
the tubular shells of certain Gastropods and Cephalopods being invariably
closed at the smaller end. Some tubicolous worms (Serpulidae) form a similar
shell, but it is composed of two layers only, instead of three as in Scaphopods,
the growth is more irregular, and its microscopic structure very different.
The shell of Scaphopods inci'eases by successive increments at the larger
end, and at the same time loses by wear and absorption at the
smaller end. The posterior slits or notches occiirring in some
species are therefore formed by resorption of the previously
solid shell wall, and have a genesis wholly different from the
slits or fissures of Pleurotomaria, Fissurella, and other Gastropods.
Various genera described as Scaphopods have since been
found to belong to the Serpulidae. Such are Pyrgopolon Montf.
(Fig. 837), from the Maestricht of Belgium, also known as
Entalium Defr., and Pharetrium Kopig ; and Hamulus Morton
{Falcula Conrad), of the American Cretaceous. The Cambrian
Fig. S37. genus Spirodentalium Walcott, in which the shell has spiral
PyrgopoionmoMti Striae, is at present too imperfectly known to justify its refer-
taceous; Boigiunt 6nce to the Scaphopods, or even to the Mollusca.
^ Literature (see also, under the liead of Molliisea, anleu) : Leshayes, (i. I'., Anatomie et
monogra]iliie du genre Dentale. Mem. Soc. Hist. Nat. Paris, 1825, vol. iii. — Lacaze-Dvthiers, II. de,
Histoire del'organisation et du developpement du Deutale. Ann. des Sci. Nat., 1856-5'/, ser. 4, vols,
vi. , viii. — Sars, M., Om Siphonodeutalium vitreum, en ny Slaegt af Dentalidernes Faniilie.
Universitets-Program, Christiania, 1861. — Stoliczka, F., Palaenntologia Iiidica. Cretaceous Fauna
of Soutliern India, vol. ii., 1867-68. — Gardner, J. S., On the Cretaceous Dentaliidae. Quar.
Journ. Geol. Soc. Loudon, 1878, vol. xxxiv. — Kovalersky, A., llltude sur I'embryogeuie, etc., du
Dentale. Ann. Mus. Hist. Nat. Marseille, 1882-83. Zoologie, Mem. No. \.— Plate, L., tiher
CLASS 11
SCAPHOPODA
50!)
Family 1. Dentaliidae Gray.
Scai)lwpoda having a conical foot with an encircling sheath expanded laterally and
interrupted dorsally. Shell tabular, curved, regularly tapering throughout, not contracted
anteriorly, sculptured or smooth. Ordovician to Recent.
Dentalium Linn. (Figs. 838, 839). Characters those of the family. Beginning
with a few species in the Ordovician, the number increases slowly until the Cretaceous.
A great acceleration then ensues, which continues to the present.
About 275 fossil and 150 recent species known. Various authors have
attempted to subdivide the genus ui^on characters 'of the posterior slit
of the shell, but this has jDroved to vary widely even among individuals.
The following subgenera based upon the system of sculpture and
shape of the tube appear more stable : —
Dentalium s. str. (Fig. 839). Shell with strong longitudinal ribs, apical
notch short or wanting. Eocene to Recent.
Antalis Adams {Entalis, Gray non Sowb. ;
Entaliopsis Newton and Harris) (Fig. 838,
A). Shell with longitudinal riblets or striae
at least in the young ; apex with a short
ventral slit and a sheath. Cretaceous to
Recent.
Heteroschisma Sirar. With longitudinal
riblets and a dorsal slit. Recent.
Fissidentalium Fischer. Large and solid,
with many longitudinal ribs or striae ; a long
ventral slit usually present. Eocene to Re-
cent. Schizodcntaliu'ui Sowb., in which the
.slit is interrupted into a series of holes, is
probably a modification of this group.
G-raj)tacme Pils. and Sharp. Surface with
close, fine longitudinal striae near ajjex only,
or throughout. Tertiary and Recent.
Lacvidentalium Cossm. Arcuate, smooth, -'- -D- i^ntalis) Uckxi Nyst. Oli-
.,, ,1 ,. 1 • T • i- gocene ; Wemneim, near Alzey. B,
With growth-bnes only, circular in section, n. (Fnstiaria)lucula-Desh. Eocene;
apex simple or notched. Silurian ? to Recent. Cuise la Mothe. Vi- '-', Posterior
Ehabdus Pils. and Sharp. Smooth, thin, portion of same enlarged, showing
Fi(!. 83S.
ill
slit.
Fin. 839.
Dentalium sex-
nnrjulare Lam.
Pliocene ; Asti,
Italy.
glossy, nearly straight, sub - circular
section, apex entire. Recent.
Episiphon Pils. and Sharp. Small and very slender, smooth, thin, the apex generally
with an inserted tube. Oligocene to Recent.
Compressidens Pils. and Sharp. Small, much tapering, vertically compressed, smooth.
Eocene to Recent.
Lobantalc Cossm. Shell compressed, with two internal longitudinal ribs. Eocene.
F'ustiaria Stol. (Fig. 838, B, C). Shell with a very long and linear ventral cleft posteriorly.
Cretaceous to Recent.
Placjioglypta Pils. and Sharp. Surface with extremely oblique, sinuous, encircling striae
(Z>. undulatiim Mxmst.). Carboniferous to Trias.
Family 2. Siphonodentaliidae Simroth.
Scaphopoda having the foot either expanded distally in a symmetrical dish with
crenate continuous edge, or simple and vermiform, without developed lateral processes.
Shell small and generally smooth, often contracted toioards the mouth. Cretaceous to
Recent.
den Bau und die Verwaiultschaftsbeziehungen der Solenoconchen. Zool. Jahrb., Abteil. fiir Anat.
mid Ontog., 1892, vol. v. [Bibliography, pp. ^M-ZiQ.]— Simroth, H., MoHusca, -in Bronn's
Classen und Ordnungen des Tierreiehs, vol. iii., 1893-95.— PiYsiry, //. A., and Sharp, B., Scapho-
poda, in Tryon and Pilsbry's Manual of Couchology, 1897-98, vol. xviL—BelNni, B., Revisione
delle Dentaliidae dei terrcni terziari e qnateniari d' Italia. Palaeont. Ital,, 1909, vol. xv.
510 MOLLUSCA phyltjm vi
Altliougli this family is usually characterised by a small smooth shell, the essential
difference from the Dentaliidae is in the form of the foot. Typical forms of Gadulus
appear in the Cretaceous ; the remaining
^ J3 (-' Z) genera are Tertiaiy and Kecent.
Entalina Monts. Shell I)entalium-Vik&,
largest at the aperture, thence taj^ering to
the apex ; strongly ribljed, and angular in
section near the apex. Miocene to Eecent.
Sifhonodentalium Sars (Pulsellum Stol. ;
Siplionentalis Sars). Shell an arcuate,
Fi"- ^*o. slightly tajjering tube, circular in section
A,Ca(tulu.^ (PolysMdes) denticulatus Desh Cal- qj, nearly SO, and smooth externally. Apex
caire Grossier ; Damery, near Bpernay. B, Cadulus it . , ,. .
(DUrhhhs) hifissumtus Desii. Caicaire Grossier ; rather large, tyjiically slit into lobes, Ijut
Gnjjnoii, near Paris. C, Cadulus omtlum. Fhil Tor- cmnptimes simnle Plioppne to ■Re.-mit
tonian ; Monte Gibbio. D, Cadulus olivi Scac. Tor- sometimes Simple. rilOCene tO Itecent.
tonian ; Monte Gibbio, near Sassuolo, Italy. Cadulus Phil. {Gadus Desh. ; Gadila
Gray ; Helonyx Stimp.) (Fig. 840, G, D).
Shell tubular, circular or oval in section, swollen near the middle or anteriorly, con-
tracting toward the aperture. Cretaceous to Recent.
Tyjiical forms with simple anal orifice appear first in the Cretaceous, Dischides,
Jeffr. (Fig. 840, B), with two lateral slits, and Polyschides Pils. (Fig. 840, A), with
several notches, appear in the Eocene. All continue to the present time.
Class 3. AMPHINEURA von Ihering.^
Aquatic, marine, hilaterally symmetrical moUusks, with the head partially or not
differentiated ; in form worm-like with a ventral groove or none, or oval, flattened,
with a foot adapted for creeping. Nervous system consisting of an oesophageal ring
with ganglia and four longitiidinal cords, two ventral and two lateral ; no cephalic
eyes, tentacles, or otocysts. Gills jMired or many, posterior or lateral ; mouth anterior,
usually with a radula ; anus posterior, median. External surface with a series of
eight shelly plates, or stiffened loith calcareous spicules.
Order 1. APLACOPHORA von Ihering.
Body vermiform, tvith a ventral groove, the skin elsewhere beset with calcareous
spicules ; no dorsal shelly plates in the adidt.
This is a degenerate group, represented in the Recent fauna by about a
dozen genera belonging to two families — Chaetodermatidae and Neomeniidae.
Fossil remains are unknown.
Order 2. POLYPLACOPHORA Blainville. Chitons.
Amphineura protected by a dorsal series of eight shelly valves and an encircling
girdle ; with differentiated head, and a ventral sole or foot adapted to creeping ; gills
^ Literature : Ihering, H. v. , Vergleichende Anatoiuie des Nervensystems mid Phylogenie der
Mollusken, 1877.— Dall, W. II., On the Genera of Chitons. Proc. U.S. Nat. Museum, 1881, vol.
iv.- — Jlnhrecht, A. A. IF., A Contribution to the Morphology of the Ainj)]iiueura. Quar. Journ.
Microscop. See, 1882, vol. xxii. [Bililiography, pp. 226, 227.]— Ruchebrune, A. T. de, Mono-
graphie des especes fossiles appartenant a la clas.se des Polyplaxiphores. Ann. Sci. Gcol. 1883, vol.
xiv. — Pruvot, O., Sur I'organisation de quelques Neomeniens des cotes de France. Arch. Zool.
Expi-r. et GencT. [2], 1891, vol. ix. [Bibliography, pp. 702, 7Q'3.]—Pilsbri/, H. A., Monograph of
the Polyplacophora. In Tryon and Pilsbry's Manual of Conchology, vols. xiv. and xv., 1892-93.
— Broili, F., Die Fauna der Pacliycardientuffe der Seiser Alp. II. Scaphopoden und Gastropoden,
Palaeoutogr. , 1907, vol. liv.
CLASS III AMPHINEURA 511
numerous, occupying the groove between foot and girdle ; radula present, heterodont ;
sexes separate.
The external covering in the Polyplacophora, or Chitons, consists of eight
valves bound together by an encircling flexible band called the girdle. The
anterior or head-plate (Fig. 841, ^-^j below) is invariably semicircular, with the
apex or mucro at the middle of the straight margin ; the six succeeding plates
are generally square (Fig. 842, below), with the apex posterior on the median
line ; and the posterior or tail- valve (Fig. 841, ^) is semicircular or subcircular,
with apex varying in position from in front of the middle to the hind margin.
All of the plates are composed of two layers — an outer porous layer, the
tegmentum, and an inner porcellanous one, the articulamentum. In most of the
lower Chitons these layers are coextensive and have smooth edges ; but in
the higher forms the articulamentum projects beyond the outer layer into the
substance of the girdle, in Avhich it is firmly inserted. These projections at
the outer or peripheral margin are termed insertion plates. They are generally
slit or notched into so-called " teeth," which may be either smooth and sharp
along the edge, or crenulated {pectinated). Insertion plates serve the function
of binding the valves firmly to the girdle.
The anterior margin of each valve except the first one invariably shows
two projections of the articulamentum called sutural laminae (Figs. 841, B,
842), which pass under the rear margin of the next anterior valve, thus pre-
venting vertical displacement of the series. The tegmentum is traversed by
a multitude of fine canals which terminate at the surface in minute sense
organs. The cavities of the latter in dry or fossil valves are visible as fine
quincuncial punctations. In the highest Chitons a certain number of these
sense organs have become enlarged and modified into eyes, easily recognised
as pigmented dots in recent, and small pits in fossil specimens.
Polyplacophora make their appearance as early as the Ordovician ; they are
rare in the Silurian and Devonian, but somewhat more abundant in the
Carboniferous. None of the Paleozoic genera is known to continue into the
Mesozoic, but the Eoplacophora are replaced by types more related to modern
Chitons {Mesoplacophora). Members of the most specialised suborder, Teleo-
placophora, first appear in the Eocene, although they doubtless arose earlier.
About twenty Paleozoic, five or six Mesozoic, and fifty Tertiary species have
been described. Recent forms number several hundreds. A good many
species supposed to be Chitons have been based upon barnacle valves, fish
scales, and other fragments. The recently described Duslia insignis Jahn is
apparently a Crustacean ; certainly not a member of the Polyplacophora.
Three suborders are recognised, according as the insertion plates are
absent, or if present, unslit (Eoplacophora) ; developed, smooth, and slit into
teeth (Mesoplacophora) ; or both slit and pectinated (Teleoplacophora).
Suborder A. EOPLACOPHORA Pilsbry.
Polyplacophora with the tegmentum coextensive with the articulamentum, or with the
latter projecting in smooth, unslit insertion plates ; gills posterior.
Family 1. Gryphochitonidae PiLsbry.
Insertion plates absent, sutural laminae small ; one or both end-valves with the
terminal margins elevated; form elongated and narroiv. Paleozoic.
512
MOLLUSCA
PHYLUM VI
Helminthochiton Salter. Valves tliin, niucro subcentral, low ; end-valves not
elevated terminally. Silurian.
Priscochiton Billings. Similar in the non-sinuous liead-valve, lait beaks of the
valves greatly produced backwards. Ordovician.
Grijphochiton Gray (Fig. 841). Elongated, with small beaks and very small sutural
laminae ; terminal margins of end-valves strongly elevated ; tail-valve with low,
decurved mucro behind the middle. Carboniferous.
^ '' Pterochiton Carp. {Anthracochiton Rochebr.). Elon-
gated, the valves strongly beaked and laterally excavated ;
tail -valve with de2)ressed post -median mucro and no
posterior sinus, anterior valve with the front margin
elevated, sutui-al laminae large. Carboniferous.
Gymatochiton Dall {Protalochiton Rochebr.). Oval,
elevated and granular, the valves short and wide, with
small, low sutural laminae and distinct lateral areas ;
mucro of posterior valve post-median, elevated. Permian.
Probolaeiim Carp. Elongated, elevated ; valves very
strongly beaked, the pleura projecting beyond the jugal
tract ; anterior valve sinuate in front, posterior valve
unknown. Devonian.
Chonechiton Carp. Median valves as in Gryphochitoyi ;
posterior valve with the mucro
thrown backward, as in Grypto'plax.
Carboniferous.
Somewhat like the Recent Lorica, Init
Fig. S41.
Gryphochiton ju-iscHS (Munst.).
Carboniferous ; Tournay, BRlgiuiii.
A, Anterior and three intermediate
valves. B, Posterior valve, ventral
and dorsal aspects. Vi-
Loricites Carp,
without insertion plates. Carboniferous.
Family 2. Lepidopleuridae Pilsbry.
Fig. 842.
Lepidopleurus virgifer
(Sandb.). Miocene ; Wald-
Insertion plates absent, or present and unslit ; end-valves biickeiheim, near Creuz-
... r, . 7j7_f ; 1.7 nacli, Germany. A median
With the terminal margins never elevated ; form oval or oolong, ^ud a posterior valve, '•^/i.
Tertiary and Recent.
Leindo'pleurus Risso {Lcptochiton Gray) (Fig. 842). Small, oval ; insertion plates
entirely absent, sutural laminae small ; girdle minutely scaly or chaffy. Eocene to
Recent.
Hanleyia Gray. Like the last, except that the anterior valve has an unslit insertion
plate, and the girdle is spiculose. Champlain to Recent.
Hemiarthrum Carp. Both anterior and posterior valves with smooth unslit
insertion plates, the others lacking them ; girdle downy, with small sutural pores.
Recent.
Ghoriplax Pils. Valves partly immersed in the minutely granulose girdle, all with
thin, smooth insertion plates. Recent.
Suborder B. MESOPLACOPHORA Pilsbry.
Insertion plates developed, slit, not vertically grooved or pectinated outside.
Family 1. Ischnochitonidae Pilsbry.
Valves having the inner layer ivell covered by the outer. Surface of intermediate
valves divided into lateral and central areas by a diagonal rib {often indistinct), extending
from the beak to each anterior aider angle of tegmentum; or ivhen this is not clearly the
case, the posterior valve has a crescentic series of wdl-developed teeth ; all valves with
slits. Eocene to Recent.
CLASS III
AMPHINEURA 513
Two subdivisions of this family are recognised, according as the anterior and side
slits correspond in position with ribs on the external surface or not. Among the
genera included under the first section {Gallistoflacinae) may be mentioned the follow-
ing : — Gallistochiton, Nuttcdina, and Callistoplax Carpenter ; Grasfcdochiton Shuttle-
worth ; and Ceratozona Dall. Eepresentatives of the second subfamily {Ischnochitoninae)
are as follows : — Schizoplax Dall ; Tonicella, Trachydermon, and Dinoplax Carpenter ;
Gallochiton and Ischnochiton Gray ; Ghaetopleura Shuttleworth.
Family 2. Mopaliidae Pilsbry.
Valves externally divided typically into central and lateral areas, the posterior valve
with a sinus behind, one or two slits on each side of it or none ; intermediate valves each
with a single slit ; teeth smooth, sharp, often ivith thickened edges on the outside ; girdle
more or less hairy. Pleistocene and Recent.
This family comprises the following genera : — Mopalia and Plaxiphora Gray ;
Placiphorella Carpenter ; and Placophoropsis Pilsbry.
Family 3. Acanthochitidae Pilsbry.
Valves more or less immersed in the smooth or hairy girdle, the tegmentum therefore
much smaller than the articulamentum ; the exposed stirface divided into a narrow dorsal
and wide latero-pleural areas, the latter formed by the union of the lateral and pleural
areas of typical Ghiton^. Insertion teeth sharp, rarely smooth; posterior valve either
slit like the head-valve, or having a. posterior sinus ; head-valve usually with five slits,
intermediate valves singly slit. Body never vermiform. Pliocene to Recent.
The following representatives are to be cited : — Acanthochites Risso ; Spongiochiton
Carpenter ; Katharina and Amicula Gray ; Gryptochiton Midd. and Gray.
Family 4. Cryptoplacidae Dall.
Elongated or vermiform Ghitons loith small valves; insertion and sutural plates
strongly drawn forward, sharp and smooth ; the anterior valve ivith three to Jive slits, the
others with one slit on each side, or none; tail-valve having the miicro far posterior,
insertion plate continuous behind ; girdle very thick and wide.
This is a highly specialised branch of a low group of Chitons, unknown in the
foasil state. Gryptoplax Blainville {Ghitonellus Lam.), and Ghoneplax Carpenter, are
examples.
Suborder C. TELEOPLACOPHORA Pilsbry.
All valves, or the first seven, with insertion plates cut into teeth by slits; the teeth
sharply sculptured {pectinated) outside by fine vertical grooves.
Family 1. Chitonidae Pilsbry.
Gharacters those of the suborder. Tertiary and Recent.
The family is illustrated ])y the following genera, of which only the first two occur in
the fossil condition : — Ghiton Linne ; Trachyodon Dall ; Eudoxochiton Shuttleworth ;
Tonicia, Schizochiton, Enoplochiton and Onithochiton Gray ; Acanthoplcura Guilding ;
Lorica Adams ; Loricella and -Liolophura Pilsbry.
VOL. I 2 L
514 MOLLUSC A phylum yi
Class 4. GASTROPODA. SnailsJ
MoUuslcs ivith distinct head, soled or more rarely Jin-like foot, and undivided
mantle, which latter usually secretes a univalve, sjnrally wound, or saucer-shaped shell.
Gastropods differ from Pelecypods in having a more or less distinctly
marked head, which usually bears tentacles, eyes, and ears, and contains a
large cerebral ganglion. The ventral aspect of the creature is commonly
formed by a broad foot ; but in the Heteropoda this is modified into a vertical,
laterally compressed fin ; and in the Pteropoda it is represented by two wing-
like swimming membranes near the head. The base of the foot is sometimes
^ Literature (see also under head of Mollusca, antea) : Ihering, H. v., Vergleiclieiide Anatomie
des Nervei) systems iiud Phylogeuie der MoUusken. Leipsic, 1877. — Koken, E., Uber die Eut-
wickelung der Gastropoden vom Kambrium bis zur Trias. Neues Jahrb. f. Mineral., 1889, supplem.
vol. vi. — Quenstedt, F. A., Petrefaktenkuude Deutsclilands. Gastropoden, vol. vi., 1881. — Simroth,
H., Gastropoda, in Broun's Klasseu uud Ordnungen des Tien-eichs, 1896. — Troschel, H., Das
Gebiss der Sclmecken, zur Begriindung einer natiirlichen Classification, vols, i., ii. Berlin, 1856-78.
A. On Paleozoic Forms. — Billings, E., Palaeozoic Fossils. Geol. Surv. Canada, 1865-74, vols, i.,
ii. — Jakoialeiu, V., Die Fauna eiuiger oberpaliiozoischer Ablagerungen Russlands. Mem. Coniite
Geol., 1899, vol. XV., No. 3. — Koken, E., Die Gastropoden des baltischen Untersilurs. Bull. Acad.
Imp. Sci. St. Petersb., 1897, vol. vii.. No. 2. — Koninck, L. G. de, Faune du calcaire carbonifere
de la Belgique. Ann. Mus. d'Hist. Nat. Belg., 1882-85, vol. vi. — LindstrlJm, G., On the Silurian
Gastropoda and Pteropoda of Gotland. K. Svensk. Vetensk. Akad. Handl., 1884, vol. xix.
— Perner, J., Gasteropodes, in Barrande's Systeme silurien du centre de la BohOme, vol. iv.
Prague, 1903-7. — Salter, J. W., Catalogue of the collection of Cambrian and Silurian fossils in
the Museum of Cambridge, 1873. — Spitz, A., Die Gastropoden des karnischen Unterdevon. Beitriige
Pal. nnd Geol. Osterr.-Ung., etc., 1907, vol. xx. — Ulrich, E. 0., and Scqfield, W., The Lower
Silurian Gastropods of Minnesota. Rept. Geol. and Nat. Hist. Surv. Minn., 1897, vol. iii., pt. 2.
B. On Mesozoic Forms. — Ahlbiirg, J., Die Trias im s. Oberschlesien. Abhandl. Preuss. Geol.
Landesanst. n. Bergakad., 1906, n.s.. Heft 50. — Bijhm, J., Die Gastropoden des Marmolatakalkes.
Paliiontogr., 1895, vol. xlii. — Brosamlen, R., Beitrag zur Kenutuis der Gastropoden des schwiibischen
Jura. Paliiontogr., 1909, vol. Ivi. — De^iingei; K., Die Gastropoden der siichsischen Kreideformation.
Beitrage Pal. und Geol. Osterr.-Ung., etc., 1905, vol. xviii. — Haberle', D., Paliiontologische Unter-
suchungen triadischer Gastropoden ans dem Gebiet von Predazzo. Verhandl. Naturh. Med. Vereins.
Heidelberg, 1 908, n.s., vol. ix. — Iludlcston. W. //., A Monograph of the British Jurassic Gasteropoda.
Paliiontogr. Soc, 1887-94. — Kanjilinven, F., Die Gastropoden der Mitstricher Kreide. Paliiont.
Abhandl., 1897, n.s., vol. iv. (viii.). — Koken, E., Die Gastropoden der Trias um Hallstadt. Jalirb.
Geol. Reichs-Anst. Wien, 1897, vol. xlvi., and Abhandl., vol. xvii. — Morris, J., and Lycett, J.,
Mollusca from the Great Oolite : Univalves. Palaeontogr. Soc, 1850. — d'Orbigny, A., Paleontologie
fran(;aise. Terrains jurassiques ii. et iii., 1850-82. Terrains cretaces ii., 1842-3. — Picard, E.,
Beitrag zur Keuntnis der Glossophoren der mitteldeutschen Trias. Jahrb. Preuss. Landesanst.,
1901, vol. xxv. — Stolii'zka, F., Cretaceous Fauna of Southern India. Gastropoda, vol. ii. Mem.
Geol. Surv. East India, 1808. — Zittel, K. A., Die Gastropoden der Stramherger Schichten. Mitt.
Mus. Bayer. Staates, 1873, vol. ii., pt. iii.
C. On Tertiary Forms. — Beyrich, E., Die Couch ylien des norddeutschen Tertiiirgebirges.
Zeitschr. Deutsch. Geol. Ges., 1853-6, vols, v., vi., viii. — Cossmann, M., MoUusqiies eoceniqnes
de la Loire-Inferieure, i. and ii. Bull. Soc. Sci. Nat. Quest Nantes, vols, vii.-ix., 1895-1901.
Contribiition .a la paleontologie franeaise des terrains jurassiques. Mem. Soc. Geol. France, 1895,
1898, Mem. Nos. 14 and 19. Essais de pah'outologie comparee, i.-iv. Paris, 1895-1904. — Cossmann,
M., and Pissarro, G., Faune eocenique du Cotentin. Bull. Soc. Geol. Normandie, 1900-2, vols, xix.-
xxi. — Dall, W. H., Contributions to the Tertiary Fauna of Florida. Trans. Wagner Free Inst. Sci.,
1895-97, vols, iii., v. — Harris, G. F., The Australasian Tertiary Mollusca. Cat. Tert. Mollusca
Brit. Mus., pt. i., 1897. — Hoernes, R., and Aninger, M., Die Gastropoden der Meeresablagerungen
der ersteu und zweiten Mediterranstufe. Vienna, 1879-91. — Martin, K., Die Fossilien von Java.
Samml. Geol. lleichsmus. Leiden, 1895-99, n.s., vol. i., pts. 2-10. — Newton, R. B., Systematic List
of British Oligocene and Eocene Mollusca, 1891. — Philipj^i, R. A., Die tertiiiren und quartiiiren
Versteineruugen Chiles. Leipsic, 1887. — Sandberger, F., Land- und Siisswasserconchylien der
Vorvvelt. Wiesbaden, 1870. — Vinassa de Regny, P. E., Synopsis dei molluschi terziari delle Alpe
venete. Palaeontogr. Italica, 1896-97, vols, i., ii. — Wood, E., Tlie Phylogeny of certain Cerithiidae.
Ann. N.Y. Acad. Sci., 1910, vol. xx. — Grufiaii, A. W., Studies of Gastropoda. Amer. N.at.,
1902-3, vols, xxxvi., xxxvii. — Phylogeny of Fusus. Smiths. Misc. Coll., 1904.
CLASS IV GASTROPODA 515
of considerable size, and in some forms (Strombidae) the animal is enabled to
spring quite a distance by contracting the foot. The mantle lobe is elevated
along the back like a hood, extending as far as the head, and usually secretes
a shell from its outer surface. The shell (which may be wanting or obsoles-
cent in the adult) covers the intestinal sac and lung-cavity, and usually permits
of retraction into it of the entire body of the animal. Body and shell are
united by muscular attachment ; in spiral shells the muscle is fastened to the
columella, but in bowl-shaped forms to the inner surface of the shell.
The nervous system consists of two cerebral ganglia, the paired pedal and
visceral ganglia, and two or three additional pairs, all of which are united by
commissures. A complete crossing of the commissures of the visceral ganglia
sometimes takes place (Chiastoneura), but in other forms they run parallel
(Orthoneura).
The peculiar armature of the mouth, although developed in all classes of
Mollusks except Pelecypods, is especially characteristic of Gastropods. This
consists of one or more horny plates on the anterior upper margin of the
oesophagus, opposed to which is a chitinous grating, strap or radula, resting
upon the tongue or odontophore. The tongue itself is merely a swelling at
the bottom of the buccal cavity. The radula is usually quite long, and is
beset with innumerable small teeth or hooks, placed in transverse and
longitudinal rows, and exceedingly constant in form throughout the several
groups. The characters of the radula among the different groups were
therefore advantageously employed by Loven and Troschel as a basis of
classification.
The oesophagus conducts into a long, coiled, intestinal canal, which is
surrounded by a large liver, the kidneys, and numerous glands. The intestine
ends in an anal opening placed anteriorly. The heart, as a rule, has one
auricle (Montocardia), more rarely two (Diofocardia), and serves as a central
organ for the supply of a much branched system of blood-vessels. When the
gills or lungs are placed in front of the heart (Prosobranchia, Pidmonata), the
auricles are antex'ior to the ventricle ; but when placed behind the heart
{Opisfhobranchia, Pteropoda) the aiu-icle is posterior.
Only a few Gastropods breathe through the general surface of the body,
and are without distinct organs of respiration ; the vast majority possess gills
or lungs. The gills are lamellar or tuft-like, sometimes branched or feathered
lobes of the integument, and are usually placed in the gill-cavity below the
mantle ; more rarely they project freely on the back or at the sides. Only
exceptionally are they present in large numbers and symmetrically developed ;
and when so disposed they are always secondary structures not homologous
with the normal ctenidia. Typically there are two gills, but the left usually
becomes completely atrophied, and the right takes up a median position, con-
sequent upon the torsion of the body, or even migrates over to the left side.
Air-breathing snails have the gills replaced by a sac-like cavity, the lung
occupying the place of the gill-cavity. The walls of this respiratory cavity
are covered with a finely branched network of blood-vessels. The Ampul-
lariidae and Siphonariidae possess both gills and lungs. The opening of the
respiratory cavity is reduced to a round or crescentic aperture, called the
breathing pore. The sides of this pore, in operculated snails, are often pro-
duced outwards, so as to form a closed or cleft tube, corresponding with which
there is frequently a canal-like process of the shell.
516 MOLLUSCA phylum vi
Gastropods are remarkable for the extreme diiferentiation of their repro-
ductive organs. The sexes are distinct in the Prosohranchia and Heteropoda,
but united in the Opisthobranchiata, Pteropoda and Pidmonata. The ovarian
and seminal ducts of hermaphrodites sometimes open into a common cloaca,
or they may terminate in separate openings.
The shell, as has already been remarked, is secreted by the mantle, and is
limited in form and size by the configuration of the intestinal sac. It is
composed of a chitinous substance (conchiolin) infiltrated with lime carbonate,
or exceptionally with sulphate of lime in small quantities. Shell characters
ai-e of great importance in distinguishing genera and species, but their value
in classifying larger groups is comparatively slight, owing to the fact that
very similar shells are often developed among forms which differ widely in
their general organisation. Two forms of shell-habit occur, the symmetrical
and the spiral. The first are flat, conical or saucer-shaped, and characterise
only a few groups (Cyclobranchia, Aspidohranchia, Pidmonata). Transition
forms between the symmetrical and spiral are to be observed in conical shells
with slightly inrolled beaks. Exceptional forms of the spiral shell are seen
in Vermetus, which is irregularly coiled, and in Planorhis, Bellcrophon and
Jtlanta, coiled in one plane (discoidal). Usually the shell forms a screw-like
spiral, and rests upon the back of the creature in such a way that the apex is
directed upward and backward, the aperture forward and downward. Holding
the shell upright so that the apex is above, and the aperture below, facing
the observer, it is said to be right-handed or dextral when the opening is on
the right side, and left-handed or sinistral when on the left side. By far the
larger number of Gastropods are dextral ; but a few (Clausilia, Physa, Spinalis)
are normally sinistral. Right-handed individuals of normally left-handed
genera, as well as pathologic sinistral individuals of normally right-handed
forms, are occasionally met with.
In drawing and describing Gastropod shells, the apex is ordinarily directed
upward, so that the right- or left-handedness may be seen at a glance. It is
also customary to employ the terms above and below in the same sense as
posterior and anterior. The height or length of the shell is measured by a
line drawn from the apex to the lower margin of the aperture.
The shell is to be considered as a more or less rapidly widening cone,
which is wound either around an axial pillar, called the columella, or about a
central tubular cavity. Each coil of the tube is termed a tvhorl, and all the
whorls except the last one form together the spire. The last or body whorl
is often very much larger than the preceding ; its lower, sometimes flattened
surface is called the base. As a rule, the whorls are in contact with each
other, each in succession either partly or entirely covering the preceding ; but
in rare cases they form a loose spiral, in which the whorls are separated from
one another. The spire is said to be convolute when the later whorls
entirely conceal the earlier ones, as in Cypraea. The line between two con-
tiguous whorls is known as the suture. According to the manner of inrolling,
various shell contours are produced, requiring numerous descriptive names,
such as conical, auriform, turbinate, fusiform, cylindrical, spherical, oval,
pyramidal, etc.
When the inner parts of the whorls coalesce to form a columella, the shell
is said to be imperforate ; it is pierforate when they do not so coalesce, but
leave a central tubular cavity instead. The opening of this perforation below.
CLASS IV
GASTROPODA
517
Apex
Suture
in the centre of the base, is designated the umbilicus. A true umbilicus
reaches to the apex of the shell ; when confined to the last whorl only, it is
called a false umbilicus. An umbilical fissure is sometimes produced through
a partial covering of the umbilicus by the reflected inner lip, or by a shelly
growth termed the callus.
The aperture is variable in form, being most commonly oval, rounded,
crescentic or half-round, but is sometimes contracted or even fissure-like. Its
margin is called the peristome, the outer part of which forms the outer lip, and
the part next the columella the inner lip. Some shells have a continuous,
uninterrupted peristome, but as a rule the inner and outer lips are discon-
nected. The aperture is said to be entire when
rounded anteriorly (inferiorly), as in the Holosto-
mata ; it is channelled when a basal notch or
canal, caused by an inbending of the margin
next the base of the columella, is developed.
This anterior canal serves for the lodgment of
the siphon, as the tube is called which conducts
water to the gills ; it may be either straight or
recurved, and in the Siphonostomata it is greatly
produced, sometimes even exceeding the aper-
ture in length. The outer lip may be entire or
incised, thin and sharp or thickened, curved
outward (reflected) or inward (inflected), even
or crenulated, or it may be produced into alar
or finger-like processes. It is sometimes chan-
nelled by a canal at the posterior border, in
which the anal or excurrent canal is placed.
The upper or posterior portion of the inner
margin is commonly designated as the parietal
wall, in contradistinction from the lower or
columellar portion. The inner lip is formed
either by the wall of the penultimate whorl, or
by a calcareous callus ; like the outer lip and
columella, it may bear spiral folds, which in
some cases extend backward as far as the
apex (Fig. 843), but sometimes are progres-
sively absorbed internally.
The external ornamentation usually consists of impressed lines or grooves,
or of elevated ridges, ribs, folds, nodes, spines and the like. The markings
are called spiral when they run parallel with the suture, and axictl or
longitudinal when they meet the suture at right angles or obliquely. Many
Gastropods are brilliantly coloured ; some have a smooth or rough, and others
a velvety or hairy epidermis. The fossilisation process is usually destructive
not only of the epidermis, but of the coloration as well.
The essential constituent of univalve shells is aragonite, which usually
forms a homogeneous, porcelain-like layer. Many families have in addition
to this an inner nacreous layer, which is made up of alternating strata of
conchiolin and calcium carbonate, running parallel with the inner surface of
the shell. The porcellanous material is composed of three distinct layers,
each of which is made up of thin laminae, and the laminae in turn of very
Canal
Fio. 843.
Mitra episcojialis Linn. View of shell
sawed through longitudinally, showing
columella with folds.
518 MOLLUSCA phylum vi
small oblique prisms. The laminae of the middle layer are disposed at right
angles to those of the adjacent layers.
Many Gastropods have a calcareous or horny plate, called the operculum,
attached to the posterior part of the foot, and serving to close the aperture
more or less completely Avhen the animal withdraws into its shell. Being
most commonly of corneous nature, it is seldom preserved fossil ; sometimes,
however, it is calcareous, and may attain considerable size and thickness. On
the outer surface it may be smooth, furrowed, granulated or covered with
excrescences. The nucleus or initial point of growth is sometimes central, or
may be eccentric or even marginal in position ; it may be surrounded by con-
centric markings, or form the origin of a spiral consisting of few (paucispiral)
or many (multispiral) whorls. Certain Solariidae have a conical operculum,
which is covered externally with numerous spiral lamellae.
The embryonic stages of Gastropods are usually completed in the egg-
capsule. Early in its development the embryo forms a small shell, the proto-
concliy which consists sometimes of several whorls, and not infrequently differs
in form from the shell of the adult. The protoconch remains attached
to the apex for a time, in the form of a small glistening knob, or a short
smooth spire, which occasionally stands at an angle to the rest of the shell, or
is even twisted in a contrary direction (heterostrophic). Should the protoconch
become decollated, a small calcareous plate closes over the apex of the spire.
All branchiate Gastropods are aqueous in habitat, but there are some
forms having a lung-cavity which live permanently in fresh water (Lymnaeidae),
and others which are exclusively marine (Siphonariidae). The greater number
of Gastropods, especially the large and solid forms, frequent the coast-line,
and inhabit comparatively shallow water. Some become attached to rocks
and plants, others burrow in sand or mud. A great reduction in the Gastropod
fauna is noticed at a depth of between 70 and 100 metres, but many genera
(Pleurotoma, Fusus, Natica, Odosfomia, Eulima, Scissurella, Turbo, Cylichna,
Tornatina, Actaeon, etc.) persist into the greatest depths yet explored. Most
marine Gastropods are killed by removal into fresh water ; a few genera,
however, are able to maintain their existence in brackish or in fresh water
(Cerithium, Littorina, Eissoa, Trochus, Purpura, etc.). On the other hand, many
fresh-water forms {Melania, Melanopsis, Neritina, Ampullaria, Lymnaea, Planorhis)
can survive in brackish or even strong salt water. There are also large
numbers of terrestrial Gastropods, especially in tropical regions.
Most Gastropods are herbivorous, but a few subsist upon living or decom-
posed animal food. Many genera {Natica, Buccinum, Murex) perforate the
shells of other Mollusks with their radula, and extract the contents.
Classification. — Ordinal divisions have been based since the time of Cuvier
and Milne Edwards upon the respiratory organs, and the structure of the foot
(whether adapted for swimming or crawling). The reproductive organs, and
the structure of the heart and nervous system, are also of prime importance.
For separating smaller groups, shell characters and the radula are largely
employed. Gastropods may be diA-ided into two subclasses : Streptoneura,
with the orders Ctenohranchiafa and Aspidohranchia ; and Euthyneura, with
the orders Opisthobranchia and Pulmonata.
CLASS IV
GASTEOPODA 519
Subclass 1. STREPTONEURA Spengel.
(Prosobranchia Cuvier ; Cochlides von Ihering.)
Gastrofods in which the visceral commissures are crossed, 'producing an S-shaped
loop ; sexes separate ; heart behind the gill ; a shell almost always developed, and
with few exceptions provided with an operculum.
The Streptoneura, or Prosobranchiates as they are often called, constitute by
far the largest group of Gastropods, and comprise at least 20,000 living and
fossil species. The shell is usually spiral, .more rarely symmetrical, saucer-
shaped or conical. The intestinal sac is twisted from left to right, so that
the anal opening is placed on the right side near the head, and the organs
normally belonging to the right side (kidneys and gills) migrate over to the
left. As a rule, one only (the right) of the lamellar gills is fully developed,
but in some cases the two are of equal size. The gill veins enter anteriorly
into the single or double-auricled heart.
The large number of Prosobranchiates have been variously classified.
Cuvier, Milne Edwards, and most of the older zoologists laid emphasis upon
the number and formation of the gills ; Troschel and Loven upon the char-
acters of the radula ; von Ihering upon the nervous system ; Morch and more
recently Perrier and Bouvier upon the structure of the heart. As none of
these characters leave a marked impress upon the shell, they are without
practical value in Paleontology. Nevertheless, the two orders Aspidohranchia
and Cfenobranchia form natural groups, and are recognised, albeit under
different names, in all classificatory systems.
Order 1. ASPIDOBRANCHIA Schweigger.
(Gyclobranchia and Scutibrancliia Cuvier.)
Nervous system not much concentrated anteriorly ; a penis generally absent ; radula,
multiserial.
This group includes most Paleozoic Gastropods, and is regarded as the most
primitive expression of the class. The nervous system and radula are of low, decidedly
generalised type, and in some families two symmetrical ctenidia or gills are developed,
as in Pelecypods.
Suborder A. DOCOGLOSSA Troschel. Limpets.
{Gyclobranchia pars Cuvier ; Heterocardia Perrier.)
Symmetrical, icith conic or bowl-shaped non-spiral shells, or ivith spiral shells coiled
in the same plane ; operculum wanting. Organs of resjnration represented either by a
ring of laminae {secondary or pallicd gills) beneath the mantle margin, or by a comb-
shaped true gill in front, anterior to the heart, or by both true and secondary gills.
Tongue set with peculiar modified teeth. Heart with one auricle. Marine. Cambrian
to Eecent.
The impression of the adductor muscle in the shell cavity is horseshoe-shaped,
open in front. In the family Tryblidiidae, the horse-shoe is broken into numerous
separate impressions. The three families Patellidae, Acmaeidae and Lepetidae have
the impression uninterrupted, and are distinguished by the structure of the gills. The
520
MOLLUSCA
PHYLUM VI
shells themselves exhibit little variation in form, and hence their
generic and
even
family affinities are almost always doubtful in the fossil state. About 400 Recent
species of limpets are known ; these are almost exclusively shallow water inhabitants,
and subsist on algae. Fossil forms are uncommon.
In this very primitive group two divisions have been proposed by Ulrich and
Scofield : (1) the Patellacea, which embraces the first three families noted below ; and
(2) the Belleropho7itacea, including the remaining five families. The latter groujj by
Meek was regarded as involute Fissurellidae, a view which is not without plausibility.
Family 1. Patellidae Carpenter.
Patella Linn. Cup-shaped, round or oval, depressed conical, with sub-central or
eccentric apex. Surface usually with radiating ribs or striae. Silurian to Recent.
Helcion Montf. Differs in having the beak strongly recurved anteriorly. Eocene
to Recent.
Helcioniscus Dall ; Nacella Schum. Recent.
Family 2. Acmaeidae Dall.
Acmaea Eschscholtz {Tectura auct.) (Fig. 844, B). Like Patella, Ijut shell having
generally a differentiated marginal band inside ; externally smooth, finely striated, or
radially ribbed. Beak anterior to the middle. Silurian to Recent. Lottia Gray is
closely allied.
Scurria Gray (Fig. 844, C). High conical, smooth, with sub-central beak. Jura
to Recent.
A BCD
A, Ai-chinac.ellaciwjidataVlT. Ordovician ; Kentucky. B, Aciiuwa TainvourUV>6s\\. Eocene; Anvers, near
Paris. C, l$curria nitida Deslongcli. Upper Jura ; Langrune, Calvados, i/j. D, Helcionopsis striata Ulr.
Ordovician ; Kentucky.
Metoptoma Phil. Depressed conical with sub-central beak. Posterior side exca-
vated. Silurian to Carboniferous.
Lepetopsis Whitf. Silurian to Carboniferous.
The genera, Palaeacmaea Hall; Archinacella Ulrich and Scofield (Fig. 844,^); and
Scenella Billings are the oldest representatives of the Bocoglossa. They are small,
smooth or radially ornamented, and scarcely to be distinguished from Acmaea.
Lepeta Gray and Lepetella Verrill are small simple limpets of the Recent and late
Tertiary, with degenerate, aborted gills. They form the family Lepetidae.
Helcionopsis Ulr. and Scof. (Fig. 844, D), and Gonchopeltis Walcott, from the
Ordovician of North America, are doubtfully referred to this vicinity.
Family 3. Tryblidiidae Pilsbry.
Limpets ivith the muscle scar broken into numerous separate impressions. Silurian.
CLASS IV
GASTROPODA
521
Tryhlidium Lindstrom (Fig. 845). Shell depressed, very thick, oval, with anterior
beak ; ornamented externally with concentric lamellae. Six pairs of muscle scars
arranged in the form of a hoise-shoe.
Ordovician and Silurian.
Family 4. Cyrtolitidae UMch and
Scofield.
Symmetrical, involute shells with two or
three volutions, barely in contact, sharply
angular dorsally ; aiierture not expanded, the
sinus V-shaped, never deep, sometimes want-
ing ; slit absent ; surface reticulate. Ordo-
vician and Silurian.
Gyrtolites Conrad (Fig. 846, A, B). Shell
carinated on the back and often on the
sides, giving a sub-quadrate cross section ; no
slit band.
Cyrtolitina Ulrich. Small thin shells
with a slit band.
Microceras Hall.
c
Pig. 845.
Tri/blUUum reticukttum Lindstrom. Silurian;
Gotland. .4, Internal, and li, external aspect
(after Lindstriim).
D
Fig. 846.
A, B, Cyrtolites ornatas Conrad. Ordovician of Boonville, New York, and Cincinnati, Ohio. C-E, SinuUes
rancellatus (Hall). Ordovician of Minnesota.
Family 5. Sinuitidae, novum. (Protmvarthiidae Ulr. and Scof.).
Symmetrical, involute shells with aperture not abruptly expanded ; outer lip and
lines of growth loith a broad or narrow dorsal sinus ; slit and band wanting.
Sinuites Koken (Protowarthia U. and S.) (Fig. 846, C-E). Aperture large with
outer lip bilobate ; dorsum convex ; umbilicus closed. Ordovician to Devonian.
Bucanella Meek. Dorsum of shell trilobate ; umbilicus large. Silurian.
Owenella Ulr. and Scof. Cambrian.
Family 6. Bucaniidae Ulrich and Scofield.
Symmetrical, involute shells with rather numerous lohorls merely in contact or
embracing slightly, all visible in the umbilicus ; aperture often expanded abruptly ; dorsal
slit band distinct with the slit long and narrow; surface with transverse lamellae or
lines usually crossed by short ribs. Ordovician to Devonian.
Bucania Hall (Fig. 847, A, B). Shell of three to five depressed volutions coiled
in a plane, generally with a wide umbilicus and with aperture never abruptly
expanded. Ordovician and Silurian.
Salpingostoma Roemer (Fig. 847, C). Aperture abruptly expanded, trumpet-like;
outer half of last whorl with a long, narrow slit closed some distance behind the
apertural expansion. Ordovician and Silurian.
Trematonotus HaU. Like Salpingostoma except that the slit band is replaced by
a row of perforations. Silurian and Devonian.
522
MOLLUSCA
PHYLUM VI
Conradella U. and S. {Phragmolites Conrad) (Fig. 847, D, E). Ordovician and
Silurian.
J -»
E
IV
,?
x^n
Pio. 847.
A, J!, Buamia hiiUl Ulr. and Scof. Ordovician ; Minnesota. C. S(tli>liiijostuma hndli (Wliitf.). Ordovician ;
Illinois. D, E, Conradella Jimbriata Ulr. and Scof. Ordovician ; Minnesota.
Tetranota U. and S. Like Bucania, Init with four doi'sal ridges. Ordovician
and Silurian.
Kokenia U. and S. Ordovician. Megalomphala Ulr. ; Oxydiscus Koken.
Ordovician to Devonian.
Family 7. Bellerophontidae M'Coy.
Symmetrical, involute sJiells ivith nqrldlij enlarginy wlturls, month expanded
laterally and ventrally but not dorsally ; umhilicus small or closed ; inner lip thickened,
outer with a short slit ; slit hand always present ; surface loith lines of growth only or
cancellated. Cambrian to Triassic.
The Bellerophontidae were classed by Montfort with the Cephalopoda ; by Deshayes,
on account of their resemblance to Atlanta, with the Heteropoda ; and by de Koninck
with the Aspidobranchiates. The
thick shells sometimes retain traces
of their original pigmentation. At
least 300 Paleozoic species have
l)een described.
Bellerophon Montfort (Fig. 848).
Distinguished by : (1), the absence
of .sculpture save the lines of
growth ; (2) the small or entirely
closed umbilicus ; (3) the moderate
expanse of the aperture ; (4) the
callosity on the inner lip, and (5)
a well developed slit band terminat-
ing in a slit in the outer lip. Or-
dovician to Permian, maximum in Carboniferous.
Patellosfimn Waagen. Like Bellerophon, but aperture greatly expanded. Devonian
and Carboniferous.
Fi(!. 848.
Bellerophon Hcarenux Leveille. Lower Carboniferous ;
Tournay, Belgium.
CLASS IV
GASTROPODA
523
Eitphemus M'Coy (Fig. 849). Differs from BeUerophon in the revolving folds of
the inner lip. Carl)onifei'ous.
Bucanopds Ulrich. Ordovician to Permian.
JVarthia, Mogidia, and Stachella Waagen. Carboniferous.
Pig. 849.
E^iphemus nrii Fleming. Lower
Ciirboniferous : Bdiiibiugli.
Fig. 850.
Carinaropsis cymhula Hall.
Ordovician ; Kentucky.
Family 8. Oarinaropsidae Ulrich and Scofield.
Symmetrical, almost patelliform shells of not more than two volutions with greatly
expanded aperture luithin which is a broad concave septum.
Garinaropsis Hall (Phragmostoma Hall, non Waagen) (Fig. 850). Dorsum carinate ;
slit band occasionally distinguishable. Ordovician and Silurian.
Suborder B. RHIPIDOGLOSSA Troschel.
{Scutibranchiata, Cuvier ; Zygobranchia and Diotocardia von Ihering.)
Symmetrical and limpet-like or with spiral shells. Gills plume-like, two and sym-
metrical, or single. Eadula with several large plates or teeth in the median portion, and
excessively numerotis, crowded, narrow, hook-shaped teeth. Operculum often present.
The Rhipidoglossa comj^rise both air-breathing and aquatic forms, and are divisible
into two series : Zygobranchia, in which two gills are developed, and the shell is
generally perforated at the apex or has a slit in the outer lip • and Anisobranchia,
with a single gill and generally unslit shell.
Family 1. Haliotidae Fleming.
Shell flattened, auriform, with wide aperture, and no operculum. Interior nacreotds,
with a row of perforations on the left outer margin. Marine. Cretaceous to Recent.
Haliotis Linn. This, the solitary genus, occurs very rarely fossil except in the
Quaternary.
Family 2. Pleurotomariidae d'Orbigny.
Shell spiral, sub-spherical, turbinate, conic, turreted or Planorboid, nacreous inter-
Fin. 851.
A, Fleurotoniaria {Ra}>histomelia) radians Wissni. Keuper ; St. Cassian, Tyrol. B, Pleurotomaria j
(firyptaenia) yolita Gqldf. Lower Lias ; GCippiugen, Wurteiuberg.
524
MOLLUSCA
PHYLUM VI
nally. Outer lip with a slit, from which a slit-hand {the anal fasciole) extends bachvard,
traversing all the ivhorls. Tlie slit sometimes replaced hy one or more perforations.
Operculum horny. Cambrian to Eecent.
Pleurotomaria Sowb. (Figs. 851-853). Shell broadly conical or turbinate; spire
sometimes liigli, in other cases depressed ; nmbilicus present or absent. Outer lip
with slit ; growth-lines strongly recurved, meeting in the slit-band. Silurian to
Recent. Four living and several hundred fossil species known. Rare in the late
Tertiary.
Subgenera : Ptycliom]}halus Agassiz ; Alourlonia, Worthcnia, Aynesia de Koninck ;
Gosscletina, Ivania (Baylea de Kon.) Bayle ; Baphistomella (Fig. 851, A), Zygitcs, Laubclla,
Piu. S52.
A, Pleurotomaria ftitorguaia Deslongchamps. Middle Lias ; May, Calvados. B, F. suhscalaris
Deslongchamps. Lower Oolite ; Bayeux, Calvados, i/o.
Fig. 863.
l'U:urotomaria(Lc2itomaria)macroin2)lialla Zittel. Tithonian ; Stramberg, Moravia.
Stuorella, Schizodiscus Kittl ; Brilunella Kayser ; Hespericlla Holzapfel ; Cryptacnia (Fig,
851, B), Leptomaria Deslongchamps (Fig. 853), etc.
Porcellia Leveille (Leveilleia Newton) (Fig. 854). Shell
discoidal, flat, widely umbilicate, nearly symmetrical, and
all but the first few whorls coiled in the same plane. Outer
lip sharp, with long slit. Slit-band prominent, traversing
the central portion of the whorls. Devonian and Carboni-
ferous.
Pjj, gr;^ Kohenella Kittl. Very flat, discoidal, and only slightly
PorceHiapwmsi LevoiUe. Car- asymmetrical, with a broad slit -band. Trias. K. fischeri
boniferous ; Tournay, Belgium. (Hoernes).
CLASS rv
GASTROPODA
525
Polytremaria de Kon. Shell turbinate, with band replaced by a row of perfora-
tions, of which the jjosterior ones are successively closed. Carboniferous.
Ditremaria d'Orb. (Fig. 855). Two oval perforations connected by a slit are
2)resent behind the outer lip ; base with an umbilical callus. Jura.
Trochotoma Deslongch. Shell turbin- a b c
ate, with conical base. A slit closed at
either end is present behind the outer
lip, and corresponding to it is a slit-band.
Trias and Jura.
Fl(,i. 855.
Ditremaria granuUfera Zittel. Upper Tithonian ;
Stramberg, Moravia.
Fig. 856.
A, Murchisonia bilineata d'Arch. and Vern.
Devonian ; Paffrath, near Cologne. B, M. hlinni
Klipstein. Trias ; St. Ca.ssian, Tyrol. C, M.
subsulcata de Kon. Lower Carboniferous; Tour-
nay, Belgium. Last two whorls, 2/j.
Schizocjonium Koken ; Temnotroins Laube ; Gantantostoma Sandb. Devonian.
Murchisonia d'Arch and Vern. (Fig. 856). Shell turreted, with numerous smooth
or ornamented whorls Outer lip with a slit, and corresponding to it a slit-band.
Cambrian to Trias. Maximum distribution in Devonian and Carboniferous.
Loi^liospira Whitf. (Fig. 857, A, B). Shell with more or less elevated spire ;
whorls angular on the , periphery and bearing from one to five distinct carinae.
Ordovieian to Devonian.
Hormotoma Salter (Fig. 857, D). Elongate, beaded, practically imperforate ; outer
lip with broad, deep notch. Ordovieian and Silurian.
Liospira Ulr. and Scof. Shell lenticular with aperture deeply notched and
band scarcely distinguishable. Ordovieian and Silurian.
Schizolopha and Turritoma Ulrich. Ordovieian and Silurian. Seelya, Plethospira
A n c D
Pig. 857.
A, B, Loplwspira sumnerensis (Safford). Ovdovician ; Tenne.ssee. C, Trepospira spherulata (Conrad). Coal
Measures ; Illinois. D, Hormotoma salteri Ulrich. Ordovieian ; Kentucky.
and Euconia Ulrich. Ordovieian. Coelocauhis CEhlert ; Clathrospira Ulr. and Scof. ;
Ectomaria Koken [Solenospira Ulr. and Scof). Ordovieian and Silurian. Bemhexia
(Ehlert ; Trepospira Ulr. and Scof (Fig. 857, G). Devonian and Carboniferous.
Family 3. Fissurellidae Risso.
Shell symmetrical, cap- or limpet-shaped, non-nacreous, ivithout operculum. Apex
erect or pointing hachward, often recurved, perforated. Anterior margin often ivith a
fissure; young shell with a, spiral protoconch. Marine; shore forms. Carboniferous to
Recent.
526
MOLLUSCA
PHYLUM VI
Of the three subfamilies into which this group is divided, the Fissxirellinae are
known only in the recent fauna. Fissurellklinae occur in the Pliocene ; all the
earlier forms are Emarginulinue.
Fissurella Brug. Shell conical, oval, with an oval apical orifice
bounded inside by an entire callus. Recent. The numerous fossil
species referred to this genus belong to Fissnridea.
Fissurellidea d'Orb. ; Piqnllaea Gray ; Megatebennus and Luca-
■pinella Pilsbry ; Macroschisma Swains. These are all Recent genera,
with the apical orifice very large.
Luccqmia Gray. Like Fissurella, but with large apical orifice
and finely crenate jjeriphery. Pliocene and Recent.
Fissuridea Swains. {Gly])his Carp. ; Fissurella auct.) (Fig. 858).
Fio. S5S.
Griind, Hungary.
truncate callus.
Fissuridea italica . „^ ^ . , . „ ,
" ^ iinsary"*' ' Sliell conical, oval, with apex in advance of the middle, giving
place to a perforation which is bounded inside by a posteriorly
Carboniferous (?) to Recent ; very abundant in the Tertiary.
Puncturella Lowe. Shell conical, with a perforation at or in front of the post-
median aitex, liehind which there is a shelf within the cavity. Eocene to Recent.
Emarginula Lam. (Figs. 859, 860). Conical or cap-shaped, with persistent post-
c
A B
Fig. 850.
Emarginula schlotheimi
Bronn. Oligocene; Wein-
heim, near Alzey, Baden.
Fig. 860.
Emarginula muensteri Pictet.
Keuper ; St. Cassian, Tyrol.
A, li. Natural size. C, Bnlaraed.
Rimiila goldfussi (Roem).
Coral-Rag ; Holieneggelsen,
Hanover. A, Natural size.
B, Enlarged.
median apex, and a slit in the front margin of the shell. Surface cancellated.
Carboniferous to Recent.
Bimula Defr. (Fig. 861). Like the last, but slit replaced by a closed hole on the
anterior slojje. Lias to Recent.
Suhemarginula Blainv. Like Emarginula, but slit short or wanting, and no slit-
band. Eocene to Recent.
Scutiis Montf. (Parmophoriis Blainv.). Shell dej^ressed, oblong, without fissure,
slit, or slit-band ; miLscle impression near the edge. Eocene to Recent.
The families Phenacolepadidae, with the single genus Phenacolepas Pils. {ScutelKna
Gray), Cocculinidae and Addisoniidae are recent groups allied to the Fissurellidae.
Family 4. Euomphalidae de Koninck.
Shell depressed conical to discoidal, spirally coiled, more or less deeply and widely
umhilicate. JFhorls sometimes in a loose spdral, smooth or angular ; the earlier w]iorls
frequently separated off by partitions. Outer lip tisually with a shallow indentation.
Operculum calcareous. Cambrian to Cretaceous.
The Euomphalidae belong primarily to the Paleozoic era. They have been
variously associated with the Trochidae, Turbinidae, Littorinidae and Solariidae. The
shells bear a strong resemblance to those of the last-named group, but in Solarium the
embryonic apex is sinistral, whereas in tlic Euomphalidae it is dextral. Opercula are
known with certainty in only a few gcmeivi, such as Maclurea. De Koninck surmised
that the deeply excavated, slipj)er-.sliaped opei'cula from the Carl>oniferous, described
originally as Gcdceola dumontiana, are referable to Euomphalus.
CLASS IV
GASTEOPODA
)27
Stra'parollina Billings. Cambrian. Ophileta Vanuxem. Cambrian to Silurian.
Maclurea Lcseuenr ; Maclurina Ulr. and Scof. Ordovician and Silurian.
Platyschisiiut M'Coy. Thin - shelled, depressed
conical, smooth. Umbilicus relatively narrow ; outer
lip with broad sinus. Silurian to Carboniferous. P.
helicoides Sowb. Carboniferous.
StraparoUus Montf. (Fig. 862). Turbinate to
discoidal, with broad umbilicus. Whorls smooth or
with fine transverse striae. Silurian to Jura ; especially
abundant in Devonian and Carboniferous.
Phanerotinus Sowb. Like the last, except that the
whorls form an open spiral. Carboniferous.
Euomphalus Sowb. {Pleuronotus Hall ; Schizostoma
Bronn) (Fig. 863). Depressed conical to discoidal, with wide umbilicus. Spire
flattened or even concave sui^eriorly ; whorls angular, the edges sometimes set with
nodes (Phymatifer de Kon.). Outer lip with emargination at the ujiper angle. Silu-
rian to Trias ; maximum in Carboniferous.
A B
Fui. 862.
StraparoUus dionysii Montf.
Carboniferous ; Vise, Belgium.
Fio. 863.
Euomphalus catUlus (Sowb.). Carboniferous ; Kiklare, Ii'eland.
-4, Superior, and B, Inferior aspect.
Fio. 864.
Discohclix orhis Renss. Middle Lias :
Hiuter-Schafberg, Austria.
Subgenera : Omplmlocirrus de Ryckholt. Devonian and Carboniferou.s. Cocluccnlrus
Zittel. Trias.
Discohelix Dunk. (Fig. 864). Flat, discoidal ; upper side flat or slightly concave,
the lower widely umlnlicate. Whorls rectangular, with sharp edges. Trias to
Oligocene.
Ecryliompliahhs Portlock ; Eccyliopterus Remele ; Helicotoma Salter. Ordovician
and Silurian.
Family 5. Raphistomidae Ulrich and Scofield.
Comprising shells intermediate hetioeen the Euoviphalidae and Pleurotoviariidae, and
regarded as ancestral. to these families and the Trochidae.
Raphistoma Hall. Shell depressed or completely flattened ; whorls angular above ;
umbilicus moderately broad ; outer lip with short notch on the keel. Ordovician
and Silurian.
Enomphalopterus Roemer. Distinguished by its more rounded volutions and
excessively developed carinae. Silurian.
Scalites Emmons, non Conrad. Turbinate, spire only moderately high and
acuminate ; whorls flattened superiorly, rising steplike one above the other, sharply
angular at the periphery, produced below. Body whorl very large, smooth ; aperture
528
MOLLUSCA
PHYLUM VI
sub-triangiilar, faintly notched ; no umbilicus. Ordovician (Cliazy), and according to
Laube, also Triassic. Tyjie, S. angulahts Emmons.
Raphistomina Ulr. and Scof. Ordovician.
Family 6. Stomatiidae Gray.
Shell depressed, composed of a few very rapidly widening whorls ; nacreous internally ;
aperture large.
With the excej)tion of Stomatia Helb. and Stomatella Lamarck, a few rare repre-
sentatives of which are known as early as the Cretaceous (perhaps also Jurassic), this
family belongs to the Recent period.
Fig. 865.
Omphalotrochus discus Sowb. Silurian ;
Dudley, England, i/j (aftpr Nicholson).
Family 7. Turbinidae Adams.
Shell turhinate, discoidal or turreted, nacreous internally. Aperture rounded or
oval ; inner lipi smooth or with callus, the outer lip never reflected. Operculum cal-
careous, very thick, convex externally. Ordovician to Recent.
The extremely abundant Recent Turbinidae are distinguished jDrincipally by
characters of the operculum ;
but inasmuch as this is
known in but few of the
fossil forms, the precise deter-
mination of the latter is
iLSually uncertain. It is
customary, therefore, to groujj
under the general head of
Turho such fossil turbinate
Fi>'- stiii- shells with a sub - circular
Omphalotrochus glohosus aperture as are not speciallv
(Schloth.). Silurian; Got- ,. . . -, t ■, ^ , '^
land. Opert-uinm pre- distinguished by some other
.served in place (after characters.
Lindstrdiii).
Omphalotrochus Meek
(Polytropis de Kon. ;
Oriostoma Lindstrijm,
non Munier-Chalm.)
(Figs. 865, 866). Dis-
coidal or depressed
conical, widely umbi-
licate. Whorls round,
ornamented with
raised longitudinal
keels. Operculum extremely thick, fiat internally, conical externally, multispiral.
Ordovician to Carboniferous ; especially abundant in Silurian.
Astralium Link (Figs. 867, 868). Turbinate; whorls rough, often spinose, and
usually keeled. Aperture depressed, witli disconnected margin. Base more or less
flattened ; ojierculum calcareous, thick, flat internally, spirally coiled, and with very
eccentric protoconch. Trias to Recent.
Subgenera: Bolma Risso (Fig. 867); Pachypoma, Lithopoma, Uvanilla (Fig. 868), Guil-
fordia Gray ; Calcar Montfort, etc.
Turho Linn. (Fig. 869). Turliinatt; to concial ; aperture nearly circular. Oper-
culum calcareous, thick, flat internally, externally convex, multispiral, with sub-central
nucleus. Silurian (?) to Recent.
Fici. 8(57.
Astrnlium (Tlolma) rugo.'^um Linn. Pliocene
Pienza, Tuscany. Shell and operculum.
Fio. S6S.
AstraUutn {UfanUhi) ilamon Laul)e.
Keuper ; St. Cassian, Tyrol.
CLASS IV
GASTROPODA
529
Subgenera : Sarmatims, Ninclla (Fig. 869), Modclia, and Callopoma Gray ; Senedus
Hiuiiphr. ; Batilhis Schum, , etc.
Collonia Gray (Fig. 870). Like Turbo, but operculum with a thin calcareous layer
disposed in a spiral rib. Eocene to Recent.
Family 8. Phasianellidae Troschel.
Shell elongated, oval, thin, smooth, lustrous, porcellanous, not
nacreous internally,
ivithout umhilicus. Body
whorl large, with oval
aperture. Operculum
calcareous, convex exter-
nally. Devonian to
Recent.
Phasianella Lam.
{Phasianus Montf.) (Fig.
871). With the.jchar-
acters of the family.
Cretaceous to Recent : Turho (Ninclla) parkinsoni
, T -r. 1 • Bast. Oligocene ; Uax, near
perJiaps also raieOZOlC. Bordeaux.
Fig. sod.
Fig. STO.
Collonia'- modcsta
Fuchs. Oligocene ;
Monte Grunii, near
Castel Gomberto,
Italy.
Fig. 871.
Phasianella gosauiai
Zeki'li. Tmonian;Qosau,
Austria.
Family 9. Delphinulidae Fischer.
Shell turhinate or discoidal, usually thick, nacreous internally, and ornamented
externally with spines, ribs or folds. Aperture circular, peristome entire; outer lip
usually expanded or thickened. Operculum horny, often strengthened by a thin calcareous
outer layer. Silurian to Recent.
Graspedostoma Lindstrom. Globose, narrowly umbilicate, Avith short spire, and
large transversely striated or cancellated body whorl. Inner lip with an alar process
at the end of the columella. Silurian. G. elegantulum Lindstrom.
Grossostoma Morr. and Lye. (Fig. 872). Depressed turbinate, smooth, without
Fio. S7-2.
Crossostoma reflexi-
lahrnm, (d'Orb.).
Middle Lias ; May,
Calvados.
FlG. SV3.
Liotia (jcrvillci
(Deshayes). Calcaire
Grossier ; Haute-
ville, near Valogne,
France.
Fio. 874.
Delphinula segregata
Heb. et Desl. Callo-
vian ; Montreuil - Bel-
lay, Maine-et-Loire.
Fig. 875.
Delphinula scohina
(Brongniart). Oligocene ;
Gaas, near Dax, France.
umbilicus. Spire short, aperture round, narrowed by a callus. Outer lip somewhat
reflexed. Trias and Jura.
Liotia Gray (Fig. 873). Depressed turbinate, with transverse swellings. Aperture
thickened by a callous rim. Jura to Recent.
Delfhinula Lam. {Angaria Bolt.) (Figs. 874, 875). Depressed turbinate, um-
bilicate. Whorls scaly, spinous or spirally ornamented. Aperture circular, lip
without thickening.
VOL. I
Trias to Recent.
2 M
530
MOLLUSCA
PHYLUM VI
Family 10. Trochonematidae Zittel.
Shell pyramidal, turbinate or discoidal, dextral or sinistral, with internal nacreous
layer. JVIiorls convex, with one or more longitudinal keels, and slightly iindulating
transverse striae or ribs. Aperture rounded, sometimes ivith faint notch. Operculum
unknown, presumably horny. Marine. Cambrian to Cretaceous.
This extinct group is very abundant in the Paleozoic, and notably so in Jurassic
rocks. The shells, as a rule, are highly ornamented, and have been associated by some
with the Littorinidae, by others with the Turbinidae or Purpurinidae. They form
a distinct family, wliich is best placed in the neighbourhood of the Turbinidae and
Trochidae.
Trochonema Salter. Pyramidal to turbinate, deeply umbilicate, longitudinally
keeled and transversely striated. Aperture round ; the umbilicus surrounded by a
keel. Cambrian to Silurian.
Eunema Salter (Fig. 876). Pyramidal, with acute, elongate spire, and no umbilicus.
Whorls with two or more spiral keels, and strong transverse striae. Aperture oval,
slightly notched anteriorly. Ordovician to Devonian.
Fig. 870.
Eunema strigilata Sal-
ter. Ordovician ; Pau-
quette Falls, Canada.
Fio. 877.
Cyclone.ma bilix Conrad.
Ordovician ; Cincinnati,
Ohio.
Fig. 878.
Amherleya capitanea
Miinst. Upper Lia.s ; La
Verpilliere, near Lyons,
France.
Cyclonema Hall (Fig. 877). Turbinate, whorls inflated and ornamented with fine
spiral striae ; apertui-e rounded, peristome discontinuous. Ordovician to Devonian.
Strophostylus and Holupea Hall ; Gyronema Ulrich. Ordovician and Silurian.
Dyeria Ulrich. Ordovician. Biicanospira, Ulrich. Silurian.
Amberleyn Morr. and Lye. (Eucyclus Deslongch.) (Fig. 878). Turbinate to
Fig. 879.
Pfntyar/ra impressa
(S('hafhautl). Lower
Lias ; Hoclifellen,
Bavaria.
Fic. SSO.
Cirrus nodosiis Sowh. Lower Oolite ; Yeovil, England.
pyramidal, with deep sutures, and no umlnlicus. Sjiiral keels usually nodose or sjjiny,
CLASS IV
GASTROPODA
531
and crossed by strong transverse striae, which are more numerous in the lower portion
of the whorls than in the iipper. Aperture rounded, sometimes with a shallow notch.
Trias to Cretaceous ; common in all divisions of the Jura.
Oncospira Zitt. Pyramidal, spirally ribbed, with one or two transverse swellings
on each whorl, disposed continuously along the spire. Jura.
Hanmsina Gemm. Sinistral, with nodose longitudinal keels, and no umbilicus.
Lias.
Platyacra v. Ammon (Fig. 8Y9). Like the last, but with flattened apex, and the
earlier whorls discoidal. Lias.
Girriis Sowb. (Scacvola Gemm.) (Fig. 880). Sinistral, turbinate shells, deejjly
and widely umbilicate. Spire acuminate ; whorls spirally keeled and striated, and
with strong transverse ribs.
Trias to Middle Jura.
Family 11. Trochidae Adams.
Shell conical, turbinate or ptjramidal, nacreous internally. Aperture trapezoidal or
sitb-circidar, peristome disconnected, inner lip often hearing a tooth. Base more or less
flattened ; operculum thin, horny. Ordovician to Recent.
Precise determination of the numerous fossil Trochidae is not less difficult than
that of the Turbinidae. Paleozoic and Mesozoic forms in many cases do not harmonise
with recent genera, but represent rather col-
lective types, in which characters now distri-
buted amongst several genera or even families
are united. Shells incapable of more accurate
determination have been commonly assigned to
the genus Trochus. Among the more ancient
true Trochidae may be mentioned the following :
the Trochus species described by Lindstrom
from the Silurian of Gotland ; also Flemingia
and Glyptobasis de Koninck, and Microdoma
Meek and Worthen, from the Carboniferous ;
Turbina (Fig. 881) and Turbonellina de
-- . , . J. ii. r-i 1 -i- i Mtinst. Keuper;St.
Koninck, ranging from the Carbomterous to cassian, Tyrol.
the Trias.
Trochus Linn. (Fig. 882). Shell conical or pyramidal ; whorls slightly convex or
flat ; base angular at the periphery. Inner lip often truncated anteriorly, thickened
or with teeth. Silurian to Recent.
Subgenera : Tectus Montf. (Fig. 882) ; Polydonta Schum. ; Clanculus Montf., etc.
Monodonta Lam. (Figs. 883, 884). Turbinate, with nearly round aperture, the
Fig. SSI.
Turbiiui spiralis
Fio. 882.
Trnelius (Tectus) luca-
sanus Biongt. Oligo-
cene ; Castel Gomberto
near Vicenza.
Fig. SS3.
Monodonta nodosa Mtinst.
Keuper ; St. Cassian, Tyrol.
Fig. 884.
Monodonta {Oxystcle) patula
Brocchi. Miocene ; Steina-
brunn, near Vienna.
Fig. 885.
Gibhula picta
Bichwald. Mio-
cene ; Wiesen,
near Vienna.
Fig. 8Si5.
Gibbula hrocchii
Mayer. Pliocene ;
Montopoli, Tuscany.
columella ending below in a tooth. Trias to Recent. In the subgenera Osilinus and
Oxystele Phil., the tooth is wanting.
532
MOLLUSCA
PHYLUM VI
Gibbula Risso (Figs. 885, 886). Turbinate or low conical, umbilicate, and with
rounded aperture. Tertiary and Recent.
Fig. 887.
Calliostoyna semi-
punctatum Miinst.
Keuper ; St. Cas-
sian, Tyrol. 2/j.
Fic. 8S8.
Callinstoma aequalis
Bnv. Coral-Rag ; St.
Mihiel, Meuse.
Fig. 889.
LeviHeUa conica (d'Orb.).
Middle Lias ; May, Cal-
vados.
Fig. 890.
Solariella peregrina
(Libassi). Pliocene ; Or-
ciano, Tuscany.
Margarites margarifula
Mer. Oligocene ; Weinlieim,
near Alzey, Baden.
Galliostoma Swains. (Ziziphinus Gray) (Figs. 887, 888). Conical, with j^eripheral
keel and flattened base. Trias to Recent.
Other genera are Cantharidus Montfort ; Lewisiella
Stol. (Fig. 889); Tegnla Lesson; Solariella Wood
(Fig. 890) ; Margarites Leach (Fig. 891) ; Danilia Brus.
(Fig. 892) ; Gamitia Gray, and many others. Most of
tliese have a more or less extensive Tertiary history.
Family 12. Umboniidae Adams.
Fir; 802
Shell small, usually depressed discoidal, smooth and
Danilia clathrata(Eta,l\.). Coral-Raff: 7 , -.i /. • i ± • 7 -,7 ,
Vaifin, Ain. 2/j. lustrous, or loitn jine spiral striae, ana without nacreous
layer. Outer lip sharp, peristome discontinuous. Um-
bilicus often concealed by a callus; operculum horny. Silurian to Recent.
Allied to the Recent genera Umbonium Link (Botella Lam.), Tsanda Adams,
Fig. 893.
Chryi^ontoma
ac)mm(d'Orb.).
Middle Jura ;
Balin, near
Cracow.
Fig. 894.
Teinostmna rotellaa-
forniis Desk. Calcaire
Grossier ; Grignon,
near Paris.
Fig. 895.
Hdicocryptiis 2'msillus (Roem.). Coral-
Rag ; Lindeuer Berg, near Hannover.
iFiG. 89(3.
Adeorhis tricostatus
Desh. Middle Eocene
(Auversien) ; Auvers,
Seine-et-Oise.
etc., are a number of fossil forms, such as Pycnomphalus Lindstriira, from the
Silurian and Devonian ; Anomphalus Meek and Worthen, and Botellina de Koninck,
from the Carboniferous ; Ghrysostoma Swaiuson (Fig. 893), from the Jura, and otliers,
Avhich are probably the ancestors of the Umboniidae.
Whether the genera Teinostmna (Fig. 894) and Vitrinella Adams, together with
their fossil allies from the Carboniferous onward, are rightly assigned to this group, is
doubtful. Helicocryptus d'Orb. (Fig. 895), from the Jura and Cretaceous, is similar to
Vitrinella. Gyclostrema Marryat, comprisiug small, lustrous shells, and the spirally
striated ones known as Adeorbis S. Woodw. (Fig. 896), present some resemblances to
the Umboniidae ; but, according to Fischer, they form separate families. All of these
genera have fossil representatives in the Tertiary.
CLA8S IV
GASTROPODA
533
^
Family 13. Neritopsidae Fischer.
Shell oval to semi-globose, with short, sometimes laterally twisted spire, and without
■mnbilicus vr nacreous layer. Body ivhorl very large; aperture oval or semicircular,
Inner lip callous, curved and occasionally notched. Operculum calca-
reous, not spiral, with sub-central nucleus, and internally with callous
cohimellar margin, vAich forms a broad, angular or rounded process in
the middle. Devonian to Recent.
The Neritopsidae are distinguished from the closely related
Neritidae, principally by the totally ditterent, non-spiral operculum,
and by the fact that the internal partitions are not resorbed, as in
the latter family. Detached opercula have been described under the
names of Peltairon, Scaphanidia, Cyclidia and Ehynchidia.
Naticopsis M'Coy {Neritomopsis Waagen) (Figs. 897-899). Shell oval to globose,
smooth or transversely striated. Aperture oval ; inner lip flattened, somewhat
Pif!. S97.
Naticopsis mandel-
sluhi (Klipstein).
Keuper ; St. Cas-
sian, Tyrol.
Fig. S9S.
A, Naticopsis ampUata Phil. Carboniferous ; Vise, Belgium.
B, Operculum of N. ylanispini Pliil., from same locality (after de
Koniuck).
Fii;. siiy.
Naticopsis lemniscata Hoernes. Trias ;
Esino, Lombardy. Original coloration
preserved.
callous, curved and sometimes transversely striated. Sparse in Devonian, but very
common in Carboniferous and Trias.
Hologyra Koken. Semi-globose, smooth, with faintly impressed sutures. Spire
short, laterally situated, not resorbed internally. Inner lip flattened, callous, covering
the umbilicits, and with sharj) margin. Abundant in the Trias. Some species, such
as H. neritacea (Mtlnst.), have the original colouring admirably preserved.
Marmolatella Kittl. Auriform to cap-shaped, with very short, incurved and
almost marginal sjaire. Last whorl much distended ; inner lip callous, broad,
arched. Trias. M. stomatia (Stopp.), M. telleri (Kittl).
Natiria de Koninck. Silurian to Carboniferous. Palaeonarica Kittl {Pseudo-
fossarus Koken).
Naticella Mitnst. (Fig. 900). Thin-shelled, depressed, with straight spire, and
large, transversely ribbed body whorl. Trias.
NaticrUa costata Miinster.
Uppei- Trias ; Wengen, South-
ern Tyiol.
A, Ncritopsis moniliformis Grat.
Miocime ; Lapugy, Transylvania. I!,
N. spiiwsa'Hih. et Deslong. Callovian ;
Montreuil-Bellay, Maine-et-Loire.
Pi(i. 902.
Operculum of Neritopsis radula.
Recent; New Caledonia. External
and internal aspects (after Crosse).
Vi-
534
MOLLUSCA
PHYLUM VI
Platychilina Koken {Fossariopsis Laube). Spire depressed, straight ; last whorl
large, surface rough, tuberculose. Inner lip even, with simple margin. Trias. P.
pustulosus (Miinst.).
Delphimdopsis Laube. Like the last, but spire composed of loosely connected
whorls. Sutures deep. Body whorl with nodose longitudinal keels. Inner lip even,
with sharp margin. Trias. D. binodosa (Miinst.).
Neritoiosis Grat. (Figs. 901, 902). Spire depressed, Ijody whorl very large.
Surface Avith sjjiral and transverse ribs or nodes, often cancellated. Inner lip
thickened, with broad, angular emargination in the middle. Trias to Kecent.
Family 14. Neritidae Lamarck.
Shell semi-globose, without 'umbilicus or nacreous layer. Spire very short, someivhat
lateral; whorls rctpidly broadening, the last very large, and earlier ones resorbed
internally. Aperture semicircular ; margin of the flattened or calloused inner lip often
with teeth. Operculum calcareous, with a lateral spiral nucleus, and a process for
■muscle attachment on the inner side. Trias to Recent.
The Neritidae are partly marine, and partly fresh-water inhabitants. The former
live usually in the vicinity of the coast, the latter often in brackish water. Since the
earlier whorls are internally resorbed, moulds of the interior reveal no trace of the spire.
This character, together with the form of the operculum, serves to distinguish the
family from the Naticopsidae, from which both it and the terrestrial Helicinidae
are probably descended. Fossil forms not infrequently retain traces of their former
coloration.
Neritaria Koken {Protonerita Kittl). Spire acuminate, suture deep, surface
smootli. Outer lip sharj) ; inner lip callous, flattened. Resorption of the inner walls
incomplete. Trias.
Nerita Linn. (Fig. 903). Thick, ovoid or semi-globose, imperforate. Surface
smooth or with sjjiral ribs. Inner lip callous, flattened, with a straight, often
denticulate border. Operculum sub-spiral. Trias (?) to Recent.
(?) Oncochilus Petho (Fig. 904). Smooth ; inner liji arched, callous, bearing two or
three teeth on the margin or smooth ; outer lip sharp. Trias and Jura.
Lissochilus Petho (Fig. 905) ; Neritodomus Morr. and Lye. ; Neritoma Morris.
Jura. Otostoma d'Ai'ch. ; Dejanirco Stol. Cretaceous.
Velates Montf. (Fig. 906). Depressed conical, only the curved apex of the sjjire
A n c
Flu. 903.
A, Nerita laffoniMeriiLJi. Citharella Limestone ; Epfen-
hofen, near Sciiaflliaiisen, Switz(>rland. B, N. (jrannlosa
Desh. Eocene (Sables Moyens) ; Auvers, near Paris. C,
Operculum of a recent Nerita.
Fii!. 904.
Oncochilus chronKiticus Zittel. Upper
Tithonian ; Stramberg, Moravia.
visible. Last whorl very large. Inner lip convex or straight, with denticulate margin.
Abundant in the European Eocene ; sometimes attaining a size of 10 or 12 cm.
Neritina Lam. (Fig. 907). Small, semi-globose, lustrous, smootli or spiny, mostly
brilliantly coloured. Inner lip flattened, with sharp or finely toothed margin ; outer
lip sharp. Inhabits brackish or fresh water. Abundant in Tertiary and Recent. The
sujjposed Mesozoic forms belong i)rincipally to Nerita.
CLASS IV ' GASTROPODA 535
Pileolus Sowh. (Fig. 908). Small, cup-shaped to depressed conical, ovoid or round.
0
Fig. 905.
Lissochilus sigaretinus Buv.
Coral-Rag ; Hoheneggelsen, Han-
nover.
Fio. DOT.
Neritina gratcloupcma Per.
Miocene ; Haufelburg, near Gunz-
burg.
Fig. 90S.
Pileolus plicahis Sowb. Bathon-
iaii ; Langrune, Calvados. 3/i.
Velates sclimiilelianus Chem. Lower Eocene
(Londinlen) ; Cuise-Lamothe, Oise.
Apex slightly curved backwards ; only the last Avhorl visible,
inner lip broad, callous. Jura to Eocene.
Aperture semicircular;
Order 2. CTENOBRANCHIATA Schweigger.
{Pectinihranchia Cuvier ; Azygohranchia von Ihering ; Monotocardia Bouvier.)
Bight cervical gill fectinate, very large, and usually transposed to the left side, Giving
to torsion of the body ; the left gill atrophied. Heart with hut one a,uricle. Eadula
small, variously constructed, hut usually armed loith fev} teeth in a transverse series.
Shell coiled in a more or less elevated spiral, rarely cup- or cap-shaped.
The Ctenobranchiata constitute the largest group of the Streptoneura. They are
for the most part marine, but some are terrestrial, and some inhabit fresh water.
Beginning in the Silurian, they attain their maximum distribution in the Mesozoic,
Tertiary and Recent periods. A division into two groups — Holostomata and Siphono-
stomata — according to the nature of the aperture, has been attempted ; but this is
iTunatural, since it emphasises a shell character which is unaccomj^anied by any
anatomical differences. Classifications based upon the structure of the radula, such as
have been j)roposed by Troschel, and more recently by Bouvier, are valueless in
Paleontology. Here it will be sufficient to recognise two suborders primarily :
Platypoda, in which the foot is typically developed ; and Heteropoda, in which it is
modified into a fin.
Suborder A. HETEROPODA Lamarck.
(Nucleohranchiata Blainville.)
To the Heteropoda belong naked or shell-covered, free-swimming and pelagic
marine Mollusks, with distinct head and highly developed sense organs. Heart, gills,
536
MOLLUSCA
PHYLUM VI
reproductive organs and nervous system agree with the corresponding organs of the
Ctenobranchiates ; the radula resembles that of the Taenioglossa. They differ con-
siderably, however, from the Prosobranchiates, since the foot is modified into a sort of
vertical fin, and imparts to them a peculiar appearance. They
rise usually toward evening in great swarms to the surface of
the ocean, where they hover about with a very rapid motion,
swimming in an inverted position, with the dorsal side down,
and the foot uppermost. They are exceedingly delicate, often
transparent organisms. The body may be either entirely
naked or provided with a very thin, light shell.
Two Recent genera have been found also in early Tertiary
deposits. Of these Carinaria Lamarck, has a keeled, cap-shaped,
glassy shell ; while in Atlanta Lesson (Fig. 909), the delicate
shell is coiled spirally in a single plane, and the aperture is provided with a slit.
Owing to a similarity in coiling of Atlanta and Oxy gyrus to that of the Paleozoic
Bellerophontidae, a relationship between the two lias been suggested. The latter
forms are distinguished by their heavier, thicker shells, but are very pi'obably related
to Emarginula and its allies.
Pig. 909.
Atlanta peronii Lesueur.
Recent : Atlantic Ocean.
Suborder B. PLATYPODA Lamarck.
Superfamily 1. GYMNOGLOSSA Gray.
Mostly holostomate forms, in tvhich the radula is usually unarmed through degenera-
tion. TJic smaller forms frequently parasitic or commensal.
Family 1. Eulimidae Fischer.
Small, iiolished, elongate-conic shells, with ovate aper-
tures; the axis often distorted, protoconch dextral. Trias
to Recent.
Eulima Risso {Melanella Bowdich) (Fig. 910). Tur-
reted, smooth, lustrous, without umbilicus. Trias to
Recent.
Niso Risso (Fig. 911). Like the last, but with deep
I
umbilicus reaching to the apex.
Trias to Recent.
Fin. 910.
A, Eutlinasuh-
ulata Don. Plio-
cene ; Coroncina,
Tnseany. B, li.
fioJlta ' (Linn.).
Miocene; Niedei-
k'is, Moravia.
Fio. 911.
Niso nhu'nica
Risso. Plio-
cfne ; Monte
Mario, near
Koine.
Family 2. Pyramidellidae Gray.
Shell turreted to elongate-oval. Aperture oval, an-
teriorly rounded, or angular ; outer lip sharp. Operculum
horny, .spiral. Marine. Cambrian to Recent.
The protoconch consists of several whorls, and in Paleozoic and Mesozoic forms is
coiled in the same direction as the remainder of the shell. But in the younger and
more typical genera it is heterostrophic, distinctly separated fi-om the rest of the
shell, and often stands at an angle with the adult spire. It is questionable whether
forms older than the Cenozoic can be retained in this family ; Fischer places most of
them in a new family, entitled Pseudomelaniidae.
Macrocheilus Phil. {Macrochilina Bayle ; Strobaeus de Kon.) (Fig. 912). Elongate-
oval, without umbilicus, smooth or with slightly curved growth-lines. Spire acuminate,
only moderately high ; last whorl large. Aperture angular posteriorly, sometimes
also in front. Inner lip with weak anterior folds. Silurian to Trias.
(?) l'tychostom,a Laube ; (?) Undularia Koken. Trias.
Loxonema Phil. Turreted, whorls arched, with S-sliaped growth-lines. Sutures
CLASS IV
GASTEOPODA
537
deei) ; aperture higher than wide, with shallow canal. Silurian to Trias ; particularly
abundant in the Carboniferous.
Zijgo2)leara Koken. Like the last, but whorls with sharp, slightly curved
transverse ribs, or transverse nodose keel. Devonian to Lower Cretaceous.
Bourgetia Deshayes {Pithodea de Kon.). Large,
elongate-oval to turreted, with large, inflated body
whorl. Surface marked with spiral striae or furrows.
Carboniferous and Upper Jura.
Pseudomelania Pictet {Chcmnitzia p.p. d'Orbigny)
(Fig. 913). Turreted, with
numerous, almost flat whorls,
and slightly impressed sutures.
Surface smooth, or marked by
fine growth - lines ; aperture
rounded anterioi'ly, or with
faint canal. Umbilicus want-
ing; rarely an umbilical fissure
present. Very abundant in the
Trias and Jura, less so in
Cretaceous and Eocene ; prob-
ably present also in the Car-
boniferous.
Subgenera : Oonia, Microscldza
Gemm. ; IIypsipleu7'a, AndptycMa ^^^ ^^^
Koken. Trias and Jura. Goe-
lostyhnc^ _ Euslylus, SpirostT/lus ^j^^j^,^^,, .,_ j^u^l^jl, ^e-
Kittl. Trias, hayania Munier- vonian; Paftrath, near
Clialni. (Fig. 914). Eocene. Cologne.
Fici. 913.
Pseudomelania
h p d d, ingt one n s I s
(Sowl).). Oxlbid-
iau ; Franco. Bands
of original colora-
tion still showing.
Pseudmnalania
(Bayania) lactea
Lam. sp. Cal-
caire Grossier ;
Grignon, near
Paris.
Pustularia Koken, non Swains. Turreted, with groove -like sutures. WhorLs
flat, with three or more spiral rows of nodes. Trias.
Gatosira Koken. Wliorls flat, with transverse ridges. Aperture canaliculate ;
base with spiral grooves. Trias and Jura.
Diastoma Desh. (Fig. 915). Like the last,
but aperture separated from the body whorl.
Whorls with transverse folds and spiral striae.
Cretaceous to Recent.
Mathilda Semper (Promathilda Andreae).
Turreted ; whorls transversely and spirally
striated or ribbed. Aperture with canal. Proto-
conch heterostrophic. Jura to Recent.
Keilostoma Desh. {ParypJiostoma Bayan) (Fig.
916). Turreted, spirally striated. Outer lip
with externally thickened margin. Eocene.
Turhonilla Risso (Ghemnitzia p.p. d'Orb.) (Fig.
9 1 7). Small, turreted, with heterostrophic proto-
conch. Whorls transversely ribbed or smooth.
Inner lip straight, or occasionally with folds.
Tertiary and Recent
Odostomia
Lamarck (Fig. 919).
Tertiary and Recent.
Fio. 915.
Diastoma costellata
(Lam.). Caloaire
Grossier ; Uamery,
near Epernay.
Fig. 916.
Keilostoma turricula
Brug. sp. {Mclanla
marginata Lamarck).
Caloaire Grossier;
Grignon, near Paris.
Fleming
(Fig. 918); Pyramidella
Cretaceous to Recent.
Palaeoniso Gemm. Trias
Syrnola Adams ; Eulimella Fischer,
and Jura.
The genera Suhulites Conrad (? Polyphemopsis Portlock), from the Cambrian t^
538
MOLLUSCA
PHYLUM VI
Carboniferous ; Fihsisinra Hall, Ordovician ; and Soleniscus Meek and Wortlien,
Fio. 917.
Tii.rbo7iilla rufa
Phil. Crag; Sutton,
England.
Fir:. 918.
Odostomin pit-
cata (Montf.).
Upper Oligocene ;
Kinder- Kaufuiigen,
near Cassel.
Fk;. 919.
PyraviiiJclIa pli-
cosa Bronn. Mio-
cene ; Niederleis,
Moravia.
Firs. 920.
Euchrysalis fusi-
formis (Minister).
Keuper ; St. Cas-
sian, Tyrol.
Carboniferous, are cliaracterised by narrow, anteriorly elongated and canaliculate aper-
tures. They probably form a separate family, in which also should be placed the
Triassic Euchrysalis Laube (Fig. 920).
Superfamily 2. PTENOGLOSSA Gray.
Teeth of the radula suhulatc, numerotis and similar in each transverse row.
Family 1. Epitoniidae, novum (Scalariidae Broderip).
Shell turreted, usually narrowly umbilicate. JFJiorls convex, transversely ribbed or
striated. Aperture round, with entire peristome. Operculum horny, paucis2oiral.
Marine. Silurian to Recent.
Holopella M'Coy (Aclisina de Kon.). Slender, turreted ; whorls with fine trans-
verse striae, sometimes cancellated. Silurian to Carboniferous.
Gallonema Hall {Isonema Meek and Worth.). Turreted, oval to
globose ; whorls covered with lamellate transverse ribs ; aperture
circular. Silurian and Devonian.
Scoliostoma Braun. Devonian. Ghilocyclus Bronn {Gochlearia
Braun) ; Ventricaria and Batycles Koken. Trias.
Epitoni'um Bolten {Scalaria Lam. ; Scala Klein ; Cirsotrema
Morch) (Fig. 921). Turreted; whorls strongly arched, with trans-
verse ribs, and often also spirally striated. Aperture round, outer
lip sometimes thickened. Trias to Recent. Many suljgenera.
Family 2.
Fid. 921.
Sadariaiumeiiom '^^«^^ depressed conical,
Brocehi. Miocene; nacreous layer. Whorls
angular ; operculum horny
spiral. The protoconch is
Marine. Cretaceous to
Solariidae Chenu.
deeply and broadly ^imbilicate, without
Baden, near Vienna.
or calcareous
heterostrophic.
Recent.
The Solariidae exhibit some resem-
blance to the Euomphalidae, from which
they are distinguished principally by the -g.^^^ 932.
heterostrophic protoconch. solarium simplex
Solarium Lam. (Architectonica Bolten) Bronn. Miocene;
(Figs. 922, 923). Aperture quadrilateral; Niederleis, Morava.
Jura to Recent.
Fio. 923.
Sdlarium hymeriei Ryckholt.
Tourtia (Cenomanian) ; Tour-
nay, Belgium.
operculum horny ; umbilical angle notched or sharp. Jura to Recent. A number
of Mesozoic forms confused with this genus probably belong to Euompihalus.
Torinia Gray. Tertiary and Recent. Bifrontia Desh. {Omalaxis Desh.). Eocene.
CLASS IV
GASTROPODA
539
Superfamily 3. TAENIOGLOSSA Bouvier.
Teeth of the radula seven in each transverse row. Mainly holostomate forms, but
some genera have deeply notched apertures, as in the higher divisions.
Family 1. Purpurinidae Zittel.
Thick-shelled, oval, unth platform-like spire, and with-
out pearly layer, TVliorls flcottened beneath the suture and
angular, the angles often beset loith nodes. Body whorl
large ; aperture oval, with anterior emargination, and
discontinuous peristome. Operculum unknoion. Carboni-
ferous to Cretaceous.
Trachydomia Meek and Worth. {Trachijnerita Kittl).
Coal Measures ; North America and Europe. Pseudoscalites
Kittl ; Tretospira Koken. Trias ; Europe.
Purpurina d'Orb. Elongate-oval. Whorls angular
superiorly, spirally ribljed, with transverse folds or costae,
highly ornamented, often with umbilical fissure. Aperture
oval, anteriorly notched. Rhaetic and Jura.
Purpuroidea Lycett (Fig. 924). Spire with successive
steps or platforms, the flattened surface beneath the suture
bounded by a row of n6des. Last whorl inflated, smooth,
canal-like notch ; outer lip thin. Jura and Cretaceous.
Brachytrcma Morris and Lycett ; Tomocheilus Gemm.
Fig. 924.
Pur}mroidea nodulata (Young
and Bird). Great Oolite ; Minchin-
hampton, England.
Aperture anteriorly with
Jura.
Family 2. Littorinidae Gray.
Shell turbinate, usually smooth or spirally ornamented, without nacreous layer.
Aperture rounded ; outer lip sharp. Operculum horny, pa,ucispiral. Marine.
Ordovician to Recent.
Fossil shells
of this family are distinguished solely from those of the Turbinidae
and Trochidae by the absence of a pearly layer. The animal,
however, differs radically. The heart has but one auricle in
the Littorinidae, two in the Turbinidae and Trochidae. The
radula in the last-named groujis is rhipidoglossate ; in the
present family it is taenioglossate. The differences in essential
structure are thus seen to be considerable ; yet the shells
when fossilised are so similar, it can scarcely be doubted that
the so-called Paleozoic Littorinidae are in many cases very
closely related to genera referred to the Turbinidae and
Trochidae. The limits of these families are therefore very
Fk;. 92o.
uncertain, so far as Paleozoic forms are concerned. Among
Turho7iUella subcostata
(Goldf.). Middle Devonian ;
Paffrath, near Cologne.
the extinct genera which exhibit great similarity to Littorina,
but are often assigned to the above-named families, may be
mentioned the following : Holopea Hall. Ordovician to
Devonian. Turbonitella de Koninck (Fig. 925). Devonian and Carboniferous.
Portlockia, Turbinilopsis and Ehabdopleura de Koninck. Lower Carbonifei'ous.
Lacunina Kittl. Trias.
Littorina Fer. (Fig. 926). Thick-shelled, turbinate to globose, smooth or spirally
striated, without umbilicus. Aperture oval. Jura to Recent.
540
MOLLUSCA
PHYLUM VI
Lacuna Turton (Fig. 927). Like the last, but thin, small, with an excavated pillar.
Tertiary and Recent.
Fic. y2G.
Littorina Utorea (Linn.).
Post-Pleistocene ; Lsle of
Skaijto.
Fig. 927.
Lacuna (?) basterotina
Bronn. Miocene ; Stein-
abrunn, near Vienna.
Fig. 92S.
Fossarus costatus Brocchi. Pliocene ;
Liraite, Tuscany.
Lacunella Deah. Eocene. Litiopa'Rang; PlanaxisLnm.; QnoyiaBesh. Tertiary
and Recent. The families Litioindae and Planaxidae are usually recognised.
The genus Fossarus Phil. (Fig. 928) forms, according to Fischer, a separate family,
Fossaridae. It occurs in the late Tertiary and Recent.
Family 3. Cyclostomatidae Menke.
Shell extremely variable in form, turbinate to discoidal, sometimes turrcted, covered
with epidermis. Aperture circular, with usually entire peristome. Operculum horny or
calcareous, spiral. Terrestrial. Cretaceous to Recent.
Like the pulmonate snails, the animal possesses a respiratory cavity. But in
other respects they approach the Littorinidae very closely, which latter . forms also
have the gill mucli reduced. The shell haljit is excessively variable. There are more
than 600 Recent species distributed thi'oughout all parts of the globe, but the majority
Fl(i. 929.
Cydostoma hi-
sidcatum Zicten.
Miocene; Brmin-
gen, near Ulin,
Wurtemberg-.
Fig. 930.
Pomatvis la}ieUiirti
(Thomas). Helix
Beds (U])per Oligo-
eene); Hochheim,
near Wiesbaden.
Fic. 931.
Cyclotus exaratus Sandb.
Upper Eocene ; Pngnello,
Italy. Shell and operculum
(after Sandberger).
Fig. 932.
Strojihostoma nnom-
phala Capellini. Oligo-
cene ; Arnegg, near
Ulm, Wiirtembeig.
of these are tropical. Fossil forms are found in fresh-water deposits as old as the
Middle Cretaceous.
Gyclostomus Montf. (Fig. 929). Turbinate, with calcareous spiral operculum.
Tertiary and Recent.
Otopoma, Tudora Gray. Tertiary and Recent.
Megalomastoma Guild. Turbinate to chrysalis-shaped, usually smooth. Peristome
with thick margins ; outer lip reilected. Operculum horny. Cretaceous to Recent.
M. mumia (Lamarck).
Pomatias Studer (Fig. 930). Turreted, transversely striated, with reflected
margins and calcareous operculum. . Tertiary to Recent ; palearctic
Leptopoma Pfeiff.; Gyclophorus Montf; Graspedopoma Pfeiff ; Gyclotus Guilding
(Fig. 931), etc. Upper Cretaceous. These genera are considered to form a distinct
family, Gyclophoridae. Strophostoma Desh. (Fig. 932). Upper Cretaceous to Miocene.
CLASS IV
GASTROPODA
541
Family 4. Capulidae Cuviei'.
Shell cup-, cap-shaped or oval, irregular, loith spirally twisted apex; in some cases
the shell is composed of several depressed whorls. Body whorl very large ; aperture wide ;
operculum absent. Marine. Cambrian to Recent.
Various genera belonging here are stationary, remaining tlirougliout nearly the
whole of their existence attached to some foreign body, to
which they gradually become accommodated in form.
Stenotheca Salter. Shell small, cap-shaped, concentrically
striated or furrowed, with slightly incurved apex, which
latter is distantly situated posteriorly. Lower Cambrian.
Fia. 933.
'Capuhis hungarlcus (Linn.).
Pliocene ; Tuscany. '
Fig. 934.
Capulus rugosus (Sowb.).
Great Oolite ; " Langrune,
Calvados. I'j
Fig. 935.
OrtJionychia clcgans Barr.
Silurian (Etage E) ; Loclikow,
Bohemia.
Capulus Montf. {Pileopsis Lam.; Brocchia Bronn) (Figs. 933, 934). Irregularly
conical or cap-shaped ; apex greatly displaced backward, more or less spirally inroUed.
Aperture wide, rounded or irregular ; internally with a horseshoe-shaped muscular
impression. Exceedingly abimdant from the Cambrian to Carboniferous, but rather
sparse from the Trias onward.
Orthonychia Hall {Igoceras Hall) (Fig. 935). Shell conical, .straight or slightly
curved, often plicated. Apex but faintly spiral. Silurian to Carboniferous.
Platyceras Conrad {Acroculia Phil.) (Fig. 936). Apex bent and spirally inroUed.
Fig. 936.
Platyceras neritoides Pliil.
Carboniferous ; Vise, Belgium.
Pig. 937.
Diaplwrostoma
Hall. Silurian ;
Indiana.
niagarense
Waldron,
Fig. 93S.
Horiostmna harrandei Mun.-Clialm.
Lower Devonian ; Gahard, lUe-et-
Vilaine (after Munier-Chalmas).
Surface smooth, striated, plicated or covered with small spines. Young shell coiled
as in Diaphorostoma, late stages non-coiling, often spinous. Commensal on Echinoicls.
Silurian to Coal Measures.
Diaphorostoma Fisher {Platyostoma Conrad) (Fig. 937). Shell composed of numerous
rapidly widening whorls. Spire low, body whorl very large. Inner lip reflected and
somewhat thickened. Aperture round, of large size. Silurian to Carboniferous.
Horiostoma Munier-Chalm. (Fig. 938). Shell thick, spirally ribbed, with short
lateral spire, and wide umbilicus. Devonian.
Tubina Barr. Silurian. Bothiiletzia Simonelli. Tertiary.
542
MOLLUSCA
PHYLUM VI
Hipponix Defr. (Gochlole'pas Klein) (Fig. 939). Shell thick, obliquely conical to
cup-shaped. Beak straight, rarely spiral, greatly removed pos-
teriorly. Aperture oval or rounded, internally with a horseshoe-
shaped muscular impression. The foot often secretes a thick,
operculiform calcareous disk. Cretaceous to Recent.
93'J.
Hipponix cornucopiae (Lamarck.) Calcaire
Grossier; Liancourt, near Paris. A, Shell.
B, Foot-plate.
Fio. 940.
Calyptraea {Trocli itn) trochiformis Lam. Calcaire Grossier ;
Damery, near Epernay.
Galyptraea Lam. {Galerus Gray) (Fig. 940). Shell thin, conical, with central
spiral apex. Whorls flattened, often spinose. Base horizontal ;
aperture wide, depressed. Cretaceous to Recent.
Crqndula Lam. (Fig. 941). Slijjper - shaped, elongate - oval, flat
or arclied. Beak at the posterior end, almost marginal, somewhat
curved. Aperture greatly elongated, wide ; inner lip formed by a
thin horizontal lamella. Cretaceous to Recent.
Crucibuhtm Schum. Tertiary and Recent.
Family 5. Naticidae Forbes.
Fio. 941. Shell tuith short spire and large body whorl. Aperture semicircular
Crepidula unjui- to oval, angular posteriorly, broadly rounded anteriorly. Operculum
Trias to Recent.
cen'et Tifscany. '°" calcareous or horny, paucispiral. Marine.
The distinction of fossil Naticidae from Naticopsis, Nerita and Ampidlaria is
attended with some difficulty, since they frequently possess nearly identical characters
in common, difl'ering mainly in the operculum, which is not j^reserved fossil.
Sinum Bolten {Sigaretus Lam.) (Fig. 942). Shell depressed, auriform, spirally
Fic. 942.
Sinum haHotoideum
(Linn.). Miocene ; Grund,
Hungary.
A, Nat'tra milhpunctata Lam.
Pliocene ; Monte Mario, near Home.
B, (Jpercnlum of N. mnUipiitictata
S. Woodw. Crag; Sutton.
Fii;. 944.
Natica (Ampullina) palnia
Lam. Calcaire Grossier ;
Damery, near Epernay.
striated or furrowed. Spire very low, with rapidly widening whorls. Aperture greatly
distended ; operculum horny. Tertiary and Recent.
Natica Scopoli (Figs. 943-946). Globose, semi-globose, ovate or pyramidal, smooth
and lustrous, rarely spirally striated, umbilicate or not. The umbilicus, when
CLASS IV
GASTROPODA
543
present, often partially or entirely filled with callus. Aperture semicircular or oval.
Outer lip sharp ; inner lip thickened by a callus. Excessively abundant from the
Trias onward.
Subgenera : Ampullina Lam. (Fig. 944) ;
Amauro2)sis Morch. (Figs. 945, 946) ; Polinices
Montlbrt ; Euspira Agassiz ; Lunatia, Cernina
Gray ; Neverita Risso, etc.
(?) Deshayesia Raul.
(Fig. 947). Lil^eNatica,
but inner lip with a
thick callus and den-
ticulated. Miocene and
Pliocene.
Fio. 945.
Nntiai, {AmpulHna)
wilhmeti. Lam. Cal-
caire Grossier ; Da-
mery, near Epernay.
Fig. 946. Fio. 947.
Natica (Amauropsls) Deshayrsia cochlearia
hnlhi/ormis Sowh. Upper (Brongniart). Oligocene;
Cretaceous; St. Gilgen Monte Grnmi, near
on Wolfgangsee, Austria. Vicenza.
Family 6.
Xenophoridae
Deshayes.
Shell turbinate, with-
0 ut nacreous layer ;
whorls flat, often covered with agglutinated foreign bodies. Base concave or flat, with
a peripheral heel. Aperture obliquely quadrilateral. Operculum horny. Silurian to
Recent.
The Xenophoridae Jlre an ancient family, the modern representatives of which
have acquired a high diiferentiation. The radula is like that of the Capulidae,
Littorinidae and Strombidae, not like that of the Trochidae. The earlier forms,
encountered in the Silurian, present a great superficial resemblance to the Paleozoic
Trochus species.
Eotrochus Whitfield (Fig. 948). Thin-shelled, turbinate, widely umbilicate.
Whorls flat, rarely with aggluti-
nated foreign particles. Base con-
cave, its periphery formed by a
compressed lamellar belt. Silurian
to Recent.
Omphalopterus Roemer. De-
pressed turbinate, widely umbili-
cate. The wide peripheral margin
at the base composed of two lamellae,
separated by a slit. Silurian.
Clisosinra Billings ; Autodetus
Lindstrom. Silurian.
Xenophora Fischer {Phorus
Montf.) (Fig. 949). Low trochiform, narrowly umbilicate.
Fiii. 948.
Eotrochus heliacus
(d'Orb.). Upper Lias ; La
Verpilliere, near Lyons.
Fig. 949.
Xenophora ngglutinans (Lam.).
Calcaire Grossier ; Damery, near
Epernay.
Whorls usuallv covered
above with agglutinated extraneous objects. Cretaceous to Recent.
Family 7. Ampullariidae Gray.
This family inhabits fresh or brackish water, and is found in Africa, Asia and
tropical America. Some of their shells are hardly to be distinguished from Ampul-
Una. The animal possesses a lung cavity above the right gill. Fossil forms occur in
fresh-water dej^osits of Cretaceous age at Rognac, near Marseilles, and also in the early
Tertiary.
544
MOLLUSCA
PHYLUM VI
Family 8. Valvatidae Gray.
Shell composed of few ivJiorls, conical or discoidal, umhilicate. Aperture round, tvith
continuous ijeristome. Operculum horny, circular, multispiral.
Upper Jura to Recent.
The genus Valvata MiiU. (Fig. 950) is small, and varies
from turbinate to discoidal. It comprises about twenty-five
Pig. 950. Eecent species, inhabiting the frcsli waters of Eiiroj^e and
Valvata piscinaiu Miiii. North America. It is initiated in the Purbeck, but does not
Transylvauia.*^'^'' ' ^'^°^*'' become at all abundant until the Tertiary.
Family 9. Viviparidae Gill.
Shell conical or turbinate, tvith thick epidermis; imperforate or tvith narroiv
umbilicus. Whorls smooth, tubular or angular. Aperture rounded, oval, sub-angular
posteriorly, with continuous peristom.e. Operculum horny, concentrically striated, ivitli
eccentric nucleus. Jura to Eecent.
Vivipctra Montf. {Paludina Lam.) (Fig. 951).
B
This, the principal genus, is
a D
abundant in fresh water
of all parts of the globe,
with the exception of
tropical and South
America. Several other
genera and subgenera
are recognised, such as
Campeloma Raf. {Me-
lantho auct.) of North
America, comprising
mostly smooth, thick-
shelled sj^ecies,
thickened inner lip ;
Tulotoma Haldem., including forms with angular whorls. North America ; Margarya
Nev., China ; Lioplax Troschel ; Laguncula Benson ; Tylopoma, Boslwvicia Brusina, etc.
Typical species of this genus are found in the Wealden clays. Vast numbers of
Vivipara occur in the Pliocene of southern Hungary, Croatia, Slavonia, Roumania
and the Island of Cos, where they are remarkable for their extreme variability.
Neumayr has described a number of mutation series from this horizon, which begin
with smooth Vivipara species, and terminate with angular Tulotoma-\ik.& forms.
Fig. 951.
A, B, Vivipara hrusinae Neumayr. C, V. (Tulotoma) forbesi Neumayr.
with Pliocene ; Isle of Cos. D, V. {Tulotoma) hoerneri Neumayr. Pliocene : Novska,
Slavonia.
Family 10. Hydrobiidae Fischer {Amnicolidae Try on).
Shell turbinate to turreted, small, usually thin, and either smooth, longitudinally
ribbed or spirally heeled. Aperture ovate; opierculum horny or calcareous, spiral or
concentric. Cretaceous to Recent.
Tliese are fresh or brackish water inhabitants, some of which, however, are able to
survive for a considerable period on land. It is difficult to distinguish the different
genera belonging to this family by means of shell characters alone. All the forms
are diminutive.
Bithinia Gray (Fig. 952). Thin-shelled, tui'binate, with umbilical fissure.
Peristome continuous, outer lijj sharp. Operculum calcareous, concentric. Wealden
to Recent.
CLASS IV
GASTROPODA
545
Staliola Brusina. Outer lip thickened ; operculum calcareous. Cretaceous to
Miocene.
A (• Fossarulus Neumayr. Like the last, but witli spiral ribs.
Upper Miocene.
Nematura Benson (Stenothyi-a Benson) (Fig. 953). Like
Bithinia, but aperture contracted. Operculum calcareous, spiral.
Tertiary and Recent.
Fig. 952.
A, Bithinia tentaenlata
(Linn.). Upper Mionene;
Miocic, Dalmatia. B,
Operculum of same. C,
B. grariUs Sandb. Fresh-
water JVIolasse ; Uber-
kirchberg, near Ulni.
Pig. 953.
Nematura pupa (Xy.st).
Oligocene ; Hackenlieim,
near Alzey.
Fig. 954.
Nystia chastelii
(Nyst). Middle Oligo-
cene ; Klein-Spouwen,
Belgium.
Fig. 955.
Hydrobia acuta A.
Braun. Miocene ;
Weissenau, near
Mayence.
Nystia Tourn. (Forbesia Nyst) (Fig. 954). Outer lip reflected; operculum
calcareous, spiral. Tertiary and Recent.
Assiminea Leach. Tertiary and Recent.
Hydrohia Hartm. (Littorinella Braun ; Tournoueria Brusina) (Fig. 955). Conical
to turreted, acuminate, smooth. Aperture oval ; operculum horny, paucispiral.
Cretaceous to Recent. The Indusia Limestone (Lower Miocene) of Axivergne is
almost exclusively composed of the shells of H. dubuissoni Bouill. Similarly, the
Littorinella Limestone ,of the Mayence Basin, which is of equivalent age, is made
up of the shells of H. acuta Braun. Strata in the fresh-water limestone of Nordlingen
are charged with H. frochulus Sandlj. ; and the Upper Eocene marl of St. Ouen is
filled with the remains of H. pusilla (Prev.).
Other genera and subgenera closely related to the foregoing are Bythinella Moq. ;
Amnicola Gould ; Belgrandia and . j, ^,
Lartetia Bourguignat ; Lapparentia
Bertlielin.
Pyrcjula Christofori and Jan.
(Fig. 956, A). Turreted, whorls
spirally keeled or ribbed. Peristome
continuous. Tertiary and Recent.
Genera allied to the last are
Micromelania Brus. (Fig. 956, B) ;
Mohrensternia Stol. (Fig. 956, C) ;
Pyrgidium Tournouer ; Prnsosthenia
Neumayr. Tertiary.
Lithoylyphns Ziegl. (Fig. 957).
Globose or ovate, with short sj)ire ;
rather thick and solid. Aperture large, obliquely oval ; inner lip thickened.
Tertiary and Recent ; Europe. Similar forms, Somatogyrus Gill, and Flmnincola
Stirapson, occur in North America. There are other related genera in south-eastern
Asia and South America.
Family 11. Rissoidae Troschel.
Shell small, thick, turbinate to turreted, usually ribbed or spirally striated, rarely
smooth. Aperture oval, angular posteriorly, often with anterior canal. Operculum
horny, pavjcispiral. Jura to Recent.
Rissoina d'Orb. (Fig. 958). Turreted, transversely ribbed, rarely smooth : outer
VOL. I 2 N
Fig. 95(3.
A, Pyrcjula eugeiiiae Neumayr.
Upper Miocene ; Arpatak, Transyl-
vania. B, Micromelania {Diana)
haueri (Neumayr). Upper Miocene ;
Miocic, Dalmatia. C, Mohrensternia
inflata Andrzewsky. Congerien Stage
(Miocene) ; Inzersdorf, near Vienna.
Fig. 957.
Litho<jJyphiiii fuscus
Ziegler. Upper Mio-
cene ; Malino, West
Slavonia.
546
MOLLUSCA
PHYLUM VI
lip arcuate, generally tliickened ; aperture somewhat notched or effuse at the base.
Dogger to Recent ; mainly
^ ^ Tertiary.
Bissoa Frem. (Fig. 959).
Turreted, transversely riljbed
or cancellated, aperture entire
l)elow. Jura to Recent.
Fio. 958.
A, Rissoina amocna Zitt. Titlion-
ian ; Stramberg, Moravia. B, R.
Ue<'Uf:sata Montf. Miocene ; Steina-
brunn, near Vienna.
Fici. 9:J9.
A, Rissoa turhinata (Lain.).
Oligocene ; Weinheini, near
Alzey. /.', R. (Alr<inia) mon-
iagui Payr. Miocene ; Steina-
brunn, near Vienna.
Family 12. Turritellidae
Gray.
Shell turreted, with liigh
acuminate spire. Whorls numerous, usually spirally ribbed or striated. Aperture oval,
round or quadrangular, sometimes ivith faint anterior canal. Outer lip thin, peristome
discontinuous. Operculum horny, muUispiral. Marine. Trias to Recent.
Turritella Lam. (Figs. 960, 961). Spire very high ; aperture oval or rounded
quadrilateral ; outer lij) thin, excavated behind, and
slightly jjroduced in front. Trias to Recent ; maximum
in Tertiary. The older Mesozoic species are usually
small.
Fic. 960.
A, Turritella tnrris Bast. ('/'.
terelira Ziet. non Linn.). Miocene
Molasse ; Enningen, near Ulni.
B, T. irnhricatarin Lam. Cal-
caife Grossier ; Grignon, near
Paris.
Subgenera : Mesalia Gray (Fig. 961
but aperture with shallow canal, and
Tertiary to Recent.
Protoma Baird
{Proto p.p. Defr. ).
Aperture oval, an-
teriorly with canal-
like contraction,
which is surrounded
externally by a thick
swelling. Tertiary
and Recent. P.
cathedralis Brgt.
Glauco)iia Gie-
bel (Omphalia
Zekeli ; Cassiope
Cocp) (Fig. 962).
Thick-shelled, coni-
cal or turreted,
narrowly umhili-
Like the last,
twisted inner lip.
Fiii. 9(3L
TurritcUa {Mesalia)
multisulcata Lam.
Eocene ; Calcaire
Grossier ; Grignon,
near Pari.s.
Glauconia kefersteini
Goldf. Middle Cre-
taceous ; Dreistiitten,
near W'iener-Nenst.
cate. Whorls
spirally ribbed, rarely smooth. Aperture oval, with faint canal ; outer lii? ^\ith
anterior and median emargination. Abundant in the Cretaceous.
Family 13. Vermiculariidae, novum. {Vermetidae Adams).
Shell tubular, the earlier whorls spiral, the later ones irregularly twisted, free or
attached. Aperture round; operculum horny, sometimes icanting. Carboniferous to
Recent.
Some fossil Vermetidae are liable to be mistaken for Serpulidae, but differ from
them neverlheless in the structure of the shell and spiral protoconch. The determina-
tion of the few Paleozoic and Mesozoic forms is uncertain.
Vermicularia Lam. {Vermetus Daudin) (Figs. 963, 964). Shell usually attached,
irregularly tubular, internally vitreous, and often with septa. Carboniferous (?) to
Recent. Abundant in the Tertiary,
CLASS IV
GASTEOPODA
547
Subgenera ;
Recent.
Thylaeodes Guettard (Fig. 963) ; Petaloconchus Lea (Fig. 964). Tertiary and
Siliquaria Bnig. (Fig. 965). Shell
free, coiled in a loose spiral. Aperture
lateral, and with a slit which continues
as a fine cleft or row of pores through-
out the entire length of the shell.
Cretaceous to Recent.
963.
Vcrmicidaria (Th yhwode-i) arenaria
Linn. Miocene ; Grund, near Vienna.
Vs.
V. (Petaloconchus) intorta Lam.
Pliocene ; Montespertoli, near
Florence. Some of the tubes are
fractured i and show the internal
lamellae.
Fir;. 965.
Siliquaria striata
Desh. Calcaire Grossier ;
Chaussy, near Paris.
Family 14. Caecidae Adams.
Shell small, discoidal in early stages, later becoming tubular. The decollated yroto-
conch replaced by a septum. Operculum roimd, horny. Tertiary and
Recent.
Caecum Flem. About one hundred Recent and twenty Tertiary
species are known.
Family 15. Melaniidae (Lamarck) Gray.
Shell turreted to oval, with thick, dark-coloured epidermis. Apex
usually truncated and corroded. Aperture oval, sometimes canali-
culate. Operculum horny, spiral. Jura to Recent.
Living species inhabit fresh, or more rarely brackish, waters of
southern Europe and the warmer zones of Africa, Asia and America.
Melania Lam. (Thiara Bolten) (Fig. 966). Shell smooth or
spirally striated, or with transverse ribs or nodes. Aperture oval,
anteriorly I'ounded. Upper Jiira to Recent.
Stomatopsis Stache. Whorls platform-like, with strong trans-
verse ribs ; aperture rounded, with entire, thickened and reflected
margins. Lowermost Eocene (Cosina Beds) ; Istria and Dalmatia.
Pyrgulifera Meek {Hautkenia Munier-Chalm.) (Fig. 967). Shell thick, elongate-
oval, with platform-like, transversely ribbed, and spirally striated whorls. Aperture
Fig. 966.
Melania escheri
Brongt. Miocene ;
Michelsberg, near
Ulni.
548
MOLLUSCA THYLUM VI
Upper Cretaceous of Europe and North
oval, sometimes with very faint canal
America.
Paramelania Smith. Eesembles the preceding. Living in Lake Tanganyika.
Fascinella Stache ; Goptostylus Sandb. ; Faunihs Montf ; Hemisinus Swainson.
Upper Cretaceous, Eocene and Recent.
Melanopsis Fer. (Figs. 968-970). Shell oval to turreted, smooth or ornamented.
Fig. 967.
Pyrrjulifcra pich-
leri (Hoernes).
Upper Creta-
ceous; Ajka,
Hungary.
Fio. 968.
Melcmopsla galln-pro-
vincialis Math. Upper-
most Cretaceous ; Mar-
tigues, near Marseilles.
Fio. 969.
UManopsis mar-
tiniana Fer. Mio-
cene ; Nnssdorf,
near Vienna.
Fio. 970.
Melanopsis (Can-
thidomus) acanthica Pleurocera tttromhi-
Neumayr. Upper formis (Scliloth).
Miocene; Miocic, Wealden ; Oster-
Balniatia. wakl, Hannover.
Base of columella truncated ; aperture with short canal ; inner lip callous. LTpper
Cretaceous to Recent. Remarkably abundant in the Miocene and Pliocene.
Pleurocera Raf. (Fig. 971). Like Melania, but aperture with faint canal, and
outer lip sinuous. Cretaceous to Recent ; occurs only in North America.
Ooniobasis Lea ; Anculosa Say {Leptoxis Raf) ; Ptychoshjhis Sandb. Wealden.
The first two occur Tertiary and Recent in North America only.
Family 16. Nerineidae Zittel.
Shell turreted, pyramidal or ovate, perforate or imperforate. Apertitre anteriorly
VK: 972.
Trorhdlin ronnolirina Zitt.
Tithonian ; Straiiiberg, Mor-
avia. Longitudinal section.
Fid. 973.
A, Nerinca defrancci d'Orb. Coral-Rag ; Coulanges sur Yonne. B, N.
dilatata d'Orb. Coral-Rag ; Oyoiinax, Ain. C-E, N. hnke,neg(inri I'eters.
Tithonian ; Straniberg, Moravia. '','■!/;,. A Vi- £, Longitudinal section.
CLASS IV
GASTROPODA
549
tuith short canal or shallow notch. Columella and lips with strong folds, continuous
throughout the entire length of the spire. Outer lip thin, posteriorly with fissure-like
incision, which leaves a small slit-hand immediately beneath the suture on all the ivhorls.
Marine. Trias to Cretaceous.
Aptyxiella Fisch. (Aptyxis Zitte], non Troscliel). Turreted, very slender, im-
perforate. Aperture quadrangular ; inner and outer lips without folds ; columella
somewhat thickened. Trias to Upper Jura.
Trochalia Sharpe {Gryptoplocus Pict. and Camp.) (Fig. 972). Turreted to
pyramidal, usually smooth and imperforate. The inner lip only has a strong, simple
fold. Jura and Cretaceous.
Nerinella Sharpe (Pseudonerinea Loriol). Turreted, imperforate. Outer lip and
sometimes also the columella with a simple fold. Jura.
Nerinea Defr, (Fig. 973). Turreted or pyramidal, usually imperforate. Columella
invariably, and inner and outer lips generally, with simple folds. Jura and Cretaceous ;
maximum in the Coral-Rag (Upper Jura).
Ptygmatis Sharpe (Fig. 974). Like the last, except that the folds on both lips
and the columella are complicated by second-
ary constrictions and branchings. Jura and
Cretaceous.
Itieria Math. (Fig. 975). Elongate-oval,
usually umbilicate. Spire short, sometimes
insunken. Body whorl very large, more or
less enveloping the preceding. Columella
and both lips with folds. Jura and Cre-
taceous.
Family 17. Oerithiidae Menke.
Shell turreted; aperture elongated oval, or
quadrilateral, anteriorly ivith short canal.
Outer lip often thickened and reflected, or thin
and sharp. Columella sometimes with one
or two folds. Operculum horny, spiral.
Marine and brackish ivater. Trias to Recent.
Fio. 974.
Ptygmatis pscndo-
linndrutana Gem-
mellaro. Titlionian ;
Iiiwald, Carpathia.
Vertical section.
Fig. 975.
Itieria staszycii Zeuschner.
Tithonian ; Inwald, Car-
pathia.
The earliest
More than 1000 living, and about 500
fossil species are known, the latter being most numerous in the Eocene,
forms ai-e usually of small size, and have a nearly entire peristome.
Cerithinella Gemm. (Fig. 976). Shell turreted, slender. Whorls numerous, flat,
ornamented with spiral ribs or rows of small nodes.
Aperture c^uadrilateral, with very faint canal.
Jura.
Cryptaulax Tate {Pseudocerithium Cossmann).
Small, turreted. Whorls with spiral ribs or rows
of nodes and transverse folds. These last usually
run continuously in a somewhat oblique direction
from one whorl to the next. Aperture oval or
Pio. 977.
Fia. 976.
Cerithinella armata
Goldf. Torulosus
Beds (.Middle Jura) ;
Pretzfeld, Franconia.
Mordf and Tyc' quadrilateral, with scarcely perceptible canal.
Great Oolite ; Min- rj,j.-j^g ^^^ j^^^,^
chinhanipton, Jing- ^ . ,, ,, . -it ,tt n^,^~^ m •
land. Ceritella Morris and Lye. (Fig. 977). Trias
and Jura. Fibula Piette (Fig. 978). Trias to
Cretaceous. Pseudalaria Huddlest. ; Ditretus Piette. Jura.
Exelissa Piette (Fig. 979). Very small, turreted ; whorls with strong, continuous
550
MOLLUSCA
PHYLUM VI
transverse ribs and spiral striae. Aperture contracted, rounded, without canal, some-
times slightly separated off, and with continuous jieristome. Abundant in the Jura.
Bittium Leach (Fig. 980). Turreted, with granulated spiral ribs,
and numerous transverse costae. Aperture with short, straight canal ;
outer liji sharp. Jura to Eecent. Abundant in the Tertiary.
Triforis Deshayes ; Gerithiopsis Forbes. Tertiary and Recent.
Eustoma Piette. Aperture with
long canal, which is often closed,
however, by margins of the inner
and oiiter lip. Inner lip callous
and strongly dilated ; outer lip
expanded. Jura.
Cerithium Brug. (Figs. 981,
982). Turreted, imperforate, with-
out epidermis. Aperture oblong,
ovate, with l)ackwardly curved
canal ; outer liji often somewhat
reflected. Columella concave, fre-
quently with one or two folds.
Certain Tertiary species attain a length of half a metre {G. giganteum). Jura to
Recent ; maximum in Eocene.
Subgenera : Vicarya d'Arcli. ; Clava Martyn (Fig. 982) ; Bcllardia Mayer, etc.
Potamides Brongt. (Figs. 983, 984). Turreted, with epidermis ; aperture with
emargination or faint canal. Inhabits only brackish water or
estuaries. Cretaceous to Recent.
Fig. 978.
Filnila undulosa
Piette. Bathou-
ian ; Eparcy,
Aisne.
Fig. 079.
Exelissa strangu-
lata (d'Arch.).
B a-t li o II i a n ;
Eparcy, Aisne.
Bittium pJicaJM7)i
Brng. Oligocene;
OriiKiy, near litampe.s,
France.
Fig. 981.
Cerithium serratum
Brug. Calcaire Gros-
sier ; Damery, near
Epernay.
Pig. 982.
Cerithium (Clava)
nudum, Lam. Eocene ;
Chaumont, near Paris.
Fig. 983.
Potamides (Tympano-
tumus) margaritaceum
Brocchi. Oligocene ;
Hackenheim, near Alzey.
Fig. 984.
Potamides (Lampaiiia)
plcurotomides Desh.
Middle Meere.ssand ;
Mortefontaine, Seine-et-
Oise.
Subgenera : Tympanotovms Adam.s (Fig. 983) ; Pyrazus, Telcscopium Montf.
Swains. ; Lampania (Fig. 984) and Pyrenella Gray ; Sandhenjeria Bosq.
Cerithidea
Family 18. Aporrhaidae Philippi.
Shell fusiform, turreted or conical ovate. Aperture produced anteriorly in a canal.
Outer lip expanded in a iving-like or digitiform fashion, or thickened. Operculum horny.
Marine. Jura to Recent ; maximum in Jura and Cretaceous.
Alaria Morris and Lye. (Figs. 985-988). Shell turreted ; aperture with long or
sliort canal. Outer \\\\ not overriding the last whorl, digitated or winged. Spire
CLASS IV
GASTROPODA
551
and body whorl often retaining traces of apertures at earlier stages. Veiy abundant
in Jura and Cretaceous.
Subgenera : Dicrolovm Gabb ; Anchura Conrad (Fig, 987).
Cretaceous. Diempterus Piette. Jura.
Jura and
Fig. 987.
Alaria myuras Desloiii;ch.
Lower Oolite ; Bayeux, Cal-
vados.
Fi(!.'!t86.
Alaria annata Morris
and Lye. Great Oolite ; Alaria (Aiichura) cari-
Minchinhanipton, Eng- nata Mant. Gaiilt ;
land. I Folkestone, England.
Fig. 988.
Sp in igc ra semica rinata,
(Goldfuss). Callovian ;
Montrei\il - Bellay,
Maine-et-Loire.
Spinigera d'Orl). (Fig. 988). Whorls keeled and ornamented with two opposite
rows of spines. Jura.
Aporrhais Ba, Costa {Ghenopvs Phil.) (Figs.
989-991). Like Alaria, but niai'gins of aperture
elongated posteriorly in a canal, whicli remains
either attached to the spire, or extends free from
the same. Outer lip expanded, digitated or lobed.
Jura to Recent.
Subgenera : Alices Conrad ; Arrhoyes, Tessarolax,
Hclicaulax Gabb ; Ceratosi'phon Gill ; Cuphosclenus,
Malaptera Piette ; Pterocercl la Meek ; Dimorphosoma
St. Gardner (Fig. 990) ; Lispodesthes White (Fig.
991). Jura and Cretaceous.
\^v
Fig. 989.
Aporrhais tridactijhis A. Braun. Oligo-
ceiie ; Hackenlieim, near Creuznach.
Fig. 990.
Aporrhais {Dimor-
phosoma) calcarata
8 o w b. Upper
Greensand ; Black-
down, England.
Fig. 991.
Aporrhais (Lispochsthcs) rcuasl Geinitz
var. megaloiitera Reuss.
Bohemia.
Planer ; Postelberg,
Family 19. Strombidae d'Orbigny.
Shell conical, turreted or fusiform, ivith acuminate spire. Aperture canaliculate ;
outer lip often expanded, anteriorly with an emargination. Opercuhim horny. Jura
to Recent.
Although the shells of this family are excessively variable, the soft parts of the
animals exhibit great uniformity of structure.
552
MOLLUSCA
PHYLUM VI
Harpacjodes Gill (Fig. 992). Spire sliort, Ijody whorl very large. Canal long,
reflected. Outer margin produced in a number of tubular spinous processes, the
posteriormost of which rests against the spire and extends
nearly to the apex. Jura and Cretaceous.
Pig. 992.
Ha'rpagodes oceani Brongt.
Kimineridgian ; Lindner Berg,
near Hannover.
Stromlms crassilaJirum Zitt. Gosan-
Cretaceous ; St. Gilgen, Austria.
Pterocera Lam. [Hepta-
dactylus Klein). Spire
short ; canal bent sideways.
Outer margin wing - like,
with tubular spinous pro-
cesses, beneath the most
anterior of which is a deep
notch. Kecent.
Pterodonta d'Orlj. ; Thersitea Coq. ; Pereiraea Crosse. Miocene.
Strombus Linn. (Oncoma Mayer) (Fig. 993). Shell ovoid, tuberculose or spinose,
solid ; spire with several whorls ; body Avhorl veiy large. Aperture
elongate, obliquely truncated and channelled anteriorly, canaliculate
I^osteriorly. Outer margin dilated in wing-like fashion, usually
thick, often proditced behind, sinuate and sometimes channelled
in front. Columellar liorder simple, enamelled. Cretaceous to
Eecent.
Pugnellus Conrad. Cretaceous. Struthiolaria Lam. Tertiary
and Eecent.
Seraphs Montf (TerebeUum Lam.) (Fig. 994). Shell elongate,
sul)-cylindrical ; spire short, summit obtuse. Body whorl very
large, smooth or striated. Aperture longitudinal, narrow pos-
teriorly, and slightly dilated anteriorly ; canal short. Outer
margin thin, simple, obliquely trimcated anteriorly, sometimes pro-
longed in the spire posteriorly by a callosity. Columellar border
smooth, straight. Tertiary and Recent.
Rosfellaria Lam. Spire high, whorls smooth. Aperture jsro-
Scrnphs sopitum '^^^^ced anteriorly in a beak -like canal, and continued posteriorly
(Brander). Caicaire as a narrow channel resting on the spire. Oitter margin with
near Paris. ° ' denticulate jirocesses, notched anteriorly. Late Tertiary and Recent.
Hi^ypochrenes Montf. {Gyclomops Gabb) (Fig. 995). Like the last.
))ut outer margin exj^anded in wing-like fashion, and destitute of processes. Uijper
Crgtaceous and Eocene.
Fin. 994.
CLASS IV
GASTEOPODA
Eimella Agassiz {Isopleura Meek) (Fig. 996). Surface cancellated,
with tliickened margin, entire or a
crenulated. Upper Cretaceous to Re-
cent.
Gablj. Spire wholly
hidden.
553
Outer lip
Orthaulax
involute and
Antilles.
Oligocene
Fig. 996.
Family 20.
Columbellariidae
Fischer.
Shell thick, elongated
oval, loith short conical ^U Rimella fismrella (Lam.).
, , ■ 77 Calcaire Grossier ; Damery,
spire, ana large, spirally nearEpernay. j:,i;.hartoncnsis
ribbed, frequenthl cancel- (Sowb.). Calcaire Grossier;
' •' ^ •> Grignon, near Pans.
lated body whorl. Aper-
ture narrow, anteriorly -with short canal, and pios-
teriorly ivith a canal directed^ obliquely outtvards.
Inner lip callous, outer lip often thickened, denti-
culated or somewhat reflected outwardly. Jura and
Cretaceous.
Pig. 995.
Hippochrcnes inurrMsoni Desli. Calcaire
Gro.ssier ; Damery, near Bpernay.
Fig. 997.
Columbellaria coral-
Una (Quenst.).
Pig. 998.
Zitteliu crassissima
Coral -Rag; Nat- (Zitt.). Titlionian ;
tlieiiii. Stramberg.
Fig. 999.
Pctersia costata
Gemm. Titlionian ;
Palermo.
Columbellaria RoUe (Fig. 997). Surface covered with numerous spiral ribs,
sometimes cancellated. Aperture long and narrow, broadening somewhat anteriorly.
Outer lip denticulated internally, not thickened, somewhat reflected. Anterior and
posterior canals short. Upper Jura.
Zittelia Gemm. (Fig. 998). Like the last, but aperture very narrow or cleft-like.
Outer lip much thickened in the middle. Titlionian.
Golumbellina d'Orb. Cretaceous. Petersia Gemm. (Fig. 999).
Tithonian.
Family 21. Cypraeidae Gray. Cowries.
Shell ovate, convolute. Spire shoii, nearly or completely covered in
the adult by the very large body whorl. Aperture of equal length with
the shell, narrotv, anteriorly and posteriorly produced in a tisually short
canal. Outer lip inflected. Operculum toanting. Upper Jura to
Recent.
Fig. 1000.
Cypraea suhexcisa
A. Braun. Oligo-
cene ; Weinheini,
near Alzey.
Recent Cypraeidae of which about 210 species are known,
inhabit principally the warmer seas. They are often remarkable for
their beautiful coloration, and sometimes attain considerable size. Jurassic species are
sparse ; Tertiary ones rather more abundant.
Cypraea Linn. (Fig. 1000). Ovoid, ventricose, enamelled, smooth, lirate or
554
MOLLUSCA
PHYLUM VI
tuberculate ; sj)ire exposed or enveloped. Aperture narrow, extending the whole
length of tlie shell, and canaliculate at each extremity. Inner lip and the inroUed
outer lip generally crenulate. Jura {G. titonica
Stefan i) to Recent.
Trivia Gray (Fig. 1001). Like the preceding,
but smaller, and sculptured with raised transverse
riblets. Anterior channel not prolonged, wide and
slightly reverted. Tertiary and Recent.
Erato Risso (Fig. 1002). Small, ovoid or pyri-
form, with sliort conical spire. Aperture narrow.
Inner lip smooth, except for anterior columellar
Canal notch-like, broad. Cretaceous to Recent.
Flo. 1001.
Trivia affin is (Diij.).
Miocene ; Pont-
levoy, Touraine.
Fig. 1002.
Erato laevis Don.
Miocene ; Nieder-
luis, Austria.
folds ; outer lip denticulate.
Family 22. Ovulidae Fleming.
Like the Gypraeidae, except that the spire is convolute instead of produced and
covered, and the marginal teeth
of the radula are peculiarly
modified. Tertiary and Recent.
Ovula Brug. Shell ovate
or fusiform, the spire completely
enveloped. Aperture produced
anteriorly and posteriorly as a
canal. Inner lip smooth ; the
outer reflected, smooth or
denticulated. Tertiary and
Recent.
Gisortia Jousseaume (Fig.
1003). Large, thick - shelled,
ovate, with short convolute
spire. Surface typically keeled
or coarsely tuberculate. Body
whorl with a blunt ridge ;
aperture anteriorly and posteriorly with a short canal.
gigantea (Goldf.).
Pedicularia Swainson. Sessile on corals. Miocene to Recent
Fig. 1003.
Gisortia tuberculosa Duclos. Lower Eocene (Londinicn);
Cuise Lamotlie.
Eocene. G. (Strombus)
Family 23. Cassididae Adams.
Shell thick, inflated, glohularly ovate, sometimes varicose; spire short, body whorl
very large. Aperture narrow, elongate, anteriorly
xvith short canal. Inner lip resting on an exten-
sive callus, sometimes granulated or ivrinkled.
Outer lip more or less thickened. Operculum horny,
with marginal nucleus. Marine. Upper Creta-
ceous to Recent.
Galeodea Link {Morio Montf. ; Gassidaria
Lam.) (Fig. 1 004). Shell ventricose, not varicose.
Canal long, twisted, reverted or bent sidewise.
Inner lip greatly expanded, outer lip reflected,
often crenulate. Columellar border plicate.
Upper Cretaceous to Recent ; maximum in
Eocene.
Fill. 1004.
Galeodea carinatu
Lam. Calraire Gro.s-
.sicr ; Grignoii, near
Paris.
Fig. lOOo.
Galeodea (.Scons iVi)
a;mhi(jua (Solander).
Oligocene ; Lattorf,
near Bernburtr.
CLASS IV
GASTROPODA
555
irregular
Subgenus : S'consia Gray (Fig. 1005)
Upper Cretaceous to Recent.
Cassis Lam. (Fig. 1006). Shell ovoid, ventricose, having
„^^j^ varices. Spire short, aperture elongate. Outer
lip thickened, reflected, usually denticulate in the interior.
Inner lip callous, expanded, denticulate, wrinkled or granii-
late. Canal very short, broad, sharply recurved, directed
uj)ward posteriorly. Tertiary and Recent.
Family 24. Doliidae Adams.
Shell thin, inflated. Spire very short, body whorl very
large, longitudinally ribbed or cancellated. Aperture ivide,
oval ; canal straight or curved. Oper-
culum absent. Cretaceous to Recent.
Last whorl with varix ; canal short and straight.
Fig. 100(5.
Cassis salmron Lam. Miocene ;
Gainfalirn, near Vienna.
Cretaceous to
Tonna Briinnich {Dolium Lam.).
Spirally ribbed. Outer lip notched
internally ; canal short, obliquely directed.
Recent.
Pyrula Lam. {Ficida Swainson) (Fig. 1007). Spirally
ribbed, grooved or cancellated. Aperture very wide ; outer liji
sharp ; canal long, broad, straight. Lower Cretaceous to
Recent ; maximum in Tertiary.
Family 25. Nyctilochidae Dall.
Fig. 1007. Shell thick, ovate to fusiform, ivith eindermis. Spire
Pyrula retimiata (Lam.), moderately high, whorls varicose, aperture ivith thickened outer
lip, and open, straight or slightly bent canal. Operculum horny,
with marginal nucleus. Cretaceous to Recent.
Miocene ;
Vienna.
Grund,
Oligo-
Nyctilochus Gistel {Tritonium Link ;
Triton, Lotorium Montf.). Spire elon-
gated. The varices do not run con-
tinuously over more than a few whorls.
Columella and inner lip callous or
granulated. Outer lip thickened inter-
nally and notched. Cretaceous to
Recent ; abundant in the Tertiary,
EtigTjrina Dall (Fig. 1008).
cene to Recent.
Distortrix Link {Personct Montf.).
Tertiary and Recent.
Bursa Bolten {Ranella Lam.) (Fig.
1009). Like Nyctilochus, but with two
opposite varices, which are continuous
over all the whorls. Tertiary and
Recent.
Superfamily 4. RACHIGLOSSA Gray.
Radula reduced to three teeth or to one tooth in a transverse series.
These are carnivorous marine forms, which have their initiation in the Mesozoic,
become somewhat numerous in the Cretaceous, and form an important element of the
Tertiary and Recent faunas.
Fig. 1008.
Eugyrina flandrica de
Kon. Oligocene ; Wein-
lieim, near Alzey.
Fig. 1009.
Bursa (Aspa) marip',iiata
Brocclii. Miocene ; Grund, near
Vienna.
5 56
MOLLUSCA
PHYLUM VI
Family 1. Oolumbellidae Troscliel.
Shell small, ovate to fusiform, covered with epidermis, imj^crforate. Aperture narrou\
.canal short. Outer lip denticulated internally, thickened in the middle.
Tertiary and Eecent.
The typical genus, Golumhella Lamarck (Fig. 1010), attains its
maximum distribution in the Tertiary and Eecent seas. It is divided
into a number of subgenera.
Fig. 1010.
Family 2. Buccinidae Troschel.
Columhella curta
Duj. Miocene ;
Lapugy, Transyl-
vania.
wide, ivith
Cretaceous
Buccinum
high
Shell elongate -oval, covered ivith epidermis. Aperture
short canal. Outer lip sharp or thickened. Operculum horny.
to Recent.
Linn. Inflated, smooth or transversely ribbed. Spire moderately
aperture wide ; canal short, wide, open. Outer lip sharp and thin, inner lip
somewhat callous. Distributed principally in waters of the more
northerly zones (B. imdatum Linn.). Fossil in the Crag and
Pleistocene.
Oominella Gray (Fig. 1011). Usually spirally ribbed. The last
whorl somewhat depressed beneath the suture, so that the aperture
forms a small groove posteriorly. Outer lip sharp or crenate inter-
nally. Upper Cretaceous to Eecent.
Pseudoliva Swains. (Fig. 1012). Like the last, but outer lip
with a small basal tooth or notch which
Fig. 1011.
corresj^onds to a groove on the body whorl.
UjJiier Cretaceous to Recent.
Pisania Bivona (Pisanella v.
Cominella cassidaria
A. Braun. Oligocene;
Hackenlieim, near
Alzey.
Koenen ;
Taurinia Bellardi). Elon-
gate-ovoid, sjjire moder-
ately high. Whorls
smooth or spirally
striated. Outer margin
thickened, notched inter-
nally. Tertiary and Re-
cent.
Cantharus Bolten
(Pollia Gray ; Tritonidea
Swains.) (Fig. 1013).
Oval, inflated ; spire and
aperture of about equal
length ; surface usually
spirally ribbed and transversely folded. Columella often with weak transverse folds ;
outer margin thickened, crenate internally. Aperture posteriorly with a short canal.
Tertiary and Recent.
Phos Montf. Shell elongate, bucciniform, turriculate ; spire sharp, elevated,
whorls ornamented with prominent longitudinal costae, and less salient spiral threads
and sulci, often varicose. Aperture oblong ; outer margin lirate within. Columella
excavated, plicate in front ; canal short, slightly twisted. Tertiary and Recent.
Eburna Lam. {Dipsaccus Klein) (Fig. 1014). Resembling Nassa, but smooth,
perforate, and with deeply incised sutures ; outer margin sharp. Tertiary and Recent.
Nassa Lam. {Alectrion Montf.) (Fig. 1015). Ovate, inflated. Aperture with short,
reverted canal ; inner lip callous, expanded ; outer margin usually crenate internally.
Fig. 1012.
Pseudoliva zitteli
Upper Cretaceous ;
Gora, Hungary.
Petlii').
Fru.sl<a
Fig. 1013.
Can tharus suhlamtus
(Bast). Miocene; Eiiz-
esfeld, neariVienna.
Fig. 1014.
EInt ma mronls
(Brongt.). Eocene;
Ronea, nearVicenza.
CLASS IV
GASTROPODA
557
Sparse in Upper Cretaceous and Eocene, abundant in Miocene and Pliocene ; living
species exceeding 200 in number, and distributed in numerous subgenera.
Cyclonassa Agassiz ; Oijllime Gray ; Truncaria Adams ; Buccino%isis Conrad.
Tertiary and Recent.
Chrysodomus Swains. {Nefhmea p.p. Bolten). Elongate-ovoid, inflated, sometimes
sinistral, with rather short and moderately bent canal. Cretaceous to Recent. C
contrarius Lam. Crag.
Siphonalia, Zemira, Metula Adams ; Euthria Gray ; Hemifusus Swainson (Fig.
1016). Tertiary and Recent. Mitraefusus and Genea Bellardi. Neocene.
Melongena Schum. {Pyrula
Lam. p.]).; Myristica Swains.) (Fig.
1017). Pyriform, inflated, with
short spire. Body whorl large,
longitudinally striated and beset
with nodes or rows of sjaines. Inner
Fig. 1015.
Na<isa clathrata Brocchi.
Pliocene ; Larniano, Tus-
cany.
Pig. lOlS.
Tudicla rusticula
(Bast.)- Miocene; Grand,
n(!ar Vienna.
Fig. 1010.
Hemifusus siCbcarinatus
(Lam.). Eocene (Sables
moyens) ; Senlis, Seine-
et-Oise.
Pig. 1017.
Melongena cornuta Agassiz Miocene ; Bordeaux.
Fio. 1019.
Strepsidura ficuhiea
(Lam.). CaleaireGrossier;
Damery, near Epernay.
lip smooth ; aperture gradually becoming merged into the short and wide canal.
Tertiary and Recent.
Busycon Bolten (Fulgiir Montfort). Tertiary and Recent.
Tudicla Bolten (Fig. 1018). Resembles Fulgur but has a straight and very long
canal ; inner lip with a fold. Cretaceous to Recent.
Strepsidura Swains. (Fig. 1019). Spire short ; body wdiorl inflated, transversely
ribbed ; canal curved. Eocene and Miocene.
Family 3. Muricidae Tryon.
Shell thick. Spire moderately high ; whorls %oith transverse swellings, ribs or folia,
and frequently spinose. Aperture rounded or oval; canal more or less elongated,
558
MOLLUSCA
PHYLUM VI
wholly or imrtially covered by margins of the inner and outer lips. OpermliLm horny.
Cretaceous to Keceiit.
Murex Linn. {Tigs. 1020-1022). Shell roimded, spire prominent. Surface with at
least three, often more than three varices or transverse rows of spines or nodes on each
whorl. Apei'ture ovate ; inner lip smooth, outer lip
thickened. Canal much prolonged, partially closed,
usually spinose. Cretaceous to Recent.
Fio. 1020.
Mwrex (Phylloiwtns) sedgwichi Miclit.
Miocene ; Gainfahrn, near Vienna.
Fig. 1022. Fig. 1023.
Fig lO'^l
Murex (Purpura) Typhis tuhifer
Murex sjiinicost a Bronn. t'nmriniituslja.m. Eo- Montf. Calcaire
Miocene ; Baden near cene ; Damery, near Grossier; Grignon,
Vienna. Bpernay. near Paris.
Subgenera : Haustellum Klein ; Rhinacantha Adams ; CMcoreus, Phyllonotus (Fig. 1020)
Montfort ; Purpura Martyn {Ptero7iotus Swsiinson) (Fig. 1022) ; Tritonalia Fleming {Ocinebra
Leach), etc.
Typhis Montf. (Fig. 1023). Like Murex, but with hollow spines. Canal short,
completely closed. Upper Cretaceous to Re-
cent.
Trofhon Montf Spire high. Longitu-
dinal ribs replaced by thin lamellae. Canal
open, somewhat curved. Tertiary and Recent.
Family 4. Thaisidae Dall,
Shell thick, usually ovoid; spire short,
body ivhorl large. Aperture wide, inner lip
and columella more or -less flattened ; canal
short. Operculum horny. Cretaceous to Re-
cent.
Fig. 1024,
Thais exilis
Partscli. Mio-
cene ; Miillcrs-
dorf, near Vienna.
Pio. 1025. Thais Bolten (Purpura Brug.) (Fig. 1024).
Rapana laxecarinahi Miclit. Imperforate ; body whorl witli transverse
ougocene ; Santa Giustina, j^.^y^g q^. ^^^^^^^ Aperture oval, columella flat-
tened, smooth. Tertiary and Recent.
Rapana Schum. (Fig. 1025). Like the preceding, but perforate. Inner lip callous,
expanded. Cretaceous to Recent.
Lysis Gabb ; Stenomphalus Sandberger. Cretaceous and Tertiary.
Sistrum Montf {Ricinula Lam.) ; Acanthina Fischer de Waldheim (Monoceros
Lam.) ; Goncholepas Lam. ; Gymia Morch, etc. Tertiary and Recent.
CLASS IV
GASTROPODA
Dot
Family 5. Fusidae Tryon.
Shell hirreted, fusiform or ovoid, generally without varices. Canal more or less
elongated. Inner lip smooth, or tvithioeak columellar folds ; outer margin thin. Oper-
culum horny. Jura to Recent.
These shells are sparse in the Upper Jnra and Cretaceous, but abundant in the
Fio. 102(5.
Fusus lonrjirostris
Brocchi. Miocene ;
15 a lie 11, near
Vienna.
Fig. 1027
Pig. 1028.
ClaveUa longiKims Lam. Siic.uinhulbiform,is{LiS.\n.). Cal-
Eocene ; Daniery, near caire Grossier ; Grignon, near
Epernay. Paris.
Fio. 1029.
Fasciolaria tarhdViaiia Grat.
Miocene ; Grund, near Vienna.
The animal differs somewhat from that of the Buccinidae and
Tertiary and Recent,
Muricidae.
Fusus Lain. (Fusinus Raf. ; Colus Humph.) (Fig. 1026). Shell narrow, elongate;
spire acuminate. Aperture ovate ; canal very long, straight, oiien. Outer margin
thin, sometimes crenulate, and often striate within ; columella smooth. Rare in
Upper Jura and Cretaceous, very profuse in Tertiary and Recent.
ClaveUa Swains. {Cyrtulus Hinds) (Fig. 1027). Thick-shelled, smooth or with
fine spiral striae. Body whorl suddenly contracted anteriorly. Canal
very long, straight. Common in Eocene; rare in Neocene and Recent.
Sycum Bayle {Leiostoma Swains.) (Fig. 1028). Spire short;
body whorl inflated, smooth, somewhat flattened below the suture.
Inner lip smooth ; canal straight. Common in the Eocene ; rare
in Miocene.
Fasciolaria Lam. (Fig. 1029). Like Fusus, but distinguished
in general ))y having a shorter spire, more inflated body whorl, a
wider and more sinuous or flexuous canal, and in that the anterior
portion of the columella has two or three oblique plications.
Cretaceous to Recent.
Latirus Montf. (Fig. 1030). Shell fusiform, turreted ; spire
costate. Aperture oblong, outer margin relatively thin, crenulate ; Lapugy j Transylvania!
Pio. 1030.
Latirus craticulatus
(d'Orb.). Miocene;
560
MOLLUSCA
PHYLUM VI
columella!' boi^der sliglitly twisted, with two or three small oblique plaits anteriorly ;
sometimes uml)ilicate. Cretaceous to Recent.
Pisanella v. Koeneii. Oligocene. Peristernia Miirch ; Leucozonia Gray. Tertiary
and Recent.
Family 6. Vasidae Adams. (Turbinellidae auct.).
Shell similar to those of the preceding family, hut with strong, horizontal columellar
folds. Tertiary and Recent.
Xancus Bolt. (Turhinella Lam. ; Mazza Adams ; Mazzalina Conrad). Thick-
shelled, ovate -conical, smooth; spire short and Idunt, body whorl large; canal
straight, elongated. Eocene to Recent.
Vasum Link {Cynodonta Schum.). Shell lieavy, strongly sculptured, often s^iinose,
with short canal. Tertiary and Recent.
Family 7. Volutidae Gray.
Shell thick, ovate to fusiform, didl or lustrous. Spire short or long, body whorl large.
Aperture elongated, with a short canal or notch; inner lip tvith columellar folds. Oper-
culum usually absent. Cretaceous to Recent.
This family, as here defined, contains genera distributed by malacologists amongst
several families — Marginellidae, Mitridae and
Volutidae — all of ^^'hich are characterised by the
strong development of columellar folds ; but it is
likely that this structure originated independently
in several I)hyla at intervals remote from one
anotlier. The initiation of well-marked genera
with Volutoid plaits occurred in the Cretaceous.
Subsequently their number increased, and a great
many generic tyjies became differentiated. The
phylogeny of Tertiary and Recent forms has been
ably worked out by Dall.^
Marginella Lam. (Fig. 1031). Shell oval or
oblong, smooth, glistening. Spire short ; aperture
narrow, slightly canaliculate anteriorly. Columella
with three or four oblique folds of about equal
size; outer margin frequently thickened and dentate.
Tertiary and Recent.
Mitra Lam. (Fig. 1032). Fusiform to elongate-
oval, solid ; spire high, acuminate ; aperture narrow,
channelled anteriorly. Columella with numerous
oblique folds, the posterior plaits
being often the strongest. Outer mai'gin commonly thickened, and
smootli internally. Abundant in the Tertiary and Recent.
Turricida Adams. Like the last, biit shell transversely ribbed.
Cretaceous to Recent.
Strigatella Swains. (Fig. 1033) ; Cylindromitra Fischer {Cylindra
Schum.) ; Imbricaria Schum. ; Volutomitra Gray ; Perplicaria Dall.
Tertiary and Recent.
Lyria Gray (Fig. 1034). Elongate -oval, transversely ril)l)ed.
Aperture narrow. Columella anteriorly with two much compressed
Fig. 1031.
Marginella crassula
Desh. Calcaire Gros-
sier ; Chaumont, near
Paris. 2/i.
Pio. 1032.
Mitra fusiformU
Brocchi. Plio-
cene ; Rhodes.
1038.
' Bull. Museum Comp. Zoology, vol. xviii., 1889 ; Proc. U.S. Nat.
Museum, vol. xii., 1890, Trans. Wagner Free Inst. Sei. Philad., vol. iii., 1890.
Strigatella InhmtnUi
(Ijam.). Eocene;
Grignon, near Paris.
CLASS IV
GASTROPODA
561
and very large plications, behind (above) which are numerous weaker ones. Outer
margiai thickened. Tertiary and Recent.
Ampulla Bolten (Halia Risso ; Priavius Beck). No columellar folds. Pliocene and
Recent.
Volutilithes Swains. (Figs. 1035-36). Shell fusiform, spire elongate-conical; proto-
conch small, rising to a more or less acute apex. Whorls costate, typically spinose.
Aperture anteriorly with short broad canal ; columellar folds variable, several in
number, those toward the anterior being generally the most pronounced. Abundant
in the Cretaceous, Eocene and Oligocene.
Allied genera : Gosavia Stol.; Leioderma and Bostellites Conrad ; Liopeplum Dall ;
Volutoderma (Fig. 1037) and Volutomorpha Gabb. Cretaceous.
Athleta Conrad. Spire short, body whorl inflated, posteriorly with a row of
Fi(i. 1034.
Lyria modeda
A.Braun. Oligo-
cene ; Weinheiin.
Fia. 1035.
Volutilithes bicorona
(Lam.). Eocene; Cour-
tagiion, near Epeinay.
Fig. 1036.
Volutilithes innriciMis Lam.
Calcaire Qrossier ; Dameiy,
near Epernay.
Fig. 1037.
Volutoderma elon-
fjitia d'Orb. Gosau-
Cretaceous ; St. Gil-
sen, Austria.
spinous nodes. Inner lip callous, much expanded ; columella anteriorly with three
strong transverse folds, behind (above) which follow a few weaker ones. Outer
margin thickened. Miocene and Pliocene.
Hcafliella Swains. Shell in this genus is elongate-oval or fusiform, solid, l)road, and
with elevated, turbinate, smooth protoconch. Spire short, longitudinally plicate, the
folds being elevated into obtuse tu].)ercles on the base of the whorls. Aperture narrow,
canaliculate behind and broad in front ; inner margin often covered by a thin callus.
Columella carrying many plaits, four or five of which are prominent, the remainder
much smaller. Tertiary and Recent.
Subgenera: Fulgoraria Schum. ; Scapha Gray; Zidona Adams; {Volutella d'Orb.);
Aurinia Adams {Volutifusus Conrad) ; CariceUa Conrad ; Adclomelon and Eucymba Dall, etc.
Valuta Linn. Spire short, protoconch small. Aperture narrow, inner lip callous,
with numerous transverse folds ; outer margin thickened. Tertiary and Recent.
Melo Humphr. {Gymhiuvi pars, Bolten). Recent.
Family 8. Harpidae Troschel.
Spire depressed ; body ivhorl inflated, with sharp, uniformly spaced transverse ribs.
Aperture wide, with short broad canal. Inner lip callous. Operculum absent. Tertiary
and Recent.
VOL. I 2 0
562
MOLLUSCA
PHYLUM VI
The typical genus Harpa Lam. {Silia Mayer) (Fig. 1038), ranges from the Eocene
to the present time.
Cryptochorda Murch (? Harpopsis Mayer)
(Fig. 1039). Elongate-oval ; spire short,
body whorl large, smooth, lustrous. Aperture
with short recurved canal ; inner lip callous.
Common in the Eocene.
Family 9. Olividae d'Orbigny.
Fig. 1038.
Harpa mutlca Lam.
CalcaireGrossier; Grig-
non, near Paris.
Fio. 1039.
Vryjitochorda strom-
hoidcs (Lam.). Calcaire
Grossier ; Uamery, near
Epernay.
Shell elongate-oval to subcylindrical, solid,
smooth and glistening. Spire short ; body
whorl very large. Aperture narrow ; outer
lip sharp ; colitmella anteriorly loith an out-
loardly reflected callus. Canal very short.
Cretaceous to Eecent.
Oliva Martyn (Fig. 1040). Shell subcylindrical ; suture line marked by a deep
groove. Columellar callus obliquely folded. Cre-
taceous to Recent.
Olivella Swainson. Small, with acute en-
amelled .spire. Tertiary and Recent.
Ancilla Lam. (Ancillaria Lam.) (Fig. 1041).
Shell oblong, occasionally acuminate. Suture
usually covered over by a lustrous enamel -like
callus. Aperture somewhat bi'oadened anteriorly ;
columellar callus slightly twisted. Cretaceous to
Recent.
Superfamily 5. TOXOGLOSSA Troschel.
1040.
(Jlh-a dai'ukt Lam.
Miocene ; Dax, near
Bordeaux.
Fig. 1041.
Ancilla ijlandi-
fonnis Lam. Plio-
cene ; Steinabrunn.
Radula typically with only two arroio-shaped
teeth in each transverse row, although occasionally as many as five teeth are developed'
Shell similar to that of the Rachiglossa.
This group is most closely allied to the Rachi-
glossa, from which it probably became differentiated
in the Cretaceous. The Tertiary and Recent species are
excessively profuse. All are carnivorous and marine.
Family 1. Cancellariidae Adams.
Shell oval to tiirreted. Spire acuminate ; body
whorl inflated ; surface transversely ribbed and in most
cases cancellated. Aperture with short canal or notch ;
columella with several strong oblique folds, outer lip
grooved internally. Upper Ci'etaceous to Recent.
The typical genus Gancellaria Lam. (Fig. 1042)
attains a maximum distribution in the late Tertiary and Recent.
Firi. 1042.
Canixllaria can
(;eHafci(Linn.). Mio
cene ; Gainfalirn
near Vienna.
Family 2. Terebridae Adams.
Shell turreted, slender, acuminate, with small body ivhorl. Aperture
oval or quadrilateral ; canal short, curved ; outer lip sharp. Oper-
culum horny. Tertiary and Recent.
Of the two leading genera, Terebra Lam. (Fig. 1043) and Hastula Adams, the first
Pio. 1043.
Terebra (wiivi inata
Borson. Miocene ;
Baden, near Vienna.
CLASS IV
GASTROPODA
503
is characterised by a line running parallel with the suture, and creating a narrow
suture band. JJuplicaria Dall has the suture channelled.
Family 3. Turritidae Adams {Plexhrotomidae Stoliczka).
Shell fusiform, with moderately high spire. Aperture elongated, j)roduced anteriorly
in a longer or shorter canal. Outer lip with a slit or notch below the suture. Operculum
horny, sometimes absent. Cretaceous to Recent.
Upwards of 700 recent and 1000 fossil species have been described, of which 28
are Cretaceous.
Turris Bolten (Pleurotoma Lam.) (Figs. 1044-1047). Shell turriculated, spire long.
A B ' C A B
Pig. 1044.
A, Turris noiata (Brocchi) var. {=T. monilis
Hoernes). Miocene ; Baden, near Vienna. B, T. (Sur-
cula) Iwmarcki Bell. Miocene ; Baden, near Vienna.
C, T. {Surcula)'hclgica Nyst. Oligocene ; Weiuheim,
near Alzey.
Fig. 1045.
A, Turris (Genota) ramosa Bast.
Miocene ; Grund, Hungary. B,
T. (Cryptono7ms)fllosa (Lam.). Cal-
caireGrossier; Grignon, near Paris.
Body whorl of nearly equal length with the spire ; canal long and straight ; columellar
margin smooth. Outer mar-
gin of the aperture with a
narrow, deep sinus, situated
at or some distance below the
suture. Operculum pointed
ovate, with ajaical nucleus.
Cretaceous to Recent.
Subgenera :
Surcula (Fig.
1044, B, C) ; Genota Adams
(Fig. 1045, A) ; Bathytoma
Harris (Fig. 1046) ; Oligotoma,
Eouaultia Bellardi ; Cryjito-
C071US V. Koenen (Fig. 1045, B) ;
Drillia (Fig. 1047) ; Bela Gray ;
Lachesis Risso, etc.
Glavatula Lamarck (Fig.
1048). Differs from Turris
Fig. 104T.
Turris (Drillia)
incrassata Duj. Mio-
cene ; Steinabnmn,
near Vienna, -/i.
notch, and the nucleus of the
operculum is situated in the middle of the anterior margin
Suljgenera : Pseudotoma, Glinura Bellardi.
Turris (Bathytoma)
proper in that the outer margin cataphracta Brocchi.
. , 1 Ti J • 1 Miocene ; Baden, near
is cut by a shallow triangular Vienna.
Pig. 1048.
Clavatula asperulata
Lamarck. Miocene ;
Grund, Hungary.
Cretaceous to Recent.
564
MOLLUSCA
PHYLUIM VI
Borsonia Bellardi (Fig. 1049). Outer margin with a shallow notch i canal long
and straight ; columella with one or two folds ; operculum unknown. Eocene to
Recent.
Mangilia Risso (Fig. 1050). Shell small, fusiform, imperforate and typically,
with longitiidinal costae or swellings. Aperture commonly narrow, witli a short.
B
Fig. 1049. •
Borsonia delvcii
Nyst. Lower Oligo-
cene ; Lattdoiff, near
Bernburg.
Fig. 1050.
Mangilia anguMa
Jan. Pliocene ;
Occiano, near Pisa.
Pio. 1051.
A, Clathurella strom
billa Duj. Miocene
Kienberg, near Vienna,
B, BeUardkila reticu
lata (Brocchi). Plio
cene ; Sassuola, near
Modena.
Fig. 1052.
Daphnclla {Raphi-
toma) vulpccnla
Brocclii. Pliocene ;
Sassuola, near
Modena.
truncated canal ; no operculum ; sinus near the suture. Outer margin usually acute,
not dentate posteriorly with shallow notch. Tertiary and Recent.
Allied genera are the following: Glathurella Carp. (Fig. 1051, A); Bellardiella
Fischer (Fig. 1051, B); Atoma Bellardi; Ghjflio-
stoma Gabb; Daphnella Hinds, with subgenus Baphi-
toma Bellardi (Fig. 1052) ; Eucythara Fischer, etc.
Family 4. Oonidae Adams.
Shell convolute, turbinate or subcylindrical,
generally smooth. Spire short, conical or flattened.
Aperture long, narrow, anteriorly notched. Outer lip
sharp, sometimes with an anal sinus belov: the suture.
Columella smooth. Operculum horny. Cretaceous to
Recent.
This family is now enjoying its acme of
development, having entered upon its ascendency
during the Tertiary. The typical genus, Conus
Linn. (Fig. 1053), is divided by malacologists into
.1, ro««s ponto-o7«,rBrocchi. Miocene; numerous subgenera, connected with one another
Lapugy, Transylvania. B, c. iMviumnis by intermediate fomis. It is initiated in the
Part. Calcaire Grossier; Grignon, near c,.ej.ace0US.
Gonorbis Swains. Characterised by a liigh
spire, and a curved, outer lip, which is deeply notched posteriorly. Eocene and
Oligocene.
FiQ. 1053.
Subclass 2. EUTHYNEURA Spengel.
Gastropods in which the visceral nerve commissures are not crossed, but form a simple
loop ; the sexes are united Qiermaphroditic) ; and the heart is often in front of the gill.
Shell spiral or saucer-shaped, fi'equently vestigial or absent ; operculum generally wanting.
Radula generally multiserial.
CLASS IV GASTROPODA
Order 1. OPISTHOBRANCHIA Milne Edwards.
Marine, ivater-breathing forms, either naked or shell-covered, in ivhicli the gills are
placed behind the heart and lie free on the back or side ; or true gills may be absent,
being replaced by secondary or false gills. Heart with a single auricle.
The Opisthobrancliiates, unlike the Streptoneura (Prosobranchiates), send the blood
into the heart from behind, instead of fi-om the anterior side. The gills, in the form
of a more or less branched plume, lie on the right side, or are replaced by false gills
not homologous with the ctenidium, arranged either in two rows on the back, or
wreath-like arouiid the anus. The gills are often covered by the mantle, and some-
times become completely atrophied. The radula generally resembles that of the
Pulmonates. The body and nervous system usually exhibit bilateral symmetry.
Three suborders are recognised in the recent fauna : (1) Nudibranchiata, in which
a shell is absent, except during the larval stage, and the ctenidium is replaced by false
gills ; abundantly distributed in all seas at present, but owing to their perishable
nature are unknown as fossils ; (2) the Tectibranchiata, in which a mantle, shell and
ctenidium or true gill is developed ; and (3) the Pteropoda, dating from the Cambrian,
and from which the second suborder is perhaps derived. A provisional fourth sub-
order, the Conularida, contains Paleozoic forms of doubtful affinities, of which part
are probably not Mollusca.
Suborder B. TECTIBRANCHIATA.^
This group, briefly defined above, has fossil representatives as early as the
Paleozoic. During the Mesozoic, a few genera now extinct were very profuse. Most
of the Tertiary species belong to existing genera.
Family 1. Acteonidae d'Orbigny.
Shell ovate, with exposed spire, the surface usually grooved and punctured, sometimes
smooth. Aperture long, rounded beloiv ; columella generally twisted, or with folds.
Operculum paucispiral. Carboniferous to Recent.
Solidula Fischer von Waldheim {Buccinulus Adams ; Dactylus Schum.). Ovate or
oblong, compact, solid, with a short conic siiire. Columella bearing two plications, the
anterior prominent and bifid, the jiosterior comparatively inconspicuous when the
shell is entire ; between them the columella is spii'ally excavated.
A few ill-defined species from the French Eocene and Miocene, one
from the Australian Pliocene, and numerous Recent tropical species
are known.
Tornatellaea Conrad (Fig. 1054). Differs from Solidula and
Acteon in the more anterior disposition of the two columellar
plications, in the marked depression on the anterior portion of the pio. 1054.
aperture, and in the greater thickness of the shell near the outer Tomatdiaea sim-
border of the aperture, which is frequently crenulated. Base of Jura ceTef ilattdof f^
to Miocene ; widely distributed. Type, T. bella Conrad. Subgenus : near Bemburg.
Triploca Tate. Eocene ; Australia.
Acteon Montf. (Tornatella Lam. ; Speo Risso ; Kanilla Silvert.). Oval, spirally
punctate-stria te, with conic spire. Protoconch not very prominent ; nucleus sinistral.
1 Literature (see also preceding bibliographies) : Cossmann, M., Essais de paleoconcliologie
comparee, i., 1895.— PiMry, II. A., Monograph of Recent Tectibranchiata, in Manual of Conch-
ology, vols. XV., xvi., 1894-95.
566
MOLLUSCA
PHYLUM TI
Columella thick, with one strong, spiral, slightly oblique plication. Upper Cretaceous
to Recent.
Adelactaeon Cossni. {Myonia Adams). Shell with sinistral protoconch, the latter
not very large. Whorls decussated by fine striae, growth -lines
inconspicuous. Columella slightly excavated, and carrying a
small but well-marked plication. Miocene of France and Ger-
many, and Recent.
Fio. 1U56.
Actaeonina myosotis
Buv. Coral-Rag; St.
Miliiel, Meuse. "-/i
(after Buvigiiier).
Fig. 1055.
Actaeonina dnrmoisiana
d'Orb. Coral-Bag; Val-
fin, Aiii.
Fio. 1067.
Cyltndrites acntus
(Sowerby). Great
Oolite; Minchin-
haiupton, England.
Fifi. 1058.
Actaeonelln girjantca Sowb. Turonian ;
Griinbach, Lower Austria.
Actaeonina d'Orb. {Orthostoma Desh.) (Figs. 1055, 1056). Shell ovoid to fusiform,
usually smooth, rarely spirally striated. Spire conical, body whorl very large,
narrowing toward the base. Columella straight, without folds.
Outer lip sharp. Carboniferous to Recent.
Subgenera : Euconactaeon, Conactacon Meek.
Lias. Douvilleia Bayle. Tertiary.
Cylindrites Fer. (Fig. 1057). Cylindrical-
ovoid with short spire. Columella with an
anterior fold. Trias to Cretaceous.
Bullina Fer. Jura to Recent. CyUndro-
hnllina v. Amnion. Trias and Lias. Etallonia
Desh. Jura and Tertiary. Bullinida Beck.
Jura to Recent.
Actaeonella d'Orb. (Figs. 1058-1060).
Thick -shelled, inflated, smooth. Spire short;
columella thickened anteriorly, with three
sharp folds. Very profuse in the Middle and
Una) laevis Sowb. Upper Cretaceous ; maximum distribution in
Turonian, Gcsau. , ■, tt • • ^ t • ^ c J.^ ^.^
tne Hippurite Limestone oi the Alps.
Fic!. ]0r,9.
Actaeonella volnta
Goldf. Turonian;
Gams, Styria.
Fio. 1060.
Actaeonella (Volrn-
Subgenus
Cretaceous.
Volmilina Stol. (Fig. 1060). Like tlie preceding, but witli iiisunken spire.
Volvaria Lam. Cylindrical, witli involute, concealed spire. Surface usually
spirally striated ; aperture narrow ; columella with four anterior plications. Eocene.
Ovulacfaeon Dall. Similar in form to Gy2)raea, l)ut without jilications. Recent.
CLASS IV
GASTROPODA
567
Family 2. Ringiculidae Meek.
Inopemdate forms resembling the Actaeonidae in having columellar folds. Creta-
ceous to Recent.
Ginulia Gray (Fig. 1061). Globose, inflated, spirally grooved or punctate. Spire
short ; ajjerture crescentic ; outer lip reflected and thickened. Columella and inner lip
with numerous transverse folds. Cretaceous.
Subgenera : Avellana, Ringinella d'Orb. ; Eriptycha Meek ; Fortisia Bayan. Eocene.
Ringicula Desh. (Fig. 1062). Small, ovoid to globose, thick-shelled, with manimil-
lated protoconch. Spire short ; body whorl large, usually smooth. Ajjerture canal-
Fi(i. 1061.
A, Cinulia {AvcUana) incrasstata (Mant.). Gault ; Perte du
Rhone. B, C. (RhigineUa) Uwhryma Mich. Gault; P^olkestone,
England. C, ('. {Eriptycha) drcurtnla Zekeli. Turonian ; Gosau,
Austria.
Fiti. 1002.
Ringicula hoernesi
Seguenza. Miocene ;
Steinabrunn, near
Vienna.
iculate jiosteriorly, excan^ated anteriorly. Columellar border thick and callous ; the
columella arched, and furnished with from two to four plications. Outer margin
usually very thick, reflected, and occasionally denticulated within Cretaceous to
Recent.
Pugnus Hedley. Cylindrical, with sunken S2)ire. Recent.
Family 3. Akeratidae Pilsbry.
Shell oval or cylindrical, thin and fragile, the spire low or concealed. Tertiary and
Recent.
Akera Miiller (Fig. 1063). Thin-shelled, flexible, with ex])osed, truncated spire.
Whorls separated from one another by deep sutures. Sutures
deep and prominent ; outer lip separated from the sjjire.
Eocene to Recent.
Haminea Leach. Oval, thin -shelled, brittle; the spire
concealed. Tertiary and Recent.
Fig. 1003.
Akera striatella Lam.
Oligocene ; Castel Goniberto,
near Vieenza.
Family 4. Hydatinidae Pilsbry.
Globose or oval, with exposed, nearly level spire and tilted
pirotoconeh. Jura to Recent.
Hydatina Schumacher. Jura to Recent. Aplustrum. Schumacher ; Micromelo
Pilsbry. Recent.
Family 5. Bullariidae Pilsbry (emend.).
Shell oval or sub-globose, involute, smooth. Spire sunken and concealed. Aperture
long, rounded anteriorly ; outer lip sharp. Marine. Jura to Recent.
Bullaria Raf. {Bulla Linn.) (Fig. 1064). Oval, inflated, with sunken spire and
perforated apex. Aperture rounded posteriorly and anteriorly. Jura (?) to Recent.
568
MOLLUSCA
PHYLUM VI
Family 6. Acteocinidae, novum (Tornatimdae Fischer).
Radula unarmed. Tertiary and Recent.
Adeocina Gray {Tornatina Adams) (Fig. 1065). Cylindrical, with projecting
spire, and sinistral, tilted j)rotoconch. Columella bearing a single
fold. Tertiary and Recent.
Retnsa Brown. Shell resembling Cyliclma. Tertiary and
Recent.
Volvula Adams {Vohulella Newton).
Fusiform, the body whorl forming a point
above the spire. Eocene to Recent.
Fk:. 1064.
Bnllaria am-piiUa
(Linn.). Pliocene ; Asti,
Italy.
Fig. 1065.
Actcocina exerta
(Desli.). Oligocene ;
JeiiiTPs, near Btampe.s
(after Uesliayes).
Family 7. Scaphandridae Fischer.
Spire concealed ; radula with few teeth in a
row. Trias to Recent.
Scaphander Montf. (Fig. 1066). Shell sub-cylindrical, with epidermis, usually
spirally striated. Body whorl of enormous capacity, much dilated
anteriorly. Columella sx)iral, leaving a false umbilicus. Creta-
ceous to Recent.
Atys Montf. Cretaceous to Recent. Diaphana Brown. Ter-
tiary and Recent. Smaragclinella Adams. Recent.
Cylichna Loven {Bullinella Newton) (Fig. 1067). Small,
cylindrical, solid ; spire deeply perforated at
the .«ummit ; body whorl covering all the
others. Aperture very narrow, outer margin
lower than the axis of the shell. Columella
thickened anteriorly and bearing a small plica-
tion ; often umbilicated. Trias to Recent.
Fk;. 1066.
Scujihaiuler coniciLs
Desli. Eocene ; Brack-
lesliam, England.
Family 8. Philinidae Fischer. ^'"- ^°'^'-
Cyliclina conoidra
Similar to Scaphandridae., but shell internal, welnhehn, neai^A^izey.'
loosely coiled, pnmctate. Cretaceous to Recent.
Philine Ascan. {Bullaea Lam.) (Fig. 1068). Cretaceous to Recent.
Family 9. Umbraculidae Pilsbry.
Shell limpet-shaped, with low sub-central apex, and sharp, thin edges. Tertiary and
Recent.
Umbracidum Schum. {Umbrella Lam.). Shell orbicular, broad,
patelliform, ornamented exteriorly with concentric lines of growth ;
internal surface with concentrically undulating striae. Eocene to
Recent.
Other families of Tectibranchiata, such as Aplysiidae, Pleuro-
branchidae, etc., aie rej)resented in the Recent fauna, but their thin,
I'hiihie pxcavata often membranous shells have not been found fossil. The suj^posed
CalVamr" Gross^er''; Aphjsias I'eported from the Pliocene by Pliilippi are flakes from the
Gri-non, near Paris.' interior of Pelecypod valves.
CLASS IV GASTROPODA 569
Suborder C. PTEROPODA Cuvier.^
Naked or shell-covered, herviapliroditic, i)elagic Molhisca, ivithout distinct head. Eijes
rudimentary, and foot modified so as to form tvjo lateral, wing-lihe fins, situated on the
anterior end of the body. The gills are placed behind the heart.
The body of these free-swimming Mollusca is sometimes elongated, sometimes coiled
posteriorly in a spiral. In some instances it is covered by a thin transj^arent shell
(Thecosomata), but oftener it is naked {Gymnosomata). The creatures associate in vast
swarms in the open sea, and rise to the surface toward nightfall. Their shells often
accumulate in prodigious quantities on the sea-bottom, forming calcareous deposits of
considerable magnitude.
Cuvier recognised the Pterojiods as an independent class of Mollusca, having equal
rank with the Gastropods. Modern researches, however, have apjjroximated them
more closely to the latter through the swimming Opisthobranchs. If we regard it as
probable that invertebrate life began in the sea, it almost certainly follows that
Pterojjods are among the earliest Mollusca. Also, granting that the conditions of
their existence have undergone no appreciable change since the ocean became capable
of sustaining siich pelagic life, there is no obvious reason why the members of the
grouji should have since experienced any radical modification.
The earlier paleontologists, d'Archiac, de Verneuil, Sandberger, Barrande and
others, recognised the true relations of the Paleozoic Pteropods, though uniting with
them some forms of similar appearance, which probably are not of molluscan nature,
such as Conularia, and perhaps Tentacnlites.
Neumayer and Pelseiieer, led by preconceived theories, have objected to the imion
of Paleozoic forms like Hyolithes with the Pteropods, though proposing no satisfactory
alternative ; and by a curious reversal of paleontologic succession, have wished to
derive the PterojDoda from the more modern Opisthobranchs. Since the anatomy of
the Cambrian forms seemed inaccessible, the uncertainty bade fair to remain permanent,
when, by the discovery of the wonderful Middle Cambrian deposits of the Canadian
Rocky Mountains, among the other fossils showing traces of the soft parts, were found
several specimens of Hyolithes carinatus Matthew, with distinct and clear impressions
of the pteropodia. These, judging from the sharpness of their anterior margins, seem
to have had there some kind of a chitinous supjDort, perhaj)s like the chitinous rods
supporting the gill-lamellae of some Nuculidae." This wholly unexpected confirmation
of the earlier view as to the relations of these fossils, falls in with the views generally
held by malacologists as to the derivation of the swimming OiJisthobranchs from the
^ Literature (see also preceding bibliographies) : Sandberger, G., Die Flossenflisser oder Ptero-
poda. Neues Jalirb. liir Mineral., pp. 8-25, 1847. — Barrande, J., Pugiunculus, ein fossiles
Pteropoden-Gesclilecht. Neues Jahrb. fiir Mineral., pp. 554-558, 1847. — Systenie Silurien du centre
de la Bohenie, vol. iii. Pteropodes, 1867. — Salter, J. W., Memoirs of the Geological Survey of
Great Britain, vols, ii., iii., 1848, 1866. — Se.guenza, G., Paleontologia malacologica dei terreni terziarii
del distretto di Messina. Pteropodi ed Eteropodi. Mem. Soc. Ital. Sci. Nat. Milauo, vol. ii., 1867.
— Karpinsky, A . , Die fossilen Pteropoden am Ost-Abhang des Ural. Mem. Acad. St. Petersbourg,
ser. 7, vol. xxxii. pp. 1-20, 1884. — Doll/us, G. and Ramond, G., Liste des Pteropodes du terrain
tertiaire parisien. Mem. Soc. Malacol. de Belgique, vol. xx., 1885. — TfWco«, C. D., Contribution
to Studies on the Cambrian Faunas of North America. Bull. U. S. Geolog. Survey, vol. iv. No. 30,
pp. 125-146, 1866. — The Fauna of the Lower Cambrian or Olenellus Zone. Tenth Ann. Rept.
U.S. Geol. Survey, 1890. — Pelseneer, P., Report on the Pteropoda. Report Challenger Expedition,
Zoology, vol. xxiii., 1888.— /c?e»i, Bull. Soc. Beige de Geol. Palaeont. et HydroL, vol. iii., 1889.—
Blanckenhdrn, M., Pteropodenreste aus der oberen Kreide Nord-Syrieus uud aus dem hessischen
Oligocan. Zeitschr. Deutsch. Geol. Ges., vol. xli., 1889. — NovCik, 0., Revision der palaozoischen
Hyolithiden Bohmens. Abhandl. Bohm. Ges. Wiss. [7] vol. iv., 1891.— i/oZm, G., Sveriges Kam-
brislv-Siluriska Hyolitlddae och Conularidae. Afhandl. Sver. geol. Underscik., Ser. C, No. 112,
l^^^.— Slater, I., Monograph of British Conulariae. Palaeont. Soc, 1%Q1 . — Walcott, C. D., Cam-
brian Geology and Paleontology. Smiths. Misc. Coll., 1912, vol. Ivii., No. 5.
"A figure of this fossil is given by Walcott in Smithson Misc. Coll., 1912, vol. Ivii., No. 5.
570
MOLLUSCA
PHYLUM VI
same stem as the Pteropoda, and their natural association with the latter in a single
lai-ge group.
Family 1. Limacinidae Gray.
Shell thin, spiral, sinistral, with vitreous, patocispiral operculum. Tertiary and
Recent.
The genus Limacina Lam. {Spirialis Eyd. and Soul. ; Embolus Jeffreys), is of
sporadic occurrence in the Tertiary (Eocene and Pliocene). Valvatina Watelet,
includes flat sinistral shells from the Calcaire Grossier of Paris, and Planorbella Gabb
comprises similar forms from the Oligocene of San Domingo.
Family 2. Cavoliniidae Fischer.
Shell symmetrical, thin, vitreous, ventricose, pyramidal, or conically tuhiform,, hut not
spiral. Cretaceous to Recent.
Gavolina Abildgaard (Hyalaea Lam. ; GamojAeura Bellardi) (Fig. 1069). Shell
globose, laterally keeled and slit, acuminate pos-
teriorly ; composed of two unequally arched pieces,
one of which projects helmet-like above the other.
Recent, and fossil in the Italian IMiocene and
Pliocene.
Clio Linnaeus {Glcodora Peron and Lesueur ;
Balantium Benson ; Flahellum., Poculina Bellardi)
(Fig. 1070, A, B). Shell somewhat angular, com-
FiG. 1060.
A, Carnlinct {Hyalaea) t
lecent. B, C,
Sism. Miocene ; Turin, Italy.
.-a m) tridrntata Porsk. pressed dorso-ventrally, with lateral keels. A crest
Recent. B, V, (J. (Gamopleura) taurmensis ., ■■, -i •. -f ]• n ^ „ f1 <a
or rib generally extends longitudinally along the
back, and usually projects. Upper Cretaceous to
Recent. A common fossil in the Pliocene of Monte Mario, near Rome, and in the
vicinity of Messina and Turin ; also in the Oligocene of the Mayence Basin, and in
the English Crag.
Fiii. 1070.
A, Clin (Claoilora) pyramidata Linn. Pliocene ;
Monte Mario near Rome. B, Clio (Balantii(.m) rc-
mrniiii A. Adams. Recent. Animal with .shell (after
Adams). C, VaijinrUa drpr(t<><a Daudin (Cleodnra
stmnguliitn Desh.). Miocene; Dax, near Bordeaux.
Pig. ion.
A, Crc.teis rrctn Lesueur. Recent (after
Ailanis). B, Styliola striatuhi. Novak. Devonian
(Etatie H) ; Hlubocep, Bohenjia. 3/,. C, Creseis
clavidnn Barr. Devonian (Etaue H) ; Ilostin,
near Prague, Bohemia. Several individuals on
slate-fragment. Vi-
Subgenus: Creseis Rang [Crisia Menko) (Fig. 1071, A, C). Shell conical, straight,
elongated ; surface smooth or faintly striated ; dorsal groove not parallel to axis of the sliell,
but slightly sjnral, with only the anterior extremity (which ends in a rostrum) in the median
lino ; enibryoni(! portion ends in a iwinted a]>e\. Tertiary and Recent.
Styliola Lesueur (Fig. 1071 H). Conical, with bulbous iirotoconeli, no dorsal groove,
aperture circular.
CLASS IV
GASTKOPODA
571
In the Devonian of Bolieniia, Nassau, Ural and North America, great nnmhers of smooth,
circnLar, longitudinally striated tubes are occasionally met with, the posterior end of which is
inflated into a small Inilb. Similar tubes have also been described by Blankenhorn from the
Cretaceous of Syria. None of these differ externally to any great extent from Clio or Hiyliola.
Vaginella Daudin (Fig. 1070, C). Shell long, ventricose, depressed
slightly caiialiculated and compressed laterally. Cross-section elliptical
Cretaceous to Recent. a h
Gumerina Boas ; Trij^tera Quoy (Tihiella
0. Meyer). Tertiary and Recent. Euchilotheca
Fischer. Eocene.
f^te
SJ
Fig. 1072.
Family 3. Hyolithidae Nicholson.
Shell symmetrical, conical or pyramidal,
straight or sharply bent ; cross-section triangular,
elliptical or lenticular ; one side often flattened,
and the other arched or with a blunt median keel.
Siorface smooth or with fine transverse striae, rarely
longitudinally striated or ribbed. Aperture com-
pletely closed by an operculum, the latter being
semicircular, triangular or lentiform, with lateral
nucleus, and concentrically striated ; pteropodia, . A, B, liyoUthes elegans Barr. Oidovician ;
•,i 7 • , • J J j7 i ■ J (Etage D) ; Lodenice, Bohemia. Slightly ve-
Wlth a chltmous support to the anterior edge. ^j,ced. C, H. maxima Ban-. Cambrian
Cambrian to Permian. (Etage C); Mleschitz, Bohemia. Anterior
portion restored, with opercnUmi, and viewed
According to Holm the typical genus, ^anfie^'"' ''''^''' ^'^' -^' '-Operculum (after Bar-
Hyolithes Eichwald {Theca Sowb. ; Pugiuncuhis
Barr.) (Fig. 1072), is divisible into two subgenera. One of these, Orthotheca Novak,
contains forms with an abruptly truncated anterior end ; and in the other, Hyolithes
s. str., the margin of the flattened side projects somewhat above the opposite wall.
^^ ;. fi The forms known as Cleidotheca, Gentrotheca Salter,
Gamerotheca, Diplotheca Matthew, Pharetrella, Hall,
Geratofheca and Bactrotheca Novak, fall within the
synonymy of Hyolithes. This genus is abundantly
distributed in the Cambrian, Ordovician and Silurian
of North America, Great Britain, Sweden, Russia and
Bohemia ; it occurs sparingly also in the Devonian,
(Jarboniferous and Permian.
Pterotheca Salter ; Phragmotheca Barrande. Silu-
rian ; Europe. Matthewia Walcott. Cambrian.
Fig. 1073.
A, Tentnculitrs accdari.'^
Schluth. Erratic block of
Ordovician age ; Berlin. C,
T. ornatus Sowb. Silurian ;
Dudley, England. C, T.
iLcnarltc^ Richt. Silurian con-
cretion ; Thuringia. A
smaller individual contained
within the larger (after
Novak).
having a circular cross
embryo7ial bulb. Surface
portion of the shell often
Ordovician to Devonian.
Suborder D. CONULARIIDA Miller and Gurley.
Paleozoic forms of doubtful systematic fodtion,
resembling some Recent Pteropoda, but probahly to be
regarded as a parallel rather than as an identical
group.
Family 1. Tentaculitidae Walcott.
Thick - walled, tapering, elongate, conical tubes,
section, and terminating posteriorly either acutely or in an
ornamented with parallel raised transverse rings. TJie apical
filled loith calcareous matter, or divided off by transverse sefta.
572
MOLLUSCA
PHYLUM VI
Tentaculites Scliloth. (Fig. 1073). Tliis, the solitary genus, is prodigiously
abundant in the Sihirian and Devonian, the strata being sometimes fairly charged
with their remains. Tlie sliell is composed of a comjjact outer layer, and an inner
layer made up of thin lamellae running parallel witli the external surface.
The supposed Tentaculites described from the Oligocene by Ludwig and Blankenhorn
are thin-shelled, transversely ribbed, conical tubes, wliich probably belong in the
neighbourliood of Stijliola or Euchilotheca.
Family 2. Torellellidae Holm.
Thick - loalled, smooth, transversely or longitudinally striated, straight or bent tubes,
acutely terminated "posteriorly, and. unthout opercula. Cambrian to Silurian.
Turellella Holm. Tubes strongly compressed, flattened at both ends, elliptical in
cross-section, and with fine transverse striae ; composed of brownish-coloured calcium
phosphate. Cambrian to Silurian ; Sweden.
Hyolithdlus and Salterella Billings ; Coleolus Hall ; and Goleoloides Walcott, from
the Lower Cambrian of North America, j^robably also belong here.
Family 3. Conulariidae Walcott.
Shell rectilinear, elongate- conical, rectangular to rhombic in cross- section, with
usually sharp edges, acute or truncated posteriorly. Each of the transversely striated or
ribbed lateral faces divided into longitudinal halves by a superficial groove, corresponding
internally to a median ridge. Posterior portion of the shell divided off by septa.
A])erture constricted by four triangular or linguiform incurved
lobes of the anterior margin. Ordovician to Jura.
Conularia Mill. (Figs. 1074, 1075). This, the solitary
genus, sometimes attains a length of 20 cm., and is represented
by about 100 species. Its maximum distribution occurs in the
Ordovician and Silurian of Bohemia, Normandy, England,
Sweden and North America, and in the Devonian of North
America and Bolivia. It is rare in the Carboniferous and
Permian,- and the last surviving species occurs
in the Tiias and Lias.
Order 2. PULMONATA Cuvier.
Air-breathing Snails.^
Euthyneura in wldch the gill cavity is
transformed into a lung for breathing free
air. Mainly terrestrial or fresh-water forms.
A few Pulmonates have reverted to ex-
clusively aquatic habits, and have the lung
. , , 'i'^"'}' filled witli water ; and in a few, secondary
risulcata Sowb. ' -mi
Upper Carboniferous gills are developed in the cavity. These,
Sc;raaM'!''fhS' however, are rare exceptions. The great
Fig. 1075.
Conularia
Fig. 1074.
Conularia aw^mnhi Barr.
Ordovician (Etage D) ;
Drabov, Bohemia.
well-preserved aper- maioritv of forms breathe air by means of a
tural margins (after / i p i n i ^ j ii
Etheridge). network 01 blood - vessels spread upon tlie
inner surface of the lung. The ordinary
aquatic forms come to the surface of the water at intervals to renew their su2:)ply of
^ Sandbergcr, F., Land- unci Siisswasser-Conchylien der Vorwelt. 1870-75. — White C. A.,
Review of Aiiiericiui non-marine MoUusca. 3rd Ann. Rep. U.S. Geol. Siirv., 1881-82. — Tryun,
G. W. an<l ]'i/sbri/, II. A., Manual of Conchology, Pnlmonata.
CLASS IV
GASTROPODA
573
air. The Pulmonates have, with few exceptions, no operculum, and tlie shell is often
vestigial or absent.
Next to the Prosobranchs the Pulmonates are the largest group of Gastropods,
there being upwards of 6000 living and 700 fossil species known. The most
important and highly diversified genera {Helix, BuUmus, Clausilia) are terrestrial in
habit ; certain others {Planorbis, Lymnaea, Physa) are confined to fresh water. The
oldest Pulmonates are of rare occurrence in the Devonian and Carboniferous ; they
are found sparingly in the Jura and Cretaceous, are of greater abundance in the
Tertiary, but do not attain their maximum distribution until the present geological
period.
The Thalassophila and Auriculidae are restricted to marine deposits ; the re-
maining Pulmonates are rarely found except in fresh -water strata, and are commonly
associated with other organisms that have been swept by rainfall or running water
into swamps or estuaries.
Suborder A. THALASSOPHILA Gray.
Shell either spiral and opeixulate, or bowl-shaped to depressed conical, without spire,
and somewhat unsymmetrical. Animal usually provided ivifh a single gill in addition
to the lung cavity. Tentacles fused tvith the discoidal head. Eyes sessile.
The Thalassophila inhabit the littoral zone of the ocean and brackish estuaries.
Fossil remains occur from
the Devonian onward.
Three families are recog-
nised— Siphonariidae, Gadi-
niidae and Amphibolidae,
but these are not readily
distinguishable by sliell
characters alone.
Siphonaria Blainville
(Fig. 1076). Shell usually
radially ribbed. Apex
directed backwards or to-
ward the left side ; inter-
nally with two unequal muscular impressions, which are interrupted on the right
side in front by a broad groove. Tertiary and Recent.
Hercynella Kayser (Fig. 1077). Devonian. Anisomyon Meek and Hayden. Jura
and Cretaceous.
Valenciennesia Rousseau. Shell very thin, broadly bowl-shaped, concentrically
ribbed. Apex situated near the posterior margin. Right side bearing a broad
plication for the respiratory tube. Found in brackish water, Congerian Stage (Pliocene)
of Hungary, Roumania and South Russia.
Williamia Monts. ; Gadinia Gray. Recent and Pliocene.
Amphibola Schuni. Shell spirally globose, thick, rugose and operculate. Recent.
This is placed in a separate family, the Amphibolidae.
Fici. lOTLi.
Siphonaria crassieoslata Desh.
Eocene ; Anver.s, near Paris.
Fig. 1077.
Herci/nella hohemica Barr. Devonian
(Etage F) ; Lodikow, Bliemia.
Suborder B. BASOMMATOPHORA A. Schmidt.
Shell invariably present. Eyes situated at the base of a pair of tentacles,
or living in the vicinity of ivater.
Aquatic,
Family 1. Auriculidae Blainville.
Shell thick, ovate. Spiire short, body whorl very large. Inner lip or columella bear-
ing plications. Shore forms or inhabitants of salt marshes. Jura to Recent.
574
MOLLUSCA
PHYLUM VI
Auricula Lam.
rounded anteriorly,
times denticulated.
Cassidula Fer. ;
(Fig. 1078). Elongate-oval, witli ei^idei-mis. Aperture narrow,
Inner lip bearing two or tliree folds ; outer lip thickened, some-
Jura to Recent.
Plecotrema Adams; Alexia Leach (Fig. 1079); Pythiopsis Sandb.
(Fig. 1080) ; Melampus Montf.
Carychium Miiller (Fig. 1081). Shell small, smooth and glossy. Inner lip
Fic. 1078.
Auricula dutemjilei
Deshaye.s. Lower
Eocene ; Sainceux
(after Deshayes).
Fio. 1079.
Alexia pisoUna Desh.
Miocene ; Pontlevoy,
Touiaine. -/i.
Fig. 1080.
I'ythiopsis la-
marcki (Desh.).
Eocene ; Houdan
(aftei- Deshayes).
Fi(i. lOSl.
Canjchiuin antiquum
A. Biaun. Miocene;
Hocliheini, near May-
ence. EnlarLred.
bearing one or two folds ; outer margin thickened, sometimes with a tooth. Jura to
Recent. Terrestrial.
Scarabus Montf. (Polyodonta Fischer von Waldh.) ; Leuconia Gray ; Blamieria
Shuttleworth, etc. Tertiary and Recent.
Family 2. Chilinidae Dall.
Shell ovdl, auriculate, with large aperture, the colitmellar margin
provided ivifh spiral folds ; surface coloured in various patterns.
Tertiary and Recent.
Ghilina Gray. This is said to be Streptoneurous. The
dentition resembles that of Physa. Miocene and Recent ; South
America.
Family 3. Physidae Dall.
Shell sinistral, oval, glossy, unicoloured. Aperture large; colu-
mella twisted or simple. Jura to Recent.
Physa Drap. (Fig. 1082). Shell brilliantly polished, thin,
sinistral. Upper Jura to Recent.
Pio. 10S2.
Physa giganteti
Michaud. Lower
Eoci^ne ; Hilly, near
Rheims.
Fi(!. 1083.
Lymnaca 'pai'hyfiastcr
Thorn. Fresli - water
Miocene ; Morsingen,
near Ulm.
Family 4. Lymnaeidae
Keferstein.
Shell thin, turreted, or dis-
coidal. Fresh-water inhabitants.
Lias to Recent ; especially abun-
dant in the Tertiary.
Lymnaca Lam. {Limnaeus
auct.) (Fig. 1083). Shell very
thin and corneous. Body whorl
very large ; spire acute, and
moderately high. A])erture wide, oval ; outer margin sharp,
to Recent ; maximum in Tertiary.
Planorbis Guettard (Figs. 1084, 1085). Discoidal (exceptionally turreted), with
!Flo. 1084.
Planorbis cornu Brongt. var. mantclli
Dimker. Upper Miocene ; Mundingen,
Wnrtcinberg.
Upper Jura (Purbeck)
CLASS IV GASTROPODA 575
many whorls. Aperture oval to crescent-shaped ; outer margin sharp. Lias to
Recent ; very profuse in the Tertiary. P. multiformis (Bronn), from the Middle
A n c D
Fig. 1085.
Planorbis multiformis (Bronn). Upper Miocene fresh-water limestone ; Steinheim, near Heidenheini,
Wtirteniberg. A, var. suprema. B, var. trorJiiformis. C, var. chgans. D, var. steinheiviensin.
Miocene of Steinheim in Wiirtemberg, is particularly interesting on account of its
extraordinary variability. The different mutations of the species are usually found
at different horizons of the fresh-water limestone occurring there, and constitute,
according to Hilgendorf and Hyatt, a remarkable genealogical sequence.
Isidora Ehr. Shell similai' to that of Physa. Recent ; trojaical countries.
Family 5. Ancylidae Dall.
Shell limpet-shaped, conical, not spiral, or ivith the apex recurved. Tertiary and
Recent.
Ancylus Geoffrey (Fig. 1086). Shell simply conical or with the apex slightly
incurved. Tertiary and Recent.
Gundlachia Pfeiff. A partial septum is developed at the end of
the first season's growth. Tertiary of Mayence Basin and Recent.
Suborder C. TELETREMATA Pilsbry.
Shell absent ; mantle coverincj the whole upper surface of the body.
Male and female orifices widely separated; lung orifice and anus Fki. losti.
ventral and near the tail. Desr^ciliJ^^G^^
Several families of this suborder are recognised (Vaginulidae,
Rathouisiidae, Onchidiidae), but owing to the absence of a shell, tlieir remains are
not preservable in the fossil state.
Suborder D. STYLOMMATOPHORA A. Schmidt. Land Snails.
Eijes borne on the extremities of two peduncles, which are capable of invagination ;
a fair of short tentacles, rarely obsolete, are placed in front of them. Male and female
genital orifices contiguous, or uniting in a common vestibule, situated at the right or
left side of the head. Buccal retractors present ; lung foramen and anus anterior to the
end of the foot, not ventral.
This suborder comprises most recent and all fossil land snails, and is divisible
into series or superfamily groups. The families proper are based almost wholly upon
characters of the soft anatomy, which are herein largely omitted or abridged.
Superfamily 1. HOLOPODA Pilsbry.
No longitudinal grooves above the margins of the foot ; jaw present, teeth quadrate.
Family 1. Helicidae Keferstein. Helices.
Shell depressed, globose or oval and elevated. Tertiary and Recent.
This comprises an enormous assemblage in the Recent fauna, but most of the genera
have not as yet been found fossil. All the typical forms will probably in time be
576
MOLLUSCA
PHYLUM VI
traced back to the Eocene. Subfamily and generic characters are based largely iijion
the genital system, and hence are of little practical importance to the paleontologist.
Polygyra Say. Globose or dejaressed,
Oligocene to Eecent ; North America.
Sagda Beck. Glossy, with many close
A, Helix (Dimorphoptychia) arnouldi Michaud. Lower
Eocene ; Rilly, near Rhelms. B, HeHx (Campylaea) inflexa
Klein. Upper Miocene ; Morsingen. C, Helicodonta osculum
Tlioin. Lower Miocene ; Hochheim, near Wiesbaden.
with the lip reflected, often toothed.
whorls, the last usually with internal
laminae and a sharp lip. Oligocene to
Recent ; Antilles.
Pleurodonta Fischer von Wald.
Solid, large, depressed and generally
keeled ; aperture often toothed. Oligo-
cene to Recent ; Antilles, Florida.
Helix Linn. (Fig. 1087, A, B).
Shell semi-globose, conical to discoidal,
manifesting great variability of form.
Aperture oblique, crescentic or rounded,
with disconnected margins. Very pro-
fuse in the Tertiary and Recent of Europe and adjacent regions of Asia and Africa,
Helicodonta Fer. (Fig. 1087, C). Similar to Helix, but with thickened or
denticulated lip. Oligocene to Recent ; Europe.
Other allied genera occur in Euroj^ean Tertiary deposits.
Recent Helicidae reproducing by extraordinarily large eggs are
the following : Helicoiihanta of Madagascar, Acavus of Ceylon,
Panda of Australia, and Strophocheilus of South America.
Family 2. Bulimulidae Fischer.
Shell elongated, ovate, with narroio umhilicus or none. Ter-
tiary and Recent.
Bulimulus Leach. Oligocene to Recent ; America. Amjihi-
dromus Alb. Tertiary ; Europe and Asia.
A
Family 3. Pupidae Albers.
Fig. loss.
A, Clausilia hulimoides
A. Braun. Lower Miocene;
Eckingen, near Ulm. B, C.
Shell small, cylindrical or oval, with narrow ivhorls. Tertiary (^ntiqua Schiibier. Same
and Recent ; also in the Carboniferous.
Clausilia Drap. (Fig. 1088). Shell turreted to fusiform, slender, sinistral.
Aperture j^yriform, with usually continuous peristome. Inner lip bearing two folds ;
A outer margin somewhat reflected ; the aper-
ture usually closed by a movable calcareous
l^late. Occurs sparingly fossil from the
Eocene onward, and represented by about
400 Recent species.
Pupa Lam. (Fig. 1089, B). Shell small,
cylindrical -ovate. Aperture semicircular,
usually constricted by teeth on the colu-
mella and inner and outer lips. The outer
margin reflected. Tertiary and Recent.
Dendropupa Dawson (Fig. 1089, A).
Like the last, but aperture without teeth.
Upper Carboniferous ; Nova Scotia.
Tertiary and Recent.
(Fig. 1090). High conical, solid, turreted.
Fii;. 10.S9.
A, Dendropupa vetusta
Dawson. Coal Measures ;
Nova Scotia (after Dawson).
B, Pupa diversidens Sandb.
Miocene; Sansan, Gers (after
Sandberger).
Vertigo Miiller.
Buliminus Ehrb.
Fio. 1090.
' Buliminus (Pet raeu.t)
c.omjtlanatus Reuss.
Lower Miocene;
Thaltingen, near Ulm.
Eocene to Recent.
CLASS IV
GASTROPODA
577
Family 4. Achatinidae Pilslny.
Ovate or elonfiate, imperforate shells, with the coluraella (jeneralhj truncated at the
base. Upper Cretaceous to Recent.
Achatina Lam. Recent ; tropical Africa.
Sfcnogyra Sliuttlew. ; Rumina Risso ; Opeas Alb. ; Rhodea
Adams. These are all small members of the group, mainly Recent.
Megaspira Lea (Fig. 1091). Turreted, slender, very long ;
columella with transverse folds. Upper Cretaceous to Recent.
Gochlicopa Fer. ; Azeca Leach ; Gaecilianella Bourg., etc.
Tertiary and Recent.
Fid 1091
Superfamily 2. AGNATHA Morch. ,,^^,^.p.,.^ ^^^^,^„,^
(Micli.). Lower
Carnivorous snails, usually vdth no jaw, thorn-shaped teeth, and Eocene; Riily, near
without furroivs above the foot edges.
Fig. 1092.
Tcstacella zcllu Klein.
Miocene ; Andelflngen
(after Sandberger).
Fanuly 1. Testacellidae Gray.
Shell spiral, of very small size, and situated near the tail of the
vermiform animal. Tertiary and Recent.
Testacella Cuvier (Fig. 1092). Shell auri-
form, borne on the posterior end of the animal.
Tertiary and Recent. jfP^\\\\\\
Parmacellina Sandberger. Eocene. Daude-
bardia Hartm. {Helicophanta Fer. p.p.).
Quaternary and Recent.
Family 2. Glandinidae Albers.
Shell oval or oblong, capable of containing the entire animal'
Cretaceous to Recent.
Glandiiia Schum. (Fig. 1093). Shell elongate-oval, with high
spire. Aperture notched in front ; columella truncated. Upper
Cretaceous to Recent. Other Recent allied genera inhabit the
American tropics.
Glandina inflata
Reuss. Miocene;
Richelberg, near Ulm.
Superfamily 3. AULACOPODA Pilsbry.
Foot with longitudinal grooves above and parallel with its lateral margins.
Family 1. Zonitidae Pfeiffer.
Aulacopoda with a spiral, conical or helicoid shell, sometimes partially imcoiled,
usually smooth and with simple lip; marginal teeth of the radula thorn-like ; foot
margin loide ; jaio rather smooth. Carboniferous (?) to Recent.
Vitrina Drap. Shell small, translucent, with short spire, .and very large body
whorl. Tertiary and Recent.
Archaeozonites Sandb, (Fig. 1094). Thick-shelled, globose, with rather high spire,
deeply umbilicate ; outer margin sharp. Oligocene and Miocene. Here also should
be placed, perhaps, the archaic ifefe-shaped snails from the Coal Measures of Nova
Scotia.
VOL. I -" ^
578
MOLLUSCA
PHYLUM VI
Zonites Montf. Like the last, but with thinner shell, granulated above, and
smooth below. Tertiary and Recent.
Fl(i. 1094.
Archaeozonit.es s^Averticlllus
Sandb. Lower Miocene;
Eckingen, near Ulni.
Fic. 1095.
Hyalinia denudata
(Reuss). Miocene ;
Tuchoritz, Bohemia.
1090.
Lychnus matheroni Requien.
Upper Cretaceous (Garumnian) ;
Rognac, Provence.
Hyalinia Fer. (Fig. 1095) ; Omphalosagda Sandb. ; Ariophanta Desm. ; Trocho-
morpha Albers. Tertiary and Eecent.
Lychnus Montf. (Fig. 1096). Body whorl large, bent upward at first, and later
decurved, so that the margins of the aperture lie in the basal plane. Upper
Cretaceous of Provence and Spain.
Family 2. Limacidae Lamarck.
NaTced sliujft havin.fi a small vestigial shell, flat and non-sfiral^ concealed within the
mantle, which latter forms a small oval shield on the forepart of the body. Foot margin
narrow ; dentition and jaw as in the Zonitidae. Tertiary and Recent.
The principal genera are Limax Linn., in whicli the intestine has four longi-
tudinal folds, and the back is keeled at the tail only ; and Amalia Moq.-Tand., with
spiral gut and strongly keeled back. Their small scale-like shells have been found
in the Tertiary and Pleistocene ; present distriliution nearly world-wide.
, Family 3. Endodontidae Pilsbry.
Shell spiral and external, varying from cylindric to helicoid and planorhoid, usually
rih-sculp>tured and with 02nique colouring ; lip thin, unexpanded. Jaw of sc^inrate or
united imbricating plates, or solid and striated ; margined teeth squarish ; genitalia
tvithout accessory organs. Carboniferous to Recent.
Punctinae. Jaw of numerous separate plates ; shell minute. Includes the
Holarctic genera Punctum Morse and Sphyradium Charp., also the New Zealand
genus Laoma Gray. Recent.
Endodontinae. Jaw-plates united more or less completely. Genera : Pyramidula
Fitz. Discoidal or low conical, with tubular ribbed whorls and ojien umbilicus.
Carboniferous to Recent. This is one of the most ancient land Mollusks known, and
is the oldest Helicoid form. Phasis, Amphidoxa, Flammulina and Endodonta Alb.
are similar austral forms, but are only known Recent.
Family 4. Arionidae Gray.
Slugs having the shell reduced, to a flat plate or a few granules, nearly or entirely
concealed, or absent. 'Mantle in the form of a shield on anterior piart of the body ; teeth
of the quadrate type. Recent.
This family is probably derived from the Endodontidae by degeneration of the
shell. Arion Fer., and Anadenus Heyn. are leading genera of Europe and Asia ;
Ariolimax Miirch, and Prophysaon Bland occur abundantly in North America.
CLASS IV GASTKOPODA 579
Family 5. Philomycidae Gray.
Slugs sometohit similar to Arionidae, hut the mantle covers the entire thpfer surface
of the body. A shell is completely absent ; hence no fossil forms are hnoivn.
Superfamily 4. ELASMOGNATHA Morch.
Ja%v ivith ct strong squarish process of attachment above.
Family 1. Succineidae Albers.
Shell thin, ovate, consisting of few whorls. p^^, ^
Succinea Pfeiffer (Ficf. 1097). Shell tliin, ovate, amber-coloured, Snwinca jwregriim
1 -,1 T \ • IT 1 1 1 T /-v J • Sandb. Lower Mio-
translucent, with short spire and large body whorl. Uuter margin cene; Tuchoritz,
of aperture sharp. Tertiary and Eecent ; abundant in the Loess. Boliemia.
Range and Distribution of the Gastropoda.
Of all classes of Mollusks, the Gastropods exhibit the most manifold
variety. Beginning in the Cambrian, they acquire a very gradual increase
and distribution, and are at present enjoying their maximum vigour. There
exist probably over 20,000 Recent species, about three-fifths of which have
gills, the remainder being air-breathers.
At the base of the Cambrian (Olenellus zone) are found such archaic
genera as Scenella, Stenotheca, Platyceras, Ehaphistoma, Pleurotomaria ; a number
of Pteropods with some doubtful forms (Hyolithes, Hyolithelliis, Salterella, Torel-
lella, etc.), which evince the great antiquity of the Aspidobranchs ; and forms
resembling the Capulidae. In the later Cambrian the Rhipidoglossa (represented
by the Pleurotonmriidae, Euomphalidae and Bellerophontidae) predominate ; and
associated with these are certain Pteropod remains, members of the Capulidae,
and a few genera probably referable to the Turbinidae. A notable genus
occurring here is Suhdites, which bears some resemblance to the Pyramidellidae,
and exhibits a distinct channelling at the base of the columella.
Unfortunately the poorly preserved remains of Cambrian Gastropods afford
but scanty information regarding the disposition of the soft parts ; neverthe-
less there are good, although purely theoretical reasons for supposing that
the Rhipidoglossa and Ctenobranchs were formerly not so widely sejjarated as
at present.
During the Ordovician and Silurian, Gastropods increased perce2:)tibly in
the number of species, and a few new families were initiated {Epitoniidae,
Purpurinidae, Trochidae, Xenophoridae) ; but the faunal aspect remained on
the whole much the same as in the Cambrian, and no essential changes were
introduced during the remainder of the Paleozoic. Accordingly, the Paleo-
zoic Gastropod fauna may be said to be characterised by its general simplicity,
being made up principally of Pteropods, Rhipidoglossa, a few Docoglossa
and Opisthobranchs, and also a scattering representation of Ctenobranchs
{Capulidae, Pyramidellidae, Littorinidae).
During the Jura-Trias, the hirge, thick-shelled varieties of Pteropod-like
Mollusks became extinct. But, on the other hand, various families of the
Rhipidoglossa reached the acme of their development (Pleurotomariidae, Tur-
binidae, Neritopsidae, Neritidae) ; and among the Ctenobranchs, the families
580
MOLLUSCA
PHYLUM VI
TABLE SHOWING THE VERTICAL RANGE OF THE GASTROPODA.
Families.
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1. Streptoneura
Order 1. Aspidobbanchia
A. Bocoglossa .
B. Rhipidoglossa
1. Haliotidae
2. Pleurotoinariidae .
3. Fissurellidae .
4. Euomphalidae
5. Raphistomidae
6. Stomatiidae .
7. Turbinidae
8. Pliasianellidae
9. Delphinulidae
10. Trochoneniatidae .
11. Trochidae
12. Umboniidae .
13. Neritopsidae .
14. Neritidae
Order 2. Ctenobranchia
A. Heteropoda.
B. Platypoda
1. Eulimidae
2. Pyramidellidae
3. Epitoniidae .
4. Solariidae
5. Purpurinidae .
6. Littorinidae .
7. Cyclostomidae
8. Capulidae
9. Naticidae
10. Xenophoridae
11. Anipullariidae
12. Valvatidae
13. Viviparidae .
14. Hydrobiidae .
15. Rissoidae
16. Turritellidae .
17. Vermiculariidae
18. Caecidae
19. Melaniidae
20. Neriueidae
21. Cerithiidae
22. Aporrhaidae .
23. Stronibidae .
24. Columbellariidae .
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RANGE OF THE GASTROPODA
581
Families.
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25. Cypraeidae
26. Ovulidae
27. Cassididae
28. Doliidae
29. Nyctilochidae
30. Columbellidae
31. Buccinidae
32. Muricidae
33. Thaisidae
34. Fusidae .
35. Vasidae .
36. Volutidae
37. Harpidae
38. Olividae
39. Cancellariidae
40. Terebridae
41. Turritidae
42. Conidae .
2. Euthyneura
OiiuER 1. Opisthobranchia
B. TectihrancJiiata
1. Acteonidae
2. Ringiculidae .
3. Akeratidae
4. Hydatinidae .
5. Bullariidae
6. Acteocinidae .
7. Scaphandridae
8. Pliilinidae
9. Umbraculidae
C. Pteropoda
1. Limacinidae .
2. Cavoliniidae .
3. HyolLthidae .
D. Coniclariida
1. Tentaculitidae
2. Torellellidae .
3. Couulai'iidae .
Order 2. Pitlmonata
A. Thalassophila .
B. Basommatophora
1. Auriculidae .
2. Chilinidae
3. Physidae
4. Lymnaeidae .
5. Ancylidae
0. Teletremata
D. Sfi/IommMtopJiora
^ —
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582 MOLLUSCA phylum vi
Pyramidellidae Nerineidae, Purjmrinidae, Turrit ellidae and Aporrliaidae multi-
plied in a great variety of forms.
The Cretaceous witnessed a decided increase among the siphonostomous
Otenobranchs, and in the Tertiary this branch asserted itself as the dominant
type of Gastropods, surpassing all other families in point of numbers, and
gradually acquiring the aspect of living genera and species. The Nerineidae,
Pyramidellidae and Aporrhaidae, which played such a prominent role along
with the Rhipidiglossa during the Mesozoic era, became in part extinct in the
Tertiary, and the remainder entered upon their decline. The great majority
of Eocene and Oligocene genera are still living, but the species have with
very few exceptions become extinct. During the Miocene, more species made
their appearance which are still in existence, and of the Pliocene species,
between 80 and 90 per cent are represented in the Recent fauna.
The geological history of the Puhnonata is remarkable. Thalassophilous
Siphonariidae are first met with in the Devonian, where they are very sparse.
Land snails (Archaeozonites, Pyramidula, Dendropupa) were initiated in still
smaller numbers during the Carboniferous; but not until the boundary between
the Jura and Cretaceous is reached do we find any traces of fresh- water snails.
We meet them first in the Purbeck. In the Wealden, and Cretaceous gener-
ally, both land and fresh- water Gastropods are quite abundant ; they became
highly developed and widely distributed dixring the Tertiary, attaining, in fact,
a differentiation nearly equal to that exhibited by the corresponding Recent
forms.
The successive approximations to present conditions among Gastropod
faunas have not been confined to the production of forms simulating more and
more those now living ; they include also the gradual demarcation of existing
geographical provinces. Mesozoic Gastropods are too dissimilar in their
general characters to admit of a close comparison with modern faunas ; but as
early as the Eocene resemblances to modern forms are observable, and a certain
correspondence is to be noted with Gastropods now inhabiting somewhat
warmer zones.
The Eocene faunas of Europe, North America, Asia and Northern Africa
share a great many genera in common, and have numeroiis others which are
vicarious. A very different aspect is presented by the Eocene fauna of
Australia, New Zealand and South America, where we find the evident fore-
runners of forms now inhabiting the southern portions of the Atlantic and
Pacific Oceans.
Still more intimate is the relationship existing between the fossil land and
fresh-water Gastropods and their descendants on the several continents. It
has been observed that Miocene faunas bear a decidedly tropical stamp. On
this account European and American forms from the inland Miocene deposits
bear some resemblance to the Recent faunas of the Azores and the West
Indies, as well as to the land and fresh- water Gastropods inhabiting the colder
latitudes of Europe and Asia. Only as recently as the Pliocene did each
geographical province come to assume its present distinctive features.
In general, the stratigraphic sequence of Gastropod groups corresponds
closely with the zoological order, the most generalised forms appearing first,
the more specialised later. Beginning with the two-gilled Rhipidoglossa and
the Docoglossa, followed by the single-gilled Rhipidoglossa, Opisthobranchs and
taenioglossateCtenobranchs,the series leads to the Rachiglossa in later Mesozoic,
CLASS V CEPHALOPODA 583
and culminates in the great increase of rachiglossate and toxoglossate families
in Tertiary and Recent times. (See tables, pp. 580, 581.)
[The text for the preceding chapter on Gastropoda was revised for the first edition of
this work by Professor Henry A. I'ilsbry, of the Philadelphia Academy of Natural Sciences,
and is reprinted here with some slight changes at the hands of Drs. W. H. Dall and
R. S. Bassler.— Editor.]
Class 5. CEPHALOPODA.!
Head sharply defined in Recent forms, except Nautilus. Foot transformed into a
^ Literature : Angdin, N. P., Fragnienta Silurica, edited by G. Lindstroni. Stockholm, 1880.
— Anthula, /.,}Uber die Kreidefossilien des Kaidcasus. Beitr. Pal. Osterreich - Ungarns, etc.,
1899-1900, vol. xii. — Arthaber, G. von, Die Cephalopodenfanna der Keiflinger Kalke. Beitr.
Palaont. Geol. Osterreich - Ungarns, etc., 1896, vol. x. — Idem, Das Jiiugere Palaozoicum aiis der
Araxes-Enge bei Djulfa. Beitr. Pal. Geol. Osterreich-Ungarns, 1900, vol. xii. — Idem, Die Trias
von Albauien. Ibid., 1911, vol. xxiv. —Barrande, J., Systenie Sihirien de la BohGme, vol. ii., Cepha-
lopodes. Prague, 1867-77. — Bayle, E., and Zeiller, R., Explication de la carte geologique de France,
vol. iv., Atlas. Paris, 1878. — Beecher, O. E. On the Development of the Shell in Tornoceras.
Amer. Journ. Sci. [3], vol. xl., 1890. — Benecke, E. W., Lebensweise des Ammoniten. Abhandl.
Spezialkarte von Elsass-Lothriugeu, N. P., 1905, Heft vi. — Billings, E., Palaeozoic Fossils. Geol.
Surv. Canada, 1865. — Blake, J. F., Monograph of the British Fossil Cephalopoda, pt. i. London,
1882. — Buhm, G., Beitriige zur Geologic von Niederliindisch - Indien. Palaeontogr. , 1904-7,
Supplem. vol. iv. — Bonarelli,'G., Osservazioni sul Toarciauo d' Aleniano. Boll. Soc. Geol. Italiana,
vol. xii., 1893. — Boide, M., Lemoine P., and Thevenin, A., Cephalopodes cretaces des environs de
Diego-Suarez. Ann. de Palcontol., 1906-7, vol. i. — Branco, W., Beitriige zur Entwickelungsge-
schichte der fossilen CephalOpoden. Palaeontogr., Bd. xxvi., xxvii., 1880-81. — Broiun, A. P., On
the Young of Baculites compressus. Proc. Acad. Nat. Sci. Philad., 1891-92. — Buck, L. von,
Uber Goniatiten, Clymenien, Ceratiten, etc. Abhandl. Berlin. Akad. 1830, 1838, 1818. — Buchnan,
S. S., Monograph of the Inferior Oolite Ammonites. Palaeont. Soc, 1887-1900. — Burckha^'dt, C,
Beitr. zur Kennt. Jura und Kreideformatiou der Kordilleren. Palaeontogr., 1903, vol. 1. — Idem,
La Faune jurassique de Mazapil. Boletin de I'lnst. geol. de Mexique. No. 23, 1906.
Canavari, M., Sui fossili del Lias inferiore nell' Appenino centrale. Atti Soc. Toscano, vol. iv.,
1879. — La Fauna degli strati con Aspidoceras acanthicuni di Monte Serra. Palaeont. Italica, vol. ii.,
1897. — Glioffat, P., Recueil d'ctudes paleontologiques sur la faune cretacique du Portugal. Travaux
geol. du Portugal, 1886-1902. — Dacque, E., Beitriige zur Geol. de.s Somalilandes II. Ob. Jura.
Beitr. Pal. Geol. Osterreich-Ungarns, etc., 1905. vol. xvii. Dogger und Malm aus Ostafrika. Ibid.,
1910, vol. xxiii. — Clarke, J. M., The Protoconch of Orthoceras. Amer. Geol., vol. xii., 1893. — Nanno,
a new Cephalopodan type. Ibid, xiv., 1894. — The Lower Silurian Cephalopoda of Minnesota.
Geol. Minn., vol. iii. pt. ii., Palaeont., 1897. — Conrad, T. A., Observations on the Silurian and
Devonian Systems, etc. Journ. Acad. Nat. Sci. Philad., vol. viii., 1839-42. — Observations on
Recent and Fossil Shells. Amer. Journ. Conch., vol. ii., 1866. — Leslongchamps, E., Memoire sur
les Teudopsides. Mem. Soc. Linn. Normandie, vol. v., 1835. — Diener, C, Triadische Cephalopoden-
faunen der ostsibirischen Kiistenprovinz. Mem. Com. Geol. St. Petersb., vol. xiv. No. 3, 1895.
— Diener, C, Palaeont. Indica, Himalayan Fossils. The Cephalopoda of the Muschelkalk, 1895.
—The Cephalopoda of the Lower Trias, 1897.— The Fauna of the Himalayan Muschelkalk, 1907.
— Ladinic, C!arnic, and Noric Faunae of Spiti, 1908. — Fauna of the Tropites. — Limestone of
Byans, 1906. — Upper Triassic and Liassic Faunae of the Exotic Blocks of Malla-Johar, etc., 1908.
— Diener, C, and Krafft, A. v., Palaeontol. Indica, Lower Triassic Cephalopoda from Spiti, Malla-
Johar and Byans. Ibid., 1909, vol. vi. — Douville, H., Sur quelques fossiles de la zone a Ammonites
sowerbyi. Bull. Soc. Geol. France [3]. vol. xiii., 1884-85. — Sur la classification des Ceratites de
la Craie. Ibid., 1890, vol. xviii. — Etude sur les ammonites oxfordiennes de Villers-sur-mer.
Mem. Soc. Geol. France, Idl2.—Dwight, W. B., Recent Explorations in the Wappinger Valley
Limestone. Amer. Journ. Sci. [3], 1884, vol. xxvii. — Favre, F., Die Ammonitiden der unt. Kreide
Patagoniens. N. Jahrb. f. Min., 1908, Supplem. vol. xxv.
Foord, A. H., Catalogue of the Fossil Cephalopoda in the British Museum, pt. i., 1888 ; ii.,
1891 ; iii. (Foord and Crick), 1897.— i^rec^, F., Lethaea Geognostica, I. Teil. Lethaea Palaeozoica,
Bd. ii. Lief. 1. Stuttgart, 1897.— Uber devonische Ammoneen. Beitr. Pal. und Geol. Osterreich-
Ungarns, etc., 1902, vol. xiv.— Neue Cephalopoden aus den Buchensteiner, Wengener, und Raibler
Schichten des siidlichen Bakony. Res. Wiss. Erf. Balatonsees, 1903, vol. i. — Fucini, A., La Fauna
del Lias medio del Monte Calvi. Palaeont. Italica, vol. ii., 1897.— Ammoniti del Lias medio
deir Appenino centrale. Pal. Ital., 1899, vol. v.— Cephalopodi liassici del Monte di Cetona. Ibid.,
1901, vol. \\\.—Gabb, W. M., and Meek, F. B., Geol. »iirv. California. Palaeontology, vols, i., ii.,
186i~69.—Gemmellaro, G. G., La Fauna del calcari con Fusulina. Palermo, 1887-89.— I Cefalopodi
584 MOLLUSCA phylum vi
funnel-shaped muscular swimming-organ ; mouth provided with jaws and radula.
del Trias superiore della regione occidentale della Sicilia. Giorn. Soc. Sci. Nat. Palermo, 1904,
vol. xxiv. — Grandjean, F., Le Siphon des Aiiimouites et des Belenmites. Bull. Soc. Geol. France,
1910, vol. x.—Griesbach, C. L., Palaeontological Notes on the Lower Trias of the Himalayas.
Records Geol. Siirv. India, vols, xiii,, xiv., 1880-81. — Grossouvre, A., Les Ammonites de la Craie
supurieure de la France. Explic. Carte Geol. France, 1893. — Gumbel, G. W., Ueber die baierischen
Alpeu. Verhandl. Geol. Reichsanst. Wien, Bd. xii., 1861-62. — Revision der Gouiatiten des
Fichtelgebirges. Neues Jalirb., 1862. — Ueber Clymeuien in den Uebergangsgebilden des Fichtel-
gebirges. Palaeontogr. , Bd. xi.. 1863-64. — Hall, J., Palaeontology of New York, vols, i.-iii., v.,
Albany, 1847-79. — Hauer, F. v., Die Cepbalopoden des Salzkammergutes iind des Mnsclielmarniors.
Wien, 1846. — Neue Cepbalopoden von Hallstadt und Aussee. Haidinger's Wissen. Abhandl.,
vols, i.-iii., 1847-50. — Beitriige zur Kenntniss der Cephalopodeufauna der Hallstiidter Schichten.
Denkschr. Akad. Wiss. Wien, Bd. ix., 1855.— Nachtriige, Sitzungsber., Bd. xli., I860.— Cboristo-
ceras, etc. Jbhl. Bd. lii., 1866.^Die Ceplialopoden des bosnischen Muschelkalkes. Denkschr.
Akad. Wiss. Wien, vols, liv., lix., l8SS-92.—Haug, E., Beitrage zn einer Monographie der
Ammoniten-Gattung Harpoceras. Nenes Jahrb. Beilage Bd. iii., 1885.^Uber die Polymorphidae,
etc. Ibid. Bd. ii., 1887. — Hoernes, Pi.,, Zur Ontogenie und Phylogenie der Cepbalopoden. Jahrb.
Geol. Reiclisanst. , 1903, vol. liii. — Holm, G'., Ueber die innere Organisation einiger silurischer
Cepbalopoden. Palaeont. Abhandl. Bd. iii., 1885. — Tvenne Gyroceras-formigt bcijda Endoceras-
Arter. Geol. Fdren. Stockliolm Furhandl., Bd. xiv. Hefte 2, 3, 1892.— Om de endosifonala
bildningarna hos familien Endoceratidae. Ibid. xvii. Heft 6, 1895. — Om apikaliiuden hos Endoceras.
Ibid. vols, xviii., xix., 1896-97. — Holzapfel, E., Die Cephalopoden-fiihreuden Kalke des unteren
Carbon. Palaeont. Abhandl. Bd. v. Heft 1, 1889.— Die Cepbalopoden des Domanik. Mem. Com,
Geol. St. Petersbourg, 1899, vol. x\\.— Huxley, T. H., Structure of Belenmites. Mem. Geol. Siirv.
United Kingdom, Monogr. ii., 1864. — Hyatt, A., The Fossil Cepbalopods'of the Museum of Com-
parative Zoology. Bull. M. C. Z., vol. i., 1868. — ^Remarks on Agassiceras and Oxynoticeras.
Proc. Boston Soc. Nat. Hist., vol. xvii., 1875. — The Jurassic and Cretaceous Ammonites collected
in South America. Ibid, xvii., 1875.— Genera of Fossil Cephalopods. Ibid, xxii., 1884.— The
Genesis of the Arietidae. Smithson. Miscell. Collect., No. 673, and Memoirs M. C. Z., vol. xvi.,
1889.— Carboniferous Cephalopoda. I., 2nd Ann. Rep. Geol. Surv. Texas, 1890; II. 4th Ann.
Rep., 1892. — Phylogeuy of an Acquired Characteristic. Proc. Amer. Philos. Soc. vol. xxxii. No.
143, 1894. — Remarks on the Genus Nanno. Amer. Geol., vol. xvi., 1895. — Pseudoceratites of the
Cretaceous. Mon. xliv., U.S. Geol. Survey, 1903. — Hyatt, .4., and Smith, J. P., Triassic Cephalopod
Genera of America. Prof. Papers, No. xl., U.S. Geol. Survey, 1905. — Karakasch, N. J., Le Cretace
inferieure de la Crimee et sa faune. Trav. Soc. Imper. Nat., St. Petersburg, 1907, vol. xxxii.
Karpinsky, A., Uber die Ammoneen der Artinsk - Stufe, etc. Mem. Acad. Sci. Imp. St.
Petersb. [7], vol. xxxvii., No. 2, 1889. — Kilian, W., Sur quelques fossiles du Cretace inferieur de
la Provence. Bull. Soc. Geol. France, vol. xiii., 1S88. —Kittl, E., Die Cepbalopoden der oberen
Werfenerschichten von Mu<5 in Dalmatien, etc. Abhamll. Geol. Reichsanst. Wien, 1903, vol. xx.
— Koenen, A. v.. Die Ammonitiden des Norddeutschen Neokom. Abhandl. Preuss. Geol. Landesan-
stalt, 1902, Heft 24. — Koninck, L. G. de, Faune du calcaire carbonifere de la Belgique, pt. ii.,
Cephalopodes. Ann. Mus. Nat. Hist. Bruxelles, vol. v., 188().—Kossmat, F., Untersuchungen
Uber die siidindische Kreideformation. Beitr. Osterreich-Ungarns und Orients, vol. ix., 1895. —
Lauhe, G. C, and Bruder, G., Ammoniten der bohmischen Kreide. Palaeontogr., Bd. xxxiii.,
1887. ^Lindstriim, G., Ascoceratidae and Lituitidae of the Upper Silurian Formation of Gotland.
K. Svensk. Vetensk. Akad. Handling., Bd. xxiii., 1889. Philos. Trans. 1848, ISbO.—Martelli, A.,
Cefalopodi triasiei-di Boljevici (Montenegro). Pal. Ital., 1907, vol. x.—Matheron, P., Recherches
paleontologiques dans le midi de la France. Marseille, 1879-81. — Meek, F. B., Report on the
Invertebrate Cretaceous and Tertiary Fossils of the Upper Missouri Country. U.S. Geol. Surv.
Territ., vol. ix., 1876.— Palaeontology, U.S. Geol. Exploration 40th Parallel Surv., vol. iv. pt. i.
(with notes on Ammonites by A. Hyatt), 1811.— Meek, F. B., and Hayden, F. V., Palaeontology
of the Upper Missouri. Smithsonian Coutrib. Knowl. vol. xiv., 1865. ^Meneghini, G., Monographie
des fossiles du calcaire rouge ammonitique (Lias superieur) de Lombardie. Paleont. Lombardie.
Milan, 18Q7-81. —Mojsisovics, E. v., Das Gebirge nm Hallstadt. Abhamll. Geol. Reichsanst.
Wien, Bd. vi., 1873-75, suppl. Heft, 1902; pt. ii., ibid., 1893.— Die Cepbalopoden der mediter-
ranen Triasjjrovinz. Ibid. Bd. x., 1882. — Uber einige arktische Trias Ammoniten des nordlichen
Sibirien. Mem. Acad. Imp. Sci. St. Petersb. (7), vol. xxxvi. no. 5, 1888.— Beitrage zur Kenntniss
der obertriadisclien Cephalopoden-Faunen des Himalaya. Denkschr. Akad. Wiss. Wien, Bd. Ixiii.,
189Q.—Milnster, G. von, Beitrage zur Petrefactenkunde, i.-viii., 1839-46.— Ueber die Clymenien und
Gouiatiten im Uebergangskalk des Fichtelgebirges. Bayreuth, 1843.
Neuvmyr, M., Jurastudieu. Jahrb. Geol. Reichsanst. Wien, Bd. xxi., 1871.— Die Cephalo-
poden-Fauna der Oolithe von Balin bei Krakau. Abb. Geol. Reichsanst. Wien, Bd. v., 1871-73.
—Die J'auua der Schichten init Aspidoceras acanthicum, etc. Verhandl. Geol. Reichsanst, Wien,
1874. — Ueber Kreideammoniten. Sitzungsber. Akail. Wiss. Wien, Bd. Ixxi., 1875 ; also in Zeitschr.
Deutsch. Geol. Ges., Bd. xxvii., 1875.— Ueber unvermittelt auftretende Cephalopodeutypen ini
CLASS V CEPHALOPODA 585
Sexes separate. Sensory organs highly developed. A circle of fleshy arms or ten-
Jura Mittel-Europa's. Jalirb. Geol. Eeichsanst. Wien, Bd. xxviii., 1873. — Zur Kenntmss tier
Fauna des uutersten Lias in den Nordalpen. Abhandl. Geol. Reichsanst. Wien, Bd. vii. Heft 5,
187 4:-82.—JVeumayr, M., and Vhlig, V., Ueber Ammonitideu aus den Hilsbildiingen Nord-
deutsclilands. Palaeontogr., Bd. xxvii., 1881. — Nickles, R., Contributions a la paleontologie du
Sud-Est de I'Espagne. Mem. Soc. Geol. France, No. 4, 1890.— i\%iYm, S. N., Der Jura der
Umgegend von Elatnia. Nouv. Mem. Soc. Imp. Moscou, vols, xiv., xv., 1879-89. — Allgemeine
geologische Karte von Russland, Blatt 56. Mem. Com. Geol. St. Petersb., vol. i., No. 2, 1884.
— Die Cephalopodenfauna der Jurabildungen des Gouvernements Kostroma. Verhandl. Russ.
Mineral. Gesellscli. [2], vol. xx. 1885. — -Noetling, F., Cambrische uud silurische Gescbiebe Ost-
uud West - Preussens. Jahrb. preuss. geol. Landesanst. und Bergsakad., 1882. — Beitrag zur
Kenntniss der Cephalopodendes Provinz Ost-Preussens. Ibid. 1883; also Zeitscbr. Deutscb. Geol.
Gesellsch., Bd. xxxiv., 1882. — Fauna of Neocomian Belemnite Beds. Palaeout. Indica, Ser.
xvi., i., pts. 2, 3, 1897. — Untersuchungen iiber den Ban der Lobenlinie von Fsetidosageceras multi-
lobatum Noetling. Palaeontograpbiea, 1905, vol. li. — O^ipel, A., Palaeontologiscbe Mittbeilungeu
aus dem Museum des baierischen Staates. Stuttgai't, 1860-65. — d'Orhigny, A., Paleontologie
franjaise, terrain cretace. I. Cephalopodes, 1840; Terrain jurassique, Cephalopodes, 1852.
— Prodrome de Paleontologie Stratigrapbique. Paris, 1850-53. — I'arona, G. F., Nuove osser-
vazioni sopra la fauna con Posidononiya alpina, etc. Palaeontogr. Italica, vol. i., 1896. — Fossili
albiani d' Escragnolles, del Nizzardo, etc. Ibid, ii., 1897.^ — Paulkc, W., Die Cephalopoden der ob.
Kreide Siidpatagoniens. Ber. Naturforscli. Gesell. Freiburg, 1905, vol. xv. — Fervinquiere, L., Etudes
de paleontologie Tunisienne, I. Cepbalopodes des terrains secondaires. Carte geol. de la Tuuisie,
1907. — Philippi, E., Die Ceratiten des oberen deutscben Muschelkalkes. Pal. Abhandl. N.F., 1901,
vol. iv. — Phillips, J., Illustrations of the Geology of Yorkshire, pt. ii. London, 1836. — Figures and
Descriptions of the Palaeozoic Fossils of Cornwall, Devon, etc. London, 1841. — Pidet, F. J.,
and Campiche, G., Description des fossiles du terrain cretace des environs de Ste. Croix. Geneva,
1858-72. — Pompech), J. F., BeitrJige zu einer Revision der Ammoniten des schwiibischen Jura, Lief,
i. , ii. Stuttgart, 1893-96. — Uber Ammonoideen niit "auormaler" Wohnkammer. Jahreshefte
Vaterl. Naturk. Wiirttemb.,' 1894.— Ammoniten des Rhat. Neues Jahrb., Bd. ii., 1895.
Quenstedt, F. A., Ueber die vorziiglichsten Kennzeiehnen der Nautileen. Neues Jahrb.,
1840. — Petrefactenkunde Deutschlands, I. Cephalopoden. Tiibingen, 1849. — Der Jura. Tubingen,
1858. — Die Ammoniten des schwabischen Jura, Bd. i. -iii. Stuttgart, 1886-88. — Remele, A.,
Zur Gattung Palaeonautilus. Zeitschr. Deutsch. Geol. Gesellsch., Bd. xxiii., 1881. — Renz, G.,
Die mesozoischen Faunen Griechenlands. I. Die triadischen Faunen der Argolis. Palaeontogr.,
1911, vol. Iviii. — Reynes, P., Monographie des Ammonites. (Text incomplete), 1879.- — Roemer,
F. v., Lethaea Geognostica. I. Lethaea Palaeontologica. Stuttgart, 1880-83. — Das rheinische
Uebergangsgebirge. Hq.nnover, 1844. — Rildemann, R., Structure of some primitive Cephalopods.
Report N.Y. State Paleontologist, 1904.— Sandberger, G., Beobachtungen iiber die Organisation
der Goniatiten. Jahrb. Ver. Naturk. Nassau, Bd. vii. p. 292, lS51.—Sandberger, G. and F., Die
Versteinerungen des rheinischen Schichtensystems in Nassau. Wiesbaden, 1850-55. — Schliiter,
C, Cephalopoden der oberen deutscben Kreide. Palaeontogr., Bd. xxi., xxiv.j 1872-77. — Schroder,
H., Untersuchungen iiber silurische Cephalopoden. Palaeont. Abhandl., Bd. v. Heft 4, 1891. —
Siemiradzki, J., Monograph. Beschreib. der Ammoniteugattung Perisphinctes. Palaeontogr., 1899,
vol. xliv. — Smith, J. P., Comparative Study of Palaeontology and Phylogeny. Journ. Geol.,
vol. v. No. 5, 1897. — Marine Fossils of the Coal Measures of Arkansas. Proc. Amer. Philos. Soc.
vol. xxxv., 1897. — The Development of Glyphioceras, etc. Proc. Calif. Acad. Sci. [3], vol. i.,
1897. — The Carboniferous Ammonoids of America. Mon. xlii., U.S. Geol. Survey, 1903. — Stein-
mann, G., Ueber Tithon und Kreide in den peruanischen Anden. Neues Jahrb., Bd. ii. , 1881.
—Stanton, T. W., The Colorado Formation. Bull. U.S. Geol. Surv. No. 106, I89o.—Stoliczka,
F., and Blanford, II. F., Fossil Cephalopoda of the Ci'etaceous Rocks of Southern India. — Mem.
Geol. Surv. India, Palaeont. Indica, 1861-66. — Suess, E., Ueber Ammoniten. Sitzungsber. Akad.
Wiss. Wien, Bd. Iii., Ixi., 1866-70. — Till, A., Die fossilen Cephalopodengebisse. Jahrb. Geol.
Reichsanst. Wien, 1907, vol. liv. — ■Tornquist, A., Die degenerierten Perisphinctiden des Kimmeridge
von Le Havre. Abhandl. Schweizer. Pal. Gesellsch., Bd. xxiii., 1896. — Toula, F., Eine Muschelkalk-
fauna am Golfe von Ismid in Kleinasien. Beitr. Paliiont. Geol. Osterreich-Ungarns u. Orients,
Bd. X., 1896. — Uhlig, V., Die Cephalopodenfauna der Wernsdcirfer Schichten. Denkschr. Akad.
Wiss. Wien, Bd. xlvi., and Sitzungsber. Bd. Ixxxvi., 1883. — Uber die Cephalopodenfauna der
Teschener und Grodischter Schichten. Denkschr. Akad. Wiss. Wien, 1901, vol. Ixxii. — The
Fauna of the Spiti shales. Pal. Indica, ser. xv., 1910, vol. iv. — Wuagen, W., The Jurassic Fauna
of Kutch, vol. i. Cephalopoda. Palaeont. Indica, ser. ix., 1873-76. — -Salt Range Fossils. I.
Productus Limestone Fossils ; Cephalopoda. Ibid. ser. xiii., 1879-88. II. Fossils from the
Cei'atite Formation. Ibid. ser. xiii., 1895. — Wdhner, F., Beitriige zur Kenntniss der tieferen
Zonen des unteren Lias der nordostlichen Alpen. Beitr. Paliiont. Geol. Osterreich-Ungarns u.
Orients, Bd. ii., ix., 1882-95. — Wagner, A., Fossile tjberreste von uackten Tintenfischen. Abh.
Bayer. Akad. Wiss., Bd. viii., 1856-60. — Wedekind, R., Die Cephalopodenfauna des hciheren
586 MOLLUSCA phylum vi
tades surround the 7nouth, and serve as prehensile and locomotive organs; in the
Dihranchiates they are armed with hooks and suckers}
The Cephalopods are the most highly organised, and include the largest-
sized of all known Mollusca. They bi-eathe by gills, and are exclusively marine.
Their nervous, circulatory, digestive and reproductive systems, their muscula-
ture and sense organs all exhibit remarkable differentiation as compared with
those of other Mollusks. A fleshy mantle, which is open above, encloses the
cavity which is occupied by the respiratory organs (the gills) and it also
serves as a covering for the reproductive, alimentary and secretory systems,
the heart and the principal blood-vessels. A large ganglionic mass (cerebral
ganglion) and sub-oesophageal ganglion connected by commissures are placed
around the oesophagus, and are surrounded by a cartilaginous enclosure in the
Dihranchiates, but in Nautilus this protects only the sub-oesophageal nerve mass.
Recent Cephalopods were divided by Owen into two groups — Tetrahranchiata
and Dibranchiata. The former is represented in the present fauna by the soli-
tary genus Nautilus, but the latter still comprises a very considerable series of
forms. A host of fossil Cephalopods abounded in the Paleozoic and Mesozoic
seas. Among these the two largest groups, the Ammonoidea and Belemnoidea, do
not aff"ord any certain information regarding the number of gills, but the shells
of the former agree essentially with those of Nautili, while those of Belemnites,
on the other hand, are more like those of certain Dihranchiates ; hence it is
advisable to associate these fossil groups with the corresponding sub-classes
established for Recent forms.
Subclass 1. TETRABRANCHIATA Owen."
Cephalopods with four plumose gills, and external chambered shells. Ambida-
Oberdevon am Enkeberg. Neues Jalirb. f. Min. etc., 1908, Supplem. vol. xxvi. — White, C. A.,
Mesozoic Fossils. Bull. U.S. Geol. Surv. No, 4, 1884.— 117; (Ye«re.s, J. F.. Mesozoic Fossils,
vol. i. Geol. Surv. Canada, 1876-79. — Palaeozoic Fossils, vol. iii., ibid. 1884-97. — Contributions
to Canadian Palaeontology, vol. i., 1885-89.^ — Descriptions of Fossils from the Devonian of Manitoba.
Trans. Roy. Soc. Canada, vol. viii. sec. 4, l^^O. — Whitfield, R. P., Several papers in Bull. Anier.
Mus. Nat. Hist., 1886-97.— Republication of Hall's Fossils, etc. Ibid. vol. i., pt. ii., 1895.
Wright, T., Monograph on the Lias Ammonites. Palaeont. Soc, 1878-86. — Wurtenberger, R.,
Stuilien iiber die Stanimgeschichte der Amnioniteu. Darwinistische Schriften, No. 5. Leipzic,
1880. — Vabe, //., Ci'etaeeous Cephalopoda from the Hokkaido. Journ. Coll. Sci. Imper. Univ.
Tokyo, Japan, 1904, vols, xix., xx. — Zittel, K. A., Cephalopoden der Stramberger Schichten.
Palaeont. Mittheil. Museum Bayer. Staates, Bd. ii., 1868. — Die Fauna der iilteren Tithonbildungen.
Ibid. Bd. iii., 1870.— Handbuch der Palaontologie, Bd. ii., 1881-85.
^ A. E. Verrill has furnished the following note regarding the arms of Cephalopods : " The
arms, together with the siphon (ambulatory funnel) of Cephalopods, must lie considered as
homologous with the foot of other Mollusca. The large nerves su])plying these organs arise from
the pedal ganglia. In the early larval stages the arms arise as bud-like, paired lateral outgrowths
at the base of the large yolk-sac, while the rudiments of the siphon (funnel) arise as two oblique
pairs of folds situated farther back. The anterior pair of these folds eventually unite and form
the central or tubular jjai't of the siphon, and the more posterior folds form the lateral or valvular
portions of the same organ. The rudimentary arms arise posterior to the mouth on the ventral
and lateral sides of the yolk-sac, and only surround the buccal region at a later stage. The
yolk-sac occupies the same relative position, behind the mouth, as the central part of the foot-
area of ordinary Gastropod larvae in the early veliger stages. Therefore the arms are muscular,
lateral outgrowths of this same foot-area. The two lateral rows of rudimentary arms are widely
separated at first by the yolk, but during the absorption of this, they rapidly approach each other
and converge around the mouth."
^ Owen, R., Memoir on the Pearly Nautilus. London, 1832. — Kerr, J. G., Anatomy of
Nautilus pompilius. Proc. Zool. Soc, London, 1895. — Griffin, L. E. , Anatomy of Nautilus
pompilius. Mem. Nat. Acad. Sci., 1900, vol. viii.
CLASS V
CEPHALOPODA
587
tory funnel divided ; ink-bag absent ; arms represented in existing Nautili by lobes
and numerous tentacles, which are tvithout hooks and suckers. Cambrian to
Recent.
Fig. 1098.
Nautilus pompilius Linn. Recent ; Indian Ocean. Shell with contained soft
parts seen from the left side, the .shell b^ing cut through along the median
line, a, Mantle ; h, Dorsal lobe of the mantle ; c, Hood ; d, Hyponome, or
Our knowledge of the soft parts of the Tetrabranchiates is based entirely
upon the single existing genus Nautihis (Fig. 1098). The soft parts are con-
tained in the outer-
most compartment
(living chamber) of
the shell, the ventral
portions being on
the external side.
The body is short
and thick, and the
head separated from
the remaining por-
tion. Around the
mouth are about
ninety external fili-
form tentacles,
placed upon the
edges of lobes, and
their basal parts
when contracted are
lodged in fleshy
sockets or sheaths.
rrii • f, , 1 " ambulatory funnel "; p, Nidamental gland ;/i, Muscle for attachment ; o, Eye ;
± ne pair OI tentacles «, Siphuncle ; t, Tentacle.s ; x. Septal chamber (after R. Owen).
on the inner or
dorsal side are fused so as to form a thicker muscular lobe or hood, which
serves to close the aperture of the shell when the animal is withdrawn into
the living chamber. On the ventral side of the head and tentacles, but
separated from them, is a very thick muscular leaf, having the free edges
external and rolled in upon themselves (Fig. 1098, (/). This is the so-called
ambulatory funnel of authors generally (Jiyponome of Hyatt), and its cavity
is contracted anteriorly and dilated posteriorly, where it opens into the
branchial chamber. It serves to conduct water which is taken by suction
into, and then violently expelled from the gill cavity of the mantle, thus
driving the creature backward by the force of reaction. Kerr suggests that the
structure of the infolding edges of the hyponome and the muscular character
of this organ would enable the animal to unroll and flatten it out so as to be
available for crawling. It is supposed to be homologous with the foot of
Gastropods, and this suggestion, if true, would show that it had not entirely
lost its normal functions in primitive forms of Cephalopoda.
On either side of the head, near the pair of lateral tentacles, is placed a
large eye of primitive structure, which is supported on a short peduncle.
The mouth is in the centre of the lobes and groups of tentacles, the tongue is
fleshy, and the radula armed with numerous rows of plates and hooks. The
remarkably powerful jaws (Figs. 1099, 1100) are largely composed of a dark
horny substance, only their points being calcified. Similar calcified beaks are
not uncommon in Mesozoic terranes, being found either associated with
588
MOLLUSCA
PHYLUM VI
Nautiloid shells or detached. The jaws belonging to Nautilus bidorsahis froni
the Trias were originally described under the name of Rhyncholites and
A i:
Upper jaw of NaiUilus pompiliiis.
A, Side view ; li, Inferior aspect, i/i.
Fin. 1100.
Lower jaw'of Mufii^ws
jMinpilius. Side view. i/j.
Fir,. 1101.
Temnoclicihis hidorsatus Schlotli. ( = ii/ii/H-
chfiUthcs hirmulo Faure-Bignet). Musciiel-
kalk ; Lainecl<, near Bayreutli. A, Upper
jaw, viewed from above ; B, from tlie .side ;
C, from below.
Conchorhyncliiis (Figs. 1101, 1102); the common Jurassic and Cretaceous
forms are known as Ehymhoteuthis (Fig. 1103) and Palaeoteuthis d'Orbigny.
The long feather-like gills are disposed in two pairs at the base of the
hyponome, and between them is the anus, closely behind Avhich is placed the
A single or double orifice
of the generative or-
gans. In the female
there is found at the
base of the gill cavity
a long, tri-
partite, nida-
mental gland,
which fuses
externally
with the
mantle.
The body
is short,
sack - shaped,
rounded pos-
teriorly, and enveloped by the mantle. The base of the latter is prolonged
at a certain point into a fleshy, hollow cord or tube (the siphon), which passes
through a rounded aperture in each of the septa, and extends as far as the
inner side of the apex in the initial chamber. The fastening of the animal
within the living chamber is accomplished by two oval muscles situated on
either side near the base of the mantle. These muscles are attached to the
inner wall of the living chamber, and have corresponding but very shallow
impressions. They are connected both dorsally and ventrally by a band of
fibres, the annulus, which also leaves its impression upon the shell. The form
and position of the muscles for attachment and the annulus are sometimes
discernible on the internal moulds of fossil shells.
The shells of existing Nautili are coiled in one plane, and composed of
several volutions, the outermost of which either envelops all the earlier ones
{Nautilus fompilius), or leaves the umbilicus partly open {N. umhilicatus).
Fig. 1102.
Temnocheilus hidorsatus Schlotheim
(= Conchorhynchus avirostris Blainville).
MiLschellcalli ; Laineck, neap Bayrenth.
Lower jaw viewed from above.
Rhynchoteuthis sahaudianus Pict. and Lor.
Neocomian ; Voirons, France. A, Dorsal
aspect, showing in part the chitinous lateral
expansions. B, The calcareous beak seen
from below.
CLASS V CEPHALOPODA 589
With the exception of the last half of the outer volution, which is occupied
by the animal as a living chamber, the shell is divided up into numerous
cavities or chambers by parallel partitions called septa, the mesal parts of which
are concave toward the aperture ; and they are disposed at regidar intervals.
The compartments thus formed are said by different authors to be filled
with air, gaseous or even fluid matter, and all are traversed by the siphon.^
The siphon has dense walls and is probably not capable of any extended
movements inside of the surrounding calcareous parts which form the siph-
uncle. The relation of the siphuncle to the septal chambers in Nautilus has
not been sufficiently investigated to enable one to state distinctly what its
functions may be. The whole exterior of the mantle and siphon is encased
in a cuticle of horny matter, the remains of which are often found in the
living chambers and siphuncles of fossil forms as well. The shell itself is
composed of two layers, an internal and an external. The outer layer is
composed of imbricated laminae, is porcellanous, light-coloured and super-
ficially ornamented with red or brown transverse bands ; the inner layer is
nacreous, and composed of thin, parallel laminae, which are crossed by fine
rectangular lines. The septa likewise consist of a pearly layer, but are
covered over like the inner walls of the chambers with a very thin, opaque,
calcareous film. A large number of fossil shells have a structure similar to
the recent Nautilus. These are divided into several groups, characterised by
peculiarities of the initial chamber, and by differences in the suture lines,
siphuncles, sculpturing and form of the aperture.
Our knowledge of the life-history of the Nautilus is very limited.
Although empty shells are cast ashore in great quantities in the Pacific and
Indian Oceans, the animal is rarely found alive. According to Kumpf, the
creature swims by ejecting water through the hyponome, and at the same time
holds the tentacles expanded horizontally, and the head protruded as far as
possible ; but when creeping, probably the head and tentacles are directed
downward." The shell is essentially alike in both cases. However, in
Nautilus po7npilius, Willey has found that the females differ in having flatter
and more convergent sides, the males being stouter and more gibbous, which
is exactly contrary to the prevalent notions with regard to sex among shell-
bearing Cephalopods. The shell is supposed to serve as a hydrostatic apparatus,
sinking when the animal withdraws into the living chamber, but sufficiently
buoyant to float itself and the animal when the head and tentacles are
protruded in the act of swimming. Moseley ^ confirms the observations of
1 These conditions are described by Professor Verrill in the following note : "The pericardium
of Nautilus pompilius communicates directly with the gill cavity by siDccial pores, which are close
to the orifices of the nephridia, but do not unite directly with latter, as in most Mollusca. Water
can, therefore, pass directly into the pericardium and other coeloniic cavities. The cavity of the
siphuncle appears to communicate directly with the pericardium, and hence with the gill cavity by
means of the special pores. Thus sea-water can readily pass into or out from the chambers of the
shell, to equalise pressure at varying depths, as in most marine Mollusca. These chambers are
unquestionably filled with fluid under normal conditions. But living as the animal does under
pressure at considerable depths, the fluid in the chambers is saturated with the gases in solution.
When the Nmitilus is rapidly brought to the surface, some of the gas is liberated in consequence of
diminished pressure, and must occupy part of the space within the chambers by forcing out some of
the fluid. Hence the shell will float until the free gases within the chambers are absorbed or
otherwise eliminated. There is no evidence that free gases are ever naturally present in the living
chambers during life. "
" Rnmphius, G. J5/. , Amboinische Rariteitkamer, p. 59. Amsterdam, 1705.
^ Moseley H. N., Narrative of the Voyage of the Challenger, vol. i. — Fischer , P., Manuel de
590 MOLLUSC A phylum vi
Rumplims, but the animal he studied was drawn up by a dredge which had
been dragged on the bottom at a depth of 300 fathoms. This individual
swam in the manner described, but was not able to sink ; and this was
accounted for on the supposition that in rising from the bottom the sudden
expansion and rarefication of the contents of the air-chambers had interfered
with the action of the hydrostatic apparatus.
Nothing has yet been ascertained regarding the mode of reproduction
and development of the animal in Nautilus. The construction of the shell
in this genus, however, renders it probable that in the youngest stage a
perishable embryonal shell was formed, the presence of which is indicated by
a scar or cicatrix on the apex of the initial chamber. Hyatt describes and
figures a more or less wrinkled lump on the apex of several species of the
Orthoceratidae, which he regards as an embryonal shell or protoconch ; and
Clarke also figures one having a nearly perfect form. The former explains
the absence of the protoconch in fossil genera and in the Recent Nautilus by
supposing it was usually membranous or imperfectly calcified, and hence
easily destroyed.
As the animal continued to grow, it advanced forward by building out
the edges of the aperture and secreted new septa at regular intervals, each
one probably corresponding to a period of repose. A tubular prolongation of
the base of the mantle was formed at each j^eriod of progress, and this
remained behind in the first septal chamber and excreted the calcareous
matter that built the last segment of the siphuncle. Each septum bends
apically into a funnel around the origin of the siphon at the base of the
mantle, and this is continuous with a calcareous but more loosely constructed
and very porous wall that prolongs the tube begun by the funnel. This
porous wall or sheath coats the funnel on its external surface in the air-
chambers, but it continues alone apically beyond the funnel, and is inserted
into the spreading trumpet-like opening of the next preceding funnel. The
siphuncle is therefore a segmented, calcareous tube surrounding the siphon,
each segment crossing only one septal chamber and consisting of a funnel and
its connecting sheath.^
In Nautilus the margin of the external opening or aperture is sinuous, the
concavities being the sinuses, the outward convexities the crests ; and the
single median concave bend on the venter is named the hyponomic sinus,
because it indicates the position of the hyponome. In some fossil genera
(Orthoceras) the aperture is often straight or simple (Fig. 1111); in others
the lateral margins are produced in the form of ear-like crests or lappets
(Lituites, Ophidioceras) ; and in some forms they approximate more or less,
forming contracted apertures.
The closure of the aperture is never complete, and may take place through
the inward growth of the lateral margins, as in Phragmoceras (Fig. 1136),
forming a direct dorso- ventral slit, or from the venter and the sides, as in
Mandeloceras (Fig. 1133), producing a T-shaped opening; or, as in Hercoceras
(Fig. 1120), it may occur principally from the dorsum and venter, resulting in
Conchyliologie, 1880-87. — Willey, A., In tlie Home of the Nautilus. Natural Science, 1895,
vol. vi.
^ Brooks, H., On the Structure of the Siphon and Funnel in Nautilus pompilius. Proc. Boston
Soc. Nat. Hist. ,1888, vol. xxiii. — Appelqf, A., Die Schalen von Sepia, Spirula unci Nautilus. Kon.
Svensk. Veten.sk. Akail. Handling., 189.5, vol. xxv. No. 7. — Grandjean, F., Le Siphon des Ammonites
et des Belemnites. Bull. Soc. Geol. France, 1910, vol. x.
CLASS V CEPHALOPODA 591
u transverse aperture. The dorsal side of the aperture is, as a rule, occupied
by a crest, known as the dorsal crest (Figs. 1115, 1121, 1138). The position
of the hyponome is indicated by the large single opening and sinus at the
termination of the longer median slit of the aperture in shells with contracted
openings that obviously had this organ (Phragmoceras, Gomphoceras, etc.) ; but
in others like Hercoceras, which have no ventral sinus in the aperture, the
hyponome was probably absent or non-functional. The sinus in the lines of
growth, however (Fig. 1120), show that this organ was present in the pre-
ceding stages of development before the contracted apertures were formed.
Ponipeckj states that contracted apertures occur only in senile stages of
growth, and small shells having this peculiarity must be regarded as dwarfs.
This is certainly true of many species, and is probably also the case with
Hercoceras and the like. T-shaped apertures often show several accessory
sinuses and crests (Fig. 1134), which probably indicate the number of their
protrusible arms or tentacles. Most curved forms have the ventral sinus on
the arched external side (exogastric shells), but some have it on the concave
internal side, as in Phragmoceras, and these are called endogastric shells. The
interior wall of the living chamber, and volutions in recent and fossil
Nautiloids (Fig. 1122), are typically marked with fine transverse and longi-
tudinal lines. In the recent Nautilus a black superficial layer, composed in
part of organic matter, is deposited by the hood immediately in front of the
aperture on the dorsum.
The internal partitions or septa, which divide the volutions into chambers,
vary exceedingly in number among different species and also at different ages
of the same individual ; but they are tolerably constant as a rule, within the
limits of one and the same species, if specimens of the same age are compared.
They follow one another in regular succession, but as observed by Hyatt, the
intervals are relatively greater in the young, more constant in the adult, and
then markedly decrease in the oldest stages of development. Each septal
chamber {camera of Hyatt) was part of the living chamber until it was cut off
by a septum and left empty as the animal moved forward. Perfectly pre-
served shells may have the living chamber alone filled up with stony matrix,
since the sediment could only pass into the preceding chambers through the
siphuncle, or as a result of injury to the walls of the camerae. Nevertheless,
these last are seldom entirely empty, their interiors being frequently lined
with crystals of infiltrated calcite, quartz, celestine, baryte, jDyrite, or with
organic secretions. Double septa occur in some forms (Actinoceras), and in
others the camerae are sometimes secondarily partitioned off by intermediate
walls or pseudo-septa, which may either run parallel with the septa proper, or
at an angle with them, and are composed of two readily separable calcareous
lamellae. The origin of these pseudo-septa has been attributed to the
calcification of regularly arched membranes at the posterior end of the body.
The line of junction between the septa and inner wall of the shell is called
the suture. This is invisible externally, except when the shell-substance has
been broken or worn, or dissolved away, and it is seen most clearly on natural
moulds. The sutures of Nautiloid shells follow, as a rule, simple, straight or
slightly undulating lines. These undulations, when convex toward the apex,
are termed lobes, and the reversed or forward curves are the saddles. Thev are
called lateral lobes when occurring on the sides, and when on the venter or
dorsum are termed ventral or dorsal lobes and saddles. The annular lobe is a
592 MOLLUSCA phylum vi
small median dorsal lol)e, usually pointed and occupying the centre of the
main dorsal lobe. It is supposed to have had some relation to the correspond-
ing inflection or point of the annular muscle among the Nautiloidea. In more
specialised shells it is associated with a conical inflection of the septum itself.
The curves are undulatory as a rule, but in some genera may be more or less
angular.
The position of the siphuncle does not enable one to determine which is
the ventral and which the dorsal side in most genera, but the hyponomic sinus
in the aperture and the curved lines of growth are an almost unfailing index
of the ventral side. The siphuncle is apt to change its position in the same
individual at different stages of development, but in shells of the same age
it is approximately constant, and is available for diagnostic purposes in a
number of genera.
The siphuncle differs in its form and characteristics among Paleozoic
genera, being tubular in some (Fig. 1110), or inflated in the interseptal spaces
in others, in such manner as to resemble a string of beads, or swollen discs
which are separated by narrow constrictions (Fig. 1126). When of consider-
able width, its cavity is partly filled up with thin calcareous lamellae (Fig.
1137), partly with the calcareous cones immediately to be described (Fig.
1105), or it is notably reduced by excretions around the interior of the
funnels forming peculiar annular swellings known as rings, and which are
generally composed of calcareous matter. The centre of the siphuncle in
these forms is usually kept open more or less perfectly by an axial tube
termed by Zittel the prosiphon (endosiphmide of Hyatt), which will be con-
sidered more fully in the descriptions of Endoceras and Adinoceras. In
Diphragmoceras the siphuncle is septate like the shell. The upper parts of
these large siphuncles were more or less unobstructed near the living chamber,
and this part (the endoconal or siphuncular chamber of Hyatt) Avas doubtless
occupied by an extension of the mantle cavity, probably containing portions
of the viscera.
The funnel of the siphuncle as described above is simple in structure, and
is plainly directed towards the apex in all Nautiloids, Avith the exception of
Nothoceras and its allies, the funnels (?) of which are turned in the opposite
direction. The funnels, as a rule, are short and incomplete, although in
the early stages of development of many shells, and in the adult stage of
primitive forms they may be complete, extending from one septum to the next
following (Fig. 1105), or even to the second preceding this (Fig. 1104, (7).
When the funnels are complete they are always contracted apically, and
inserted one within the other. The siphuncle in most Nautiloids, as in the
existing Nautilus (Fig. 1123), is apt to be more or less dilated in the younger
stages, especially in the second and first air-chambers, and it is closed at the
end within the fii'st air-chamber by what is termed the caecum. The external
shell is perforated by an elongated scar or cicatrix (Fig. 1122), closed by a
plate, against some part of which the bottom of the caecum impinges in the
interior. The presence of the cicatrix, as already stated, leads to the inference
that a deciduous embryonal shell or protoconch must have been present. The
shell on the apex is so much thinner than at later stages, and is so easily
abraded or destroyed, and the cicatrix itself in consequence so slightly marked
even in perfect shells, that good examples are rarely found, and when met
with require careful preparation and close observation.
CLASS V CEPHALOPODA 593
In some Paleozoic Nautiloids with large siphuncles (Endoceras, Actinoceras),
the apical end of the siphuncle is solid and dilated to form the nepionic bulb
(Hyatt), and this sometimes practically fills the camerae, and besides being
very large in a number of succeeding chambers. The endosiphuncle expands
near the apex in these genera, and forms a good-sized conical perforation or
cicatrix, which is obviously open at its termination (Actinoceras, Nanno).
Closely coiled shells have the apical part bent so as to enclose a vacant
space (the umbilical perforation) in the centre of the whorls (Fig. 1119).
This is present in all the Nautiloidea having this mode of growth, although in
some genera it is very minute. The Nautiloid shell is invariably cone-shaped,
but this may be straight or curved, or coiled in open or closed spirals, but in
rare instances it is even screw-like, or similar to a Gastropod shell. Along
with perfectly smooth shells, or those marked only with fine growth-lines,
which in some rare cases may retain traces of their original coloration, there
are others with external transverse ridges, keels, rows of tubercles or laminae ;
but this ornamentation is of a simple kind, and never attains the degree of
complexity observed among the more highly ornamented forms of Ammonoids.
Classification. — Great importance has always been attributed to the external
configuration and curvature of the shell in distinguishing genera, and the
principal groups usually named Orthoceras, Cyrtoceras, Gyroceras, Nautilus, etc.,
have been founded upon such characters. Barrande emphasised in addition
the shape of the aperture, direction of the funnels, and structure of the
siphuncle, but considered these subordinate in most cases to the general
form, and the majority of writers have followed his example. Hyatt,
however, regarded the general form and involution of the shell as relatively
minor characters, and depended upon coincidence of structure, outlines of the
aperture, and especially resemblances in developmental stages, as surer guides
to the affinities of the species and characteristics of the genera.
Terminology. — For sake of convenience, it is preferable always to speak of
the embryonal shell as the protoconch, and the later or epembryonic stages of
the shell as the conch, the term " shell " being really applicable to the entire
external skeleton inclusive of the protoconch. The history of the individual
and its shell can be divided into the following stages and substages : The
embryo or protoconch ; the nepionic stage or infancy, represented by the apical
part of the conch ; neanic stage or adolescent part of the more mature cone ;
ephebic or adult stage of the same ; and gerontic or senile stage with which it
terminates in a complete example.
All of these stages differ materially from each other as a rule, and it is
often convenient to divide them into substages, connoted by the prefixes ana-,
meta-, and para-. Thus the nepionic can be separated into ananepionic, meta-
nepionic and paranepionic, and it is often essential to treat the neanic and
gerontic stages in the same manner.^
The many different forms of Nautiloid shells may be grouped into a few
leading types, as follows : An orthocone is the young of the straight as well as
of many of the coiled forms. In this, although straight, the bands of growth
are broader on the venter than on the dorsiim, and there is no hyponomic
sinvis. A cyrtocone is the similar stage which replaces or, as is oftener the
case, succeeds this and is curved. Both of these may have crests in the bands
1 For a more extended discussion of terminology that can 1 >e advantageously used in descriptions
of shells of this class see Hijatt, A., Phylogeuy of an Acquired Cliarat:teristic, 1894, p. 422 ct seq.
VOL. I 2 Q
594 MOLLUSCA phylum vi
of growth, on both the dorsum and venter, thus indicating that the young
animal did not possess a large hyponome. An orfhoceracone is the older stage
of a straight form, and is nearly or quite straight on both venter and dorsum ;
the bands of growth are approximately equal, but there is usually a hyponomic
sinus. Cyrtoceracones are shells curved like Cyrtoceras on both venter and dorsum.
Gyroceracones are curved in a loose spiral like Gyroceras, the volutions being
sometimes in contact, but there is no impressed zone, i.e. the venter is not
involved by the overgrowth of the dorsum belonging to the next outer whorl.
The impressed zone in its primitive form is the longitudinal impression
formed in the dorsum by the contact of the whorls. This is divisible into
two kinds — the contact furrow, arising and lasting only when the whorls are
in contact ; and the dorsal furrow, arising through inheritance in the young
before the whorls come in contact. There is also a third modification, which
for the present may be called the 'persistent dorsal furrow. This occurs in the
free senile whorls of some shells, and is a remnant of the impressed zone.
Finally, there is a furrow arising only from contact in the old age of some
distorted Ammonoids, and hence may be called the gerontic contact furrow.
Cyrtoceracones and gyroceracones do not usually have impressed zones, but
an exception is furnished by Cyrtoceras depressum.
Nautilicones are closely coiled shells having an impressed zone. This may
be only a very slight contact furrow, or a hereditary dorsal furrow deepening
by growth and involution, as in Nautilus. Torticones are asymmetrical spirals
like those of a Gastropod, either loosely or closely coiled. These may or
may not have impressed zones. Among Nautiloids they may be distinguished
as trorJioceracones, etc., according to their form, and among Ammonoids as
turriliticones, etc., when more precise descriptive terms are required. A special
nomenclature is employed in describing the position of the siphuncle, which
is of convenience in technical treatises, but may be omitted here. The septal
chambers have been termed camerae in the sequel, because this avoids any
assertion with regard to their contents, such as is implied by " air-chambers "
and the like. The less appropriate term "loculus " has been used with the same
meaning by Holm.
Order 1. NAUTILOIDBA Zittel.
The conchs are camerated orthocones and cyrtocones in the young of primitive
forms, becoming cyrtoceracones like the adults of these same ancestral shells in the young of
more si^ecialised and coiled shells. Apertures have, as a rule, ventral or hyponomic
sinuses, and crests on the dorsum. Septa are concave along the mesal plane towards tlie
apex. Sutures straight or undulated, rarely with sub-angular lobes and saddles, and these
are probahly never acutely angular, as in the Ammonoidea. Each segment of the siph-
uncle is composed of a funnel and sheath as among primitive Ammonoids, hut the funnel
persists throughout life in the ontogeny of all forms {except perhaps Nothoceras). Collars
around the oral openings of the funnel are present in the later stages of Ascoceras (and
Nothoceras ?). Apex cup- or saucer-shaped, and marked by a circular or elongated cavity
or cicatrix, ivhich is more or less compressed elliptical, never transversely elliptical or
depressed, and is sometimes hidden by the protoconch or its shrunken remnants.
The order may be subdivided according to the general external features of
the shell and structure of the siphuncle into five sub-orders, as follows, named with
reference to peculiarities of the funnels : — Holochoanites, Mixochoanites, Schistochoanites,
CLASS V
CEPHALOPODA
595
OrthocJioanites and Gyrtochoanites. The characters of these different groups are defined
under their proper headings.
Suborder A. HOLOCHOANITES Hyatt.
Funnels of siphuncular segments reaching from the septum of origination to the plane
of the next septum apicad or beyond this, or in some genera even to the plane of the second
septum.
I. DiPHRAGMiDA Hyatt.
This group contains but one family, Diphragmidae^ having the same characters as
the following unique genus : —
Diphragmoccras Hyatt. Orthoceracones and cyrtoceracones having simple septa
and sutures as in Endoceratida, but siphuncle divided by tabulae alternating with the
septa of the camerated shell. Chambers of siphuncle empty, as are also the camerae.
Quebec group.
II. Endoceratida Hyatt.
Orthoceracones, cyrtoceracones, gyroceracones and nautilicones having siphuncles of
variable diameter, but as a rule large in proportion to the width of the shell. Tlieymay be
empty or filled with internal organic deposits, but are invariably tubular, and the funnels
completely shut off the interior from the interiors of the camerae. The latter are without
organic deposits.
Family 1. Endoceratidae Hyatt.
Smooth or annulated orthoceracones. Siphuncle ahvays more or less filled with
organic deposits.
A B c
Fig. 1104.
A, Vaginoceras duplex (Wahlenberg). Ordoviclan ; Kinnekulle,
Sweden. Much reduced. B, V. coi/iv/iHnc (Wahlb.). Ordovician ;
Oranienbaum, Russia. The anterior endocone of the siphuncle is
filled up with matrix so as to form a dart (" Spiess "). i/.j. C, Dia-
grammatic longitudinal section of the last, showing siphonal
funnels. D, Detached camera of V\ujinoceras with long siphonal
funnel. (Figs. C and D after Dewitz.)
Fig. 1105.
Endoceras proteiformc Hall. Ordovi-
cian ; New York. Longitudinal section
showing funnels and endocones.
Vaginoceras Hyatt (Fig. 1104). Ordovician. Gameroceras Conrad {Sannionites
Fischer von Waldheim ; Suecoceras Holm). Ordovician and Silurian.
Endoceras Hall {Golpoceras Hall; Diploceras Conrad) (Fig. 1105). Smooth or
596 MOLLUSCA phylum vi
annulated orthoceracones. Funnels reach from septum of origination to the next
apicad of this, but no farther. Septa pass entirely around the siphuncle. Organic
deposits in the form of endocones, and taper off at tlie centre into a spire that is
sometimes tubular and hollow, or again flattened and elliptical. This is the enclo-
siphunde. Ordovician and Silurian.
Narthecoceras Hyatt. Long, cylindrical, staff-like orthoceracones. Siphuncle
large and filled with organic deposits having a radiating fibrous structure like the
guard of a Belemnite. Endocones and an endosiphuncle developed. Septa continuous
around the siphuncle. Ordovician.
Nanno Clarke. Similar to the preceding, but endosiphuncle present only at the
apical end. Siphuncle close to the shell, so that sutures appear to bend apically into
a lobe passing around the siphuncle. Trenton Limestone.
Family 2. Piloceratidae Hyatt.
Shorter and stouter orthoceracones and cyrtoceracones loith relatively larger siphuncles
than in Endoceratidae, and more variable in their internal deposits. Septa are more
concave and sutures more sinuous. Camerae empty and funnels similar.
Piloceras Salter. Breviconic cyrtoceracones with very large siphuncle and well-
defined endocones. Ordovician.
Family 3. Cyrtendoceratidae Hyatt.
Gyroceracones and nautilicones having large siphuncles filled with organic deposits or
empty, hut with endocones obscure or absent, and no endosiphimcles.
Gyrtendoceras Remele. Gyroceracones with siphuncle near the dorsum and filled
with calcareous deposits. Ordovician.
Suborder B. MIXOCHOANITES Hyatt.
Orthoceracones and cyrtoceracones having expanded living chambers with contracted
apertures in the gerontic stage of specialised genera. Tlie oldest septa arc bent sharply
orad, forming a series of dorsal saddles, and the siphuncle becomes highly modified.
Primitive genera have the septa deeply concave or approximately sub-conical, the siphuncle
small and empty, and the septa sometimes more or less imperfect on the ventral side in the
gerontic stage. Specialised forms have siphunchs with short, straight funnels in ths
younq, and in the ephcbic stage collars are built around the oral openings, thus becoming
parallel to some forms of Goniatitidae that have similar composite funnels.
Family 1. Ascoceratidae Barrande.
Cyrtoceracones, smooth or annulated. Siphuncle with long funnels only in the young
and later stages of primitive genera, but collars are added in later stages of specialised
forms, and segments become nummuloidal in the gerontic stage. Septa often more or less
imperfect around the siphuncle and on the ventral side.
Ghoanoceras Lindstr. Sections depressed elliptical. Gerontic stages have no
saddles, and living chamber uncontracted. Ordovician and Silurian.
Aphragmites Barr. Only gerontic li\'ing chambers known ; these are similar to
those of Ascoceras, but have no internal sigmoidal dorsal saddles. Silurian.
Ascoceras Barr. (Figs. 1 106, 1107). (Terontic living chambers internally contracted
by the formation of large sigmoidal saddles, and septa more or less incomplete
CLASS V
CEPHALOPODA
)97
ventrally. Sipliuncle with funnels only in the young, the collars in ephebic stages
becoming nummuloidal and often incomplete in old age. Aperture open. Silurian.
Glossoceras Barr. Known only by gerontic living chambers,
which are like those of Ascoceras, except that the aperture has dorsal
f^^^p' and lateral crests. Silurian.
Volborthella Schmidt. Minute orthoceracones with conical
septa, small siphuncle, perfectly plain upon the surface of the septa.
Living chamber flaring and uncontracted. Lower Cambrian ;
Finland, Esthonia. St. John Group ; Nova Scotia.
Family 2. Mesoceratidae Hyatt.
Depressed elliptical cyrtoceracones, hnoion only hy their gerontic
living chavibers, and affinities therefore uncertain. They are globular
at this stage, and have highly contracted, transversely elongated, and
approximately dumb-bell shaped apertures.
^,
FiC!. 1106.
Ascoceras inanuhrium
Linilstrom. Silurian ;
Gotland. i/.i. (Re-
stored after Lindstrom.)
Fig. 1107.
Ascoceras bohemicum Barr. Silurian (Etage E) ; Kozorz, Bohemia. A,
Specimen with shell partially preserved. ]J, Mould of living chamber detached
from preceding portion. C, Longitudinal section, w, Living chamber ; c 1-4,
Camerae ; I 1-4, Saddles contracting the living chamber, i/i (after Barrande).
Mesoceras Barr. Aperture with very shallow hyponomic sinus. No internal
gerontic sigmoidal septa. Silurian.
Billingsites Hyatt. Aperture without hyponomic sinus. Gerontic living chamber
partly filled by dorsal sigmoidal saddles as in Ascoceras, but septa complete on the
ventral side. Silurian.
Suborder C. SCHISTOCHOANITES Hyatt.
Funnels usually more or less imperfect, present on the internal side, cmd absent or
split on the outer side.
The typical form of the suborder is Conoceras Bronn.
Gyrfocerina Billings. Breviconic cyrtoceracones. Siphuncle large, on tlie concave
side and empty, but having internal ridges alternating with septa of the camerae.
These ridges appear to indicate affinity with Conoceras. Ordovician.
Conoceras Bronn {Bathmoceras Barr.) (Fig. 1108). Breviconic orthoceracones,
598
MOLLUSCA
PHYLUM VI
known only in tlieir later stages of development. Sipliiincle of moderate size, sub-
ventran. Funnels reaching half-way across each camera, steeply inclined orad, and
split on the outer side. Closure of the walls effected by a
plate extending from the apical opening of each funnel through
the funnel itself orad to the apical opening of the next
beyond, and projecting into the interior as a flattened fold,
which is incomplete or open along the central axis. These
internal collars or flat semiconical rings have been described
as complete cones (Dwight). Ordovician.
Suborder D. ORTHOCHOANITES Hyatt.
Gerontic stages have uncontracted volutions and open aper-
tures, except in a few uncoiled pliyloyerontic genera. Siphun-
FiG. 1108. cular segments may be slightly niimmuloidal, fusiform or tubular,
Conoceras irracpost^rwm but are never markedly nummuloidal, nor are the funnels bent
D)"vosdf'^Boh(fmia^fafter s/i-ar^^^ outwards as in Cyrtochoanites. Deposits formed only in
Barrande). the siphuncles of Orthoceratidae and Kionoceras, and in them
they are irregular and no endosiphuncles occur ; other genera
have empty siphuncles. Funnels, as a rule, both longer and straighter than in Cyrto-
choanites, and in Atu,ria almost equal to those of Holochoanites.
Tliis group includes the greater number of Nautiloid forms, passing from the
smoothest to the most highly ornamented of Paleozoic shells, continuing in the Trias
as nautilicones of comjilex ornamentation, and terminating with smooth shells that
range from the Jura to the present time. The sutures become more sinuous and com-
plex in one of the subdivisions than in all other Nautiloids. The increase in number
of lobes and saddles begins in the Trias with Clymenonautilus, and ends with Aturia
in the Tertiary.
I. Orthoceratida Hyatt.
Orthoceracones and cyrtoceracones with smooth or ornamented shells, and not as a
rule contracted in gerontic stage ; apertures open throughout life. Although often short,
none are brcvicones, strictly speaking. Section circular or elliptical, very rarely oval.
Siphuncle with slightly nummidoidal, fusiform or tubular segments, and generally near
the centre.
Family 1. Orthoceratidae M'Coy.
Section circular or compressed, living chamber uncontracted or only slightly so,
and aperture always open. Surface smooth or with only transverse bands, rarely
longitudinal striae, never longitudinal ridges. Siphuncle small (except in Baltoceras),
segments fusiform or cylindrical, never nummuloidal. Deposits when present irregular,
and gathered about the funnels as in the Cyrtochoanites; no definite endosiphuncles ever
formed.
Baltoceras Holm. Sii^huncle large, but with short, straight funnels, and sheaths
as in Orthoceras. Ordovician.
Orthoceras Breyn (Figs. 1109, 1110). Long tapering orthoceracones and cyrto-
ceracones, smooth, or with only transverse striae and growth bands. Siphuncle
generally larger than in Geisonoceras, centren or slightly dorsad of centre. Deposits
when present gathered about the funnels as in the Annulosiphonata. Silurian to Trias,
Geisonoceras Hyatt (Fig. 1111). Similar to the last, but sides spreading more
rapidly, and sii>huncle empty, centren or slightly ventrad of centre. Ordovician to
Carboniferous.
CLASS V CEPHALOPODA 599
Protobactrites Hyatt. Long pencil-sliajied orthoceracones and cyrtoceracones,
(hthocerasinterm,ediumMa,Tk\m. Silurian ;
Gottland. Longitudinal section showing
siiiliuncle, si^pta and pseudosepta ; cainerae
lilled up vvitli calcite.
Fio. 1110.
Orthocrras michclini
Barr. Silurian ; Kozorz,
Bohemia. Longitudinal
section showing short
siiilioual funnels.
circular, or compressed ellii)tical in section, ornamented with
transverse and sometimes longitudinal striae. Si])huncle
tubular, centren or near the centre. Truncation occurs in some
species, and others are more or less transitional to Bactrites
among the Ammonoids.
ceras) styloid eum (Barr.).
boniferous.
Type P. {Ortho-
Silurian to Car-
Family 2. Cycloceratidae Hyatt.
Fig. 1111.
Geiaonoceras timidum
(Barr.). Silurian ; Loch-
kow, Bohemia.
Fio. 1112.
Daicsonocrras annula-
twill (Sowb.). Silurian
(Etage B) ; Viscocilka,
Bohemia. Terminal por-
tion showing shell of
living chamber and
sectioned canierae (after
Barrande).
Orthoceracones and cyrtoceracones having annuli with transverse
sfridje or hands of grototh at all stages ; longitudinal ridges, when
present, more or less discontinuous. The earliest forms often have
large siphuncles, and are apparently more directly connected ivith
primitive Endoceratida than with the Orthoceratidae.
Protocycloceras Hyatt. Annulated orthoceracones and cyrto-
ceracones without longitudinal ridges. Siphuncle large. Type
P. (Orthoceras) lamarcki (Bill.). Ordovician.
Gy cheer as M'Coy (Dictyoceras, Heloceras Eichw.). Annulated
orthoceracones and cyrtoceracones with discontinuous longitudinal
ridges. Siphuncle generally tubular or with fusiform segments ;
deposits when jaresent irregular as in Orthoceras. Annuli often
become obsolete in paragerontic stages. Ordovician to Permian.
Dawsonoceras Hyatt (Fig. 1112). Similar to Cycloceras, but
liaving prominent frilled bands of growth between and on the
annulations, the frills sometimes forming more or less discon-
tinuous longitudinal ridges. Silurian and Devonian.
Ctenoceras Noetling. Cyrtoceracones like Dawsonoceras dulce
(Barrande), but with fine longitudinal ridges between the annuli,
and living chamber with three internal folds or processes — one
median dorsan, and a pair on the A^enter. Siphuncle dorsad of
centre. Oidovician.
Family 3. Kionoceratidae Hyatt.
Orthoceracones and cyrtoceracones with more or less well-marked continuous longi-
600
MOLLUSCA
PHYLUM VI
tudinal ridges, and either with or without annulations. Spinous processes or ttihercles
often appear at the intersections of the longitudinal and transverse hands of growth.
Siphuncle toith faintly nummuloidal, fusiform or tuhular
segments.
Kionoceras Hyatt. Longitudinal ridges present as a rule
only in tlie earlier stages, after wliich inconspicuous annuli
appear, but with some few exceptions become obsolete before
the epliebic stage. Silurian to Carboniferous.
Spyroceras Hyatt. Very long, slender, annulated shells,
with more or less prominent longitudinal ridges in the ephebic
stage. Ordovician to Carboniferous.
Thoracoceras Eichw. {Melia Eichw.) (Fig. 1113). Like the
last, but with more or less sinuous longitudinal ridges. Silu-
rian to Carboniferous.
II. Plectoceratida Hyatt.
Orthoceracones, gyroceracones, and very discoidal naittilicones
with comparatively slight impressed zone. Volutions of gerontic
stage often have a centrifugal tendency, becoming sometimes
straight and. even bending slightly in the opposite or ventral direction.
Shells annulated. or costated, and often with longitudinal striae or
Thoracomms r'u-hniaium fi''^'^ ridges, especially in the young, btht these generally disappear
(Barr.). Silurian (Etage before the ephehic stage. Siphuncular segments slightly num-
15): Dvoretz, Bohemia (after 7 • j 7 -f -^ j 7 7
Barrande). m.'ulmdal, jusijorm or tubular.
Family 4. Tarphyceratidae Hyatt.
Orthoceracones, cyrtoceracones, gyroceracones and nautilicones, compressed oval in
section, venter narroioer than the dorsum. Shell smooth or sometimes ivith primitive fohl-
liJce costae, Siphuncle empty, tubular and ventrad of centre.
Ap)hctoceras, Deltoceras, Barrandeoceras, Tarphyceras Hyatt ; Planctoceras, Eury-
stomites Schroder ; Falcilituites Eemele. Ordovician. (For descriptions see Hyatt's
Phytogeny, 1894.) Eurystomites and Tarphyceras are wholly nautilicones, the remain-
ing genera are eitlier cyrtoceracones or gyroceracones.
Family 5. Trocholitidae Hyatt
Nautilicones resembling those of the preceding family, and not easily distinguished
from them in the young. As a ride they have excessively broad volutions with, reniform
section and an impressed zone at a very early age; the siphuncle is then ventrad of the
centre, but in the ephebic stage it is tubular and dorsad of centre.
Schroederoceras, Litoceras, Trocholitoceras Hyatt ; Trocholites Conrad (Palaeo-
nautilus, Palaeoclymenia Eemele). Ordovician. JDiscoceras Barrande. Ordovician
and Silurian.
Family 6. Plectoceratidae Hyatt.
Gyroceracones, nautilicones and torticones having annular costae from the neanic
stage until late in life, and in some genera, more or less prominent longitudinal ridges,
which usually disappear in the ephebic stage. Siphuncle ventrad of centre.
CLASS V
CEPHALOPODA
601
Pledoceras Hyatt.
Ordovician and Silurian. Sphyradoceras Hyatt (Peismoceras,
Hystrofhoceras Hyatt) (Fig.
1114). Silurian and
Devonian. The first is gyro-
ceraconic, with some discoidal
nautilicones, and the second is
almost exclusively torticonic
of the trochoceran type.
Family 7. Ophidio-
ceratidae Hyatt.
Discoidal nautilicones,
costated from the neanic stage
onioard. Volutions of the
yoicng small and numerous.
Section during the ephebic stage
generally compressed, venter
narrower than the dorsum.
Siphuncle tubular, small.
Ophidioceras Barr. (Fig.
1115). Nautilicones with
straight lateral costae and
raised bands on the venter,
and longitudinal ridges in
Siphuncle dorsad or ventrad of centre during ephebic
stage, but ventrad during the nepionic.
Gerontic apertures with prominent dorsal
and lateral crests, and very deep hypo-
nomic sinus. Silurian.
Homaloceras Whiteaves. Cyrtocera-
cones with section similar to that of Oj^hi-
dioceras, venter narrow and channelled,
bordered by creniilated ridges ; the dorsum
gibbous aiid rounded. Siphuncle near
the venter. Devonian.
Viv.. 1114.
f
Sphyradoceras optatum (Barrande). Silurian
(Etage E) ; Loclikow, Bohemia (after Barrande)
the young.
Family 8. Lituitidae Noetling.
Excepting the supposed ancestral,
primitive genus, Cyclolituites, this is a
series of phylogerontic uncoiled forms with
an extreme modification in the almost
completely uncoiled Bhynchorthoceras.
Apertures quite distinct from those of the preceding family ; hyponomic
sinus shallower, there are narrow ventro-lateral crests, and small lateral
sinuses and crests, some forms having altogether as many as five sinuses
and five crests. Siphuncle tubular and usually large.
Fii;. 1115.
Ophidioceras simplex Barr.
Silurian (Etage E) ; Loclilcow,
Boliemia. i/i (after Barrande).
Pig. 1116.
Lituites lituus
Montf. Ordovician
drift ; East Prussia.
1/.J (after Noetling).
Cyclolituites Remele ; Lituites Bveyn {Fig. 1116); Angelinoceras.
Holmiceras Hyatt. Ordovician. '^i^?ictsiroceras Boll, and Bhynchorthoceras Remele
Ordovician and Silurian. (For re-descriptions see Hyatt's Phytogeny, 1894.)
602
MOLLUSCA
PHYLUM VI
III. Pleuronautilida Hyatt.
Comparatively smooth nautilicones, the inimitive genera discoidal hut leading uf to
some highly involute shells in the Trias. The later Mesozoic and Tertiary shells nearly
all deeply involute. Some of the Triassic Glydonautilidae have more sinuous sutures
and a greater number of lobes and saddles than any other Nautiloids, and this
complexity persists, although to a lesser degree, among the Jurassic, Cretaceous and
Tertiary forms. Siphuncle tubular and small, with mostly short funnels except in
Aturia, where they are very long.
Family 9. Grypoceratidae Hyatt.
Primitive forms have discoidal volutions with very simple sutures, but are succeeded
by involute shells having more complete sutures. The latter have prominent ventral
saddles sometimes divided by a lobe, and large latercd and dorsal lobes. All genera
save one known to have annular lobes. Shells less higlily ornamented than in -preceding
family, and sutures simpler than in the next following.
Syringoceras Hyatt. Discoidal with primitive, ap2)roximately tubular, or slightly
compressed volutions. Surface marked hy longitudinal ridges, sometimes intersecting
the transverse lines so as to produce a cancellated surface. Sutures with faint ventral
saddles, slight lateral and dorsal, and minute annular lobes. Siphuncle very small
and near the venter. Trias.
Grypoceras Hyatt. Volutions more or less deeply involved, but umliilicus open,
the venter narrow and often channelled. Sutures with narrow, sometimes deep A-entral
lobe, broad, sweeping lateral lobes, and deep dorsal with annular lobes. Siphuncle
dorsad of centre. Trias,
Family 10. Glydonautilidae Hyatt.
Shells have folds in some species, and all are deeply involute except the primitive genus
Glymenonautilus. Lateral lobes of sutures more
or less deep and often sub-angular, suggestive of
the Clymenidae among Ammonoids. Some highly
specialised, and involute species have the umbilical
lobes exposed, on the sides, and an additional
pair of laterals developed near the venter, thus
making three pairs of lobes on each side. The
compressed volutions, narrow venter, and aspect
of the young and primitive forms seem to in-
dicate close affinity with the Grypoceratidae, but
only a few species of late Mesozoic time are
hioion to have annular lobes.
Clym.enonautilus Hyatt. Smooth, discoidal
shells with more or less compressed volutions,
and narrow convex venter. Sutures with pro-
minent ventral saddles, one pair of deep lateral
lobes, and large marginal saddles. Siphuncle
supposed to be near the venter. Type C.
(Nautilus) ehrlichi (Mojs.). Trias.
Fi.:. 1117. Clydonautilus Mojs. Deeply involved
Hercoglossafmnconica(OpT?e\). Upper .Jura ; nauiil'i('ones with compressed volutions, narrow
concave ventei-, and umbilicus small or closed.
Sutures with prominent ventral saddles undivided by ventral lobes in adults hells. Trias
CLASS V CEPHALOPODA 603
Hercoglossa Conrad {EncUmatoceras Hyatt) (Fig. 1117). Deeply involute, with
sutures like those in Glyphioceratidae, l)ut the ventral saddle not divided by even the
shallow lobe usually found in that family. Annular lobes present
only in some species. Siphuncle small, centren or dorsad of centre.
Trias to Tertiary.
Pseudonautilus Meek. Similar to Hercoglossa, but with lolies
on the venter, and two saddles on either side. Large annular
lobes present. Jura.
Aturia, Bronn (Fig. 1118). Similar to Hercoglossa, but with
large siphuncle close to the dorsum from an early stage onward,
and funnels very long and larger than in any genus of Mesozoic
or Tertiary Nautiloids. Eocene and Miocene.
IV. Ryticeratida Hyatt.
Cyrtoceracones, gyroceracones and nautiliconcs having shells
covered with more or less x>'>'ojecting hands of growth which often Miocene; Bordeaux'.
become sinuous or develop into spout-like spinose, or nodose promi- ^}^^^^ broken open to
■'..-' -^ ' T n 1 snow sipnonal tunnels.
ncnces. In the more speciahsed shells these are apt to he confined,
to the venter. The frills in the hands often form coarse longitudinal ridges. Siphuncle
tubular or slightly nummuloidal, and commonly ventrad of centre.
Family 11. Halloceratidae Hyatt.
Orthoceracones and cyrtoceracones having depressed elliptical or suh-trigonal sections,
venter broader than the dorsum. Shell ivith closely set and frilled projecting bands of
growth, having large ring-like bands at intervals that sometimes expand so as to form
ivide collars. The highly specialised nautilicones may have a row of large nodes on
either side ^ringing from the bases of large spout-like spines. Siphuncle tubular, small,
and near the venter.
Zitteloceras Hyatt. Cyrtoceracones of depressed elliptical section, the venter
narrower and more gibbous than the dorsum. The layers finely frilled and closely
set in the intervals between more prominent annular bands. Ordovician to Devonian.
Halloceras Hyatt. Gyroceracones of sub-trigonal section, the venter broad and
dorsum sub-angular, with one row of large nodes at each of the ventro-lateral angles.
Devonian.
Family 12. Ryticeratidae Hyatt.
Cyrtoceracones and gyroceracones resembling Halloceratidae, but much larger, with
coarser crenulated bands, and often ivith roios of spout-like spinous processes ivhich some-
times form coarse longitudinal ridges. Siphuncle more or less nummuloidal, and larger
than in the Halloceratidae.
Byticeras Hyatt {Rutoceras Hyatt), Gophinoceras, Strophiceras Hyatt. Devonian.
V. Rhadinoceratida Hyatt.
Cyrtoceracones, gyroceracones and nautilicones having smooth or spinous longitudinal
ridges in the young, lohich become large and fluted in some genera, but disappear in
others. Ridges more or less sporadically combined with fold-like annulations, thus
suggesting direct descent from the Kionoceratidae.
Family 13. Rhadinoceratidae Hyatt.
Primitive discoidal gyroceracones and nautilicones with stout volutions, circular or
depressed elliptical in section, but becoming reniform in later stages of nautilicones.
604
MOLLUSCA
PHYLUM VI
Shells ivith longitudinal ridges and sometimes annular folds in the young, hut often
smooth in the epliehic stage. Sutures with ventral, lateral^and dorsal lobes, or almost
straight. Siphunde nummxdoidal and often dorsad of centre. Annular lobes knoion to
be present in specialised forms.
Bhadinoceras, Nephriticeras Hyatt. Devonian.
Family 14. Trigoiioceratidae Hyatt.
Gyroceracones and nautilicones having at some stage or throughout life trigonal
volutions, a more or less concave venter, and generally fluted shell. Sidures with ventral
saddles in the young, becoming divided by shallow lobes in later stages, and in some genera
the dorsal lobes of the young become divided subsequently by dorsal saddles. Gerontic
living chamber occasionally free near the aperture. Annular lobes observed in only one
species {Apheleceras disciforme). Young have longitudinal ridges roiujhened by transverse
bands as in Thoracoceras. Siphunde small, ventrad of centre.
Trigonoceras M'Coy ; Goelonautilus Foord {Trematodiscus Meek; Trematoceras
Hyatt) ; Subclymenia d'Orb. ; Stroboceras,
Apheleceras, Diorugoceras, Ephippioceras
© v Hyatt. Carboniferous. All nautilicones
but the first, wliicb is gyroceraconic.
Family 15. Triboloceratidae Hyatt.
Gyroceracones and nautilicones similar
to Trigonoceratidae, and with concave
venter at an early stage or until late in
life. The venter afterioards becomes more
or less elevated, and in most species convex.
Sutures also similar, but annular lobes
are present in all the nautilicones save
Goloceras.
Fi(i. 1119.
Vest i nautilus kcinincli (d'Orb.). Lower Carboniferous ;
Tournay, Belgium. Oral and lateral aspects of young
individual, with umbilical perforation.
Triboloceras Hyatt; Vestinautilus Ryckh. (Fig. 1119); Planetoceras, Stearoceras,
Goloceras Hyatt. Carboniferous.
Family 16. Rhineceratidae Hyatt.
Gyroceracones and nautilicones like Tlioracoceras in nepionic stage, but subsequently
becoming biangular in section, and generally developiing solid, more or less tetragonal,
volutions. Longitudinal ridges and flutes also developed, but are more uniform in size
than in the preceding family, and venter is always convex. Annular lobes present in
all nautilicones so far as hnoivn.
Rhineceras, Lispoceras, Thrincoceras, Phloioceras, Discitoceras {Discites ]\I'Coy),
Leuroceras, Phacoceras Hyatt. Carboniferous.
VI. Hercoceratida Hyatt.
Primitive shells have projecting bands of groivth and p)rocesses similar to those of
primitive Ryticeratida, but less numerous, being present in only one row, and evolving
more rapidly into nodose or symmetrical, spout-lilce, spinous processes. More sp>ecialised
forms are t-uherculated as in Ryticeratida, but there are never more than three rows of
nodes on either side, and these are regularly distributed — one on the umbilical shoulder,
another on the ventro -lateral angle, and the third close to the median ventral line.
CLASS V
CEPHALOPODA
605
Annular lobes absent except in a few Triassic forms. SifMmcle generally more or less
nummuloidal.
Family 17. Hercoceratidae Hyatt.
Gyrtoceracones, gyroceracones, nautilicones and torticones having depressed elliptical
suh-quadrate or trapezoidal sections. Aperture has two deep sinuses with projecting edges
Hercoceras mirnm Barr.
Piri. 1120.
Devonian (Etage G) ; Hlubocep, Bohemia
(after Barrande).
Fli:. 11-21.
rtenoeernt' (Gyr.) alatiim
(Ban-.). Silurian (F) ;
Konieprus, Boh(
(after Banande).
at the ventro-lateral angles, and these are usually persistent, foroning tioo lines of more or
less spout-like processes. Suttires with ventral, lateral and dorsal lobes. Siphuncle
ventrad of centre.
Hercoceras Barr. (Fig. 1120), Trochoceras Barr.; Ptyssoceras, Ptenoceras (Fig. 1121),
Anomaloceras Hyatt. Devonian.
Family 18. Tainoceratidae Hyatt.
Discoidal nautilicones with more or less massive volutions which at some stage or
Ihrotighout life are trapezoidal in section, tuberculated, and without well-defined lateral
and umbilical zones. Sutures have ventral, lateral and dorsal, but no annular lobes.
Spiinous processes are complete, never spout-lihe. Siphuncle small, tubular.
Temnocheilus M'Coy {Endolobus Meek and Worth ; Cryptoceras d'Orb.). Section
trapezoidal throughout life, and one row of persistent spines and nodes on either
side at the ventro-lateral angles. Devonian to Carboniferous.
Foordiceras Hyatt. Permian. Metacoceras and Goelogasteroceras Hyatt. Carboni-
ferous. Biadiploceras Hyatt. Devonian. Tainoceras Hyatt. Carboniferous.
Family 19. Oentroceratidae Hyatt.
Gyroceracones and nautilicones with young similar to early stages of Temnocheilus
btfore the impressed zone is formed. Shell subsequently becoming tetragonal in section,
the venter is flattened or concave, and dorsum remaining convex until a late stage.
Nautilicones have a persistent convex centran area in the impressed zone. No annular
lobes knoivn.
606 MOLLUSCA phylum vi
Gentroceras Hyatt. Devonian to Carboniferous. Tetragonoceras Whiteaves.
Devonian.
Family 20. Pleuronautilidae Hyatt.
More or less discoidal nautilicones with stout volutions and large umhilical perfora-
tions ; the young, especially in primitive species, remaining cyrtoceracones until a late
stage. More specialised shells are costated and tuherculated on the sides. Sutures have
annular lobes except in Pselioceras. Siphuncle ventrad of centre in the young, but
becoming dorsad in later stages.
Pselioceras Hyatt. Permian. Pleuronautihos Mojs. ; Encoiloceras, Enoploceras,
Anoploceras Hyatt. Trias.
VII. KONINCKIOCERATIDA Hyatt.
Nautilicones with biangular sections at an early stage of groivth, developing later
into modified trapezoidal outlines as in many of the Hercoceratida, but shells are smooth,
and the trapezoidal form as a rule evolves during the phylogeny into quadrangular, and
finally into involute coils ^oith compressed sections, or may become simply more or less
trigonal through elevation of the venter. Anmdar lobes present in most genera.
Aperture constantly open, and in some forms remarkable lateral projections are developed
during the gerontic stage.
Family 21. Koninckioceratidae Hyatt.
Shells of primitive forms similar to Temnocheilus, but leading into those with
tetrago7ial sections, and finally into highly compressed volutions. All are smooth and
have marked umbilical saddles. Volutions vnth broad umbilical zones lohich become
lateral in the more involute species. Siphuncle ventrad of centre.
Koninckioceras, Domatoceras Hyatt. Carboniferous. Potoceras Hyatt. Devonian (?).
Stenopoceras, Peripetoceras Hyatt. Permian.
Family 22. Solenocheilidae Hyatt.
Compressed elliptical in section during early stages, but full-grown of primitive forms
and young of specialised derivatives have a more or less trigonal section in neanic stage.
Later this stock evolves shells with volutions having depressed elliptical or broadly hemi-
spherical outlines. Sutures generally have large ventral saddles, and saddles on the
umbilical shoulders. Umbilical zone very broad, the increase by groioth of the dorsum
being remarkably rapid. Shells smooth, but the aperture in the gerontic stage may develop
peculiar lateral projections, especially at the umbilical shoulders, which are usually very
prominent. Siphuncle sub-ventran.
Aipoceras, Oncodoceras Hyatt ; Asymptoceras Kyckliolt ; Solenocheilus Meek.
Carl)oniferous. Pteronautilus Meek. Permian.
Acanthonautilus Foord. Nautilicones with sub-hemispherical volutions, the dorsum
flattened or concave. Aperture developing laterally into two projecting spines at the
umbilical shoulders. Carboniferous.
VIII. DiGONIOCERATIDA Hyatt.
Pririiitive forms constantly retain depressed volutions having a more or less biangular
or sub-trigonal section ; specialised shells repeat these stages in the young, but subsequently
become more involute, and the sections change to reniform, sub-quadrangular or sub-
elliptical. Shells smooth except in the single genus Cymatoceras. Aperture simple and
open at all stages ; gerontic living chamber only slightly contracted.
CLASS V
CEPHALOPODA
GOT
Family 23. Estonioceratidae Hyatt.
Gyroceracones and discoidal nautilicones having slightly depressed, broad, rapidly
increasing biangular sections in the young, but becoming depressed oval or depressed
sub-trigonal in later stages. Siphuncle variable in position.
Estonioceras Noetl. Ordovician. Edaphoceras, Remeleoceras, Lophoceras Hyatt ;
Diodoceras Hyatt. Tyjie D. {Endolobus) avonense (Dawson). Carboniferous. Digonio-
ceras Hyatt. Jura.
Family 24. Nautilidae Owen.
Nautilicones with more or less involved volutions, the siphuncle slightly mimmuloidal
and variable in position, but never near either the dorsum or venter except in the young,
when it is frequently either near the dorsum or is centren. Biangular stage much
abbreviated or absent, the trigonal stage present in
most shells for a more or less prolonged period, but
developing invariably by spreading of the venter into
Fig. 1122.
NawtiUis pompilius Linn.
Recent. Portion of conch showing
linear cicatrix at apical end (after
Hyatt).
Fig. 1123.
Apical chamber and first
volution of N. pompilius,
sectioned longitudinally,
s, Siphuncle; c, Blind
origin of caecum; .r, Empty
space or uniljilical perfora-
tion (after Bianco).
Fig. 1124.
Nautilus intermedins Sowb. Middle
Lias ; Hinterweiler, Wiirtemberg.
tetragonal, reniform or hemispherical outlines. Never decidedly dis-
coidal, although the umbilicus is often open. More specialised forms
have a minute umbilicus, and in some cases it is completely hidden
during the ephebic stage, although invariably open in the young.
Zone of impression present on the dorsum before the whorls are in
contact. Annular lobes often developed at an early stage, but liable
to disappear in the adult ; absent in some Tertiary species.
Genoceras Hyatt. Jura. Gymatoceras Hyatt. Cretaceous.
Eutrephoceras Hyatt. Cretaceous and Tertiary.
Nautilus Linn. (Figs. 1122-1125). The young resembling
adults of Digonioceras until a late stage, and adults of i>rimitive
species (like N. umbilicatus) similar to Genoceras. Sutures slightly
inflected, with faint ventral lobes ; annular lobes present. Volu-
tions sub-globose, and umbilical perforation comparatively large.
Siphuncle centren in the apical camera, but later becoming ventrad
of centre. Tertiary (?) to Recent.
Fig. 1125.
Nautilus geinitzi
Pictet. Tithonian ;
Stramberg, Moravia.
608 MOLLUSCA phylum vi
Suborder E. CYRTOCHOANITES Hyatt.
Shells varying from orthoceracones to nautilicones, none of them highly ornamented,
although some are annulated or costated, and in rare cases slightly nodose. Sittures as a
rule simpler than in the Orthochoanites. Siphnncle varies exceedingly, passing from tubular
in the young, and even in the full-groion of immitive forms, to highly nummuloidal in the
adults of specialised genera, or again in some groups retaining constantly its primitive
character. The funnels, however, are as a rule bent outward or crximpled, and generally
short.
I. Anndlosiphonata Hyatt.
Mostly orthoceracones and cyrtoceracones, ivith a few gyroceracones and very rarely
natitilicones, the last-named being invariably discoidal. Apertures constantly open.
Siphuncle may be empty, but organic deposits when present always gathered about or
encrusting the funnels as hollow or solid internal rings. Deposits sometimes sufficient to
form more or less annulated endosiphuncles, the rings being optposite the camerae, alter-
nating with the septa, and extending outivardly.
Family 1. Loxoceratidae Hyatt.
Smooth orthoceracones and cyrtoceracones similar to the Orthoceratidae, but siphuncle
distinctly nummuloidal, and funnels very short and crumpled. Deposits not uncommon,
but irregular, and only irregular endosiphuncles occasionally formed.
Loxoceras M'Coy {Sactoceras Hyatt). Mostly ortlioceracones, circular or ellijstical
in section. Siphuncle supjiosed to be tubular in tbe young, but highly nummuloidal
in later stages, centren or near the centre. Septa invariably single, and camerae
empty. Ordovician to Carboniferous.
Campyloceras M'Coy (Aploceras d'Orb.). Breviconic cyrtoceracones or orthocera-
cones with smooth or finely ridged shells, circular or depressed elliptical in section.
Sij)huncle centi'en or ventrad of centre. Carboniferous.
Family 2. Uranoceratidae Hyatt.
Cyrtoceracones, gyroceracones and na%itilicones, with stout volutions. Siphuncle in
primitive forms highly nummuloidal, but invariably empty ; in nautilicones it has less
nummuloidal segments, and is uniformly ventrad of centre, but not near the venter.
Sutures with ventral saddles, lateral lobes, and also dorsal saddles in primitive forms as
toell as the young of all shells. Ventral and dorsal lobes arise .subsequently in the
ontogeny of nautilicones.
Uranoceras Hyatt. Stout, more or less breviconic cyrtoceracones, compressed
elliptical or sub-quadrangular in section. Sutures with broad veutral saddles, lateral
and dorsal lobes. Siphuncle large, nununuloidal, centren or ventrad of centre.
Devonian and Carboniferous.
Gigantoceras Hyatt. Gyroceracones similar to the preceding, but having longer
living chambers and more compressed volutions. Includes the largest known Nauti-
loid shells. Type G. (Gyroceras) inelegans (Meek). Silurian.
Family 3. Actinoceratidae Saemann.
Orthoceracones and cyrtoceracones with siphuncle more or less filled by rings of
organic deposits, and having an endosiphuncle in the central axis. Camerae may be
empty or filled to various degrees tvith organic deposits, even to the extent of solidifying
the entire shell previous to the gerontic stage. Shells smooth or anmilated, but not longi-
tudinally ridged, at least in the latter stages.
CLASS V
CEPHALOPODA
609
Actinoceras Bronn. (Figs. 1126-1127). Orthoceracones and cyrtoceracones of usually
dejjressed elliptical section, Avitli large, excessively nummuloidal siphuncle. Funnels
very short and crumpled, sheatli almost globular. In-
ternal dejjosits contracting tlie central axis into an
annulated endosiiiliuncle with tubuli radiating from the
annuli. Septa often double, with an interspace between
the two layers near the
siphuncle, but solid near
the shell. Ordovician
to Carboniferous.
Subgenera : Ormo-
ceras Stokes (Fig. 1128).
Fig. 1126.
Actinoceras coMcatiim (Scliloth.).
Silurian ; Gotland. Abraded ' frag-
ment showing single septa and thick
annulated endosipliuncle. 1/2.
Pig. 1127.
Actinoceras vertcbratiim Hall.
Silurian ; Lockport, New York.
Longitudinal section showing
organic deposits of siphuncle
(alter Barrande).
1128.
Actinoceras (Ormoceras) hayfieldi
Stokes. Ordovician ; Longitudinal
section showing organic deposits
of siphuncle partly dissolved away
(after Stokes).
Ordovician to Carboniferous. Par actinoceras Hyatt (Fig. 1129). Shells longer and
more slender than in the preceding, large siphuncular segments confined to early
stages, and very long living chamber. Type P. (Sactoceras)
canadense (Whiteaves). Silurian.
Gyrt actinoceras Hyatt. Type G. (Gyrtoceras) rebelle (Barr.).
Deiroceras Hyatt; Huronia Stokes (Fig. 1130); Discosorus
and Gonioceras Hall.
Fig. 1129.
Actinocems {Parartinocerds)
(locens (Barr.) Silurian (E);
Dvoretz, Bohemia. Vertical
section showing senile stage
without organic deposits,
preceded by adult stage with
siphuncular rosettes (after
Ban-ande).
Fig. 1130.
Huronia vertehralis
Stokes. Ordovician ; Isle
Drummnnd, Lake Huron.
Siphuncle.
Silurian.
(?) Tretoceras Salter. Orthocera-
cones having a centren nummuloidal
siphuncle, similar to that of Acti-
noceras but smaller, and with a
superficial tubular siphuncle (so-
called), having very long but not
Holochoanoidal funnels. Sheath not
yet shown to be present. It is pos-
sible that the structure referred to
is a peripheral pseudo - siphuncle
formed by abnormal condition of the
septa. Silurian.
II. ACTINOSIPHONATA Hyatt.
Qrthocerctcones,
gyroceracones, and a
cyrtoceracones,
few discoidal
nautilicones. Shells frequently breviconic, in lohich case the gerontic living chambers and
apertures are more highly contracted than in all other Na%itiloids. Siphuncle sometimes
empty ; organic deposits, ivhen present, in the form of laminae radiating from the sheath
VOL. I 2 R
610
MOLLUSCA
PHYLUM VI
of each segment towards the interior. These internal calcareous septa are united only in
their 'peripheral I'tarts, not meeting at the central axis so far as known, and also liable
to be more or less interrupted in the transverse plane of each funnel. The interior is
consequently an actiniform endosipihuncle toith rays extending outwardly between the
laminae of the deposits.
Family 4. Jovellanidae Hyatt.
Orthoceracones and cyrtoceracones with slightly compressed oval, or depressed and
more or less sub-trigonal sections. Shells smooth or partially annulated. Siphuncle large,
with well-developed actiniform. lamellae, and distinct endosiphuncles. Aperture open and
living chamber uncontracted in the gerontic stage.
Includes Jovellania Bayle ; and Tripleuroceras Hyatt. Silurian and Devonian.
Mixosiphonoceras Hyatt. Type M. {Gyrtoceras) desolatum (Barr.). Silurian and
Devonian. Projovellania Hyatt. Type P. (Gyrtoceras) athleta (Barr.). Silurian.
Family 5. Rizoceratidae Hyatt.
Orthoceracones and cyrtoceracones expanding regularly by growth throughout life, the
living chamber very slightly or not sensibly contracted in the gerontic stage. Aperture con-
stantly open, and with slight dorsal as well as somewhat deeper and
broader hyponomic sinuses. Siphuncle generally small and empty,
but actiniform lamellae and an endosiphuncle sometimes occur.
Shells as a rule smooth or with transverse bands only, hut longitu-
dinal striae are often present in earlier stages.
Rizoceras Hyatt (Fig. 1131). Orthoceracones and exo- or
endogastric cyrtoceracones having circular or elliptical sections.
Living chamber extraordinarily large and long as compared with
camerated part. Silurian to Carboniferous.
Cyrtorizoceras Hyatt. Sections more com-
pressed than in Rizoceras, living chamber
shorter and apt to be more or less laterally
compressed in gerontic stage, but the dorso-
ventral diameters only very slightly so or not
at all. Sutures more sinuous, and vi^ith decided
ventral and dorsal saddles. Type C. (Gyrtoceras)
minneapolis (Clarke). Ordovician and Silu-
rian.
Fig. 1131.
Rizoceras rohustum
(Barr.). Silurian (E) ;
Butovvitz, Bohemia.
Aperture open. i/.j.
Family 6. Ooceratidae Hyatt.
Orthoceracones and gyroceracones with closely set septa and yig 1132.
large nummuloidal siphuncle in later stages of the ontogeny, hut ooceras (Ci/rtuceras)
tubular in the younq. Actiniform. deposits oftener nresent than in ''«?/'ei (Barr.). Silurian
J, Ti- s-1 i^ i 7 T. 7 -77 . (E); Lochkow, Bohemia
the mzoceratiaae, but not generat. Jiunnels very variable, sometimes (after Barrande).
minutely plicated or hook-like in section, confined to dorsal side of
tube, or sometimes absent altogether. Living chamber short and like that of Cyrto-
rizoceras; aperture not infrequently suh-trigonal in outline, but always open.
Ooceras Hyatt (Oonoceras Hj^att) (Fig. 1132). Cyrtoceracones more elongated
and usually more compressed than in Gyrtorizoccras, but otherwise similar except in
structure of the siphuncle. Septa rise rapidly on ventral side, and may bend sharply
orad, forming a funnel ridge or shoulder on tliat side, but disappearing on the
CLASS V
CEPHALOPODA 611
opposite side of the same fuunel. When the funnel itself is absent, the ridges look
like reversed funnels or collars. Silurian.
Cyrtoccras Goldf. Large exogastric, breviconic cyrtoceracones ; sections depressed
elliptical or approximating to trigonal, the dorsum more or less flat, and venter
elevated. Aperture contracted in gerontic stage to a T-shaped opening, and placed at
an acute angle with the central axis, so that the dorsal side is very much shorter than
the ventral. Siphuncle large, iiummuloidal, with well-developed actiniform lamellae,
and with an endosiphuncle in later stages of ontogeny. Devonian.
Family 7. Oncoceratidae Hyatt.
A phylogerontic group of breviconic orthoceracones and cyrtoceracones similar to
Gyrtorizoceras, but shells much shorter and living chamber Visually contracted, especially
in their transverse diameters during the gerontic stage. Siphuncle tubular or highly
nummuloidal, tvithout deposits.
Ercmoceras Hyatt. Cyrtoceracones similar to Cijrtorizoceras, but living chambers
longer, and aperture more or less flaring and open. Siphuncle more or less nummu-
loidal. Type E. (Cyrtoceras) syphax (Bill.). Ordovician.
Cyclostomiceras Hyatt. Slender, short, exogastric orthoceracones and cyrtocera-
cones, circular or compressed in section. Living chamber as compared with camerated
part longer and larger than in most forms, less contracted, and Avith open aperture in
gerontic stage. Type C. (Gomphoceras) cassinense (Whitf). Ordovician to Devonian.
Oncoceras Hall. Compressed exogastric cyrtoceracones with sections like Gyrtori-
zoceras, but shells as a rule much shorter and smaller, and siphuncle more distinctly
nummuloidal. Living chamber also more flattened laterally, the aperture elongated
and often sub-trigonal, but typically open. Ordovician.
Sul>genus : Meloceras (Melonoceras) Hyatt. Similar to the last, but lateral edges
of the gerontic aperture grow inwards, and form pear-shaped outlines. Silurian.
Family 8. Poterioceratidae Foord.
Smooth, breviconic orthoceracones and cyrtoceracones having circular or depressed
elliptical sections. Gerontic aperture, except in primitive forms, is contracted and apt to
assume a sub-trigonal outline; it is laterally narrowed and approximates those of the
next family only in Streptoceras. Outlines of aperture entire; sutures straight or only
slightly sinuous. Siphuncle in this and remaining families, so far as knoivn, slightly
mmimuloidal and empty in the young, but becomes larger ; in specialised forms it is apt
to be more or less filled with radiating lamellae, and in late stages has an endosiphuncle.
Glinoceras Mascke. Ordovician to Devonian. Sycoceras Pictet. Devonian.
Poterioceras M'Coy {Apioceras Fischer ; Acleistoceras Hyatt). Orthoceracones and
exogastric cyrtoceracones, short and stout, with sub-trigonal gerontic aperture. Brachial
area not decidedly difl'erentiated from the hyponomic sinus, and contraction may take
place in all diameters or more extensively in the lateral. Ordovician to Carboniferous.
Streptoceras Bill. Like the last but more arcuate, with laterally contracted
aperture, and a short hyponomic sinus distinct from the brachial area. Silurian.
Family 9. Trimeroceratidae Hyatt.
Smooth breviconic orthoceracones and cyrtoceracones similar to Poterioceras in aspect
and sutures, but more slender, especially in the young, and aperture very distinct in
primitive forms. Even the latter usually have the brachial distinctly marled off from
hyponomic area by ingrowth of sides of the aperture, and in all specialised shells the
612
MOLLUSCA
PHYLUM VI
hyponomic sinus and special inflections known as " brachial sinuses " are formed by bases
of the arms on edges of the brachial area. Finally, the aperture becomes reduced to a more
or less Y- or T-shaped figure, with an open semicircular sinus at the end of the hyponomic
slit or area, and similar sinuses in the edges of the brachial slit, corresponding to the
number of arms. Silurian.
Mandaloceras Hyatt {Dimorion Barr.) (Fig. 1133). Differs from Poterioccras in
the gerontic aperture, which is laterally contracted, and has hyponomic and brachial
areas distinctly differentiated in all but the most primitive species. More specialised
forms have these areas narrowed down, but sjjecial sinuses are not formed.
Trimeroceras Hyatt {Trimorion, Trimeres Barr.) ; Pentameroceras, Septameroceras
Hyatt. Silurian. Aperture in the first has a median and
two brachial ; in the second a median and four brachial ;
and in the last a median and six brachial sinuses.
Fio. 1133.
Mandaloceras (Gom'phoccraf:) hohcmicum (Barr.). Silurian (Etage B) ;
Dvoretz, Bohemia. A, Side view of conch. B, Aperture.
Fig. 1134.
Tetrameroccras panderi
(Barr.). Silurian (B) ; Dvoretz,
Bohemia, i/i (after Barrande).
Hemiphragmoceras Hyatt. Compressed endogastric cyrtoceracones having a
narrowed hyponomic area like Phragmoceras, but with brachial areas as in Dimeroceras.
Type H. {Phragmoceras) piisillum (Barr.).
Tetrameroccras Hyatt {Tetramorion, Tetrameres Barr.) (Fig. 1134). Like the last^
but with more highly contracted aperture and four lateral sinuses.
Hexameroceras Hyatt. Brachial area with six lateral sinuses. Octameroceras
Hyatt. Brachial area with eight lateral sinuses. Type 0. (Phragm.) callistoma (Barr.).
Family 10. Phragmoceratidae Hyatt.
Smooth hreviconic cyrtoceracones and gyroceracones rapidly expanding by growth in
their dorso-ventral diameters, and having open apertures only in primitive types or the
young and ephebic stages of more specialised forms. In the latter gerontic apertures are
laterally contracted and have co very long hyponomic area terminated by a large
hyponomic sinus. The brachial area may be more or less open and ellipitical, or
narrowed and transversely elongated, but always has an entire outline. Siphuncle
generally large, nummuloidal, and often has actiniform lamellae and endosiphuncles in
later stages. Shells mostly endogastric.
Godoceras Hyatt. Excessively short and rapidly expanding cyrtoceracones like
some species of Rizoceras, Init with large living chambers, narrow venter, and large
.siphuncle just ventrad of centre. Aperture constantly open. Type G. {Gyrtoceras)
domitum (Barr.). Silurian.
Protophragmoceras Hyatt (Fig. 1136). Similar to the last, but form more com-
CLASS V
CEPHALOPODA
613
pressed, and siphuncle near the venter (internal). Diifers from Phragmoceras in
having ajierture open throughout life. Type P. (Gyrtoceras)
murcliisoni (Barr.). Silurian.
Gomphoceras Sowb. Stout short orthoceracones and
cyrtoceracones similar to some species of Phragmoceras, but
straighter, stouter and less compressed in form, and gerontic
aperture less contracted laterally. Hyponomic sinus
shorter, and curvature exogastric. Ordovician and Silurian.
Phragmoceras Sowb. (Figs. 1136, 1137). Compressed
endogastric cyrtoceracones and gyroceracones, oval in
section, and venter narrowly rounded. Sijjhuncle large
and near the venter (internal). Gerontic aperture much
contracted laterally, the hyponomic area very long and
narrow. Silurian.
Incertae Sedis.
Fio. 1135.
PTotcyphrcKjmoceras murcliisoni
(Barr.). Silurian (Etage E) ;
Lochkow, Bohemia. Vo-
Nothoceras Barr. Represented by the single species N.
bohemicum Barrande, in which the septum turns orad,
forming an inverted funnel. This funnel connects with
a more or less inflated sheath that closed the siphuncle, and connected it with the
distal opening of the next succeeding septum, thus completely reversing the relative
positions of funnels and sheaths in other forms. The appearances as described by
,A1^S^
Fig. 1136.
Phragmoceras hroderipi Barr. Silurian (Etage E) ; Lochkow, Bohemia.
i/o (after Bairande).
Fig. 1137.
Phragmoceras loveni
Barr. Silurian (E) ; Loch-
kow, Bohemia. Section
showing lamellar organic
deposits (after Barrande).
Barrande are not deemed sufficient to prove the truth of this statement, and it is
unsafe to accept it absolutely until the development has been studied. The cavity is
divided by radiating lamellae running longitudinally as in the Actinosiphonata.
614 MOLLUSCA phylum vi
Range and Distribution of the Nautiloidea.
Fossil Nautiloidea have been recorded Ly Billings as occurring in Canada earlier
than the Quebec Group, but his statement lacks confirmation. An abundant Cephalo-
podan fauna makes its appearance in the earliest Quebec or Calciferous, and is quite
distinct from other later assemblages. Diphragmoceras and other orthoceracones and
cyrtoceracones with veiy peculiar siphuncles occur here, but gyroceracones and nautili-
cones are absent. However, the information we have at present of this fauna is
limited, and but few positive conclusions can be drawn.
All the suborders of Nautiloidea are initiated in the Ordovician, and one of them,
Schistochoanites, is confined to this period. Holochoanites and Mixochoanites become
extinct in the Silurian, and only Orthochoanites survive the Paleozoic. The sub-
orders that disapi^ear at this early date are remarkable for their complicated siphun-
cular structure, and peculiar sigmoidal septa observed in the gerontic living chambers
.of certain forms (Ascoceras, Gonioceras), while their prevailing habit is gyroceraconic.
The sigmoidal septa do not become complicated in correlation with closer coiling of the
shell, but occur in cyrtoceracones correlating with highly compressed cones, and in
orthoceracones correlating with strongly depressed cones.
The older classifications recognised the straight orthoceracones, curved cyrtocera-
cones, loosely coiled gyroceracones, and more closely coiled nautilicones as distinct
natural divisions. Although it is possible to employ the habit of curvature in con-
junction with family groups as a convenient means for tracing laws of distribution and
the like, yet for more accurate data the genera must be considered independently.
For instance, some families made up largely of gyroceracones and nautilicones also
contain a few orthoceracones and cyrtoceracones, and these have to be neglected in
estimating the relative proportions of straight and coiled conchs. Other sources of
error are presented by sporadic uncoiled or gerontic forms which occur in families
having coiled shells. In a general way, however, it is possible to state the morphic
succession as follows : —
Orthoceracones, together with their almost invariably associated cyrtoceracones
exceed gyroceracones in the Quebec in the proportion of three families to one, and this
horizon contains but one family of closely coiled nautilicones, and one of the uncoiled
or gerontic type. In the Ordovician are found no less than fourteen families having
straight or approximately straight shells, as against seven families of gyroceracones and
nautilicones. Thereafter until toward the close of the Paleozoic, the proportions of
straight and coiled forms remain approximately equal. The Permian has but one
surviving family of orthoceracones, and four of the coiled groups ; in the Trias the
ratio is one to six, and in the Jura coiled forms alone persist. Thus, a slowly working
tendency is apparent, leading to the production of more and more closely coiled cones,
and the elimination of straight and slightly curved forms. Gyroceracones disappear
with the Carboniferous, and the more discoidal nautilicones with the Trias.
Some curious features are presented by the phylogerontic or uncoiled shells. Only
one family, the Silurian Lituitidae, have all the genera uncoiled save the probable
ancestral close-coiled type. Other families have isolated genera or species exhibiting
similar tendencies, and becoming partially uncoiled during their later stages, although
close-coiled in the young. Such forms occur throughout the Devonian, Imt none have
yet been found in the Carboniferous, where uncoiling of the volutions, when it
occurred, took place earlier than the gerontic stage. From the ]\Iesozoic and later
horizons, no species is known in which the gerontic stage is to the slightest degree
uncoiled.
Torticones are more aberrant than any other conchs, and may be best classified as
phylogerontic forms, since tendencies toward unsymmetrical development of the
volutions occur in the gerontic stage, and are genetic in but a few genera, where they
CLASS V CEPHALOPODA 615
appear during the early stages and are preceded so far as known by a symmetrical
volution. The first manifestation of torticones is in the Ordovician, and their acme is
attained during the Silurian. As regards ornamentation, annulated shells appear in
the Calciferous, and those with longitudinal ridges later in the Ordovician, together
with tuberculated and costated gyroceracones and nautilicones. The last-named, how-
ever, are much .more abundant in the Devonian and Carboniferous, after which they
disappear. Very highly ornamented shells exist in the Trias, but following this
period the conchs are smooth.
Very striking is the marvellously sudden rise of the Nautiloidea as a group,
reaching its maximum in the Silurian, and followed by a decline extending from the
Devonian to the Trias. Then the forces acting unfavourably upon their existence
were arrested, or their violence lessened, and the group has been affected by only very
slight changes, and an exceedingly slow process of retrogression until the present time.
The acme of siphuncular differentiation occurred in the Ordovician, of general morphic
diversity in the Silurian, of ornamentation in the Devonian, and of sutures in the
Trias.
Geographically considered, some facts of distribution are of general interest. The
fauna of the Quebec or Calciferous, which in Newfoundland, Canada, Vermont, and
the vicinity of Poughkeepsie, New York, is rich in fossil remains, is represented by
a few camerated conchs in the Durness Limestone of Scotland. Holochoanites and
Schistochoanites 'are most plentifully represented in the American faunas, but Mixo-
choanites very sparsely so, at least as compared with the Ordovician and Silurian of
Bohemia. The same is true of the Lituitidae, Ophidioceratidae and Hercoceratidae
among Orthochoanites, and of the Jovellanidae, Trimeroceratidae, and kindred families
among the Cyrtochoanites. The Devonian and Carboniferous faunas of America
and Europe are nearly on a par, but the Permian of the western hemisphere is
very deficient in Nautiloid remains. The Jurassic faunas of America have so far
yielded but one specimen of a Nautiloid, but they were probably present to some
extent, since they are represented in the Cretaceous of this country. During the
Cretaceous and Tertiary the princijml distribution of the Nautilidae was in the
eastern hemisphere, and the last surviving species of Nautilus are now restricted to
oriental waters. The following table shows the range of the leading Nautiloid
famili-es.
[The systematic portion of the foregoing,' chapter on Nautiloidea was revised for the first
edition of this work by the late Professor Alpheus Hyatt. In the earlier edition some nine-
teen new genera of fossil Nautiloids were proposed by Professor Hyatt, as well as many new
genera of Ammonoids. The type species of these new genera were designated, but the author's
intention to publish suitable generic diagnoses has remained for the most part unfulfilled.
— Editor.]
[Table
616
MOLLUSCA
PHYLUM VI
Table showing Vertical Range of the Nautiloidea.
Families.
c
.5
*o
'>
o
o
1
3
a
.S
'S
o
>
Q
2
1
3
g
i
1-5
O
o
u
-4^
A. HOLOCHOANITES
1. Dijihragmidae .
2. Endoceratidae .
3. Cyrtendocferatidae .
B. MiXOCHOANITES
1. Ascoceratidae .
2. Mesoceratidae .
C. SCHISTOCHOANITES
D. Orthochoanites
1. Ortlioceratidae .
*
2. Cycloceratidae .
3. Kionoceratidae
4. Tarphyceratidae
5. Trocholitidae .
6. Plectoceratidae
7. Ophidioceratidae
8. Litnitidae
9. Gryi)Oceratidae
10. Clydonautilidae
11. Halloceratidae .
12. Ryticeratidae .
13. Rhadinoeeratidae
14. Trigonoceratidae
15. Triboloceratidae
16. Rhineceratidae
17. Hercoceratidae .
18. Tainoceratidae.
19. Centroceratidae
20. Pleuronautilidae
21. Koninckioceratidae
22. Solenocheilidae
23. Estonioceratidae
24 Naiitilid-ip
E. Cyutochoanites
1. Loxoceratidae .
2. Uranoceratidae
3. Actinoceratidae
4. Jovellanidae
5. Rizoceratidae .
(). Ooeeratidae
7. Oncoceratidae .
8. Poterioceratidae
9. Trinieroccratidae
10. Piiragmoceratidae
CLASS V CEPHALOPODA 617
Order 2. AMMONOIDEA Zittel.^
Shells similar to those of the Naiitiloidea in some primitive Paleozoic groups, hut
these give rise to others with more highly ornamented shells, the apertures of which
have ventral rostra instead of hyponomic sinuses. Sutures, as a rule, have ventral
lohes in the later stages of ontogeny ; the inflections become more numerous than in
Nautiloids even in Paleozoic genera, and their outlines during the Mesozoic are
extremely complex. Siphuncle invariably small, and (except in the Clymeniidae)
situated near the venter. Funnels short, retrosiphonate in primitive forms, but
becoming sometimes prosiphonate during the Paleozoic, and as a nde, prosiphonate
during the Mesozoic,
The ontogeny begins with a calcareous protoconch, the apical stage of the
conch being an open neck built in continuation of the permanent aperture of
the protoconch. The first septum is concave as in Nautiloids, and sutures are
straight or have more or less of a saddle on the venter. Young stages of
Mesozoic shells recapitulate the primitive adult characters of Paleozoic forms.
The aperture was closed when the animal was retracted by a single horny plate
{anaptychus) or a pair of calcareous plates (aptychus), probably secreted by
muscular lobes homologous with the hood in Nautilus.
Shell Characters. — There are apparently no characters, not even the presence
of a calcareous protoconch, which can be relied upon to separate Bactrites from
the orthoceraconic Nautiloids. Nevertheless, the position of the siphuncle and
its peculiar funnels are features which seem to place this form with true
Paleozoic Ammonoids. There is but one series of straight shells among
Ammonoids, and these are obviously not the same as orthoceracones, but are
more properly called hactriticoyies (Fig. 1169). Similarly, the loosely coiled
Mimoceras shells (Fig. 1170) are not gyroceracones, but only their morphic
equivalents in a different genetic stock ; hence the term mimoceracone should
be substituted for gyroceracone. In the same sense the closely coiled sym-
metrical shells, comparable in external aspect and intimate structure with
nautilicones, should be described among Ammonoids as ammoniticones. The
term torticone, however, can be conveniently applied to both groups, since it
does not connote any special structures, but is a general name for all asym-
metrical spirals.
Ammoniticones in some Paleozoic forms are mimoceracones during
nepionic stages, and consequently in later stages a perforation is present
passing through the umbilicus as in Nautiloids. However, in most Paleozoic
and all later ammoniticones, the coiling is so close even at the beginning
^ Besides the works cited the following may be consulted : — Buckman, S. S., Divisions of so-
called Jurassic Time. Quar. Jouvn. Geol. Soc, 1898, vol. liv. — Ctor^e, J. M., The Naples Fauna.
16tli Ann. Rep. N.Y. State Geologist, 1898.— C'nc^-, G. C, Muscular Attachment of the Animal
to its Shell in Ammonoidea. Trans. Linn. Soc, 1898, ser. 2, vol. vii. — Haug, E., Etudes sur les
Goniatites. Mem. Soc. Geol. Fraiice, Paleont., 1898, vol. vii. — Levi, G., Fossili degli strati a
Terebratnla aspasia. Boll. Soc. Geol. Italia, 1895, vol. xv. — Parana, C. F., and Bonarelli, G.,
Faune du Callovien inferieur (Chanazien) de Savoie. Mem. Acad. Savoie, 1897, vol. vi. — Semenoff, B.,
Anwendung der statistischen Methode zum Studium der Vertheilung der Ammoniten. Ann. Geol.
Mineral. Russie, 1897, vol. n.Smith, J. P., Development of Lytoceras and Phylloceras. Proc. Calif.
Acad. Sci., 1898, vol. i. — Choffat, P., Les Ammonees du Bellasien, des Conches a Neolobites Vibra-
yeanus, du Turonien et du Senonien. Faune cret. du Portugal, 1898, ser. 2, vol. ii. — Jackson, R. T.,
Localised Stages of Development in Plants and Animals. Mem. Boston Soc. Nat. Hist., 1899, vol. v.
— Novak, J., Untersuchuugen iiber die Cephalopoden der oberen Kreide in Polen. II. Die Scaphiten.
Bull. Acad. Sci. Cracovie, ser. B, 1911.
618
MOLLUSCA
PHYLUM VI
of the conch, that the protoconch is closely enwrapped by the first volution,
and no perforation is visible even under a magnifier. There are two pits,
however, one on either side of the apical end of the conch, which remain as
remnants of this perforation, and are present in all ammoniticones (except
perhaps certain Clymeniidae). The bactriticone obviously represents the
primitive or primary radical of the Ammonoidea, and the mimoceracone the
next or secondary radical of this order.
Ammoniticones of the Nautilinidae introduce a peculiar form of volution,
the anarcesfean (Fig. 1171), w^hich is depressed and crescentic in section, and
may be regarded as an ancestral radical. These forms evolve a series becoming
more involute and compressed (Fig. 1172), and some with elevated or narrow
venters and w^ell-defined lateral zones (Fig. 1173), but still retaining in the
young more or less of the anarcestean aspect. The Clymeniidae have a few
radical forms of similar aspect and with somewhat similar sutures (Fig. 1165) ;
they then produce a series of compressed discoidal shells having cordiform or
quadrate sections (Figs. 1166-1168), and these also develop involute forms
among specialised species. The Gephyroceratidae and Beloceratinae have a
similar history, but in the Glyphioceratidae coronate or gastrioceran forms with
trapezoidal section arid broad venter become common in the ephebic stages
(Fig. 1196). In the more specialised groups, the anarcestean character re-
appears only during the young stages.
Phylogeronetic series (Bhabdoceras, Cochloceras) make their appearance in the
Upper Trias, become more abundant in the Jura, and still more important
during the Cretaceous. They have their own peculiar radicals, sometimes
found among discoidal and again among more involute shells, but for the
most part they do not originate from smooth shells.
The same descriptive terras are used for shell characters among
Ammonoids as among Nautiloids. Obviously the first stage of the conch
Fig. 1138.
Asellate protoconch of Gephyroccras calculi-
forme (Beyr.). Upper Devonian ; Budesheim,
Eifel. A, viewed from in front. B, Prom the
side (after Branco).
Fig. 1139.
Latisellate stage of Arcesies cymblformis (Wulfen).
Trias ; Aussee, Austria. A, Viewed from in front.
JS, From the side (after Brauco).
was that of a living chamber, the protoconch being without internal septa
or siphuncle (Fig. 1150). Then, after building out the usually flattened
neck or apical part of the conch, the animal rested, and the first septum as
well as the caecum (or incipient stage of the siphuncle) was secreted. The first
septum closed the aperture of the protoconch, and the caecum jDr ejected into
its interior. The caecum is connected with the internal surface of the proto-
conch by bands (Figs. 1150, 1151), or semiconical prolongations, described
by Munier-Chalmas as the frosiphoii. But these bands are of various shapes,
are not connected with the interior of the caecum, and appear to be merely
CLASS V
CEPHALOPODA
619
Pig. 1140.
Angustisellate stage of PhyUocnras
hetewphyllum (Sowb.). Lias.
calcareous supports for the bottom of the caecum. The earliest sutures,
described in a masterly way by Braneo, are divided by him into three classes :
asellate, laiisellafe and angustisellate (Figs.
1138-1140). The asellate cross the venter as
a straight line or very slight saddle, and are
present only in the ephebic stages of Cyrto-
dymenia{1) and in the young mimoceran stage
of the Nautilinidae. In all except primitive
forms it is confined (as are most of the
purely nautiloidean characters) to the first
septum. The latisellate stage is character-
ised by a decided broad saddle on the
venter, with corresponding deeper and broader lobes on the sides. The
angustisellate stage has prominent, sometimes almost sub -acute ventral
saddles with corresjDonding deep lateral lobes, accompanied by definite saddles
at the umbilical depressions.
The last two stages are progressive modifications confined to the larvae of
Ammonoids, and are not present in the ephebic stages of any known species.
The asellate condition of the first septum is found in the ananepionic stage of
one species of the Clymeniidae, according to Braneo, but his figure shows a
saddle on the venter. The Nautilinidae and Gephyroceratidae are asellate, and
the Glyphioceratidae also in some primitive Devonian genera, but latisellate in
others, and angustisellate in the Trias. The Triassic Lobitidae and Arcestidae
are latisellate, while the Cladiscitidae and the Phylloceratidae are angustisellate
4 P, c throughout. The
embryos of theCera-
tidae are very little
known, but are sup-
posed to be latisel-
late, while the
highly specialised
Pinacoceratidae are
angustisellate. The
remaining system-
atic groups are
wholly Jurassic and
Cretaceous, and so
far as known, the
first septa are an-
gustisellate.
Sutures} — The second septum (Fig. 1141) in all but the most primitive
forms becomes divided by an entire azygous lobe on the venter, often termed
the "siphonal lobe," but hereinafter referred to as the ventral lobe, and by a
^ The terminology commonly in vogue designates the siitural inflections as follows : — The ventral
or external lobe is boinuled on either side of the niesal plane by the laxge. first or superior -lateral
saddle. This is followed liy the first or snperior-lateral lobe, and then come the second or inferior-
lateral saddle and lobe in the order named. All additional inflections occurring between the second
lateral lobe and the line of involution are termed auxiliaries, and are numbered in regular order.
The antisiphonal is also known as the internal, dorsal or columellar lobe. By "lobes" are always
understood the angulated or digitated portions of the suture which are directed backwards, away
from the mouth of the shell ; "'saddles" are the elevations between them, which point towards the
aperture of the shell.
'■^VWV^:
HrvAAAf "
■}•
Gastrioceras diadcma
Same in a latjsellate
Fig. 1141.
A, Development of sutures in a latisellate Qoniatite,
(Goldf.). Lower Carboniferous ; Choquier, Belgium. B,
Ammonite {Tropitcs fuhbuUatiis Hauer). C, Same in an angustisellate Ammonite
(all after Braneo). Sutuies of the first volution are lettered consecutively from
y to I; those of the second from m to s.
620
MOLLUSCA
PHYLUM VI
smaller azygous lobe (shown to the left in Fig. 1141, A-C) on the dorsum,
usually termed the antisiphoiial. This undivided ventral lobe (Figs. 1143,
1144, EL) persists
throughout the Nau-
tilinidae so far as
known, and is obliter-
ated by a secondary
ventral saddle only
in the Clymeniidae.
It is present throughout the ontogeny of the simplest or radical forms of
Glyphioceratidae, Beloceratinae and Arcestidae. But in the Devonian Gephyro-
ceratidae and
Fn:. 114'J.
.Suture - line of Ct/rto-
dymenia laevigata Miiii.st.
Devonian.
L EL
Pig. 1143.
Sut\ue-lin(^ of Anarcestes suhnautiUnus
(Schloth.). Devonian.
in the Triassic
Ceratidae, shells
having undivided
ventral lobes have
not been recorded ;
in the Tirolitinae
but one such
species has been doubtfully described.
these
L EL
Fig. 1144.
Sutiire-line of Aganides sulcatus
(Munst.). Devonian.
«72 aU
Left half of suture-line of Ceratites nodosus
de Haaii. Trias.
n /,S'
A
^nwki
EL
I
Fig. 114G.
This class of radicals is replaced in
the ventral lobe divided by a small saddle
usually called the ventral or
siphonal saddle (Fig. 1146, m).
The class of radicals having
entire ventral lobes disappears
before the close of the Trias.
The entire antisiphonal lobe
has a more extensive distribution
than the entire ventral lobe, being
present throughout the ontogeny
of Nautilinidae, Clymeniidae and
Gephyroceratidae. Most of the
Glyphioceratidae have this lobe
entire, but it becomes bifid in the
later stages of specialised forms.
The radicals of Beloceratinae have it entire, but in specialised genera it becomes
bifid or even trifid. It is known to be entire in only a few of the Lecanitinae,
and is bifid in most of the Ceratitidae and Arcestidae, besides having for the
most part entire sides. It is also entire in some phylogerontic species of the
Trias. In the Desmoceratidae and Ly toceratidae it is generally bifid, but may
be trifid or irregular in some species, and is accompanied by an extraordinary
growth of two of the branches inwards in a large number of forms. In
Jurassic and Cretaceous Ammonoids, it is as a rule more or less complicated
by the development of secondary inflections on the sides, termed marginals.
Paired or zygous lobes and saddles (Fig. 1141) appear between the two
azygous lobes and belong to two series, the laterals or externals, and the
dorsals. The first broad external lateral inflections, called the " first pair of
lateral saddles," are formed by the ventral lobe and the corresponding first
pair of dorsals by the formation of the antisiphonal lobe ; and between these
there appears a broad lobe, either wholly or the most part external (Fig.
Right suture-line of Conmireras hit^nlrntumBrug. Lias, m,
Sii)lional saddle ; n, Line of involution. EL, Ventral (also
called siphonal or external) lobe, traversed by the siiihtincle.
L, First or superior-lateral lobe ; /, Second or inferior-lateral
lobe. ii'.S, 7,.s'i, LS^, First second, and thiid lateral saddles.
[S, Dorsal saddle. IL, Antisiphonal lobe, i, First dorsal
lube lying on line of involution.
CLASS V
CEPHALOPODA
621
1141, J). This is the stage marked by four lobes and saddles — two azygous
and two zygous lobes, and four zygous saddles. The wide lateral lobes in the
next stage (Fig. 1141, Ck) are divided by saddles that arise on or near the lines
of involution. These divide the two lobes into four, one pair being in part or
Avholly dorsal, and becoming eventually the first pair of dorsal lobes ; the
others develop into the "first pair of lateral lobes." There are accordingly
six lobes and six saddles at this stage. In the next stage (Fig. 1141, A, Bin,
Cm) the saddles bridging the lines of involution become divided by lobes
arising on or near the lines of involution, and the inner arms of the saddle so
formed thus become the second dorsal saddle, while the outer form the second
lateral saddles ; but in some forms they may both pass into the lateral series.
This stage, therefore, has eight lobes and eight saddles — three paired lobes
and four saddles on either side of the mesal plane, and two azygous lobes.
Additional inflections arise in like manner along or near the line of
involution during succeeding stages. But there is considerable irregularity in
their advent even in the eight-lobed stage, and still more so at later periods ;
hence the above description must be regarded as a very general one, although
serving to indicate a few primitive lobes and saddles that are generated during
the younger stages, and are usually recognisable in the adult.
In subsequent stages additional inflections arising on or near the lines of
involution pass outward as the sides of the shell broaden by growth ; and the
fWlfl
Pio. 1147.
Pinacoceras m et t r rn khi (Hannr). Keuper ; Sonieraukogt'l, near Hallstadt, Austria. Left suture-line, much
reduced, showing auxiliary (inner) and adventitious (outer) intleutions. The three longest lobes in the middle
are the first, second, and third laterals (after Hauer).
same law holds true for the dorsum, but of course here the inflections pass
inward toward the mesal plane. The number of inflections on the dorsum is
more limited in all forms than the laterals, and they have simpler outlines.
The inflections added to the sides after the first two or three saddles and lobes
appear are usually called the auxiliaries (Figs. 1145, al; 1147), but the current
use of this term is not consistent with the development of the inflections, and
the distinctions are based for the most part on the contrast in size between
the saddles and lobes as they appear in the adult of diff'erent types. When
the ontogeny is known, however, the auxiliary inflections can be properly
discriminated and described, but otherwise are liable to confuse the nomen-
clature. Adventitious inflections (Fig. 1147) arise between the first pair
of laterals and the median line of the venter, either by the growth of
marginals in the arms of the ventral lobe, or by division of the outer parts of
the first lateral saddles, or by division of the inner parts of the siphonal
saddle.
The regions of greatest metabolism or growth-changes in each genetic
series are near the lines of involution, and it is here that new inflections are
usually formed. The later formed lobes and saddles in these regions repeat
622
MOLLUSCA
PHYLUM VI
in their own development the ontogenetic stages of modification through
which the older ones have already passed. It follows also from this that the
lobes and saddles nearest the umbilical lines of in-
volution are simple and often entire, and are parts
of a series that become progressively more compli-
cated outwards to the lines or columns of the oldest
class — the first lateral lobes and saddles. When
there are adventitious lobes, this series is reversed
on the ventral side of the first pair of saddles. The
inversion is sometimes quite complete, as in some of
the Beloceratinae, thus indicating unusual metabolism
on the venter like that of the regions of involution.
Jackson's law of the localised recapitulation of onto-
genetic stages is well exemplified by the history of
Is AL
Fir;. 1148.
Lytoceras fimhrlatum (Sowerby).
Middle Lias ; Wiirtemberg. Traiis-
venTrarfote" "fLj^AntSiphonai s^^tures among Ammouoids as already shown by him
lobe ; L, Siiperior lateral lobe ; in PlacenticevaS.
I, Inferior lateral lobe ; ES, Ex-
ternal saddle ; LS, Is, First and
second lateral saddles.
The above method of designating the lobes and
saddles as paired in the external aspect and on the
dorsum on either side of the mesal plane disregards, for sake of convenience,
an important fact that should be noted ; namely, that the azygous ventral and
dorsal lobes are in reality paired with each other in the mesal plane ; also
that the primitive dorsals and external lateral inflections correspond in the
same sense to one another, and are also more or less united across the septa
in some forms.
The outlines of the paired lobes and saddles first become complicated in
the Carboniferous Glyphioceratidae. Minor or marginal inflections are intro-
duced, and what are termed bifid or trifid lobes occur in the arms of the ventral
lobe (Fig. 1182) ; they then aff"ect the primitive first lateral lobes and saddles,
and extend thence toward the line of involution (Fig. 1187). These marginal
inflections increase greatly in number and complexity during the Permian,
become preponderant in the Trias, and universal in the Jura and Cretaceous.
During the Carboniferous it is the lobes only, as a rule, that are thus modified;
but in the Permian the saddles too are often affected. The modifications
in outline proceed from the lobes to their sides, and thence to the saddle bases,
except in certain cases when direct division of the saddles takes place by the
outgrowth of secondary median lobes that divide their bases. All these
secondary lobes and saddles are termed marginals.
Siphwncle. — The caecal condition of the siphuncle is apparently confined to
the ananepionic stage or first septum, but J. P. Smith has shown that some
species of Lytoceras and Phylloceras have a bulbous enlargement of this organ,
which may persist in several nepionic camerae. This is apparently a persistent
remnant of the caecal enlargement. The siphuncle of all Ammonoids is larger
in proportion to the volution, and apt to be nearer the centre (Figs. 1149, 1 150)
during the young than at later stages, and is also retrosiphonate, as in Nauti-
loids. It remains retrosiphonate in the Clymeniidae, Nautilinidae, and most
Gephyroceratidae,as well as primitive forms of Glyphioceratidae; but it becomes
transitional (having both funnels and forwardly directed collars) in more
specialised Carbonifei'ous Glyphioceratidae, and finally prosiphonate (funnels
lost, collars alone remaining) in Permian genera. Most Triassic and all Jurassic
and Cretaceous genera have the siphuncle chloiochoanitic. The above stages
CLASS V
CEPHALOPODA
623
;ire repeated in regular succession during the ontogeny of chloiochoanitic forms
(Fig. 1149) except when accelerated development {tacliy genesis) occurs, and
Fig. 1149.
Tropites cf. phoebus Dittm. Trias. En-
larged section in the median plane of the
young, showing retrosiphonate funnels in
the nepionic stage, then transitional, and
later prosiphonate funnels, a, Position of
protoconcli (after Branco).
1150.
Ainaltlieus spinatus Brug. Lias.
Section parallel to median plane, show-
ing position of the siphuncle. a, Pro-
toconch ; c, Caecum (after Branco).
then the monochoanitic stage may disappear. The reduction in size of the
siphuncle among Ammonoids is obviously correlated with loss of functional
importance, as is also 'the case among more specialised Nautiloids ; and con-
sequently organic deposits are not found in the camerae of these shells.
Living Chamber. — This varies greatly in
all of its dimensions, thus indicating differ-
ences in the size and proportions of the
animal, since its body parts were probably
wholly contained within this cavity. The
lines of growth and the few apertures known
among Nautilinidae and Clymeniidae show
that they had hyponomic sinuses on the
venter, and were swimmers like Nautiloids.
The same was probably true of the Gephyro-
ceratidae, except during the gerontic stage of
some species when a ventral crest arises, as
demonstrated by Clarke. In the Glyphio- Farkinsonia parkinsoni (Sowevhy). Middle
,• ^ iT->i j_-i -ji. Jura. Median section showing siphuncle
ceratidae and ijeloceratidae many species that with bulbous enlargement (c), prosiphon (p),
retain the so-called goniatitic form have ji,nd position of protoconch (a) (af^^^^
hyponomic sinuses, but occasionally short
ventral crests appear, and later these become general. Only radical
Paleozoic forms of the Arcestidae have retained the hyponomic sinus ; short
obtuse crests appear in the Trias, and continue thereafter. Jurassic and
Cretaceous Ammonoids have as a rule more pointed rostra than those of the
Trias, and frequently develop lateral crests and lappets (Figs. 1152, 1156).
Very decided decrease in the dimensions of the living chamber during the
senile stage does not occur as a rule among Paleozoic forms ; but this con-
dition appears among the Triassic Haloritinae and Tropitidae with a corre-
sponding contraction of the aperture. The Arcestidae (Fig. 1222) and some
species of the Ceratitidae also often have very narrow openings during the
Fir.. 1151.
624
MOLLUSCA
PHYLUSr VI
paragerontic substage, but the condition is in no sense phylogerontic except
Lohites, and the like (Figs. 1217, 1218).
Pompeckj, in an important essay, asserts that contracted living chambers
are invariably developed in old age, and that
small shells possessing them are consequently not
immature individuals, but dwarfs (Fig. 1156).
It is probable that large numbers of shells are
indeed dwarfs, but it is also a fact that contrac-
tion of the living chamber and volutions occurs
in some forms during comparatively early stages ;
and sometimes in such a way as to affect the
ephebic stages of the ontogeny, when the forms
become truly phylogerontic. This latter term is
used to designate shells in which the ontogeny
has become permanently modified by the assump-
tion of retrogressive characters that were intro-
duced first in the senile stages of allied pro-
pjy ^^5^ gressive species. Whether these peculiar forms
sciiioenhachia cristata (Deiuc). have contracted apertures in their earlier stages,
Gauit. Aperture with ventral ^^^^ ^^^jj resorb them before building further, or
rostrum. o '
whether they never add lateral lappets, rostra,
etc., as claimed by Pompeckj, until the last resting stage of the ontogeny
(Fig. 1156), it is obvious that they are permanently affected by phylogerontic
Spliaeroceras tironcj-
niarti (Sowb.). Oolite.
Apertui'e with bi-oad,
contracted ventral ros-
trum.
Fin. 1154.
Normann ites hraiken-
ridijl (Sowb.). Oolite.
Apei'ture with lateiul
lappets.
FiiJ. 1155.
Oppclia nimhata
(Oppel). Jura.
Latei'al lappets.
Fio. 1156.
Oecoptychius re-
fractus (de Haan).
Jura. Living chamber
contracted, with ros-
trum and lappets.
characters. These forms are comparatively rare in the Trias {Loldtes,
Cochloceras), but their number is sensibly increased in the Jura, although
usually confined to special localities. During the Cretaceous they become
more numerous and more widely distributed (Figs. 1261, 1262). In their
extreme modifications they become more or less uncoiled and finally per-
fectly straight.
Crick and Waagen maintain that Ammonoids had an annular band as well
as shell muscles, and that these served both to hold the animal in the living
chamber, and also formed an air-tight band around the face of the mantle,
fastening the latter to the shell (Fig. 1157). Such was, however, probably
not the only means of attaching the animal to the shell. The steady pro-
gressive complication of sutures, affecting both lobes and saddles as well as
CLASS V
CEPHALOPODA
625
Fio. lir)7.
Oppelia sferaxj)^ (OpppI).
Upper Jura; SolenhotVii. Com-
pressed shell with aptychus (a)
preserved in living- chamber and
distinct impression of shell
muscles ()i) (after Waagen).
their marginal inflections, is directly correlated with the outgrowth of rostra.
The presence of a rostrum indicates the disuse and disappearance of the
swimming organ {hyponome), which in Nautilus causes
the formation of the hyponomic sinus in the aperture,
and flexed growth-lines on the venter. These facts
and the gregarious littoral habits of Ammonoids show
that they probably crawled along the bottom with
their shells carried above them, very rarely swimming.
Their shells are also less bulky in proportion than
those of Nautiloids, and correspondingly less buoyant.
All these observations justify the hypothesis that the
progressive complication of Ammonoid sutures took
place because of their utility in helping to carry and
balance the shell above the extruded parts when the
animal was crawling. The greater complication of
the marginals in Jurassic Ammonoids, where the
number of auxiliary lobes and saddles is often reduced
(Fig. 1253), and the multiplication of the principal
inflections in Fseudoceratites of the Cretaceous in com-
pensation for the suppression of marginals (Fig. 1309), are all accounted for
by this theory. The phylogerontic forms, in which the lobes and saddles are
sometimes reduced in number, and the
marginals are also less complex^ — together
with the position, form and mode of growth
of the last volution, and the short rostra
— suggest that these creatures could not
have been active crawlers during the
greater part of their ontogeny.
The occurrence of broods of young
shells in the living chamber may be taken
as suggesting that some Ammonoids were
viviparous, but the examples of this are
too rare to be relied upon for
general statement.
Opercula. — Plates have been found iw
situ closing the aperture and correspond-
ing in position to the hood of Nautilus in
a number of Ammonoid shells (Fig. 1158).
This positive fact, and the obvious fitness
of such plates to serve as opercula, lead
to the inference that they were formed by
an organ similar to the hood of Nautilus,
and protected the animal when it was re-
tracted into the living chamber. When composed of a single piece, the plate
is called an OMapfychns ; in such cases it is invariably carbonaceous, and was
doubtless horny in the living animal (Fig. 1160). The anaptychus is rare in
the Paleozoic, and has not yet been found in the Trias, but occurs among the
Arietidae and Amaltheidae of the Lower Jura. The operculum, when formed
of two plates, is termed an apitychus, and is always of calcareous composition.
It is noteworthy that these plates occur uniformly in the same position among
VOL. I ■ 2 s ^
Fio. 1158.
Oppelia suhradiaia
(Sowb.). Inferior
Oolite ; Dundry.
Aptychus in place,
closing apei-tnre
(after Owen).
making
a
Fio. IIJO.
Apt yd) U.I lamdkitius
preserved as in Fig. 1157.
Upper .Jura; Solen-
hofnn, Bavaria.
626
MOLLUSCA
PHYLUM VI
Fig. 1160.
Anaptychi. A, Amaltheus
spUialwf Brug. Lias. i/j.
B, Goniatites uchtensis Keys.
some species from certain localities, inside the living chamber and close to the
venter (Figs. 1159, 1161), a circumstance that led
Waagen to suppose they served to protect the nida-
mental gland of female shells. As shown by Michael
in Ojjpelia, even the embryonic shells were furnished
with aptychi.^
Aptychi are composed of three layers, of which the
middle one is the thickest and exhibits a cellular struc-
ture, whereas the two outer layers are comparatively
dense (Fig. 1164). Detached aptychi have been
classified by Zittel into several groups according to
their structure. Cellulosi (Fig. 1163) are smooth, thick
plates, with punctate external surface; Imhricati (Fig. 1159) have the
surface traversed
by oblique folds
or costae; Pundati
(Fig. 1164, C)
have rows of
punctae and over-
lapping folds;
Gramdosi include
thin plates having
the external sur-
face covered with
concentric folds or
rows of tubercles
or spinules ; liiigosi
are thick plates
with irregularly
arranged granules
or rows of nodes
Fic. 1161.
Ifarpoceras lythense (Sowb.).
Boll, Wtirtemberg. Aptychus
chamber.
Upper Lias ;
in the living
Scaiihites spiniger Schltiter.
Upper Cretaceous ; Coesfeld,
Westphalia. Detached
aptyclius.
on the outer surface
Nigrescentes (Fig. 1161) are covered
with a thin carbonaceous coat-
ing; and Coalescentes (Fig. 1162)
have the two thin plates fused
along a median depression. This
last is a phylogerontic condition
of the aptychus occurring in
Sulphites.
Classification. — Leopold von
Buch prepared the way for a
general classification of the
Ammonoidea by pointing out
three grand divisions which he
called "genera."' These were
the Paleozoic Goniatites, Ceratites,
from the Trias and Cretaceous,
and Ammonites, from the Jura
Von Buch's chief distinctions were based on the outlines of
Fui. IKB.
Aptychus laeris v. Meyer. Lithographic Stone ; Solenhofen,
Bavaria. ^1, External aspect; B, Internal. Vi-
and Cretaceous.
1 Michael, R., Zeitsclir. deiitscli. geol. Ges., 1894, vol. x]vi.—Retowski, 0., Neues Jahrli. Miii.,
1891, vol. \\.—lilackmore. If. P., Geol. Mag., 1896, dec. 4, vol. iii.
CLASS V
CEPHALOPODA
627
the lobes and saddles, and were as natural and well-founded as the knowledge
ABC
Fio. 1164.
Vertical sections of aptychi belonging to A, Cdhdosi (^Ammonites zonatus Stopp.) ; B, Imhricati (Ammonites
■jirafmidus Voltz); and C, Punctati (A. punrtatux Voltz). 3/i (after Menegliini and Bornemann).
of the time permitted. D'Orbigny, Quenstedt, Sandberger and Barrande
greatly increased our knowledge of structure and variation, and defined a
number of new genera.
The next marked epoch dates from the publication of Mojsisovics's great
works on the Trias, which made known a fauna as rich and complex as that
of the Jura. Suess, Neumayr, Branco, Waagen, Buckman, Grossouvre, Haug,
Diener, Douvill6, Kilian, Zittel, Karpinsky, Hyatt and others made advances
of essential importance along different lines. All of these authors attempted
to trace phylogenetic histories which of necessity crossed the lines of the
older classifications at, right angles, and sometimes bridged over the divisions
of geologic time.
Suborder A. INTRASIPHONATA Zittel.
Family 1. Clymeniidae Giimbel.
Conchs varying from forms like Anarcestes to those that are more or less compressed in
section, and from completely discoidal to compressed and highly involute shells, the surface
being either smooth or with large spines. The characteristic ventral saddles o,re almost
imperceptible in some primitive species, and although entire and large as a rule, are
in some genera divided by entire ventral lobes. Septa concave along the mesal plane.
Siphuncle dorsally situated. Living chamber occupying about three-fourths of a volution ;
aperture tvifh hypionomic sinus.
The ventral saddles are developed by the obliteration of primitive ventral lobes
and fusion of the first pair of saddles (Branco). It is at present questionable whether
the ventral lobes of some genera are secondary modifications or retentions of the
primitive ventrals, and also whether these can be regarded as divided ventrals even in
Gymaclymenia. The antisiphonal lobe is large and long, and often fused with the
siphuncular funnels. The dorsal sutures, so far as known, are very peculiar, having
only a pair of large saddles confluent with the last pair of external saddles ; or one
pair of zygous saddles, and one pair of zygous lobes, the second pair of zygous saddles
being confluent wdth the innermost external pair.
- The perforation through the umbilicus, so constant in Nautiloids, is absent, and so
too are the umbilical depressions on either side of the neck of the protoconch, common
in other Ammonoids. The forms are nevertheless ammoniticones, having the proto-
conch and other characters of the order. The first septum is described as asellate
(Branco), but is figured as having a broad saddle on the venter.
Primitive forms similar to Anarcestes, but differing in that the sutures have broad
entire ventral saddles and broad rounded lobes ; or if the latter are angulated, they
628
MOLLUSCA
PHYLUM VI
are incomplete internally, rising to saddles at the lines of involution. Siplumcle
tubular and small, and funnels comparatively short (Giimbel).
§ 1. Cijrtoclymenia (Fig. 1165), Oxyclymenia (Fig. 1167) Giimbel; Platyclymenia
Hyatt. Devonian.
Fio. 1166.
§ 2. Conchs similar to those
of preceding genera, but sutures
have two pairs of lateral saddles,
and there is a ventral lolje with
a median saddle.
Cymaclymema (Fig. 1166), Sellaclymenia Giimbel. Devonian.
§ 3. Conchs differ from preceding genera in that the sutures have deep undivided
Fig. 1165.
Suture-line of Cyrtody-
menia !(ui'i(iatri (Miinst.).
Suture-line of Cymadymenm
striata (Miinst.).
Fig. 1167.
Oxydymenia undulata (Miinster).
Upper Devonian; Elber.sreutli,
Fichteltrebirge.
l-'ic;. 1168.
Ooniodyncnia f:peeiom (Miinst.). Upper Devonian ;
Sehiibelhammer, Fichtelgebirge. 1/2-
ventral lobes, and sometimes two pairs of lateral saddles are present. These last may
be either in part or AvlioUy divided by marginals.
Gonioclymenia (Fig. 1168), Cycloclymenia, Discoclymenia Giimbel; Cryptoclymema
Hyatt ; Acanthochjmenia Hyatt. Type A. (Glymenia) neapolitana (Clarke). Devonian.
Suborder B. EXTRASIPHONATA Zittel.
The Extrasiphonata include straight, open-coiled and close-coiled forms, embracing
the old groups of Goniatites, Ammonites and Ceratites, between which there are no
sharp lines.
The Goniatites are the oldest and most primitive Ammonoids, chiefly confined to
the Devonian and Carl:)oniferous. They are mostly small in size, distinguished from
the Clymeniidae by their external siphuncle, and from the rest of the Ammonoidea by
their simple septa. Tlie older Goniatites are retrosiphonate, and the aperture usually
has a ventral sinus. They grade over into Ceratites and Ammonites, the septa
becoming serrated or digitate, usually with an increase in the number of lobes, and
with the development of the forward-pointing siphonal collars.
Family 1. Bactritidae Hyatt.
Bactriticones and cyrtoceracones, usually compressed elliptical in sceiion, and con-
necting through Protobactrites with the Naxitiloidea.
CLASS V
CEPHALOPODA
629
Bactrites Saiidb. (Fig. 1169). In this, the only genus, the shell is straight,
gradually tapering, and round or compressed elliptical in section. Devonian.
Family 2. Nautilinidae Hyatt (NauUlini Beyrich, pars).
Mimoceracones and
avimoniticones, rounded
in section. Body-
cJiamber long. Sutures
have narroio saddles on
cither side of the un-
divided ventral lohe,
and broad lateral lohes
iDith saddles at the lines
of involution or on the
umbilical zones, tvhen
the latter are differen-
tiated. Antisiphonal
lobe absent. Dorsum
with a broad azygous
saddle. Aperture with
a deep and narrow
hyponomic sinus, crests
on the ventre - lateral
angles,and broad lateral
sinuses on either side.
Mimoceras Hyatt
Fig. 1170.
iMiiiwcerds coviprcfsiuii (Beyr.). Lower Devonian ;
Wissenbach, Nassau. A, B, Natural moulds, i/j. C,
Nepionic individual enlarged.
Fig. 11(59.
Ikwti'ites
clrijdns
Fiu. 1171.
(Fig. 1170); Anarcestes Sandb. Upper De-
Ar • /XT'' iit-ri „^l vonian ; Budesheim,
:\rojs. (Figs. 1171 and ^^^^^^ j, Conch, i/,:
1112)' ProlobitesK.a,V\). J>, Sutm-e - line, s/j Anarcestes plehejus (\i^n.). Lower Devonian (Etage G) ;
^ ". ^' (after Sandberger). Hlubocep, Bohemia (after Barrande).
Devonian.
Family 3. Aphyllitidae Freeh.
Ammoniticones icith truncated venters, compressed whorls and short body -chambers.
L EL
Fig. 1172.
.1 narcpstes subnautilin us
(Schlotli.). Middle Devonian ;
Wissenbach, Nassau.
Fig. 1173.
Agoniatites occultus (Barr.). Lower Devonian (Etage G) ;
Hlubocep, near Prague, Bohemia (after Barrande).
Sutures similar to those of the Nautilinidae, except that a dorsal azygous lobe is sometimes
present.
630
MOLLUSCA
PHYLUM VI
Acjoniatites Meek (Ajjhyllites Mojs.) (Fig. 1173); Palaeogoniatites Hyatt. Type
P. (Goniatites) lituam (Barrande). Devonian.
Paraphtjllites Hyatt. Type P. (Goniatites) tabuloides (Barr.). Dorsum of this
involute form is entirely occupied by a large azygous lobe terminating in a minute
annular lobe and partial cone similar to that observed in Nautiloids and in Pinacites.
The inner extension or cone is not present elsewhere among Ammonoids so far as
known. Devonian.
Pinacites Mojs. Highly involute, compressed ammoniticones with acute venters.
Septa biconcave, owing to a division of the lateral lobes by narrow saddles which
are conncctefl by ridges with corresponding saddles on the dorsum. There are also
saddles at the umbilical angles and on either side of the ventral
lobes. The azygoiis dorsal lobe is large. Dorsum with one pair
of narrow zygous saddles and one pair of broad zygous lobes,
giving a formula of eight lobes and eight saddles. European
Devonian.
Family 4. Tornoceratidae Giirich.
Involute forms, with ventral sinus, simple septa like those of
Fig. U7-4. ^^'^^ Apkyllitidae, and relatively short body-chambers.
Tornoceras simplex (v. Tomoceras Hyatt (Fig. 1174), Maeneceras Hyatt (Fig. 1176).
Buch). Upper Devonian; i-. . J \ b /> J \ a /
Budesiieim, Eifei. Devonian.
Family 5. Cheiloceratidae Freeh.
Ammoniticones varying from discoidal and Anarcestes-like to highly involute, com-
FiG. 1175.
Suture-line of Sjioradoceras
miinsteri (v. Buch).
Fig. 1176.
Suture-line of Manneceras
tcrehratus (vSandb.).
Fig. 1177.
Suture - line of Agnnidcs
xulcutns (Miin.ster). Upper
Devonian ; Fichtelgebirge.
Fig. 117S.
Aganides rotatorius (de Koninck). Lower Carboniferous ;
Tournay, Belgium.
pressed shells with narrow venters. Shells smooth, but with frequent labial constrictions.
Body chamber long. Aperture without hyponomic sinus.
In this family the septa are concave along the mesal plane as in Nautiloids,
becoming convex only internally and laterally, following the broad internal saddles in
the zone of involution. Lobes and saddles entire. Primitive forms may have only
CLASS V
CEPHALOPODA
631
two broad saddles on either side, but more specialised sliells may have two pairs of
principal saddles formed by division of the primitive first laterals. There is a corre-
sponding development of narrow saddles and lobes on the dorsum, but primitive forms
have only two broad saddles here as in Aiimxestes. Antisiphonal lobe narrow, entire,
pointed. From this family sprang the Glyphioceratidae of the Carboniferous, and
through them came the Tropitidae and Arcestidae of the Triassic.
Cheiloceras Freeh (Parodoceras Hyatt); Sitomdoceras (Fig. 1175); Aganides Montfort
(Figs. 1177, 1178). Devonian and Carboniferous.
Family 6. Gephyroceratidae Hang.
Evolute to involute forms, mostly laterally compressed, with short body -chambers, deep
ventral hyponomic simis, and ivithout labial constric- a
tions. This group includes forms vnth simple
goniatitic septa, forms with ceratitic septa, and forms
with exceedingly complex ammonitic septa.
The external sutures in primitive forms some-
times approximate to those of Anarcestes, but the
dorsals have only one large azygous lobe, the saddle
being confluent at the line of involution with the
second external pair. In more involute forms the
antisiphonal lobe is large, entire and pointed ; there
is one pair of dorsal saddles, and one of broad
dorsal lobes ; the second pair of saddles, when
present, is confluent with the second pair of lateral
saddles.
Subfamily A. Primordialinae Hyatt
{Primordiales Beyrich).
Distinguished froui Anarcestes by the divided
ventral lobes, large siphonal saddles, and especially
the first lateral saddles, which are very prominent
on the sides. Adventitious lobes and saddles are
formed by division of the first lateral saddles. Septa
in the young are concave and similar to those of
Anarcestes, but in later stages become convex along the mesal plane as in typical
Ammonoids. Siphuncle small, subventran, without calcareous sheath ; funnels retro-
siphonate and short, except in Manticoceras, where they are prosiphonate.
Gephyroceras (Figs. 1138, 1119), Manticoceras Hysitt; Frobeloceras GleiTke ; Timanites
Mojs. Devonian. Nomismoceras Hyatt. Gonioloboceras Hyatt. Type G. (Goniatites)
goniolobus (Meek). Carboniferous. Koenenites Wedekind. Devonian. (This and
related genera are described by Wedekind in Sitzber. Ges. Naturf. Freunde Berlin, 1913).
From the Gephyroceratidae probably sprang the Meekoceratidae of the Permian
and the Lower Trias, and through them came the Ceratitidae.
Fu;. 117y.
Gephyroceras Lntumescens (Beyi.). Upper
Devonian ; Nassau. A, Conch, i/i. B,
Suture-line.
Subfamily B. Beloceratinae Freeh.
Form compressed, discoidal, involute, with high whorls and narrow acute venters.
Lobes and saddles lanceolate, with numerous adventitious and auxiliary lobes.
Includes the genus Beloceras Hyatt (Fig. 1180), of the Upper Devonian. From
the Beloceratinae probably came the Sageceratinae, the Hedenstroeminae, and the
Carnitinae, and possibly the Pinacoceratidae. Beloceras was probably derived from
Timanites with Probeloceras as a connecting link.
632
MOLLUSCA
PHYLUM VI
Family 7. Prolecanitidae Hyatt,
IVie young have a long undivided ventral lobe. Primitive forms are compressed ^
discoidal, and more specialised genera become involute and assume a modified anarcestean
aspect. Saddles are entire in the former, but the first laterals become very large and are
subdivided by simple marginal lobes. 'Lateral lobes entire in primitive genera, and
become bifid or trifid in specialised forms, but rarely have more numerous digitations.
Antisiphonal lobe entire or pointed. Hiphuncle without calcareous sheath ; funnels piro-
siphonate so far as knoicn.
yVVVV/^V
Fig. ll.Mi.
Bdoix ras iaultUoliiitwin (Bpyrich). UpixT
DHVouiaii ; Ailorf, Westphaliu.
.^xniUunjiM/^
Kic. nsi.
PfDlecaniies lunulicotttii (Saiidli. ).
Upper Devonian '; Nassau (alter
Sandbergei).
Subfamily A. Prolecanitinae Freeh.
Shells diwcoidal or evolute, compressed or subquadrate in section. Primitive forms
with undivided ventral lobes, and rounded saddles and lobes of the lecanitean type.
More specialised shells have entire hastate lobes and saddles, and similar but divided
ventral lobes. Aperture with well-marked hyponomic sinus. Shells smooth or
costated, and often with longitudinal ridges.
Phenacoceras Freeh ; Prolecanifes Mojs. (Fig. 1181). Devonian to (Jarljoniferous.
Subfamily B. Noritinae Karpinsky.
Similar to Prolecanitinae, but the ventral lobe instead of ])ecoming divided in the
usual way, retains the larval trifid stage throughout life in primitive species. In
specialised forms the larval siphonal saddles enlarge in the neanic stage, thus building
up a single siphonal saddle with a comparatively large siphonal lobe. First lateral
lobes may be bifid, trifid or completely .-serrated in specialised shells, and the second
and other lateral lobes also may become ceratitic. The saddles, however, retain more
or less of their primitive outlines, and their bases are entire. Sutures with adventitious
GLASS V
CEPHALOPODA
633
inflections. Apertures have crests at the A'^entro-lateral angles ; straight or with faint
sutures at the venter.
Pronorites Mo^s. (Figs. 1182, 1183); Triainoceras Hyatt (Fig. 1185); Farapronorites
Fi<;. 1184.
Septa of Gonlillerites angulatus Hyatt aud Sinitli.
Lower Trias ; Idaho.
Fic. I isj.
I'rono ri ies i-ycloluh us (Ph i 1 1. ).
Lower Carboniferous ; Gra.ss-
innton, Yorkshire (after
Phillips).
Fiu. 1183.
Fig. 11S5.
.Septa of I'ronorite.s arkansaaansis Suture-line of Triainoceras
.Smith. Lower Carboniferous; Arlcansas. tiiherculoso-costatnin (Sandb.). Up])er
1/.. (after J. P. Smitli). Devonian.
Fk.'. Il8(j.
Suture-line of Norites
gondola Mojs. Muschelkalk ;
Schreyer Alp, near Hallstadt,
Austria.
Geinni. ; CurdiUerites Hyatt trnd Smith (Fig. 1184); (1) Ambit e.sWaagen ; NoritesUoy
(Fig. 1186); Daraelites Geium. Devonian to Trias.
Sulifamily C. Medlicottiinae Karpinsky.
Shells compressed, discoidal and involute, with smooth or costated sides, and
often costated or tuberculated and channelled venter.
Ventral lobe entire in primitive species, and trifid or
divided as among the primitive Noritinae in more specialised
forms. First lateral saddles simple but divided in primi-
tive genera, and acquire in Medlicotiia through hyper-
trophy and the development of marginals extraordinary
serrated outlines. Aperture as in the Noritinae.
Sicanites Gemm. ; Promedlicottia Karp. ; Propina-
coceras Gemm. ; E'piscujeceras Noetling ; Medlicottia
Waagen (Figs. 1187, 1188). Permian to Lower Trias.
Fiii. 11S7.
Suture-liue of Medlirottiajirimas Waagen. Permo
Carboniferous ; Salt Range, India (after Waagen).
Medlicottia trautscholdi Genini.
Fernio-Carboniferous ; Sosio,
Sicily (after Gemmellaro).
634
MOLLUSCA
PHYLUM VI
Family 8. Pinaooceratidae Mojsisovics.
Forms vntli involute, compressed, hi(jh ivhorls, vnth narrow and often acute venters.
Body-chamher short. Septa goniatitic to ceratitic, to digitate, but always with adventitious
and auxiliary lobes in addition to the regular series.
The group is probably derived from tlie Beloceratiiiae, at least in so far as it is
a unit. This is almost certainly true of the Sageceratinae and the Hedenstroeminae ;
the Carnitinae are probable derivatives of the Hedenstroeminae, and the Pinaco-
ceratinae apparently are derivatives from the Sageceratinae.
Subfamily A. Hedenstroemiinae Waagen.
Principal lobes and saddles with ceratitic outlines, but adventitious lobes and
saddles have Sageceras -like outlines.
Antisiphonal lobe bifid and very long.
Dorsal inflections more complex than
in preceding families. Aperture with
ventral crests.
Hedenstroemia Waagen (Glypites
Waagen) (Fig. 1189); Prodromites
Smith and Weller (Fig. 1190);
Aspenites H. and S. ; Longobardites
Mojs. Carboniferous to Trias.
.:fy
VV^Ii^^
J-f'
'n(^xA.
U'
'-.C'7 <£■ :
Fio. 1189.
Hedenstm-mia. hissmati H. and 8. Lower Trias ; Idalio.
Fig. ll'JU.
Prodromites gorhyi Miller. Lower Carboni-
ferous ; Missouri. 1/2 (after J. P. Smith).
Subfamily B. Sageceratinae Hyatt.
Similar to the last, but lateral lobes bifid, and saddles acutely spade-shaped.
Adventitious and auxiliary lobes numerous. Antisiphonal lobe bifid. Aperture has
sinuous lateral outlines with crests at the A'entro-lateral ridges.
Pseudosageceras Diener (Fig. 1191); Sageceras Mojs. (Fig. 1192). Permian and
Trias.
CLASS V
CEPHALOPODA
635
Subfamily C. Carnitinae Arthaber.
Form and sculptiu-e like that of the Sageceratinae, except that in the Carnitinae
there is a tendency towards the development of ribs and knots. The septa are no
\
j/
Fit,, iiyi.
Pseudosageceras intermontanum H. and S.
Lower Trias ; Idaho, x '^U-
Fig. 1192.
Sageceras haidirujeri (Hauer). Upper Trias ;
Hallstadt, Austria.
Fni. 1103.
Septa of A rihaberites alexandrac Diener. Middle
Trias ; Alps (after von Arthaber).
longer lanceolate, but ceratitic or even largely digitate. The adventitious series of
lol)es is short, but usually highly complex. This
group probably serves as a connecting link be-
tween the Sageceratinae and the Pinacoceratinae.
Garnites Mojs. ; Procarnites Art. ; Arthaberites
Diener (Fig. 1193); Lanceolites Hyatt and Smith;
Hauerites and Bambanagites Mojs.; Bosnites Hauer;
Tibetites Mojs. Trias.
Sul)faniily D. Pinacoceratinae Mojsisovics.
Forms thin, compressed, with acute venters.
Lobes and saddles all finely digitate. Adventitious
and auxiliary lobes numerous.
The Pinacoceratinae reach the highest degree
of complication of the septa found in any group
of Ammonites. The general plan of their septa
suggests a derivation from the Carnitinae, and
through them from either Hedenstroeminae or
Sageceratinae.
It is also possible that the sub-
Fio. 1104.
Plnacoceraf: layer!, (Hauer). Upper Trias ;
Rothelstein, near Aussee, Austria.
636
MOLLUSCA
PHYLUM VI
groups under the Pinacoceratidae may have no near kinship with each otlicr but
may rather be merely i^hylogerontic developments in different stocks.
j__ Pinacoceras Mop. (Figs. 1194, 1195); Placites Mojs.
AdL EL
Pinacocerm metttrnicM (Hauer). Keuper ; Someiiiukogel, near Hallstadt, Austria,
Suture-line reduced (after Hauer).
Family 9. Glyphioceratidae Hyatt.
Form, robust and involute, or evolute and trapezoidal in section. Body -chamber long.
Labial constrictions always present. Spiral ridges often present, especially on the venter.
External septa somewhat like those of the Primordialinae, but the dorsal or internal septa
have narrovi saddles and an interior lateral lohe on either side of the pointed anti-
siphonal lobe.
Siphuncle small, and funnels generally prosiphonate. Aperture usually with
hyponomic sinus, but some species have ventral crests during ephebic stages. Shells
smooth, tuberculated or costated, but costae do not cross the venter as a rule. Venter
.sometimes with well-marked longitudinal ridges.
This group is probaldy descended from the Cheiloceratidae, and is the ancestral
stock of the Tropitidae and the Arcestidae,
possibly also of the Ptychitidae. Muenstero-
ceras, Gastrioceras (Figs. 1196, 1197), Glyphio-
¥ia. lino.
Gastrioceras josaae (M. V. K.). Permo-
Carboniferous ; Artinsk, Ural.
Gastrioceraii diadciiia (Goldf.).
Lower Carboniferous Lime-
stone ; Choquier, near Liege,
Belfriura.
Fl(3. 1199.
GU/phioccras sphaericum Faralcgoceras newsoini
(Goldf.). Lower Carboniferous Smith. Coal Measures ;
Limestone ; Suttrop, West- Arkansas, x V2 (after J. P.
phalia. Smith).
ceras (Fig. 1198), Paralegoceras (Fig. 1199), Schistoceras Hyatt; Pericyclus Mojs. ;
Pronannites Haug. ; Praeghjphioceras Wedekind. Devonian and Carboniferous.
Family 10. Thalassoceratidae Hyatt.
Forms robust, involute, laterally compressed. Septa from goniatitic to ceratitic to
CLASS V
CEPHALOPODA
031
complex digitate, but always with few lobes and saddles; auxiliary series, if present,
short ; adventitious series consisting of not more than one lobe.
Fio. liiOl.
Septa of ThalasDocerrtf!
'phillipsi Gemmel. Permian ;
Sicily (after Geininellaro).
Fio. 1200.^
Dimorphoceras texanum Smith. Coal
Measures ; Texas, x i/i (after J. P. Smith).
Fio. 1202.
Septa of Ussuria waacjeni Hyatt and Smith.
Lower Trias ; Idaho.
This family is jirobably derived from Aganides of the Devonian and Lower
Carboniferous. There is a
general resemblance to the
development of the Carni-
tinae, in the formation of
adventitious lobes, but
there is probably no kinship
with that group.
Dimorphoceras Hyatt
(Fig. 1200). Carboniferous.
Thalassoceras Gemm. (Fig.
1201). Permian. Ussuria
Diener (Fig. 1202). Lower
Trias. Sturia Mojs. Alpine
Trias.
Family 11. Ptychitidae
Mojsisovics.
Similar in aspect to
the more robust forms of
Meekoceratidae, but having
subacute venters, more com- Fio. 1203.
plex sutures, and the auxil- Pty'Mtes flexuosusUojti. ( = Amviuiiites stndeH'H.a.wr ■{).p.). Muschelkalk;
. • , • 7 J Schreyer Alp, Salzburg, Austria.
lary series stratghter.
Ptychites (Fig. 1203), Japonites and Nannites Mojs.; Parannites Hyatt and Smitli.
Owenites Hyatt and Smitli. Trias.
638
MOLLUSCA
PHYLUM VI
Family 12. Tropitidae Mojsisovics.
Forms usually robust, but ranying from compressed-discoidal to heg-shaped. Body-
chamber long. Surface usually highly ornamented with ribs and knots. Septa are
goniatitic in some reversionary genera, ceratitic in the most primitive forms known, but
mostly slightly digitate. TJiere are no adventitious lobes, and not more than one
auxiliary lobe.
The Tropitidae are derived from the gastrioceran branch of the Glyphioceratidae,
witli such forms as Protropites and Columbites as connecting links.
Siilifamily A. Tropitinae Mojsisovics.
Similar to the Anarcestidae in the ephebic stage, but the young frequently have
volutions Avith highly trapezoidal sections,
section of a system of longitudinal
ridges and transverse costae. Sutures
have deep, narrow ventral lobes divided
by siphonal saddles with peculiar trun-
cated bases, which are often retained in
later stages. Sutures in ejjhebic stages
of some forms are similar to those of
Haloritinae ; the young have a more or
less prolonged coronate stage, and are
Shells highly ornamented by the inter-
Fio. 1204.
Maryarite.i jol'elyi (Hauer).
Upper Trias ; Sandliiig, near
Aussee, Austria.
Fir,. 1205.
Tropites siMu/luliix (Hauer). Upper Trias ;
Aussee, Austria. Vi-
Fk;. 1206.
Discotropitrn samUingcnsis (Hauer). Up|ier Tiias ;
California (after Hyatt and Smitli).
also keeled on the venter. Aperture narrower and with more ]iointed ventral crests
than in the Haloritinae.
Margarites (Fig. 1204), Tropites (Figs. 1141, C; 1149; 1205), Paratropites (Micro-
tropites), Barrandeites, Silbyllites Mojs. ; Discotropites H. and S. (Fig. 1206). Trias.
CLASS V
CEPHALOPODA
639
Subfamily B. Haloritinae Mojsisovics.
Shells luore globose and more involute in the young than in the Tropitidae, and
usually keelless, but having
similar volutions in a number
of species during later stages.
Ornament as a rule simpler
than in Tropitidae. Aper-
ture usually with ventral
crests, but these are primitive
in outline, broad, and in some
species scarcely indicated by
the lines of growth.
Halorites {Homerites),
Fig. 1207.
Juvavites suhintrrniptus Mojs.
Upper Trias ; California (after Hyatt
and Smith).
Fio. 1-208.
Sagenites herbichi Mojs. Upper Trias ; California
(after Hyatt and Smith).
Jovites, Parajuvavites, Juvavites (Fig. 1207), (Anatomites, Griesbachites, Dimorphites),
Miltites, Metasibirites,
Sagenites (Trachysagenites)
Mojsisovics (Figs. 1208,
1209). Trias.
Fig. 1209.
Septa ot Sagenites herUchi Mo.js. Upper Trias ; California
(after Hyatt and Smith).
^W-W ^
Fic. 1210.
Septa of AcrochonUceras hyatti
Meek. Middle Trias; Nevada (after
Hyatt and Smith).
Subfamily C. Sibiritinae Mojsisovics.
Forms robust and highly ornamented, with strong lateral ribs and knots. Septa
640
MOLLUSCA
PHYLUM VI
ranging from ceratitic to moderately digitate. This group is probably the connecting
link between the Glyphioceratidae and the Haloritinae.
Acrochordiceras RysLtt (Fig. 1210); Ste2}hanit es Waagen ; Sibirit es Mojs. Trias.
Subfamily D. Celtitinae Mojsisovics.
Forms discoidal, evolute and slender in most genera. In jJi'iniitive forms with
strong umbilical ribs, frequent constrictions and low whorls resembling Gastrioceras.
Septa always consisting of few lobes
and saddles, ranging from goniatitic,
through ceratitic, to slightly digitate.
Paraceltites Gemm. Permian.
Geltites and Tropiceliites Mojs. ; Colum-
bites Hyatt and Smith (Fig. 1211);
Proteusifes Hauer ; Margarites Mojs.
Trias.
This group is the connecting link
between Gastrioceras of the Paleozoic
and the Tropitinae of the Middle and
Upper Trias.
Fh,;. liill.
Columhi.frf; pnrisiaims Hyatt and Suiith. Lowit Trias
Ifl.ilio (after Hyatt ami Smith).
Fig. 1212.
Jgiithiceras cisooense Smith. Coal
Measures ; Texas (after .1. P. Smith).
Family 13. Arcestidae Mojsisovics.
Forms smooth, involute, robust, with frequent labial constrictions. Body -chamber
long. Septa ranging from goniatitic, to complex digitate, but ahvays with a tendency
towards the nuiltiplication of the lateral lobes, both external and internal. This family
is undoubtedly derived from the gastrioceran branch of the Glyphioceratidae, but may
be polyphyletic, inasmuch as both Agathiceras and Schistoceras may be radicals of
subgroups.
Subfamily A. Popanoceratinae Hyatt.
Forms very robust and involute. Septa relatively simple, ranging from goniatitic
(Agathiceras), though slightly serrated (Stacheoceras), but never becoming completely
digitate. This is the oldest and the most primitive group of the Arcestidae, and pro-
bably branched out from Schistoceras, with Stacheoceras as the connecting link.
CLASS V
CEPHALOPODA
641
Agathiceras Gemm. (Fig. 1212). Carboniferous. Stacheoceras Gemm. (Fig. 1213).
Carboniferous and Permian. Popanoceras Hyatt (Fig. 1214). Permian. Parapopano-
FiG. 1213.
Septa of Stacheoceras ganti Smith. Coal
Measures ; Texas (after J. P. Smith).
Fig. 1214.
Popanoceras midti striatum Gemm.
Permo - Carboniferous ; Sosio, Sicily.
'•^/■j (after Gemmellato).
B
Fio. 1215.
A, Megaphyllites inseclus
Mojs. Upper Trias ; Sand-
line;, near Aiissee, Austria.
B, Suture-line of M. jarbas
(Miinster).
f
^ f *
Fig. 1216.
Septa of Megaphyllites haugi Hyatt and Smith. Middle
Trias ; California.
Fig. 1217.
Lohites delphinocephalus (Hauer). Upper
Trias; Sandling, near Aussee, Austria. A, li,
External aspect. '', Median section. D,
Suture-line, Vi-
Fig. 121S.
Lohites pisum (Miinster).
Keuper (Caraiolan) ; St.
Cassian, Tyrol.
ceras Haug ; Megaphyllites Mojs. (Figs. 1215, 1216). Trias ; Europe. (?) Lohites Mojs.
(Figs. 1217, 1218). Trias; Europe.
VOL. I 2 T
642
MOLLUSCA
PHYLUM VI
Fio. 1219.
Septa of Shximardites simondH
Smith. Coal Measures ; Texas
Subfamily B. Cyclolobinae Zittel.
Forms as a rule much larger and with more complex septa than in the Popano-
ceratinae. There is a distinct tendency towards a
phylloid development of the saddles. This subfamily
probably came from the Popanoceratinae, although the
most primitive and oldest genus assigned to the group,
Shumardites, almost certainly is descended directly from
Schistoceras.
Shumardites Smith (Fig. 1219). Carboniferous. Cyclo-
lolus Waagen (Fig. 1220); JVaagenoceras Gemm. (Fig.
1221). Permian.
Sulifamily C. Arcestinae
Mojsisovics.
This comprises smooth, globose,
deeply involute anarcestean forms,
discoidal only in primitive genera.
Gerontic living chamber usually more
or less contracted laterally, becoming
sometimes subacute at the venter ; in
extreme age depressed, and truncated
or concave at the aperture. The
latter has typically in the ephebic
stage a low In-oad ventral crest, but
loses this in the parage ron tic sub-
stage, and acquires a ventral sinus
simulating that of Paleozoic and more
primitive forms. Saddles and lobes
completely divided by more or less
complex marginals, the monophyllic
outline being completely obscured
except in the young, and in dorsal
sutures of some species. Siphonal
saddles long, and not very deeply
incised by marginal lobes. Antisi-
phonal lobe bifid or trifid, and com-
plex in specialised forms. Other
dorsals may also become quite com-
23lex, and as a rule are completely
divided, although of course simpler
than the external sutures. Dorsal
sutures in the young resemble those of the Popanoceratinae. Funnels prosiphonate
in ephebic stage.
Sphingitea, Arcestes (Figs. 1139, 1222), Stenarcestes, Proarcestes, Pat-arcestes,
Ptycharcestes, Joannites (Fig. 1223), Didymites Mojs. (Fig. 1224). Trias.
Fig. 1220.
Cyclolohus stacTiei Gemm. Permo-Carboniferons ;
Sosio, Sicily (after Gemmellaro).
Fin. 1221.
Septa of Waagenoceras hilH Smith. Permian
Texas, x 1/2 (after J. P. Smith).
Family 14. Cladiscitidae Mojsisovics.
Involute, laterally compressed, ivith abruptly rounded ventral shoulders and flattened
venter. Umbilicus closed. No contraction of the ajjerture, and no labial constrictions.
Body-chamber long. Surface spirally striated. Lobes and saddles numerous, deeply and
CLASS V
CEPHALOPODA
643
Fro. 1222.
Arcestes intuslahiatus Mojs, 4 Upper Trias ; Steinbergkogel, near Hallstadt, Austria.
A, B, Externaliaspect. C, Median section. D, Sutuje-line.
finely divided, arranged serially.
The stems of the saddles are long
and narrow, divided anteriorly into
two or four branches.
The shape and ornamentation
of the shell suggest a derivation
from Ayathiceras of the Carboni-
ferous and Permian, but no con-
necting links are known.
Gladiscites Mojs. {Hypocladiscites
Mojs.) (Fig. 1225). Trias.
Family 15. Meekoceratidae
Waagen.
Compressed discoidal and in-
FiG. 1223.
Joannites cymhiformis Wulfen. Upper Trias ; Raschberg,
near Aussee, Austria. Natural mould showing the living
chamber (after Mojsisovics).
Fio. 1224.
Suture-line of Didymitcs suhglobus
Mojs. Upper Trias ; Someraukogel,
near Hallstadt (after Mojsisovics).
volute forms. Surface nearly smooth, radial folds being often present, but constrictions
and spines always absent. Body-chamber short. Septa simple goniatitic in primitive
forms, becoming ceratitic in most genera, but rarely reaching a digitate stage of com-
plexity in even the most specialised groups. The ventral lobe is divided in all forms ;
644
MOLLUSCA
PHTLUSI VI
the dorsal (antisiphonal) lobe is undivided, in the most primitive forms, and bifid in the
more specialised groups.
The entire family
is supposed to have
been derived from
Lecanites, and through
that genus to have been
connected with Nomis-
moceras of the Carboni-
ferous, and Gephyroceras
of the Devonian.
Fig. 1225.
Cladiscites torruxtus (Bronn). Upper Trias ; Steinbergkogel, near Hallstadt, Austria.
A, B, Lateral and anterior views. C, Suture-line.
Subfamily A. Lecanitinae Hyatt.
Primitive discoidal shells like those of the Prolecanitidae, with short rounded entire
saddles and lobes like those of Prolecanites, but ventral lobes divided by short com-
paratively broad and entire siphonal saddles. There are all
stages in the development of these saddles, so that their
aspect is rather variable. There are as a ride but two
principal lateral saddles and lobes, with one auxiliary .saddle
and shallow lolie on either side in primitive species, but in
others the number of auxiliaries may be considerably in-
creased. Antisiphonal lobe entire, and often
long and acute. The zygous dorsal lobes are
very slight so far as known, and entire ;
merely marginals in the dorsal saddles.
Paralecanifes Diener (Fig. 1226). Per-
mian and Triassic. Lecanites Mojs. ; Kyma-
FiG. 1226. Fjo. 1227. tites, ParaTcymatites Waagen ; Proavites
Parahcaniles arnoMl H. BiuliotiUi^ eryx Avthsihei' ; Badiotites Moisisovici^ (¥ IS. 1221).
and S. Lower Trias ; Idaho (MUnst.). Keuper ; rp ■ \ o /
(after Hyatt and Smith). St. Cassian, Tyrol. J- nas.
Subfamily B. Meekoceratinae Waagen.
Shells smooth, compressed, discoidal and involute, and as a rule with narrow and
more or less flattened venter. Sutures in many forms have a tendency to extend the
inner lateral saddles or lobes, and to develojj a corresponding series of auxiliaries ;
and this is carried to an excessive extent among some highly involute shells. The
ventral lobes, however, are apt to remain broad and shallow ; their arms become
highly denticulated excejit in the Lecanitinae where they are narrow and rounded.
Saddles entire and generally somewhat elongate and linguiform, but plainly of the
Lecanites type. Antisiphonal lobe, so far as known, long, nari-ow and bifid. Ex-
CLASS V
CEPHALOPODA
645
tremities or dorsal sutures produced and corresponding with the inner parts of the
external sutures.
MeeJcoceras Hjatt (Fig. 1228); Nicomedit es Toula (Koninckites) ; Clypeoceras i\om.
nov. (Aspidites Waagen), of which the type is Aspidites
superb as Waagen ^ ; Proptychites Waagen. Triassic.
Family 16. Gymnitidae Waagen.
Smooth, compressed, discoidal shells loith rounded
venter in pirimitive forms, becoming involute with acute
renter in specialised species. Septa not reaching above
the ceratitic stage of development in most genera, but not
remaining in the goniatitic stage in any hnoivn genera.
Sutures in specialised groups similar in convexity and
general aspect to those of the Pinacoceratidae, but
having peculiar, highly inclined auxiliaries which are
developed apparently from marginals on the umbilical
sides of the saddles; no corresponding adventitious
inflections. Siphonal saddle similar to that of Meeko-
ceratidae, and arms of the ventral lobe narrow. First
lateral saddles are dependent on, or attached to the
large siphonal saddles, and, often simulate adventitious
saddles.
Gymnites Mois. (Fig. 1229); Buddhaites Diener ;
Anagymnites Hyatt. Type A. (Gymnites) lamarcki (Diener).
Type P. (Plac.) sakuntala (Mojs.). Trias.
Xenodiscus and Xenaspis Waagen. Permian and Trias. Ophiceras Griesbach (Fig
1230). Trias. Flemingites ^Yaagen {Fig. 1231).
Trias. Japonites Mojs. Trias. Europe and Asia.
The Gymnitidae are commonly regarded as a
subfamily under the Ptychitidae, but they are
X
Fig. 1228.
Mcckoceras inushhaclMnum White.
Lower Trias ; Idaho. x 1/2 (after
Hyatt and Smith).
Paragymnites Hyatt.
PIT
Fig. 1229.
Gymnites pahnal Mojs. Muschelkalk ;
Schreyer Alp, near Gosau, Austria.
Fic. 123U.
Ophiceras jacksoni H. and S. Lower Trias ;
Idaho (after Hyatt and Smith).
more probably an offshoot from the Lecanitinae, and through them from the
Gephyroceratidae.
1 The uaiue Aspidites was preoccupie<l when Waagen u.sed it, and a new one becomes necessary.
646
MOLLUSCA
PHYLUM VI
Family 17. Hungaritidae Diener.
Form involute^ laterally compressed, ivith keeled venter. Surface often ornamented
/ .
Fir;. 1231.
FlemingUes russeUi H. and S. Lower Trias ;
Idaho 1/2 (after Hyatt and Smith).
with folds, ribs or knots. Body
chamber short. Septa usually cera-
titic, not reaching the digitate stage
in any genera, but persisting in the
goniatitic stage in Beneckeia.
This group is not regarded as
a side brancli from the Meekoce-
ratidae, but as an old and persistent
stock, coming down with little modification from the Gephyroceratidae, j^robably
from the keeled form Timanites. The Hungaritidae have been confused with the
group of keeled Ceratites, and also with compressed members of the Tropitidae, but
the resemblance is one of convergence, and bespeaks no near relationship.
Hungarites Mojs. ; Otoceras Griesbach. Permian and Trias. Beneckeia Mojs. ;
Inyoites Hyatt and Smith (Fig. 1232); Dalmatites Kittl. Permian and Trias.
Eutomoceras Hyatt {Halilucites Diener). Trias.
Fig. 1232.
Inyoites oweni H. and S. Lower Trias ; California
(after Hyatt and Smith).
Family 18. Oeratitidae Mojsisovics.
Forms evoluta to involute, laterally com,pressed to robust and rounded. Surface
usually ornamented vnth folds, ribs, knots, spines or tubercles. Venter in some genera
provided loith a keel, in others with a median furrow ; and occasionally biangalar. Body
chamber rather short. Septa ranging from the goniatitic stage in some arrested or re-
versionary forms, through the typical ceratitic stage, to complex digitation.
This family may be, and probably is, polyjihyletic, but a large part of it, including
the typical Ceratites, .seems to have been derived from MeeJcoccras or from some member
of that group. Only the more primitive members of Ceratites show a youthful stage
similar to Meekoceras, but there seems to be a perfect intergradation between the more
complex species of Meekoceras and the more primitive species of Ceratites.
Subfamily A. Ceratitinae Mojsisovics.
Primitive forms are discoidal or involute, but stout-whorled and keelless, becoming
more compressed, and having a broad, sliglitly elevated median ventral ridge in more
specialised genera. Sides have at least one line of nodes in primitive forms, and are more
cl:^.ss V
CEPHALOPODA
647
or less completely costated with several lines of tubercles in specialised shells. Sutures
in the young and in primitive genera have a magnosellarian aspect, but when the broad
internal saddles become divided, the internal inflections resemble those of Lecanitmae.
Kic. 1233.
Cn-atitefnodosnxde Haan. Muschelkalk ; Wurzburg, Bavaria. .4, B, Conch, 1/3. C, Left half of suture-line.
D First and second lateral saddles and auxiliaries to left of line of involution (n) ; half of dorsal suture-line to
right. (AL, Antisiphonal lobe ; other lettering as in Figs. 1145, 1146.)
In primitive forms (Olenikites) the saddles are broad and very shallow ; lobes entire,
and ventral lobe divided by a larviform siphonal saddle, which is sometimes entire.
The large nodes and stout volutions of primitive
forms indicate parallelism with Sfephanites. Saddles
and lobes have the typical ceratitic outlines, as a rule,
))ut in some forms the auxiliary line may be extended as
in the Meekoceratinae. Occasionally, also, costae may cross
the venter as in Sibiritinae.
Ceratites de Haan (Figs. 1233, 1234); Danubites and
Balatonites Mojs. ; Beiflinyites Artlial). Gymiiotoceras and
Olenilcites Hyatt. Type 0. (Din.) sinni-plicatus (Mojs.).
Keyserlingites Hyatt. Type K. (Ceratites) subrobustus
Mojs. Beyrichites Waagen. Subgenera : Hollandites and
Phillippites Diener. Trias.
Subfamily B. Tirolitinae Mojsisovics (pars). Fm. 1234.
Ceratites fri)iorfos!(s Hauer. Mus-
Compressed, discoidal or involute shells resembling chelkalk ; Bakony, Hungary (after
i ' ^ Moisisovics).
Dinaritinae in their sutures and having entire saddles
and slightly denticulated lobes. Ventral lobe may remain entire until a late stage
in some forms, but as a rule it is divided, and the siphonal saddle is small and often
648
MOLLUSCA
PHYLUM VI
LS
entire. Shells have a line of nodes on the ventro-lateral angles, and the venter is
invariably smooth and convex.
Includes Tirolites (Fig. 1235) and Mctatirolites Mojs., from the Alpine Trias and
from Idaho. The subfamily of Clydonitinae has sutures
similar to Tirolites, but costae interrupted on the venter,
which is often channelled. Includes Clydonites and Eremites
Hauer ; and Edolcites Mojs. Trias.
Subfamily C. Dinaritinae Mojsisovics ^pars).
Sutures resembling Tirolites in having only two broad
saddles, one pair of first lateral lobes, and incomplete lobes
at the umbilicus. Shells smooth, or with coarse_ folds
most prominent at the umbilical shoulders ; sides more or
less flattened or jilanoconvex, and venter rounded.
Dinarites Mojs. ; Guceoceras Diener. Trias.
Subfamily D. Buchitinae Hyatt.
Primitive forms similar to Celtitinae, with smooth
elevated venter ; more specialised shells with slight keel on
Fig. 1235.
Tirolites cassianus (Quenst.) the narrow venter, and simple costae or folds on the sides.
Lower Trias ; GronR.s-Hof, near Sutures have entire outlines, or lobes but slightly denti-
st. Cassian, Tyrol. ' & •'
LUilated ; and when the saddles are comj^letely divided
Sutures otherwise similar to those of Dinaritinae, and the
young have a Dinarites stage. Antisijihonal lobe entire and bifid in some forms.
Buchites, Helictites, Phormedites, Parathisbites and Glyphidites Mojs. Trias.
their marginals are small.
Suljfamily E. Arpaditinae Hyatt.
Dift'ers from the Buchitinae in the tendency to form channelled venters bordered
by two ridges, which may be either tuberculose or smooth.
Arpadites (Fig. 1236), Klipsteinia, Dittmarites, Muensterites, Steinmannites, Daph-
nites, Dionites, Drepanites, Heraclites, Guembelites,
Cyrtopleurites and Acanthinites Mojs. Trias.
Subfamily F. Trachyceratinae Hyatt.
Discoidal and involute shells with well-defined and
often profusely tuberculated costations which are
interrupted on the ventral aspect by a smooth zone
or channel. This may in some specialised forms
become a distinct channel bordered by tuberculated
ridges. Lobes and saddles completely divided by
marginals, but these do not become very long nor
complex.
Distichites, Trachyceras (Fig. 1237), Protrachyceras (Fig. 1238), Anolcites, Sand-
linyites, Sirenites, Anasirenites, Diplosirenites and Glionites Mojs. (Figs. 1239, 1240).
Trias. (?) Heqyerites Pompeckj. Rhaetic.
Fig. 1236.
Arpadites cinensis Mojs. Keuper ;■
Esino, Lombardy.
Subfamily G. Chorlstoceratinae Hyatt.
Discoidal anmioniticones in primitive forms, becoming uncoiled phylogerons, and
finally even complete baculiticones in the most specialised species. Sutures also
CLASS V
CEPHALOPODA
649
phylogerontic, having only six entire or very faintly denticulated lobes, and six
entire saddles. Ventral lobe divided, and the antisiphonal either entire or bifid at
.1 i-
Fig. r_'37.
Tmchycrras austriaciim Mojs. Upper Trias ;
Riithelstein, near Anssee, Au.stria.
Fig. 1238.
Protradiyceras archelaus Laube. Upper Trias (Norian) ;
Bakony, Hungary (after Mojsisovics). i/o.
Fio. 1-230.
Clionites fairbanlsi H. and S. Upper Trias ;
California (after Hyatt and Smitli).
Fig. 1240.
Septa of Clionites fairbanlcsi H. and S. x V2-
^y\;^^'v./-
Fio. 1241.
Polycydiis nastiir-
tiwrn (Dittmar).
Keuper ; Sandling,
near Aussee.
Fio. 1242.
Choristoceras inarsTd
Hauer. Rliaetic ; Kendel-
ongraben am Osterhorn,
near Salzburg.
its extremity. Dorsal lobes and .saddles otherwise entire. Connected through
Polycyclus with Buchites, according to Mojsisovics.
Pohjcyclus (Fig. 1241), Peripleurites Mojs.; Choristoceras (Fig. 1242), Rhabdoceras
Hauer (Fig. 1243). Trias.
650
MOLLUSCA
PHYLUM VI
/tw^i/
Subfamily H. Cochloceratinae Hyatt.
Turriliticones with costae similar to those of the preceding group, but more or less
asymmetrical in consequence of the asymmetry
^/aA of the sjiires. Lobes reduced to four in number,
and there are other phylogerontic supj^ressions.
Funnels monochoanitic, collars absent.
Gochloccras Hauer (Fig. 1244) ; Paracochloceras
Mojs. Trias.
Family 19. Phylloceratidae Zittel.
Fig. 1243.
Rhahdoceras suessi
Hauer. Keuper ;
Sand ling, near
Aussee (after
Hauer).
Fig. 1244.
Cochlocera s fisch e r i
Hauer. Sandling,
near Aussee (after
Hauor).
Shells smooth, with radial striae or weak folds.
Form compressed, with rounded venters. Body
chamber taking up one-half to threefourths of the
last volution. Aperture sim])le, with short ventral
crest. Lobes and saddles numerous, decreasinfj in
size towards the umbilicus. In primitive genera the
saddles have monophyllic bases resembling those of the Popanoceratinae, but in the more
specialised groups only the marginal saddles retain the rounded outline, the others
becoming deeply divided, although always remaining phylloid in termination.
Monophyllites is the oldest and most primitive of the Phylloceratidae, and
MonophylUks xlmoiiyi (Hauer). Ujipor Trias ;
liothelstein, near Aussee, Austria.
Fig. 1246.
Monophyllites billingsianus Gahb.
Middle Trias ; Nevada (after Hyatt
and Smith).
probably connects the family with Nomismoceras or some other derivative of the
Gephyroceratidae. The resemblance of Phylloceras to the Permian Arcestidae is
purely one of convergence, for neither the young of Phylloceras nor the adults of
Monophyllites resemble any genera of the Arcestidae. But the young of Phylloceras are
like adult Mono'phyUites, and the young of Discophyllites are at first like Nomismoceras,
and the adolescent stages like Monophyllites. The development of Monophyllites
itself has not yet been studied.
CLASS V
CEPHALOPODA
651
The family of the Phylloceratidae is the most persistent and the longest-lived
among the Ammonoids, being continuous from the Permian to the Upper Cretaceous.
Subfamily A. Monophyllitinae Smith.
Shells compressed, discoidal, evolute. Septa with primitive monopliyllic saddles,
and more regular in the relative size of the lobes and saddles than the succeeding
group. Antisiphonal lobe bifid, but otherwise entire. Monoi)hyllites Mojs. (Figs
1245, 1246) (Mojsvarifes Pompeckj); DiscophijUifes Hyatt (type Lytoceras patens Mojs.).
Triassic. Discophyllitcs forms a connecting link with the Phylloceratinae, and might
with equal propriety have been classed with that group.
Subfamily B. Phylloceratinae Zittel.
Form usually involute. Septa very complex, with the saddles deeply digitate,
Rharoi^lryllites ncojuniisis {Ql\iiii\sie.At). Keuper ; Hallstadt, Austria.
Fig. 1248.
PhyUoceras heterophyllum (Sowb.). Upper
Lias ; Whitby, Yorkshire.
Fio. 1249.
PhyUoceras ptychoicum (Quenstedt). Tlthonian ; Stramberg,
Moravia. AL, Antisiphonal lobe.
652
MOLLUSCA
PHYLUM VI
but retaining the pliylloid ending, and with the marginal saddles retaining the
monoijhyllic outlines. Antisiphonal lobe with entire sides, or with only one pair of
lateral branches, and extremities bifid.
Rhacophyllites Zittel (Fig. 1247); Euphyllites Wiihner ; Phylloceras Suess (Figs.
a6 a^ a-i a3
Fig. 1251.
I Li AL
Suture-line of Sovcrbiceras fortisulcatum (d'Ovb.)
(after Queustedt).
Suture-line of Phj/lloccras nihsoni (Heb.).
Upper Lias.
SL, Ventral or siphonal lobe ; /., First, and /, Second lateral lobes ; ai -8, Inner or so-called auxiliary lobes ;
n, Line of involution ; Li, Second dorsal lobe ; AL, Antisiphonal lobe.
1140, 1248-1250) ; Soicerbiceras Paroni and Bon. (Fig. 1251) ; Basijceras Hyatt. Type
D. (Phylloceras) rakosense (Herbich). Schistoplmjlloceras Hyatt. Type 8. {Phylloceras)
aulonotum (Herbich). Geyeroceras Hyatt. Type G. {Phyll.) cylindricum (Geyer).
Tragophylloceras Hyatt. Type T. (Phylloceras) heterophyllus-numismalis (Quenst.).
Menecjhiniceras Hyatt. Type M. (Phylloceras) lariense (Menegh.). Trias to Cretaceous.
Family 20. Lytoceratidae Neumayr.
Shell widely umhilicate, sometimes forming a loose or snail-like spiral, sometimes
even hook-shaped. Body chamber two-thirds to three-fourths of the last volution. Aperture
rounded, irhorls little embracing. Surface often ornamented with simple ribs or rows
of knots. Septa deeply divided., with usually turn latercd lobes and an auxiliary. Tlie
first and often the second lateral lobes and saddles are deeply bifid.
In all probability the family Lytoceratidae is not monophyletic, some of the
Scapthites and other degenerate groups coming from different stocks. The Lytoceratinae,
however, ajipear to be monophyletic, and to have been derived from Monophyllitcs.
Subfamily A. Lytoceratinae Mojsisovics (pars).
Includes only closely coiled, discoidal and involute shells with somewhat prominent,
often crenulated, transverse bands of growth. Antisiphonal
lolje with two long internal bi^anches bending inwards and
attached to surfaces of the septa. Sij^honal lolie short
like that of Phylloceras, and siphonal saddles narrow. The
first lateral saddles small and short, the first lateral lobes
much longer than the ventral.- Eeduction of lobes along
the line of involution is such that there are commonly
only six to eight in full-grown shells.
Lytoceras Suess (Thysanoceras Hyatt) (Figs. 1252,
1253). Jura and Cretaceous. Alocolytoceras Hyatt (Fig.
1254). Type A. (Amm.) germainei (d'Orb.). Pleurolytoceras
T.!itiM-riwjimhriatnm(Sov!h.). Hyatt. Type P. (Amm.) Mrcinum (Schloth.). Jura.
Cross-secti'on^cf^^'' ms^^^^^^ TchYtr/o « ?'<es Kossmat ; Gaudryceras Grossouvre. Cretaceous.
Subfamily B. Macroscaphitinae Hyatt.
Symnu^trical, closely coiled, discoidal ammoniticones during young stages (and
persistently so in primitive forms), but becoming uncoiled in gerontic stages or earlier
CEPHALOPODA
653
Fici. 1253.
Lytoceras liehigi (Oppel). Tithonian ;
Stramberg, Mora\'ia.
in the ontogeny of phylogerontic forms,
and finally straight in some genera.
Antisijjhonal lobe short, and in some
genera trifid. Shells have constrictions
and large costae at intervals, but no
tubercles at any stage.
Alacroscaphites Meek (Fig. 1255);
Leptoceras, Costidiscus Uhlig ; Tropaeum
Sowb. ; Hamites Parkinson (Fig. 1256) ;
Phjchoceras d'Orb. (Fig. 1257) ; Dijify-
h'ui. 1264.
Alocolytoceras gennainei, (d'Oii^.).
Upper Lias ; Pinperdu, near
Salins, Jura
Fici. 1255.
Maeroscaphites ivanii (d'Orb.).
Upper Neocomiaii ; Malleuewitz,
Carpathia.
Fio. 1256.
Hamites rotunilatus (Sowb.).
Gault ; Folke.stoue.
Fin. 1257.
Ptychoceras jmzo-
sianum (d'Orb.).
Barremian ; Vergons,
Basses Alpes.
654
MOLLUSCA
PHYLUM VI
choceras Gabb ; Cyrtochilus Meek
Fi(!. 1258.
A, Baculites anccpx Lam. B, B. faiijasi
Lam. Upper Cretaceous ; Maestricht. I
Fig. 1259.
Suture-line of Diplomocerascylindraeeum
Defr. Uppermost Cretaceous ; Tresville,
Manclie.
(Sci^nonoceras Hyatt); Baculites Lam. (Fig. 1258).
Diplomoceras Hyatt (Fig.
1259). Tyi^e D. (Ham.) cylin-
draceum (d'Orb.). Hamulina
d'Orb. (Fig. 1260, A). Cre-
taceous. Baculina d'Orb.
Jiiras.
Subfamily C. Turrilitinae
Hyatt {pars).
A heterogeneous group
of turret-shaped cones, with
shells highly ornamented
with ribs and tubercles. In
Turrilites the spire is sym-
metrical and close-coiled ; in
most other forms it is un-
symmetrical, and more or less
open. The relationship of
this group to the Lytocera-
tidae is extremely problema-
tical.
Turrilites Lamarck. (Fig.
1261); Heteroceras d'Orb.
(Fig. 1262); Eviperoceras
Hyatt ; Helicoceras d'Orb.
Cretaceous.
Fic. 12(50.
A, Hamulina suhcylhi-
drica (d'Orb.). B, Suture-
line of A. lorioU (Uhlig).
Neocouiiaii ; Angles, Basses
Alpes (after Uhlig).
Family 21. Aegoceratidae Neumayr.
For7n discoidal, mostly widely u'liibilicate. IVhorls
smooth, or with straight radial ribs that occasionally
bifurcate at the venter. Aper-
ture xoithout lateral ears.
Venter with keel, or with for-
ward pointing crest. Body
chamber comprising from
three-foiirths to more than a
complete revolution. Suture
line not deeply digitate;
usually with only two lateral
lobes and an auxiliary.
Subfamily A. Psilocera-
TINAE Zittel.
Widely umbilicate,
whorls laterally compressed,
smooth or with simple ribs
which do not cross the
rounded keelless venter.
Fig. 12G2.
Fig. 1261.
Tnrrilitrs catenntna d'Orb. Heteroceras polyjilocum (HoeTneT).
„, T^ -1 .■ Gault ; Escragnolles, France (after Upper Cri'taceous ; Haldeni, West-
The Psiloceratmae are d'Orbigny). piiaiia.
CLASS V
CEPHALOPODA
655
commonly supposed to have been the progenitors of all the other Aegoceratidae.
It is, however, just as likely tliat they are a degenerate grouj), reversionary towards
the ancestral radical. They have a certain re-
semblance to Monophtjllites, which has given rise
to the idea that they may be an offshoot from the
Phylloceratidae. This too is improbable, the re-
semblance being most likely a convergence pheno-
menon.
Psiloceras Hyatt (Fig. 1263); Tviaegoceras
Hyatt. Lias.
Subfamily B. Arietitinae Zitteh
Venter with strong keel. Form evolute, volu-
tions of discoidal forms more quadrate than in
preceding families, and often with a channelled
venter. Costae more strongly developed as a rule,
and with prominent ventro -lateral angles, which
are sometimes tuberculated. Sutural inflections
reduced in number and complexity as compared
with preceding families, and phylliform marginals
Fig. 1263.
Psiloceras planorhis (Sowb.). Infra-
replaced by saddles of more irregular aspect. '^^t^^.^J^'^'''^- ^"^
Ventral lobe long and narrow, with corresponding
siphonal saddle. Usually only two pairs of large lateral saddles, the second often
the most prominent. Fir3t pair of lateral lobes large, second and third pairs successively
smaller ; third and fourth pairs of saddles also smaller, the last often partially on
the line of involution. Antisiphonal lobe
bifid, very long, and sometimes complex.
One pair of large dorsal saddles, and one of
short, often incomplete lobes. Anapytclius
observed in several species.
There are two types of young in the Arieti-
tinae, which afterwards become separated in
other related groups : a broad depressed or
coronate type occurs in typical Arietites and
some others, and the compressed Psiloceran
type in Arnioceras, etc. Pseitdotropites shows
that Cocloceras may have originated from
the Arietinae tiirough persistent develop-
ment of a trapezoidal form of young with
correlative changes. Arietites Waagen (Figs.
1264, 1265).
Subgenera : Vermiceras, Coroniceras (Fig.
1146), Arnioceras, Discoceras, Asteroceras, and
Ophioceras Hyatt. Lias.
Vui. 1264.
Arietites histdcatus Brug. Lower Lias ; Cote d'Or
(after d'Orbigny).
Subfamily C. Aegoceratinae ZitteL
Form widely umbilicate. Whorls with lateral ribs which frequently either divided
or undivided extend across the keelless venter. Under this subfamily are two groups
of genera, the first being that of Aegoceras Waagen which Hyatt has called the " Lijjaro-
ceratidae." In this the volutions remain rounded in section and frequently retain a
primitive discoidal aspect. Costae almost entirely disapj^ear on the venter of some
forms, but form very large continuous folds in others. Sutures become excessively
com2:dex, saddles narrow and deeply cut by complex marginals, and ventral lobe corre-
sponds, but usually of about equal length with the lateral lobes. Antisiplional bifid,
656
MOLLUSCA
PHYLUM VI
and resembles (as do also the two dorsal saddles and small dorsal lobes) those of
the Arietitinae. a
■1,1 KS LSI LS^ % IS
k M
Fin. 1-265.
Arii'tites hisulcatus Brug. Lower Liiis ; Wiirtemburg. A, Suture line ; IS, (\ Portion of volution .seen from
the Lateral and ventral aspects.
Aegoceras Waageii (Fig. 1266)
Hyatt has proposed the following
subgenera : Liparoceras, Microdero-
ceras and Androc/ynoceras. Lo\\er and
Middle Lias.
The second group is that of Schlo-
fheimia Bayle, called by Hyatt the
" Angulatidae." This includes more
or less compressed and costated shells,
the costae sometimes crossing the
venter in the young or extreme age,
l)ut usually interrupted in the adult
by a smooth and occasionally sunken
median zone. Sutures inclined apicad
near lines of involution, more com-
plex in outline than in tyjjical Arie-
'■ tites, and with phylliform marginals
Ventral lobe broader and shorter, with larger siphonal
Fii;. ItiOt;.
ras capricornns (Sclilotli.). Middle I^ias
Gniiind, Wilrtemberg.
Aegoce
more like those of Psiloceras.
CLASS V
CEPHALOPODA
657
saddles than Arietites, and antisiphonal lobe bifid, longer and more complex. First
pair of dorsal saddles large and long, otlier
dorsal inflections variable, Imt generally more
numerous than in Arietites.
Schlotheimia Bayle (Fig. 1267); Waeh-
neroceras Hyatt. Lower Lias.
Subfamily D. Polymorphinae Haug.
Shells compressed discoidal, with smooth
young like those of Psiloceras. Costae apt
to be inclined or slightly sigmoidal, and
continuous across the venter. This is crenu-
lated in primitive forms, but becomes smooth,
cliannelled or keeled in specialised shells.
The latter have sutures similar to those of
Schlotheimia, but less complex.
Agassiceras Hyatt {Paroniceras Bonar. ;
Gymbites Neumayr ; Amm. glohosum 0\)\). ;
Amin. miserabile Quenst.). Liparoceras Hyatt (Ammonites bechei Sow.) ; Pohjmorphites
Sutner ; Dumortieria Haug ; Amphiceras Gemm. Lias.
Family 22. Harpoceratidae Neumayr.
Discoidal and involute shells, with sigmoidal costae. Vender icith smooth or crenulated
keel. Aferture vdth curved sides or with projecting lateral ears, and rounded ventral
crest. Septa simply digitate, loith the lobes and saddles arranged in a straight line, and
usually with several auxiliary lobes.
This family, which i)robably originated from the Arietitinae, ranges from the
Lias to the Lower Cretaceous.
Vu:. 1267.
Srhhthtimia anijulatu (Schlotli.). Lower Lias ;
Goppingen, Wiirteniberg.
Subfamily A. Harpoceratinae Zittel.
Discoidal involute shells with sigmoidal costae separated throughout or confluent
Fig. 12(58.
Hildoccras bifrons (Brug.). Upper Lias ;
Whitby, Yorkshire.
Fig. 1269.
Lioceras opnlinum (Rein.). Lower Dogger ;
Teiifelsloch, near Boll, Wiirtemberg.
on the median lateral line, and sometimes bifurcated externally. Nodes never present,
VOL. I 2 u
658
MOLLUSCA
PHYLUM \I
although prominent crescentic ridges may arise on the sides through confluence of
costae. The latter are straiglit in primitive Gatulloceras, which resembles Culoccras
in aspect. Discoidal forms often both
keeled and channelled on the venter, and
sometimes have broad furrows on the
sides. Specialised involute shells have
solid keels, but usually no channels, and
lateral zones often become smooth. Sutures
comparatively simple, and in discoidal
forms are similar to those of Arnioceras,
but more complex in highly involute
forms.
Harpoceras Waagen, and subgenera :
Hildoceras (Fig. 1268), Lioccrcn^ (Fig.
1269), Grammoceras Hyatt (Fig. 1270);
Catulloceras Gemm. ; Aridieras Seg. ;
Hyperlioccras, Graphoceras, Brasilia and
Darellia Buckiuan. Upper Lias and In-
ferior Oolite.
Poecilomo rp h u s, Hu (Idle .s- 1 o n i «,
Brodieia, Gosmogyria, JVelschia Buckman ;
These are also subgenera from the Inferior Oolite.
Fio. 1270.
Ilarpoceras Grammoceras thouarsensi d'Orb.
Lias ; Heiningen, Wiirtemberg.
Upper
Ludwiyia Bayle.
Subfamily B. Oppeliinae Hang.
Discoidal and highly involute shells with sutures, form and markings in primitive
species that show affinity with Harpoceran stock, and aj)parent derivation from Poecilo-
morplius through typical Oecotraustes. Costae highly flexed and sometimes fused, but
no well-marked lateral channels as in hollow-keeled groups. Venter often truncated
and sides flattened, except in primitive species. The keel
may Ijecome very prominent, and filled with shell layers,
but never hollow. It disappears on the body chamber.
Aperture with ventral crest. The sigmoidal ribs often end
in marginal knots. Septa finely digitate. This subfamily
rano-es from the Middle Jura to the Cretaceous, its maximinn
fallinfT in the Upper Jura. Typical genera are Oppelia
Waagen (Figs. 1155, 1157, and 1158), and Oecotraustes
Waagen (Fig. 1271). A revision of the group has recently
been published by Douville (1913).
Oppelia has been subdivided into a large number of
groups, or transitional series (" Formenreihe "), some of which |3^}.'|^J^OTav
mi<dit even take rank as subfamilies, but most of them
are'' hardly more than subgenera. The largest group, which Hyatt distinguished
under the name " Glochiceratidae," includes discoidal and involute
shells, smooth in primitive species, Imt acquiring highly inflected
costations, sometimes with two rows of tubercles on the sides, and
a median ventral row that may fuse into a continuous solid keel.
One line of ventral tubercles may also arise directly from folds that
appear in otherwise unornameuted shells. Ajterture sometimes
with long lateral lappets. Sutures similar to those in the Haplo-
ceratidae.
Gadoinoccras, Grmiceras, Mun.-Chalm. (Fig. 1272); Phhjcticcras
{Lophoceras Bonar.) ; Ochetoceras Hang (Fig. 1273); Gymaceras
Quenst. (emend. Hyatt). Type C. {Ammonites) guembeli (0pp.). Strigoceras Quenst.
Fig. 1271.
Oecotranntes macrotelvs
Titlionian ; Stram-
ia.
Kio. 1272.
Crcnireras rewigeri
(Oppfil). Oxfonlian ;
Saliiis, Jura.
CLASS V
CEPHALOPODA
659
(Buckman) ; Streblites Hyatt (Fig. 1274). Type S. {Ammonites) pictus-costatus
(Quenst). Glochiceras Hyatt. Middle and Ui)per Jura.
Another group, which Hyatt called " Distichioceratidae," includes the genera
Fig. 1273.
Ochetoccras flexiwsum (v. Buch). Upper
Jura (j3) ; Laufen, Wiirtemberg.
Fig. 1274.
StrchlUes tenuilohatus (Oppel). Upper Jura ;
Pappenheim, Bavaria.
Horioceras and Distichoceras Munier-Chalmas, with septa simpler than in Glochiceras,
owing to arrested develoiyment. The young of Distichoceras repeat the characteristic
form and costae of Glochiceras, with smooth venter and lateral tubercles, and then
acquire the features of Horioceras before the
median continuous keel of Distichoceras arises.
Family 23. Amaltheidae Fischer (pars).
Form laterally compressed, usually involute,
high whorled. Sides with gently curved ribs or
folds, and often with lateral knots or spiral
lines. Venter keeled, and the keel is often
crenulated by ribs or thickened growth lines.
Aperture simple, or with narrow ventral crest.
Sutures deeply digitate with several auxiliary
lobes.
Subfamily A. Amaltheinae Hyatt.
Discoidal and involute shells, the young of
which have fold -like costae rising into heavy
nodes just inside the lines of involution. Costae
became prominent and sharp at the umbilical ^/maWmis margariwm Montf Middle
.j.^v^u,iiiv- |_j.v^ ii ^ Lias; Wurtemberg. Living chamber broken
shoulders and ventro- lateral angles, and true away and exposing " wrinkled layer " on
,11 • „ „,.^,-,,^c "VronfoT. l-colorl ventral surface. This is homologous with the
tubercles appear m some groups. Venter keeled «biack layer" of iVaufHus.
and sulcated in discoidal forms, the keels alone
persisting in more involute species. Keel solid and crenulated by the passage of costae
or folds across the venter. Anaptychus present. Nodes prominent in the young of
primitive species ; costae with only one row of tubercles in later stages or none ; keel
invariably present and crenulated. Amaltheus Montf. (Figs. 1 150 ; 1160, ^ ; 1275) ;
Paltopleuroceras Buckm. {Pleuroceras Hyatt). Middle Lias.
Fio. 1275.
660
MOLLUSCA
PHYLUM VI
In another group of tlie Amaltheinae, tlie young usually have gibbous volutions with
a single row of nodes, which either persist, or are followed by a bispinous stage, and
inner ends of the short costae also become
tuberculated. Venter smooth at first, and
may remain so or may have a solid keel.
Costae single, and usually bend at ventro-
lateral angles tOAvard the keel, but do not
cross the venter except in late stage of
Pseudotrojntes. Haplopleuroceras and
Dorsetensia Buckm. ; Psexidotroioites
Canav. ; Ganavarites Hyatt. Type C.
(Arietites) discretum (Canav.). Lias to
Inferior Oolite.
The Amaltheinae are usually classed
as derivatives from the Arietitinae, but
this is doubtful. Oxynoticeras Hyatt
(Fig. 1276) from the Ijias, is classed by
most writers with the Amaltheidae,
although Hyatt regarded it as a member
of the Arietitinae. In this genus the
shells are compressed and more involute than in the Arietidae, with narrower and
more acute keeled venter, but no ventral channels. Sutures have extended and
liighly modified auxiliary inflections ; keel hollow in adult of some species. Lower Lias.
Fi(i. 1276.
Oxynoticeraa oxywitum (Quenst.).
(j3) ; Wiirtemberg.
Lower Lias.
Subfamily B. Hammatoceratinae Buckman.
Discoidal forms with single or bifurcated costae, keeled and often channelled
Young similar to those of the Harpo-
ceratinae in compressed forms. Keel
hollow.
Cycloceras and Hammatoceras Hyatt ;
Lillia Bayle ; Haugia, Polyplechis, Chart-
ronia, Denckmannia Buckm. ; Zurcheria
Douville.
Upper Lias and Inferior Oolite.
The Hammatoceratinae have usually
been classed as near relatives of the
Arietitinae but their systematic position
should probably be in the Amaltheidae,
with which they show near affinities in
form and septation.
Buckman placed two genera or sub-
genera of this subfamily in a separate
group '■^ Sonniniinae." /Son?!^^ includes
discoidal forms with a keeled but not
channelled venter, and sides with coarse
bifurcated costae diverging from a row
of nodes along the median line of the
rounded sides and continued internally
by single costae. Witchellia has nodes
only in the young, and costae become
single or only slightly confluent. Sonninia Bayle {JVaagenia Bayle) (Fig
Jl'^itchellia Buckman. Inferior Oolite.
venters.
B
Fic. iL'vr.
SonnUiia so}t'erhyi (Miller). Middle Dogger ;
(after SteinmaTin and Diiderlein).
Lorraine
1277);
CLASS V
CEPHALOPODA
661
Fig. 1278.
Haploceras elimaUim (Oppel). Tithonian ; Stramberg, Moravia.
Family 24. Haploceratidae Zittel.
Shell smooth, tvifh fine groivth lines, ivithout const notions. Venter rounded, ivithout
keel. Apertures with lateral ears or lap2)ets. Septa deeply digitate.
This family is supposed to be an off-shoot from the Harpoceratidae, and nearly
related to Oppelia.
Haploceras Zittel
(Lissoceras Bayle) (Fig.
1278). From Middle J ura
to Lower Cretaceous.
Family 25. Stephano-
ceratidae Neumayr.
Forms usually robust
and inclined to he coronate,
at least in youth. Surface
tvith bifurcating ribs that
extend across the rounded
venter. Aperture ivith
lateral ears or lappets,
and usually constricted.
Septa deeply digitate, tvith
two lateral lobes and two,
or three auxiliaries. Keel
present in some genera.
The Stejihanocera-
tidae were derived from the Aegoceratidae of the Lias, and in turn gave rise to
^ most of the Ammonite families of the later Jurassic
and Cretaceous, so much so that it might be well to
include these and their descendants in a superfamily,
or suborder Stephanoceratoidea.
The group has been subdivided into numerous so-
called families, most of which, in so far as they are
deserving of recognition at all, are here treated as
subfamilies, for the sake of uniformity in classifica-
tion. It is not meant to imply by this that they
all have equal taxonomic rank.
Subfamily A. Dactylioceratinae Hyatt.
Discoidal forms with costae Ijifurcated and always
crossing the venter. Sutures with very complex
outlines, but only three or four pairs of lateral lobes
and saddles. Dorsal sutures have two pairs of saddles
and one pair of zygous lobes.
This series is usually termed the Planulati of the
Lias, but although an offshoot of the same common stock,
it is quite distinct from its supposed congeners of the
Middle and Upper Jura. Sutures are straight, not in-
clined apicad as in Perispliiuctinae. The subfamily com-
prises a complete cycle of forms varying from the broad
A, Coelocera, suharm.UuM (Young), ti-apezoidal, tuberculated volutions of Coeloceras through
Whitby, Yorkshire. B, Suture-line of Armatoid species to Dactyhoccras, 111 wiucli the costae
Coeloceras pettos (^uenst. Middle Lias. are smooth and sometimes even single.
jB
Fig. 127!>.
662
MOLLUSCA
PHYLUM VI
Goeloceras {Deroceras Hyatt) (Fig. 1279), Dadylioceras (Fig. 1280) trndPeronoceras
Hyatt ; Pimelites and Diafhorites Fuciiii ;
(?) Praesphaeroceras Levi ; (?) Gollina Buckm.
Middle and Upper Lias.
Subfamily B. Stephanoceratinae
Steinmann.
Primitive radicals, liiglily coronate, dis-
coidal, giving rise apparently to involute and
partially compressed forms that in Macro-
cephalites and some others are without tubercles.
Venter always rounded, costae bifurcating on
the sides and continuous across the venter.
Fi<;. 1280. Only one line of nodes or tubercles at the
Dactylioccnui commune (Sov/h.). Upper Lias ; umbilical shoulders, and the division of costae
England. '
Pig. 12S1.
Sphaeroceinshronfjniarti (Sowb.). Inferior
Oolite ; Bayeux, Calvados.
Fu;. liiiS'J.
Normannitcs bniikenrklgci (Sowb.). In-
ferior Oolite ; Bayeux, Calvados, i/i-
takes place along these lines in most forms. Sutures of the same type as in Dacty-
Fifi. 12S3.
Macrorephnlltcs mcwroccphdus (Scliloth.). Upper Do,CK'er (CalloviaTi) ; EliniiiKen, Wiirtcniberg.
lioidinae, but iiuRh more complex, witli usually more inflections, and lobes and saddles
CLASS V
CEPHALOPODA
663
more nearly t'qual. Dorsal sutures generally have three pairs of zygous saddles and
two pairs of lobes in the coronate discoidal
forms.
Stcjihanoceras Neum. (Fig. 1285); Gado-
mites Mun.-Chalms. ; Sphaeroceras Bayle (Fig.
1281); Eniileia Bucknian ; Normannites
Mun.-Chalnias (Fig. 1282); Macrocivphalites MSt^ /
Sutner (Fig. 1283); Sutneria Zittel (Fig. 1284).
Inferior Oolite.
. 12.S4.
Siitiirria platynotii (llfnn.). Upper
Juni (Ti'iiiiilobatu.s Buds) ; Balinyen,
Wiirteiiiberif.
Stejihanocerns coronatus (Brug.). C'allovian :
Dept. Niovre, France. V;;.
Subfamily C. Cadoceratinae Hyatt.
More specialised, compressed, and involute forms tend to evolve shells with
creniilated keels, and sometimes channels also. Costae of Cadoceras divided as in
Stephanoceratinae, but other genera usually develop two lines of tubercles. Young
of Neumayria more or less costated, but sides and keel become smooth, and in some
.sijecies resemble the adult of Qnensfedtoceras.
This group is remarkablo for tlie closo parallelism of some of its genera with Aiualtheidae,
but the young are very distinct. Development and adult stages of Cadoceras with its discoidal
and much depressed volutions plainly show derivation from Coeloccran stock, while its form
and sutures also show relationshi[) with Stephanoceratinae.
Cadoceras Fischer ; Quenstedtoceras Hyatt ; Gardioccras Neumayr and Uhlig ;
Neumayria Nikitin. Kelloway.
Subfandly D. Perlsphinctinae Steinmann.i
An extensive series of discoidal genera having rounded or subquadrangular
volutions, and costae single on the sides, but split into two, three or more on the
venter, which they cross uninterruptedly. Splitting does not begin as a rule at
umbilical shoulders, but near the ventro-lateral angles. Inner parts of sutures steeply
inclined apicad, and dorsal sutures have a long pair of first dorsal saddles, usually two
additional pairs of saddles, and two pairs of lobes. All of these are so decidedly
inclined apicad that they often appear as a single pair of complex saddles.
These genera are morphic equivalents of the Liassic Dactylioidina6 and are derived from
the same common stock. Young have depressed trapezoidal volutions and often nunute
tubercles on ventro-lateral angles, but are otherwise smooth, like the young of Cadoceras
sablaeve. They become compressed in the neanic stage and rapidly assume the discoidal
Perisphinctean form and costae without tubercles.
Perisplmides Waagen {Grossbuvria, Procerites, Ghoffatia Siemirad.) (Figs. 1286-
vol
^ Siemiradzki, ./., Monographische Beschreilnuig der Gattung Perisphinctes. Palaeontogr. 1898,
, xlv. See also R. DuavtlU's recent studies of Cardioceras, etc., 1913.
664
MOLLUSCA
PHYLUM VI
1288) ; Ataxioceras Font.; Fro2)lanulites Teiss. ; Pictonia Bayle ; Crasj^ecUtes Pavl. and
Lampl. Inferior Oolite and Cretaceous.
Fig. 1286.
Suture line of Perisphinctes colubrinus
(Rein.).
Fi(i. 12S7.
Pcris'phincies polyplocus (Rein.). Upper
Jura ; Pappenlieim, Bavaria, i/o.
Fio. 1-288.
I'crisphinctcs tiziani (Oppel). Upper Jura (Biniamniatu.s Buds) ;
Hundsriick, near Streichen, Wiirtemberg.
Subfamily E. Morphoceratinae Hyatt.
Globose and usually involute forms with open umbilici showing the young to Ije
highly coronate until a late stage. Costae on umbilical zones single and widely
separated, Init divided into
very broad bundles of fine,
closely - set, ventro - lateral
costae differing from those of
all other grouj^s except some
Perisphinctinae. Only one
line of tubercles or nodes,
which usually occur at um-
bilical shoulders. External
and dorsal sutures resemble
those of Perisphinctinae, but
not so uniformly inclined
apicad. In discoidal coronate
shells the lobes and saddles
are of equal length, and
dorsum has two pairs of
z3'gous lobes and two pairs of
saddles.
Mori^hoceras Douv. ;
Garantiana Siemirad. ; Olco-
stephanus Neum. {Holcostephanus auct.) ; I'olyptychites, Simhimkites, Astieria, and
Virgatites Pavl. and Lampl. Upper Jura and Cretaceous.
Fic. 128ii.
Reineckid hrancoia (Steiinn.). Caracole.s, Boliva (al'lcr Stciiimaiin).
CLASS V
CEPHALOPODA
665
Subfamily F. Reineckiinae Hyatt.
Discoidal shells with costae single on the lateral zones but bifurcated on their
outer parts, and
with one or two
lines of tubercles,
the first being
near the point of
bifurcation of the
costae, and the
other near their
ventral termini.
Division of costae
takes place along
ventro - lateral
angles and not on
or near the um-
bilical shoulders.
Costae cross the
venter only in
the coronate
young, when the
section is trape-
zoidal as in Goeloceras. Sutures as in the preceding subfamily.
Eeineckia (Fig. 1289), Parkinsonia Bayle (Fig. 1290); Occoptychius Neum. (Fig,
1291); ^tt/acos<e2^/i.a'ft«s Sutner and Pomp ; (?) Waagenia Neum.; /S'ircnocfirtts Hyatt
Type S. {Ammonites) niortense (d'Orb.). Middle and Upper Jura.
Fig. 1290.
Parkinsonia jparlcinsoni (Sowb.). Inferior Oolite ;
Bayeux, Calxados.
Fig. 1291.
OecoptycMus rcfractus
(lie Haan). Callovian ;
Niort, France (after
d'Orbigny).
Family 26. Aspidoceratidae Zittel.
Earlier volutions costate, later ones with one or tivo rows of tubercles. Venter broad,
never keeled. S&pta resemhlinf/ those of Dactylioidinae, but saddles and lobes broader, and
Fig. 1292.
Aspidoceras 'perarmatiim {Bowh.). Oxfordian ;
Dives, Calvados. 1/2.
Fio. 1293.
Svmoce.ms volanensc. (Oppel).
Lower Tithonian ; Monte Catria,
Central Apennines.
dorsal sutures with only one large pair of inner or first dorsal lobes, the outer or second
pair being incomplete in the wore discoidal species as in the Arietidae.
Aspidoceras Zittel (Fig. 1292); Peltoceras Waagen (Fig. 1294); (?) Aurigerus
666 MOLLUSCA phylum vi
Oppel; (?) Simoceras Zittel (Fig. 1293); Siemiradzkia Hyatt. Type S. (Ammonites)
PcUoccras athlctd (Pliill.). Uppei' Callovian ; Vaclies noires,
Normandy, i/i.
Fi(i. 1295.
Physodoceras circum-
spmosum (Oppel). Upper
Jura ; Swabian Alps. i/w.
hakeriae (d'Orb.) [Terr. Jurass. PL 149, Fig. 1, non PL 148]. Physodoceras Hyatt
(Fig. 1295). Type P. (Ammonites) circumspinosum (Oppel). Upper Jura.
Family 27. Desmoceratidae ZitteL
Discoidal moderately . involute forms, loith simple or divided ribs. These continue
toithout interruption across the rounded keelless venter. Constrictions or varices at
regular intervals. Septa finely diyitate, with aiixiliary lobes arranged in a straight roiv.
The Desmoceratidae are slightly modified descendants of the Stephanoceratidae,
and preserve in youth the characters of the ancestral family.
Subfamily A. Desmoceratinae Zittel (ixirs).
Mostly involute shells, smooth, or with constrictions and fold-like costae without
tubercles that commoidy follow the
lines of growth across the rounded
venter uninterruptedly. Spines
sometimes present as in preceding
family. Sutures have blunt
siphonal saddles, never pointed.
First lateral lobes shalloAver than
in the Lytoceratidae, the first
lateral saddles broader, and less
deeply cut by marginals. Anti-
siphonal lobe long, straight, and
trifid. Lateral zygous inflections more numerous, and there are often three or more
zygous dorsal saddles.
Fio. 1290.
Suluie-liiio of Dcxtiioceras latidorsatmn Midi.
Peite du Kliniie.
Gault ;
CLASS V
CEPHALOPODA
667
Eurynoticeras Canavari. Jura. Desmoceras Zittel (Fig8. 1296, 1297); Puzosia
Eayle ; Ghonoceras Paroiii and
^ Bon. ; Scldueteria, Hauericeras
^V^ <^V"^? ^ Grossouvre. Cretaceous.
Subfamily B. Silesitinae
Hyatt.
Similar to. the Desmoceratinae,
but costae more strongly de-
veloijed, and sometimes spinous.
Fio. 1297.
Desmoceras mayorianura (d'Orb.). Gault ; Perte du Rhcjne
(after d'Orbigiiy).
Fio. ]298.
Pachydiscus iieranvplus (Maiitell). Lower Chalk ; England.
Fig. 1299.
Pwhyiliscus loittcldmli (Scliliiter).
Upper Cretaceous ; Haldem, Wost-
pVialia. Vs-
Silesites, Holcodiscus Ulilig ; PacJiy discus Zittel (Figs. 1298, 1299); Parapachy-
discus Hyatt. Type P. {Ammonites) gollevillensis (d'Orb.). Cretaceous.
Family 28. Cosmoceratidae Zittel.
Shells richly ornamented tvith ribs that are divided, or broken uf into rows of knots.
Usually with rows of umbilical and marginal knots on the ribs. Sculpture interrupted
by a furrow on the venter. Aperture often with lateral ears or lappets. •! Septa deeply
digitate. One or tivo auxiliary lobes present.
668
MOLLUSCA
PHYLUM VI
The Cosmoceratidae are probably a polyphyletic group, derived from several
branches of the Steplianoceratidae.
Subfamily A. Cosmoceratinae Hyatt.
Discoidal and involute forms having at a comparatively early stage or throughout-
.^ {»ri!*Ti»^ ^^^^ ^^'^ *^^" ^^^'^^ rows of large tubercles
on each side, and costae interrupted on
the venter by a smootli median zone or
channel.
Gosmoceras Waagen (Fig. 1300).
Middle Lias to Oxfordian.
Subfamily B. Hoplitinae Hyatt.
Discoidal and involute forms with
costae bifurcated on the sides at umbilical
Fi(!. 1300.
Vosmoceras oniatnm (Sowb.). Callovian (Ornaten-
thon) ; Gammelsliausen, Wurteniberg.
Fii^ 1301.
HoplUes tuhercujatus (Sowb.). "'■
Gault ; Folke.stone, England. HoplUes noricus (iiovih.). { = Hoplites amblygonius 'Neum.). Neocomian ;
Siphiincle broken away.j Acliim, near Borsuni, Prussia.
shoulders ; prominent tubercles at their forks, and also at or near their ventral
termini, these last being separated by a median zone or deep channeL Young of
some species have costae continuous across the venter, and resemble those of Sonneratia.
Parallelism with Cosmoceratinae very close. Sutures resemble those of Mammites,
but more comi:)lex. Lateral saddles narrower and more deeply cut, and first lateral
saddles often trifid in late stages. Dorsal series with two pairs of complex zygous
lobes and saddles on either side of a long, narrow, complex, antisiphonal lobe.
Hoplites Neum. (Figs. 1301, 1302); Genomanitea Haug {Discoceras Kossmat) ;
Sonneratia Bayle ; Neocomites Uhlig. Cretaceous.
CLASS V
CEPHALOPODA
669
Subfamily C. Acanthoceratinae Hyatt.
Robust and moderately evolute forms. Surface highly ornamented with ribs
either simple or bifui'cating. Rows of tubercles usually present on ribs, and often a
Fii:. 1303.
Acanthoccrcif rhotoiAaijerise (Del'r.). Cenoinanian ; Rouen, France (after QiieiLstedt).
Fia. 1304.
Douvilleiceras mamillare {Schloth..). Gault; Macheromenil, Ardenne.s.
median row^, sometimes uniting in a keel. Septa deeply digitate, the first lateral
saddle being bifid.
Acantlwceras Neumayr (Fig. 1303); Douvilleiceras Gj'oss. (Fig. 1304); TJiur-
viannia Hyatt ; Steueroceras Cossmann {Odontoceras Steuer) ; Mammites Laube and
Bruder : Muniericeras and Barroisiceras Gross. Cretaceous.
Subfamily D. Crioceratinae Hyatt.
A heterogeneous group of degenerate forms, probaljly derived from several different
normal groups. Forms highly ornamented with ribs and spines or knots. The
670
MOLLUSCA
PHYLUM VI
yoiitliful whorls ai'e coiled spirally in a jilane ; at maturity the whorl straightens out
tem^jorarily, often bending Lack again in a hook-shaped body-chamber.
Pig. 13C5. Fi«- 130G.
Spiroceiw hifiircatum (Qunnst.)- Upper Dog.uer (Cal- Aiicyloceras -mathcroriianum(VOrh. Neocomian ;
lovian); Ehniii;,'en, Wiirtcmlierg. J, Shell with i)rotocoiicli Castellane, Basses AJpes. .(, Conch, r,, Suture-
bi-oken away, Vi- ' ^'> Portion of venter. (', Sntnre-line. line.
Sjiiroceras Quenstedt (Fig. 1305), Lower Oolite, supposed to be derived from
Parkinsonia. Grioceras Leveille i Anryloceras d'Orb. (Fig. 1306). Cretaceous.
Subfamily E. Scaphitinae Meek.
Whorl close-coiled in youth, opening out at
maturity into a hook-
shaped body - chauiber.
Form robust, thick -set,
involute, surface highly
ornamental with ribs
and knots. Sej^ta finely
digitate, usually with
several auxiliary lobes.
Scaphites Parkinson
(Figs. 1162, 1307, 1308);
Fici. 130S. Discosraphites Meek ;
Scaphitcs aeijualis Sowb. Jalinites Hyatt. Creta-
Ceii oni an i an ; Rouen,
Fi(i. 1307.
SccqihUea sjiinifii'r Schliitei-. Uppi'i- Creta
ceous (Senonian) ; Cousfeld, Westphalia.
France, i/i
ceous.
CLASS V
CEPHALOPODA
671
Subfamily ¥. Placenticeratinae Hyatt.
Compressed, involute, liigli-wliorled forms, with venters flat compressed or concave
in youth, becoming somewhat rounded with age. Surface either tuberculate or
Septa complex, with
outlines, and narrow-
smooth.
irregular
saddles.
This group appears to be little
modified from the ancestral Cosmo-
ceratinae,! and of all the so-called
Pseudoceratttes of the Cretaceous it
is nearest to the typical form.
Placenticeras Meek ; Dvplacomo-
ceras Hyatt ; Forbesiceras Kossmat.
Cretaceous.
Family 29.
Engonoceratidae
Hyatt.
Fi.;. 1300.
hidoceras ismaiili (Zittel). Upper Senonian ; Libyan
Desert west of Oasis Dachsel.
Shell compressed, imtdliform,
narro%vly wmhilicate, high whorled.
Venter flattened or rounded, or
acute. Flanks with broad low folds
which often end in marginal keels,
more seldom in knots pr spines.
Septa not deeply digitate, lobes xLsually only moderately serrated, saddles often rounded
and entire. The external saddle is often divided into several secondary lobes. Tliere
are several auxiliary lobes in most genera.
The Engonoceratidae were probably, derived from the Placenticeratinae, and
through them from the Cosmoceratinae.
Engonoceras Neumayr ; Metengonoceras
Hyatt ; Hoplifoides von Koenen ; Tndoceras
Noetling (Fig. 1309) ; Sj^henodiscus Meek.
^^ .. issx Cretaceous.
Ax
' '^""' Family 30. Pulchelliidae Douville.
Form involute and high iohorled. Venter
flattened or rounded or acute. Flanks smooth,
or ornamented with ribs or knots. Septa not
digitate, being mostly either ceratitic or gonia-
titic in character. Lobes and saddles shallmo,
with broad saddles and narroio lobes. External
saddle divided into several secondary lobes.
Auxiliary lobes txvo to three in number.
The Pulchelliidae were j)robably derived
from the Hoplitinae. Pulchellia Douville ;
Metpicoceras Hyatt ; Knemiceras J. Boehm ;
i>«c/w"ce?'rts Hyatt; /t'oewCT'ocer-as Hyatt ; Tissotia
Douville (Fig. 1310). Cretaceous.
Fui. 1310.
Tissotia fourneli Bayle. Cenomanian
M'sai, Algiers (after Bayle).
Mzabel-
^ Smith, J. P., The development .iiirl phylogeny of Placeuticeras.
Sci., Srd ser.. Geol., 1900, vol. i. No. 7.
Proc. California Acad.
672
MOLLUSCA
PHYLUM VI
In this family 1 probably belong several genera commonly classed witli Oxynoticeras
or Amaltheus, as follows : — Garnieria Sajai. ; Lenficeras Gehr. ; Euloplwceras Hyatt.
Cretaceons.
Family 31. Prionotropidae Zittel.
Form evolute, discoidal, laterally compressed. Flanks with strong, simple or
dichotomous ribs that form one or more rows of knots on the sides, and one on the
ventral shoulders. Venter with strong median heel, either smooth or broken ^ip into a
Fig. 1311.
Scldoenbachia varians (Sowb.). Cenomanian ;
Quedliiiburg, Saxony.
Fio. 1312.
Schloenhachia cristata (Dehic).
Lower Cretaceous.
row of knots. Septa only moderately digitate. External and first lateral saddle broad,
lateral lobes bifid, only one auxiliary lobe present.
This group is commonly supposed to have been derived from the Amaltheidae,
but proofs of the connection are lacking.
Schloenhachia Neumayr (Figs. 1311, 1312); Hystatoceras Hyatt; Barroisiceras
Gross. ; Murtoniceras Meek ; Peroniceras Gross. ; Prionotropis Meek. Cretaceous.
Range and Distribution of the Ammonoidea.
The Ammonoids are more than twice as rich in forms as the Nautiloids. While
of the latter about 2500 species have been described, the number of Ammonoids has
reached far beyond 5000 species. These are without exception extinct, and are
especially characteristic of the Mesozoic eia.
Although Ammonites are unknown later than the Cretaceous period, nevertheless
this group must be regarded on the whole as the younger brancli of the stock of
Tetrabranchiates. After the Nautiloids had passed their culmination, the Goniatites
and Clymenias appeared as the oldest representatives of the Ammonoids. The time
range of the Clymenias is limited to a short epoch in the Upper Devonian ; the
Goniatites appeared first in the Upper Silurian (Kellerwald), develojied a great
variety of forms in the Devonian, and continue until the close of the Paleozoic era.
Until a few yeais ago it was believed that only Goniatites and Clj'menias occurred
in the Paleozoic deposits. The discovery of genuine Ammonites in the Permian of
the Salt Range of India, in the Ural Mountains, in Texas, in the Fusulina limestone
of Sicily, etc., and later the discovery of primitive Ammonites in the Coal Measures
of Texas and in the Lower Carboniferous of the Mississij)pi Valley, pushed their range
* Danville, //., Involution et classificatiou des Pulcliellides, Bull. Soc. Gcol. France, 1911, vol. xi.
CLASS V RANGE OF THE AMMONOIDEA 673
considerably further back into tbe Carboniferous system. These Paleozoic Aiimionoids
stand in the development of their septa between the Goniatites and the more highly
specialised Mesozoic Ammonites.
With the beginning of the Mesozoic era, the true Ammonites developed with
great rapidity. In the middlq European Muschelkalk only the genera Geratites,
Bcneckeia, Hungarites, Balafoniies, Arniotites, Acrochordiccras and Ptychites have as
yet been discovered. On the other hand, in the Alps, Spitzbergpn, the Himalayas,
in western North America and 'in Siberia, there have been found great numbers of
Ammonites in rich faunas of the Lower, Middle and Upper Triassic. The families
of Tropitidae, Ceratitidae, Ptychitidac, Cladiscitidae and Pinacoceratidae belong
exclusively to the Triassic ; the Arcestidae begin in the Coal Measures, but reach
their greatest development in the Triassic.
In the development of their septa the Triassic Ammonites show an unexpected
variety of form and complexity. Certain genera {Sageceras, Lccanites, Lohites) scarcely
pass the goniatitic stage of development ; many others (Meekoceras, etc.) only reach the
ceratitic stage. In the Arcestidae, Tropitidae, Cladiscitidae, Ptychitidae and Phyllo-
ceratidae the lol^es and saddles have become digitate. Indeed, in Pinacoceras is found
the greatest complexity of development of the septa that has been observed among the
Ammonites. Along with the typical forms the Upper Triassic of the Alps has fur-
nished also a number of reversionary types or aberrant forms (Gochloceras, Rhahdoceras,
Ghoristoceras), which are distinguished by reduction of the septa to great simplicity.
■ With the Lias a fundamental change in the Ammonites occurred. Of the
numerous Triassic genera and families, with the exception of the Phylloceratidae, all
have come to an end and are replaced by new forms. The causes that made the
Cephalopods so rare in tlie Rhaetic are unknown. It may be that not all these
groups were extinguished, but that they lived on in other, as yet unknown regions,
and when we next see them in the Jurassic they have changed beyond recognition.
In the Lower Lias the Aegoceratidae are almost the only forms ; the -genera
Psiloccras, Arietites and Schlotheimia, are confined to this stage. In the Middle Lias,
along with the Aegoceratidae, are represented the Harpoceratidae, the Amaltheidae
{Oxynoticeras, Amcdtheus), the Phylloceratidae (Phylloceras), the Lytoceratidae
(Lytoceras), and the oldest members of the Stephanoceratidae (Goeloceras, Dactylioccras).
It is noteworthy that in the Liassic Ammonites the antisiphonal lobe is frec[uently
bifid (as in the Aegoceratidae and Amaltheidae).
With the exception of the Aegoceratidae all the families that appeared in the
Lias lasted into the Middle and Upper Jurassic, although tlie Harpoceratidae are
reduced in numbers, and perished in the Malm or Upper Jura. The only new
families added in the Middle Jurassic are the Haploceratidae and the Cosmoceratidae.
The most common genera in the Middle Jurassic are : Harpoceras, Oppelia, Stephanoceras,
Sphaeroceras, Morphoceras, Macrocephalites, Oecoptychius, ReinecJcia, Parkinsonia,
Gosmoccras, Perisphindes, Hap)loceras, Phylloceras, Lytoceras.
In the Malm are found nearly all those genera named under the Middle Jurassic,
but the number of species has changed greatly. Thus Harpoceras, Stephanoceras,
Reineckia, Parkinsonia and Gosmoceras, are reduced, while Oppelia, Haploceras,
Olcostephanus, and especially Perisphinctes have increased greatly. Perisphinctes is
decidedly the dominant genus in the Upper Jurassic, and along with it Aspidoceras,
Simoceras and PeUoceras show a large number of species. Aberrant forms are rare
in the Jurassic, and are confined to a few species of Spiroceras and Baculina.
A change like that seen at the beginning of the Jurassic takes place also at the
end of this period. The Ammonites of the Cretaceous belong largely to new genera.
Indeed a remarkable metamorphosis occurs in the entire habitus of the Cephalopod
fauna. Only the oldest Neocomian beds of the Alps contain a few species that had
lived in the Tithonian epoch, and show the continuity of the two systems. The least
degree of change is shown by the Phylloceratidae and the Lytoceratidae. In place of
VOL. I 2 X
674
MOLLUSCA
Table showing Geological Kange of Ammonoidea
Families.
•
u
a
§
>
Q
2
c
o
O
d
.2
Ph
.2
*C
1
(D
o
1. Clymeniidae
Extrasiph onata
1. Bactritidae
2. Nautilinidae
3. Aphyllitidae
4. Tornoceratidae .
5. Clieiloceratidae .
6. Gephyroceratidae
A. Primordialinae .
B. Beloceratinae .
7. Prolecanitidae
A. Prolecanitinae .
B. Noritinae .
C. Medlicottiinae ,
8. Pinacoceratidae
A. Hedenstroemiinae
B. Sageceratinae
C. Carnitinae
D. Pinacoceratinae
9. Glyphioceratidae
10. Thalassoceratidae
11. Ptychitidae
12. Tropitidae
A. Tropitinae
B. Haloritinae
C. Sibiritinae
D. Celtitinae
13. Arcestidae
A. Popanoceratinae
B. Gyclolobinac
C. Arcestinae
14. Cladiscitidae
15. Meekoceratidae
A. Lecanitinae
B. Meekoceratinae
16. Gynmitidae
17. Hinigaritidae .
18. Ceratitidae
A. Ceratitinae
B. Tirolitinae
C. Diuaritinae
D. Buchitinae
E. Arpaditinae
F. Trachyceratinae
G. Choristoccratinae
H. Cochloceratinae
..... «>
—
__....
... —
__...
1
RANGE OF THE AMMONOIDEA
675
Faniilie.s,
d
'5
o
>
CD
Q
Carboniferous.
Permian.
X
1
o
-2
O
19. Phylloceratidae
A. Monophyllitinae .
B. Phylloceratinae .
20. Lytoceratidae
A. Lytoceratinae
B. Macroscaphitinae
C. Turrilitinae
21. Aegoceratidae
A. Psiloceratinae
B. Arietitinae .
G. Aegoceratinae
D. Polymorphinae .
22. Harpoceratidae
A. Harpoceratinae .
B. Oppeliinae .
23. Amaltheidae
A. Amaltheinae
B. Hammatoceratinae
24. Hajiloceratidae .,
25. Stephanoceratidae
A. Dactylioceratinae
B. Steplianoceratinae
C. Cadoceratinae
D. Perisphinctinae .
E. Morphoceratinae .
F. Reineckiinae
26. Aspidoceratidae .
27. Desmoceratidae
A. Desmoceratinae .
B. Silesitinae .
28. Cosm.oceratidae
A. Cosmoceratinae .
B. Hoplitinae .
C. Acanthoceratinae
D. Crioceratinae
E. Scaphitinae
F. Placenticeratinae
29. Engouoceratidae
30. Pulchelliidae
31. Prionotropidae .
1
i
'
—
... —
Ml
tlie Haqjoceratidae we find the Desmoceratidae, of which the genera Desmoceras and
Silesites especially characterize the Neocomian and Gault, and Pachydiscus the higher
stages of the Cretaceous. Of the Stephanoceratidae the genera Perisphinctes and
Olcostephanus, which had survived from the Jurassic, are extinguished in the Lowei'
Cretaceous. In the place of the Jurassic Cosmoceratidae appear Ho-plites, Douvilleiceras
and Acanthoccras. A peculiar retrograde development of the septa, a reversion to the
ceratitic stage, is seen in two families of Cretaceous Ammonites, the southern
676
MOLLUSCA
PHYLUM VI
Pulclielliidae and Engonoceratidae, which were probably connected with the younger
Cosmoceratidae (Hoplites). The Cretaceous Ammonitic fauna derives a sj^ecial
character from the great development of aberrant forms, which are most abundant in
the Neocomian, l)ut in jjart last into the higher stages of the Cretaceous. The genera
Macroscaphites, Pictetia, Hamites, Anisoceras, Turrilites, Baculites, Crioceras and
Bcaphites are confined exclusively to the Cretaceous.
The sudden extinction of the Ammonites at the end of the Cretaceous is one of
Diagram showing the Relationships of Paleozoic and
Early Mesozoic Ammonoids
the most remarkable phenomena in the history of the organic world, and one as yet
without explanation. Great changes in conditions of life must have taken place at
the border between Cretaceous and Tertiary to have brought about the extinction of
this flourishing and highly organised group of animals not only in Europe, but also
in all other parts of the world.
The system of nomenclature now commonly in vogue has placed oljstacles in the
way of a clear view of the general characters of the whole group of Ammonoids.
And this is especially unfortunate because in more recent years the genera and
families named have been difficult to distinguish, and in many cases have received
very vague definitions. At present the i^revailing tendency is to subdivide rather
than to unite, and some authors are in a fair way to change every time-honoured
species into a special genus or family.
Few divisions of the animal kingdom liave left such a perfect record of their
SUBCLASS II
DIBRANCHIATA
677
development, and such a great mass of evidence in favour of tlie tlieory of evolution
as have tlie Ammonites. Indeed, in this group, on account of the uncommon thinness
of the shell, internal moulds are of as much importance from the standpoint of precise
identification as those sjiecimens which have the shell perfectly preserved.
The first attempt to study a large number of species of Ammonites in their
genetic relationships was made by Waagen in the series of Oppelia supradiata.
Similar attempts were made by Neumayr in the Phylloceratidae, Perisphinctinae, etc. ;
by Hyatt in the Arietitinae ; and with especial minuteness by Leopold Wiirtenberger
in the Jurassic groups Aspidocei-as, Simoceras, Waagenia, Peltoeeras, Perisphindes and
Stephanoceras. Also Mojsisovics, Uhlig, Hang, Douville, Freeh, Diener, Pompeckj and
others have paid special attention to the genetic relationships of the various groups of
Ammonites. All these authors come to the conclusion that in the Ammonites there
are numerous genetic series of which the development may be followed step by step in
the species that occur in the various successive strata.
In the last few years great progress has been made in the study of the Ammonite
faunas, especially of the later Paleozoic and Triassic horizons ; also in the most various
divisions of the many branched family tree of the Ammonites, much light has been
thrown ujion the genetic relationships of nr;merous genera and families. But in
spite of this it is not yet possible to give a graphic representation of the development
and kinship of the Ammonoidea that is true of the whole group, and beyond suspicion
in any of its parts. However, in the above diagram a tentative efl:ort is made in this
direction, and in this scheme the probable relationships of the Paleozoic to the
earlier Mesozoic genera are indicated in the light of ^
the present status of our knowledge.
[The foregoing chapter on Ammonoidea has been revised
for the present work by Professor James Perrin Smith, of
Leland Stanford Junior University, California. — Editor.]
Subclass 2. DIBRANCHIATA Owen.
Cefhalopods with only two. arhoi'escent gills in the
mantle-cavity : provided round the mouth with eight
or ten arms hearing suckers or hooks, two of them
(when ten in all are present) being often developed
into long tentacles. Funnel closed; ink-sac usually
present. Shell internal, or if external, it is not
chambered ; in many forms entirely wanting.
The body of the Dibranchiates or Cuttle-fishes
is elongated, cylindrical or sac-shaped, and fre-
quently provided with two lateral fin-like append-
ages. The anterior cephalic region gives off" a
circlet of eight or ten powerful, muscular arms,
the inner sides of which are armed with suckers
(acetahula), or a double row of hooks, and assist
in swimming or creeping, and also serve for the
capture of prey. The Sepioidea have two of
their ten arms developed into very long tentacles
which bear hooks or suckers only at their
thickened extremities (Fig. 1313). The lower surface of the suckers is disk-
or cup-shaped, perforated in the middle, and occupied by numerous radially
Pig. 1313,
Enoploteuthis leptura. Recent;
Pacific Ocean. A, Ventral aspect.
B, Internal shell or "pen."
678 MOLLUSC A— CEPHALOPODA phylum vi
arranged muscle fibres ; they are also occasionally furnished with horny hooks
or sharp claws. Each sucker is able to create a partial vacuum by pressing
the cartilaginous rim against some object and then contracting the inner
folds, and hence can be used like a cupping-glass.
The jaws resemble those of Nautiloids in form, but are never calcified ;
and owing to their perishable nature, usually horny, they are not preserved in
the fossil state. The cartilage of the head forms a complete ring enclosing
the central portion of the nervous system. The eyes are of large size,
protected by a capsule, and recall those of vertebrates in structure.
The body is constricted at the mantle opening, which occurs just behind
the head, and at this point on the ventral surface is placed the respiratory
orifice, bounded by a projecting fold of the mantle. Here also terminates
the cylindrical or conical funnel, on either side of which lie the dendriform
gills ; in this region also are placed the anal and genital openings.
The abdomen is sac-shaped, and contains besides the viscera and circu-
latory systems a rather large pyriform vessel called the ink-bag. Its reservoir
is filled with an extremely opaque brownish-black fluid, which can be voided
at will through an excurrent canal terminating near the anus. Menaced or
alarmed, the creature discharges a dense cloud of ink, which serves to
conceal its retreat. One often finds within the body of fossil Dibranchiates
not only a cast or mould representing the ink-bag, but often a dark-coloured
residuum of the carbonaceous particles suspended in the ink.
The abdomen is completely covered by the mantle, which is a thick and
frequently brilliantly coloured muscular envelope. Traces of it are occasion-
ally found among fossil forms, owing to a slight secretion of calcareous matter
within it.
Most Dibranchiates secrete an internal shell within the mantle. Only
among the Octopoda is a shell absent entirely, or replaced in the female by a
thin, simple, unchambered spiral ; but this last is in nowise homologous with
the usual Dibranchiate shell. Spirula has a spiral, camerated shell, the septa
of which are traversed by a siphuncle, and the coils are not in contact. It
is situated in the hinder portion of the body and is partially enveloped by the
mantle. Among extinct Belemnites the internal shell consists of three parts :
a chambered cone {phragmacone), which is prolonged forwards on the dorsal
side into a delicate corneo - calcareous proosfracum, and is inserted at the
posterior end into a finger-like calcareous piece called the guard (sheath or
rostrum) (Fig. 1314, C).
Some living Cuttle - fishes have a horny, elongated-oval, feather-shaped
pi-oostracum or "pen" (Fig. 1332), which is situated dorsally in a closed sac
of the mantle. It is sometimes extremely thin, and composed of conchyolin
or lime carbonate. The sepion, gladius, or " cuttle-bone," as the shell is called
when calcified in some genera, exhibits at its posterior end a small point (the
mucro) corresponding to the guard in Belemnites, and extends in front as a
broad shelly plate, like a proostracum. This forward extension, when viewed
from the front side, is seen to be covered by a mass of thin shelly lamellae,
which correspond to the septa more distinctly observed in Belosepia.
Many living Dibranchiates are gregarious, and swim in the open sea in
hordes ; others creep on the bottom or lead a separate existence along rocky
shores. They are extraordinarily active, voracious animals, and prey upon
mollusks, crustaceans and fishes. A few species are esteemed as food by man.
SUBCLASS II DIBRANCHIATA 679
In size Dibranchiates are extremely variable ; some forms are only 2 or 3 cm.
long, others attain gigantic dimensions. Architeuthis, for example, reaches
a total length of 12 metres, the body being 2*5 long, and over 2 metres in
circumference. Its arms are thick as a man's leg, and the suckers sometimes
as large as ordinary coffee-cups.
Dibranchiate Cephalopods are divided into three orders, as follows : —
Belemnoidea, Sepioidea and Odopoda.
Order 1. BELEMNOIDEA. (Phragmophora Fischer.)^
Shell infernal, chambered, and the septa traversed by a sijdiuncle ; conical or more
rarely spiral, and {with the exception of Spirilla) terminating ^posteriorly in a calcareous
sheath or guard. Arms ten in number, provided ivith hooklets. Trias to Recent.
Save for the genus Spirula, all forms belonging to this suborder are extinct. Their
camerate shells, perforated by a siphuncle, betoken a kinship with Tetrabranchiates, but
there are decided differences both in the structure and function of the shell. Tetra-
branchiates have the shell always external, enclosing the body, but in Dibranchiates it
is more or less enveloped by soft parts. Genetic connection between the Belemnoidea
and Sepioidea is apparent, and although their shells differ in form and structure, yet
a rudimentary phragmacone persists in the latter at the posterior end of the skeleton.
This rudiment is much more perfectly developed in Belosepia of the Tertiary, which is
a connecting link between Belemnoidea and Sej^ioidea. It is possible to explain the
entire internal shell of Spirula as homologous with the phragmacone of Belemnites.
It begins as a globular or inflated protoconch, which is constricted off from the first
camera, and is devoid of a cicatrix. The siphuncle originates as a caecal tube, and is
continued apicad as a prosij^hon, the same as in Ammonoids.
Family 1. Belemnitidae de Blainville.
Shell composed of a conical camerate phragmacone, continued on the dorsal side as a
proostracum, and an elongated solid rostrum or guard. Arms ten in number, of equal
length, provided with hooklets. Ink-bag present. Trias to Eocene.
This family, owing to its great morphological diversity and geological importance, occupies
a foremost position among Belemnoidea. The shell may be considered as the prototype of that
in all Dibranchiates, since it has all the component parts fully developed, whereas in other
groups some of these become atrophied or wanting.
The shell of Belemnites (Fig. 1314) consists of three fundamental portions : (1) A solid
calcareous piece, usually much elongated, and of subcylindrical, conoidal or fusiform shape.
This is called the guard (rostrum, osselet, gaine, Scheide), and is excavated at its anterior
^ In addition to the literature cited under the head of Cephalopoda (v. antea) see the following :
Angermann, E., tjber das Genus Acanthoteuthis Minister, etc. Neues Jahrb. Miner., 1902,
supplem. vol. xv. — Blamville, H. D. de, Mumoire sur les Belemnites. Paris, 1827. — Crick, G. C,
On Acanthoteuthis and Coccoteuthis. Geol. Mag., 1896-97, dec. 4, vols iii., iv. — Idem, Notes on
Actinocamax. Ibid., 1904, 1907, vols, i., iv. — Idem, On the Proostracum of a Belenniite from the
Upper Lias of Alderton. Proc. Malacol. Soc., London, 1896, vol. ii. pt. 3. — Idem, On the Arms of
the Belemnite. Ibid., 1907, vol. vii. , no. 5. — Ide^ni, Buccal Membrane of Acanthoteuthis. Ibid.,
1898, vol. iii. pt. 1. — Idem, On Belemnocamax boweri from the Lower Chalk. Proc. Geol. Assoc,
London, 1910, vol. xxi. — Danford, 0. G., Notes on the Belemnites of the Speeton Clays. Trans.
Hull Geol. Soc, 1906, vol. v. — Grossouvre, A. de, Quelques observations sur les Belemnitelles, etc.
Bull. Soc. Geol, France, 1899, ser. 3, vol. xxvii. — Huxley T. H.,On the Structure of Belemnitidae,
etc. Mem. Geol. Surv. United Kingdom, 1864, Monogr. ii. — PlbilUiJS, J., Monograph of British
Belemnitidae. Palaeontogr. Soc. , 1865-70. — Suess, ii\, UeberdieCephalopoden-Sippe Acanthoteuthis.
Sitzber. Akad. Wiss. Wien, 1865, vol. Ii. — Voltz, P. L., Observations sur les Belemnites. Paris,
1827. — Idem,, Observations sur les Belopeltis ou lames dor.sales des Belemnites. Mem. Soc. d'Hist.
Nat. Strasbourg, 1840, vol. iii. — Appeliif, A.. Die Schalen von Sepia, Spirula und Nautilus.
Kongl. Sveuska Vetensk. Handl., 1893, vol. xxv.
680
MOLLUSCA— CEPHALOPODA
PHYLUM VI
broad extremity into a conical cavity or alveolns. Within the alveolus is placed (2) the
phrag iiiaconc. This consists of a conical series of chambers (loculi), the sejita of which are
pierced at the ventral margin for the passage of the siphuncle. The phragmacone begins with
a globular protoconch, and its last or anterior chamber is of comparatively large size. It is
invested with a thin proper wall (conotheca), which is jn-olonged forwards on the dorsal side
into a more or less calcified plate called (3) the proostracum. This last corresponds to the
" pen " of living cuttle-fishes. There is evidence that its anterior margin is convex, but it is
so extremely thin that it is never perfectly preserved, and like the phragmacone, is wanting
in by far the greater number of specimens.
Notwithstanding the fragmentary condition in which the proostracum invariably occurs,
it is possible to reconstruct its outlines from the iieculiar conothecal striae, or markings of the
membranous substance with which it is invested. The conotheca is made up of three very
thin superimposed laminae, the outermost of which usually shows the markings alluded to
most distinctly (Fig. 1314, C). The conical surface of the phragmacone and proostracum is
divided by Voltz into four principal regions radiating from the apex : A dorsal area, including
all the space between two straight lines called the asyvvptotes, which extends from the apex of
the cone as far as the aperture. Tiiis area occupies about one-fourth of the circumference, and
' is marked with loop lines of growth convex toward the front. On either side of the dorsal
area and separated from it by the asymptotes is a lateral or
hyperbolic area, each one occupying about one-eighth of the
circumference, and covered with very obliquely arched lines
in a hyperbolic form. The ventral area is covered with numer-
ous transverse striae, of which there are many on each alveolar
chamber, and they are closer together the nearer they are to
the apex of the ])hragmacone. The striae of the dorsal area
are less numerous than those of the rest of the shell, and
usually are less pronounced, being sometimes imperceptible.
"The guard oi Bclemnites consists of prismatic calcareous
fibres, which are directed perpendicularly to the surface, and
radiate in all directions from an axial line, which is not
strictly central, but is somewhat nearer the ventral than the
dorsal side. The growth of the guard is ett'ected by the
deposition of successive conical layers or sheaths, which are
secreted over the entire surface, but are thickest behind, and
become gradually attenuated in front. The surface of the
guard is smooth ; or may be wholly or partially granulated
or wrinkled ; or, again, may be marked with branched vasculnr
impressions, which are especially conspicuous on the ventral
side. In many cases a well-marked groove^ — the ventral furrow
— runs from the edge of the alveolus backwards on the ventral
side, extending for a short distance only, or reaching to tlie
]ioint of the guard (Fig. 1318, 6'). The apical portion of the
guard often shows two symmetrical grooves (the dorso-lateral
grooves) which diverge slightly and become shallower as they
extend forwards, and which mark the dorsal side of the shell."
(Nicholson).
As shown by vascular impressions on the rostrum, the shell
of Belemnoids was eomi)letely enveloped by the mantle. AVell
preserved impressions of the animal in tlie Englisli Lias (Figs.
1315, B ; 1327) exhibit an elongated form of body, contracted
anteriorly, with a small head surrounded by ten eijual arms.
An ink-sac is present, and the arms are provided with hooks.
The maximum size attained by Belemnoids is between 2 and
I
Aulacoceras Hauer {Didyoconites Mojs.) (Fig. 1314).
Guard elongated, clavate, contracted anteriorly, thickened
^'"- ■'^^^- in the posteiior third, and pointed at the tija ; composed
u;S''S;''SSuf^:^; of concentric, loosely superimposed lamellae. Each side
Aussee, Austria. .1, Guard and marked by a deep broad lateral groove reaching from
pliraf,'macoiie, -/•;. 11, Guard, i/i- ,i .■ o ■, ■ n i • -ni
a. Portion of piiraHiiKicoue siic-ed the tip as far as the anterior alveolar margin. FJiragma-
funm'iT ■''''*""^'''' '""' ■'^'1^1'^""'' cone at least twice as long as tlie rostrum, slowly increas-
ing in width anteriorly, ornamented externally with
raised longitudinal lines, which are crossed on the dorsal side by a transverse series,
SUBCLASS II
DIBRANCHIATA
681
convex toward the front ; closely resembling Orthoceras. Septa rather distantly
spaced ; siphuncle marginal, thin ; proostracum unknown. Guards of this genus
are rare, but detached jshragmacones are not uncommon. Uj^per Alpine Trias.
Atractites Giimbel. Like Aulacoceras, but guard large, smooth and without lateral
furrows. Phragmacone either smooth, or with fine asymptotic lines, and dorsal area
A B c marked with extremely fine
growth - lines, convex toward
the front. Guards and phrag-
macones almost always occur
detached. Tlie latter were
originally mistaken for Ortho-
ceratites, but are distinguished
by their marginal siphuncle
and characteristic conothecal
striae. Upper Trias and Lias
of the Alps ; also Trias of
California.
Ph
Pig. 1315.
A, Vertical section of a Belenmite, the proostracum broken away
above the phragmacone. B, Behmnltes hrugicrlanus Miller. Lower
Lias ; Cliarmouth, England. Impression of complete individual. 1/3
(after Huxley). C, Restoration of a Belemnite shell.
Abbreviations: R, Rostrum or "guard"; Ph, Phragmacone; Po,
Proostracum ; a. Apical line reaching from apex of guard to bottom of
alveolus (0) ; h, Impression of arms ; c, Camerae of phragmacone ; i, An-
terior end of proostracum ; 0, Protoconch ; si, Siphuncle ; x. Ink-bag.
Pio. 1316.
Bclcmnitescomprcssiis. Lias ;
Gundershofen, Alsace.
Phragmacone with well-pre-
served conotheca. a, Asymp-
totic line ; h. Hyperbolic
area ; v, Ventral area.
Xiphoteuthis Huxley. Middle Lias ; England. X. elongata Huxley.
Belemnites Lister (Figs. 1315-1319). Name first ajjplied by Agricola in 1546.
Guard dactyliform, subcylindrical or conoidal, sometimes short and thick, sometimes
slender and much elongated ; retral portion tapering, submucronate or obtusely
rounded. Owing to irregularity in secretion of calcite layers on the periphery of the
guard during growth, individuals belonging to the same .sjjecies but of difierent ages
frequently differ considerably in form. Such difterences are well illustrated in B.
acuarius Schloth. The young are sometimes fusiform, but grow cylindrical or
conical with age. About 350 species are knoAvn, ranging from the Lower Lias to
G82
MOLLUSCA— CEPHALOPODA
PHYLUM VI
the uppermost Cretaceous ; maximum from the Middle Lias to Lower Cretaceous.
Distribution world-wide ; most abundant in Europe, Asia and North America. As
an index fossil of the Jura
and Cretaceous, this genus
is scarcely less important
than the Ammonites.
Subtfenera : I'achytcufJiis
Bayle (Fig. 1318, A).' Guard
perfectly smooth. Contined
to the Lower Lias. £. acutus
Mill.
Mcgateuthis Bayle , {Dac-
U/loteuthis Bayle, Paxillosi)
(Fig. 1318, B). Apex of
the guard with two or three
Fig. 1317.
Belcmnites (Duvcdia)
dilaMtus' Blv. Neo-
comian ; Justithal,
Lake of Tliun, Switzer-
land.
-I
i::-J
fe,--'JI
Fig. 131S.
-4, U. (Fachyteuthis) acutus Miller. Lower
Lias ; Lyme Regis, Dorsetshire. B, B. (Mega-
teuthi':) 2mxiUosus Schloth. Middle Lias ; Metzin-
gen, Wiirtemberg. (', B. (P^eudohdus) hijiariitiifi
Blv. Lower Cretaceous ; Castellaiie, Basses
Alpes. a, h, c, Dorsal and ventral aspects and
cross-section, i/j. /), B. {Brlcinnopsis) canalicu-
kit us Schloth. Inferior Oolite ; Wiirtemberg.
E, B. (Bdemno}isls) liastatus Blv. Oxfordian ;
Dives, Calvados.
§M
Fig. 1319.
Belernnitcs {Actinocamax) quad-
ratus (Blv.). Upper Creta-
ceous ; Germany. -1, Dorsal
view of guard with deformed
phragmacone projecting from
alveolus. B, Ventral aspect of
guard. C, Alveolus from above
(after Schltlter).
usually short grooves. Middle Lias to Lower Cretaceous. B. paxillosus and B. giganteus
Schloth. ; B. clongatns Mill. ; B. subquadratus Roem., etc.
Belemnopsis Bayle (Hiholithcs Montf., Gastrocoeli, Canaliculati, Hastati) (Fig. 1318, D, E).
Guard with deep and usually long ventral furrow extending from alveolar margin toward the
apex, with or without dorso-lateral lines. Middle Jura to Middle Cretaceous. B. canaliculatus
Schloth. ; B. absoliitus Fisch. ; B. unicanalicu.lcdus Zeit. ; B. minimus Lister.
Fscudohclus Montf. (Bijiartiti) (Fig. 1318, C). Guard thin, slender, with deep dorso-
lateral grooves, with or without ventral furrows. Upper Lias to Lower Cretaceous. B. cxilis
d'Orb. ; B. hipartitus Blainv.
Adinocnmax l\Iiller [Goniotcuthis Bayle) (Fig. 1319). Guard cylindrical, subniucronate,
with short but very deep ventral furrow ; anterior end foliaceous, and very liable to dissolu-
SUBCLASS II
DIBRANCHIATA
683
guard.
Fig. 1321.
Diploconus helem-
nlUddra Zittel. Ti-
tlKuiian ; Strainberg.
tion. Phragniacone only very slightly inserted in the guard, the two portions usually
separated by an interval. Middle and Upper Cretaceous. B. subventricosus Wahlb. ; B.
quadratus Blaiuv.
BcleitinitcUa d'Orb. (Fig-
1320). Guard cylindrical, with
short, deep ventral furrow fall-
ing short of the alveolar margin.
Pliragmacone inserted in guard.
Vascular impressions often
beautifully preserved. Upper
Cretaceous.
Diploconus Zitt. (Fig.
1321). Guard short, obtusely
conical, and having a con-
centric lamellar structure, not
radial and fibrous. Phragnia-
cone reaching nearly to the
posterior end of the
Tithonian.
Bayatioteuthis Mun.-
Chalni. Guard long, cylind-
rical, mucronate, with shallow
lateral grooves. Dorsal area
roughened. Pliragmacone very
slender and long, oval in
section. Eocene ; Paris /Basin
and Ronca, Italy. B. rugifer
Schloenb.
Vasscuria Mun. - Chaliii.
Guard slender, elongated -
conical, with a number of
longitudinal grooves extending
from the apex. Pliragmacone more than one -half as long as the guard. Septa
oblique, their necks extending from one septum to the next. Very rare in the Eocene
of Brittany.
Belemnosis Milne Edw. Very rare in the English Eocene. Styracoteiithis Crick.
Intermediate between Belemnitella and Bayanoteuthis. Eocene ; Arabia.
Beloptera Blainv. (Fig. 1322). Guard short and somewhat swollen at its forward
end, which makes a slight angle with the pliragmacone ; on either side it is expanded
into a conical projection. Eocene.
Belopterina Mun.-Chalm. Like Beloptera, but without the lateral wing-like
expansions. Eocene.
Fig. 1320.
licli'mnitcs (BclcmniteUa) mucronatua
Schloth. Upper Cretaceous ; Drenstein-
furtli, Westplialia. A, B, 0, Ventral, dorsal
and lateral aspects. %.
Pig. 1322.
Beloptera be.lcm-
nitoidai Blv. Calcaire
Grossier; Paris Basin.
Ventral aspect.
Family 2. Beleninoteuthidae Zittel.
Shell composed of a conical phragmocone and proostracum, the guard being reduced
to a thin calcareous or horny investment of the pliragmacone. Ten arms of nearly equal
length, each heset ivith a douhle roio of hooJcs. Ink-sac 'present. Trias and Jura.
Acanthotcuthis Wagner and Miinst. {Belemnites Quenst. p.p. ; Ostracoteuthis Zitt.)
(Figs. 1323-1325). Pliragmacone with numerous septa, and siphuncle having short
siphonal funnels ; enveloped externally in a thin granular calcareous layer rej)resent-
ing the guard. Surface of proostracum divisible into a broad dorsal, and two narrow
lateral areas which are longitudinally striated and taper toward the front. Dorsal
area ornamented with fine parabolic and also straight longitudinal lines ; anterior
684
MOLLUSCA— CEPHALOPODA
PHYLUM VI
margin rounded. An impression of tlie animal found in the Lithographic Stone
Pio. 1324.
A can thofeu this spec losa
Miinst. Lithographic
Stone ; Eichstiidt. A,
Impression of shell, the
proostracum accident-
ally bent sideways. /;,
Prcjostraeiini showing
se]ita and siphonal
funnels, -/g.
"^'^^
^^\
'^.=^^»''
ff
\
a
V, ''^\ "of I
^^v^^\> ^N
B
"TW
!^_ £'^g~-^'~/
K4t
r^^) \E:::1^
"p^'-'yff
^xi^
=^^fc-C— y''
r--W
=-^ I _j^
^^^
Fig. 1324.
I II lu2'').
Acfi nthotcuthis spcc'iosa
Miinst. Lithographic
Stone ; Solenhofen. Pro-
ostracum. -/;>
• Fiii. 1323.
AccmthofeutJds speciosa Miinst. Lithographic
Stone ; Eichstiidt, Bavaria. Impression of arms
and body. l/.i.
shows an ink-bag and ten powerful arms about the head,
which arc beset with two rows of ojjposite, hornj^, falciform
booklets. Upper Jura.
Phrucjmoteuthis Mojs. (Fig. 1326). Proostracum twice
as long as the conical phragmacone, with dorsal area
bounded by asymjitotic lines, and two shoiter lateral areas ;
anterior margin of all ai-eas rounded. Phragmacone invested
liy a brownish horny layer representing the guard. Trias
(Raibl Beds).
Belemnoteuthis Pearce (Gonoteuthis d'Orb.) (Figs. 1327-
1328). Like Acanthoteuthis but with smaller and curved
phragmacone, which is not produced into a long proostracum.
Upper Callovian and Lower Cretaceous.
Family 3. Spirulidae Zittel.
Shell reduced to a chambered, ^^h/ragmncone coiled into aflat
spiral, the coils not in contact ; situated in posterior jjart of
the body, and the greater portion contained within the mantle, hi
SUBCLASS II
DIBRANCHIATA
685
addition to the eight arms, two long tentacles ivithout hooka are placed between the third
and fourth pairs. Oligocene to Recent.
Vo-
Fig. 13-20.
A, PhragmoteiUhis hiainiiata
(Bronn). Trias ; Raibl, Car-
iutliia. I'll, Pliragmacone ; I'o,
Proostractuii ; L, Lateral area
of proostracum ; </, Ink-bag.
B, Hooklets of arms, i/i (after
Suess).
■<i<.A ..r
B
Fig. 1327.
U clc m note nth i s ft n t i q u a
Pearce. Oxford Clay ; Chris-
tian Malford, Wilts. .1 , Partly
restored specimen, i/.j. oo.
Eyes ; m, Mantle. Other
letters as in Fig. 132i;. B,
Hooklet, -i/i (after Mantell).
Fig. 132S.
Belemnoteuthis sp. Oxford Clay ; Gam-
melshausen, Wtirtemberg. A, C, Dorsal
and ventral aspects. B, Septum and
siphuncle.
B
■-- Ph
Fig. 1320.
Spindirostra hellardU (Mich.). Mio-
cene ; Siiperga, near Turin, Italy. .1,
Side view. J!, Longitudinal section. /',
Guard ; Ph, Pliragmacone. i/'i (after
Munier-Chalmas).
Spirulirostra d'Orb. (Fig. 1329). Shell composed of a
short triangular pointed guard, which is excavated anteriorly
for the reception of the chambered phragmacone. The latter
begins as a spiral, but speedily becomes straight, and has
septa pierced on the concave ventral side by the marginal
siphuncle. Only one species. Oligocene of Westphalia and
Upper Miocene of Turin.
Sfirnlirostrina Canavari. Like the preceding, but guard
reduced to two small, lateral wing-like appendages. Neocene
of Sardinia.
Spirula Lam. (Fig. 1330). Shell thin, guard wanting.
Chambered phragmacone enrolled with the ventral side
concave, the coils not in contact, composed of nacreous sub-
stance ; septa concave ; protoconch globular. Siphuncle tocon'ch"
ventral and marginal in position, the septal necks directed ^^^X^! sfS^^
backwards between the septa. Prosiphon present. Recent ; (after Munier-Chalmas).
Fig. 1330.
Spirula pernnii Lam.
Recent ; Pacific. Longi-
tudinal section, i/i. a, Pro-
e, Caecal com-
686
MOLLUSCA— CEPHALOPODA
PHYLUM VI
inlialjits tropical seas. For description of the animal see Keport on Spirula, by
Huxley and Pelseneer, in Appendix to Challenger Keports, Zoology, part Ixxxiii.,
1895.
Order 2. SEPIOIDEA. (Squids and Cuttle-fishes).
Shell internal, without differentiated •phragmacone and guard, hut consisting essenti-
ally of the proostracum or ^'' pen" which is either oval or narrow and elongated. Arms
ten in number, provided with suckers or hooks. Ink-bag present.
Family 1. Sepiophoridae Fischer.
Shell or " sepion " a calcareous, elongated-oval plate, terminating piosteriorhj in a
thickened mucro which represents a rudimentary guard, and encloses a conical cavity.
Siphuncle wanting.
The thickened posterior mucro is a nidimentary structure probably corresponding
to the guard of Belemnoids, and
its conical cavity to the alveolus.
Belosepia retains a vestigial cham-
bering but no .siphuncle, and in
Sepia a recognisable phragmacone
is wholly wanting. These forms
are undoubtedly descended from
Belemnoids like Beloptera.
Belosepia Voltz (Fig. 1331).
As a rule only the posterior portion
of the ijroostracum is preserved.
This ends in a bent spine, which
is thickened anteriorly, laterally
expanded, and contains near the
apex a conical alveolus. The
latter shows on the dorsal side
incomplete traces of septa, and a
wide funnel - like depression
occupies the place of a siphuncle.
Eocene ; not uncommon in Paris
Basin and the London Clay. Rare
in Claibornian sands of Alabama.
Sepia Lam. (Fig. 1332). Shell
or "pen" of equal length with
the mantle, elongated - oval,
rounded anteriorly, thickened
posteriorly and terminating in a
short mucro. The latter contains
a conical alveolus. Dorsal and
ventral walls of the jien consisting of two brittle calcareous laminae, separated by a
horny layer. Internally with a mass of extremely fine parallel calcareous lamellae,
increasing in thickness anteriorly ; the lamellae separated from one another by
minute vertical I'ods, thus producing a spongy texture. The familiar cuttle-bone of
commerce, or ossa Sepiae, is the pen of Sepia officinalis Linn., and is found in great
quantities along the coasts of certain countries. Several Tertiary species known.
(?) Gampylosepia Picard. Muschelkalk ; Thuringia. Belosepiella De Alessandri.
Eocene ; Paris Basin.
Pig. 1331.
Belosepia hlainvillei De.sli.
Eocene ; Aiivers, near Paris.
A, Posterior end of shell,
ventral aspect. B, Same fioni
the sid(! (after Deshayes).
Fifi. 1332.
Scpki officltinlis Linn. Recent.
Ventral view of .shell, a, Cal-
careous shelly plates represent-
ing vestigial septation. h, Pcsi-
tion of rudimentary phragma-
cone in front of mucro, '•^/.■j
SUBCLASS II
DIBRANCHIATA
687
Family 2. Ohondrophoridae Fischer.
Internal shell in the form of a much elongated thin plate or proostracum, divided
lengthrvise into three areas, composed of conchiolin or of alternating layers of calcareous
and horny matter, thickened posteriorly, and with very little trace of any chambered
portion or phragmacone. Jura to Recent.
The members of this family show a further reduction of the guard and phragmacone
than occurs in the stage represented by Belemnoteuthis, and their horny, non-septate
.b'iG. ibab.
Coccoteuthis hastiforinis (Riipp.).
Lithographic Stone ; Eichstiidt,
Bavaria.
Fk;. 1334.
Geuteuthis boUensii Ziuteu.
Upper Lias ; Holzmaden, Wiirtem-
bt'i-g. Shows ink-bag and cono-
thecal striae. V;?-
Fig. 1335.
Udoteuthis schuehleri Quenst.
Upper Lias ; Holzmaden, Wiir-
teniberg. '/a (after Quenstedt).
shells should be compared with the pen of the common squid or calamary, Loligo
vulgaris Lam.
Coccoteuthis Owen {Trachyteuthis v. Meyer) (Fig. 1333). Proostracum elongated-
oval, composed of calcareous and horny laminae, rounded posteriorly or with but
slightly projecting mucro ; external surface roughly granulated, and marked by lines
diverging from the apex. These lines limit the boundaries of two wing-like
expansions projecting from the sides of the elongated median portion. Impressions of
the body and arms are occasionally found in the Lithographic Stone of Bavaria.
Upper Jura.
Leptoteuthis v. Meyer. Proostracum very large, thin, narrowing posteriorly and
composed of several layers of calcareous and horny layers. Median area ornamented
with fine undulating transverse striae, convex toward the front, and separated from the
lateral areas by longitudinal lines diverging from the apex. Lateral areas marked
with oblique inwardly directed lines, and bordered by lateral expansions which are
widest posteriorly. L"''i)per Jura of Southern Germany. L. gigas v. Meyer.
Geoteuthis Mlinst. (Fig. 1334). Proostracum composed of thin alternating horny
688
MOLLUSCA— CEPHALOPODA
PHYLUM VI
fC(i~^
^
m^
and calcareous layers, widest in front, rounded jjosteriorly. Median area divided into
halves by a longitudinal line, and bounded on either side by lateral areas with
^1 hyperbolic striae. Ink-bag frequently preserved, the
contents transformed into a jet -like substance. It is
jjossible to dissolve the carbonaceous particles so as to
prejiare a wash resembling India ink. Upi^er Lias of
Germany, France and England.
Beloteihthis Miinst. (Fig. 1335), Proostracum very
thin, elongated, feather -shaped, broadly rounded pos-
teriorly, pointed in front, traversed by a median
longitudinal keel. Upper Lias of Wiirtemberg.
Teuthopsis Desl. Lias. Kclaeno- Miinst. Upper
Jura. Phylloteuthis Meek and Hayden ; Actinosepia
Whiteaves. Cretaceous ; Canada.
Plesioteuthis Wagner {Dorateuthis Crick) (Fig. 1336).
Proostracum very thin, long, narrow, lanceolate, pointed
posteriorly, rounded in front, with a median longi-
tudinal keel and a raised line along each of the lateral
edges. Very abundant in the Lithographic Stone, and
impressions of the liody and head not uncommon. Also
found in the Cretaceous of Maestricht and Syria.
Order 3. OCTOPODA Leach.
Body vnthout internal shell, and only the female of
Argonauta secreting a single- chavihered external shell.
The two tentacles are not present, and the eight arms
bear sessile suckers withoid horny rims. Eye relatively
small, ivithout sphincter -like lid. Body short and rounded,
usually without fin-like appendages.
The majority of genera belonging here aie naked
and therefore without fossil representatives. The small
male of Argonauta Linn, is without a shell, but the
large female bears a delicate, boat -shaped, spiral shell
which is secreted partly by the mantle, and partly by
two fin-like expansions of the dorsal arms. Outer surface
of shell ornamented by folds and tubercles, and two
„,.,,. . ,„ . „ nodose ventral keels are present. Late Tertiary (Pied-
Pleswtenlhis prisca (Ruppel). \ i -n j
Lithographic Stone ; Eichstadt. mont) and Kecent.
;'• I"'P7««ion "f aniinal showing q^^i^^ j | q g ^ g^ ^ ^ ^ j
anus and ink-bag. B, 81iell, i/.,. ... . .
provided with triangular lateral fins, not united behind.
Head small, with relatively stout tentacttlar arms, these being of nearly uniform
length and size, and each bearing a single row of suckers. This is the earliest known
Octopod genus. Upper Cretaceous ; Mt. Lebanon, Syria.
Fi(i. 133(5.
Vertical Range of the Dibranchiata.
As compared with Tetrabranchiates, the Dibranchiata are of minor geological
importance. Their entire organisation renders them less well adapted for preserva-
tion in the fossil state, and accordingly we shall never be able to form even an
ajiproximate idea of their importance in their contemporaneous faunae. The earliest
representative of Belemnoidea ajspears in the Trias (Aulacoceras), and the Sepioidea
SUBCLASS II DIBRANCHIATA 689
are initiated in the Lias. From what group Dibranchiates are descended, whether
from the Tetrabranchiates or from primitive naked ancestors, we have at present no
certain means for determining. Tliey aj^pear suddenly in a high state of develoj)-
ment ; but a still more remarkable fact is the swift culmination and decline of the
group of Belemnoids. In contrast to the small numbei' of forms met with in the Trias,
we find even in the Lias, as well as other divisions of the Jura and Lower Cretaceous,
a ]'ich and varied Belemnite fauna. At the close of the Cretaceous only two genera,
Belcmnitella and Actinocamax, persist in relatively large numbers, and although a
few antiquated relics of the same stock continue into the Eocene, their rarity
demonstrates waning vitality. The sole living representative of Belemnoids is the
genus Spirilla.
In all probability the Sepioidea are descended from Belemnoids. Belosepia of the
Tertiary has tolerably distinct indications of a phragmacone, but in Sepia proper the
sejjtation has become vestigial. Jurassic Chondrophoridae apj)roximate closely to
Recent squids and cuttle-fishes. All the evidence at our disposal justifies the conclusion
that Mesozoic Sepioids possessed an essentially similar organisation to that of Recent
forms.
[For certain changes introduced in the present treatment of Dibranchiate Cephalopods,
as compared with the original German edition, the Editor alone is responsible.]
VOL. 1 2 Y
Phylum VII. ARTHROPODA. (Articulates.)
Heteronomously segmented animals with, typically, a pair of appendages to each
somite of the body ; the whole enclosed in a chitinous segmented exoskeleton, the joint-
ing of which extends to the appendages.
In the Arthropoda the segments are unequally developed, and the
appendages, primitively locomotor in function, may be modified on one or
more somites to subserve special functions, such as the seizure aad comminu-
tion of food, respiration, sensation, copulation, oviposition, fixation, etc.
These modifications of the appendages and the more or less complete union
of the segments into groups may result in the differentiation of three distinct
regions : head, thorax and abdomen. Of these regions the head is concerned
largely in sensation and feeding, the thorax is chiefly locomotor in function,
and the abdomen frequently defensive.
The braii| lies above and in front of the oesophagus, and consists of a
fusion of several pairs of ganglia. The rest of the central nervous system con-
sists of a chain of ganglia lying in pairs on the ventral surface, with typically
a pair in each somite. Not infrequently there is a more or less extensive con-
centration or fusion of these ventral ganglia. The eyes may be simple,
aggregate or compound, with in some cases an inversion of the retinal layer.
Respiration in the smaller forms is by the general surface of the body,
whereas in the larger certain regions become S2:)ecialised for this purpose.
When respiratory outgrowths protrude from the body wall they are known
as gills or branchiae ; when invaginated they are termed Inngs if they be
lamellar in arrangement, or tracheae if they consist of fine tubes ramifying
through the tissues.
Excretion is effected either by " segmental organs " (true nephridia)
which open at the inner end into the true body cavity (coelom) and at the
other to the exterior, or by diverticula developed at the hinder end of the
alimentary canal. The nephridia when present occur in only a few segments
of the body. The diverticula of the alimentary canal (Malpighian tubes) are
of two kinds — one developed from the mesenteron, the other from the procto-
daeum. In all Arthropods the ducts of the reproductive organs are apparently
modified nephridia, and the organs themselves consist of gonads developed
from the coelomic walls. The circulation depends upon a dorsal heart enclosed
in a vascular pericardial sac, and metameric blood - vessels terminating in
" lacunar " spaces.
Arthropods are divisible into three groups or subphyla, distinguished
according to the nature of the respiratory organs, segmentation of the body,
690
CLASS I CRUSTACEA 691
and structure of the appendages as follows : Branchiata, Myriapoda and
Inseda. These are in turn divided into several classes, all of which have
fossil representatives. As to the origin of the Phylum, Paleontology affords
no certain evidence. The entire organisation of Arthropods indicates a close
relationship with Vermes, and especially with the group of Annelid Worms ;
nevertheless, the differentiation of the Arthropod type must have antedated
the Cambrian, since several orders of Crustacea are encountered in the oldest
fossiliferous rocks which are almost as widely divergent from the supposed
ancestral stock as many Recent forms. The relatively late appearance of
Myriapods, which are the most worm-like of all Articulates, may be accounted
for by their terrestrial habitat and the destructibility of their body parts.
SuBPHYLUM A. Branchiata.
Arthropods breathing by means of gills (or lungs or tracheae modified from gills)
developed always in connection with the appendages. Head and thorax rarely distinct,
but usually more or less completely united in a cephalothorax. The genital ducts
open to the exterior near the middle of the body, and true nephridia usually occur.
Malpighian tubes, when present, are derived from the mesenteron. Anterior append-
ages all midtiarticulate, the basal joints of one or more pairs serving as organs of
manducation.
The branchiate Arthropods include two classes : Crustacea and Arachnida.
Class 1. CRUSTACEA.^
Arthropods of usually agnatic habitat, and breathing by gills {exceptionally
through the general body surface) ; with one or two pairs of appendages {antennae) in
front of the mouth, the first of which is jnirely sensory, and several pairs of post-oral
appendages, some of which are modified into organs of mastication. Appendages with
typically a basal joint {protopodite) giving rise to ttvo or three branches.
The segmentation of the body is distinct in all except certain parasitic
foi'ms, where it is lost in the adult stage through degeneration. Usually the
demarcation between head and thorax is obscure, and the anterior region of
the body consists of a cephalothorax, the number of whose segments varies
within wide limits ; this being in sharp contrast to the Arachnids, where the
segments are constantly six in number. The cephalothorax is frequently
covered by a chitinous shell or carapace, developed from the dorsal portion of
the second and third segments, and is frequently strengthened by deposits of
carbonate and phosphate of lime. Although the carapace is usually a single
^ Literature : Brongniart, A., and Bemarest, A. O, Histoire naturelle des Cnistaces fossiles
sous les rapports zoologiques et geologiques. Paris, 1822. — Milne Edwards, H., Histoire naturelle
(les Crustaces, 3 vols. Paris, 1834-40. — Woodward, H., and Salter, J. W., Catalogue and Chart of
Fossil Crustacea. London, 1865. — Woodward, H., A Catalogue of British Fossil Crustacea.
London, 1877. — Gerstctecker, A., Crustacea, in vol. v. of Bronn's Classen und Ordnungen des
Thierreichs. Part 1 (Cirripedia, Copepoda, Branchiopoda, Poecilopoda, Trilobita), Leipsic, 1866-
79 ; part 2 (Isopoda to Decapoda), 1881-94. — Vogdes, A. W., A Catalogue of North American
Palaeozoic Crustacea confined to the non-trilobitic Genera and Species. Ann. N.Y. Acad. Sci.,
1889, vol. V. — Grohben, K., Genealogy and Classification of the Crustacea. Sitzungsber. Akad.
Wiss. Wieu, 1892, vol. ci. Translated in Ann. and Mag. Nat. Hist. [6J, vol. xi. — Kingsley, J. S.,
The Classification of the Arthropoda. Amer. Nat., 1894, vol. xxviii. Reprinted in Tufts College
Studies, No. 1, 1894, with bibliography.
692 AKTHROPODA phylum vii
piece, yet in some forms (Estheriiform Branchiopods and Ostracods) it may
consist of two lateral valves, which enclose the body like a Pelecypod shell ;
or of four parts, as in certain Phyllocarida ; or again (Cirripedia) of a number
of calcareous plates. The abdomen is usually well developed and its seg-
ments are free, but occasionally it becomes greatly reduced, as in certain
Entomostraca.
The total number of body somites varies within wide limits in the
Entomostraca and Trilobita, but in the Malacostraca they are almost constantl}^
twenty -one, ranging slightly higher in the Phyllocarida, and falling shorter in
the parasitic Laemodipoda. '
In all living Crustacea there are two pairs of antennae, although in some
forms {Apus, Oniscids) one or the other pair may become greatly reduced.
In the Trilobites, on the other hand, but a single pair has been discovered.
The appendages are exceedingly variable in form, according as they serve
for sensation, comminution of food (" mouth parts "), locomotion, respiration,
capture of prey or copulation. The primitive form was a lamellar appendage
like those found in the thoracic region of Branchioj)ods, but the typical leg is
usually stated to consist of a basal portion (protopodite) of one or two joints,
and a distal portion made up of an inner (endopodite) and a lateral branch
(exopodite). In many cases the exopodite becomes greatly modified or even
entirely atrophied in the adult.
Most of the lower Crustacea escape from the egg in a larval condition
known as the nauplius stage. In the nauplius the body is unsegmented, there
is but a single median eye, and but three pairs of appendages, correspond-
ing to the two pairs of antennae and mandibles of the adult. The nauplius
gradually becomes metamorphosed into the adult Crustacean, the changes being
accomplished by several moults of the external chitinous crust. In the higher
Crustacea this free-swimming nauplius stage is omitted, the animal already
having the form of the adult as it escapes from the egg. The Decapods have
a larval stage known as the zoea, in which seven pairs of appendages and a
segmented abdomen are present. These larval stages are of great value in
determining relationships, but most modern authorities regard them as adaptive
rather than ancestral ; or, in other words, it is not believed that existing
Crustacea are descended from an ancestral form resembling the nauplius.
Two subclasses are recognised : Trilobita and Eucrustacea. The term
Entomostraca is here used in a collective sense to distinguish the lower orders
of Eucrustacea from the highest, or Malacostraca.
Subclass A. TRILOBITA Walch. Trilobites.'
Marine Crustacea, with a variable number of metameres ; body covered with a
hard dorsal shield or crust, longitudinally trilobate into the defined axis ami pleura ;
^ Litei-ature : A. General Works. — Brongniart, A., Histolre naturelle des Crustacus fossiles. 1822.
— Dalmicn, J. IF., Ueber die Palaeadeii oder die .sogeiiannten Trilobiten. 1828. — Green, J.,
Monograph of the Trilobites of North America, with coloured models of the species. 1832. —
Burmeister, H., Die Organisation der Trilobiten. 1843. — Beyrich, E., tjber einige biihniische
Trilobiten, Berlin, 184.'J-46. — Cort^a, J. C, and Jlmvle, J., Prodrora einer Monogi-aphie der
liohmischen Trilobiten. Prag 1847. — IIccU, J., Palaeontology of New York, vols, i.-iii., 1847-59. —
Barmnde, J., Systunie Hilurien du centre de la BohOnie, vol. i., 1852 ; Supplement, 1872. — Angelin,
N. P., Palaeontologia Scaudinavica. Parti. Crustacea formationis transitionis, 1854. — Neiszkuivski,
J., Versuch einer Monographic der in den silurischen Sehichten der Ostseeprovinzeii vorkoninii'inlen
Trilol)iten, 1857. — Hoffmann, E., Siinmitliche bisjetzt bekaunte Trilobiten Ivusslands. Vcrhandl.
SUBCLASS I
TRILOBITA 693
cephahn, thorax and abdomen distinct. Cephalon covered with a shield composed of
a primitively pentamerous middle piece, the cranidium, and two side pieces, or free
Mineral. Gesellscli. St. Peterslmrg, 1857-58.— Salter, .T. W., A Monograph of British Trilobites.
Palaeontographical Society, 1864. — Idem and Woodward, H., Ibid., 1867-84. — Schmidt, F.,
Revision der ostl)altischen silurischen Trilobiten. Mem. Acad. Imp. St. Petersbourg, 1882-1907,
ser. 7, vol. XXX., and ser. 8, vol. xii. — Brogger, W. C, Die silurischen Etagen 2 und 3 in Kristiana-
gebiet und auf Eker, 1882.— Hohn, G., De Svenske Arterna af Trilobitslilgtet Illaeuus. Bihang
Sveusk. Vetensk. Akad. Handl., 1882, vol. vii., no. ^.—Matthew, G. F., Illustrations of the
Fauna of the St. John's Group, 1882-93. — Woodward, H., Monograph of the British Carboniferous
Trilobites. Palaeontogr. Soc, 1883. — Hall, ./., and ClarU, J. M., Palaeontology' of New York,
1888, vol. \\\. — Walcott, C. D., The Fauna of the Lower Cambrian or Olenellus Zone. 10th Ann.
Rept. U.S. Geol. Surv., 1890. — ,/aekel, 0., tjber die Organisation der Trilobiten. Zeitschr. Deutsch.
Geol. Ges., 1901, vol. liii. — Lake, P., Monograph of British Cambrian Trilobites. Palaeontogr.
Soc, 1906-1913. — Lorenz. T., Beitrage zur Geologic und Pahiontologie von Ostasien, der Provinz
Schantung, etc. Zeitschr. Deutsch. Geol. Ges., 1906, vol. Iviii. — Monk, H., Beitrage zur Geologic
von Schantung. Jahrb. Preuss. Geol. Landesanst. Bergakad., 1905, vol. xxiii. — Moberg, J. C, and
Segerberg, C. 0., Bidrag till Kannedomen om Ceratopygeregionen med Siirskild Hansyn till dess
Utveckling 1 Fogelsangstrakten. Acta Universitatis Lundensis, 1906.- — Olin, E., Om de Chasmops-
kalkeu och Trinucleusskiffern Motsvarande Bildningarne 1 Skiine. Acta Universitatis Lundensis,
1906. — Raymond, P. E., The Trilobites of the Chazy Limestone. Annals Carnegie Mus., 1905,
1910, vols, iii., vii. — Idem, and Ka.rraway, J. E., Notes on Ordovician Trilobites. Ibid., 1906,
1910, vols. iv. , vii. — Reed, F.R. G., Lower Palaeozoic Trilobites of the Girvan District. Palaeontogr.
Soc, 1903-1 906. ^/f?e?*(-, The Lower Palaeozoic Fossils of the Northern Shan States. Burma.
Palaeont. Indica, 1906. — Idem', The Cambrian Fossils of Spiti. Palaeont. Indica, 1910. — Walcott,
G. D., The Cambrian Faunas of China. Proc U.S. Nat. Mus., 1906, and Smithson. Misc. Coll.,
vol. xxix., 1911. — Idem, Cambrian Trilobites. Geology and Paleontology. Smithson. Misc. Coll.,
1908-11, vols, liii., Iv. — Weller, S., Paleontology of the Niagaran Limestone in the Chicago Area.
Bull. Chicago Acad. Sci., 1907,' no. 4.
B. Structure and Appendages : Burmeister, H., vide supra, 1843. — Billings, E., Notes on
some Specimens of Lower Silurian Trilobites. Quar. Jouru. Geol. Soc, 1870, vol. xxvi. — Woodward,
II., Note on the Palpus and other Appendages of Asaphus from the Trenton Limestone in the
British Museum. Quar. Journ. Geol. Soc, 1870, voL xxvi. — Walcott, G. D., Preliminary Notice
of the Discovery of the Natatory and Branchial Appendages of Trilobites. 28th Rept. N.Y. State
Mus. Nat. Hist., 1875. — The Trilobite ; New and Old Evidence relating to its Organization. Bull.
Mus. Conip. Zoology, 1881, vol. viii.— iVom^, 0., Studienan Hypostomen biihmischen Trilobiten.
Sitzungsber. Bohm. Ges. Wiss., Jahrg. 1879, 1886. — Clarke, J.M., The Structure and Development
of the Visual Area in the Trilobite Phacops rana Green. Journ. Morphology, 1888, vol. ii. —
Matthew, W. D., On Antennae and other Appendages of Triarthrus beckii. Amer. Journ. Sci., 1893,
(3), vol. xlvi.— JSeecAer, C. E., On the Thoracic Legs of Triarthrus, ibid., 1893.— On the Mode
of Occurrence, and the Structure and Development of Triarthrus becki. American Geologist, 1894,
vol. xiii. — The Appendages of the Pygidium of Triarthrus. Amer. Journ. Sci. 1894 (3), vol. xlvii.
— Further Observations on the Ventral Structure of Triarthrus. Amer. Geologist, 1895, vol. xv. —
The Morphology of Triarthrus. Amer. Journ. Sci., 1896 (4), vol. i. — Structure and Appendages
of Trinucleus, ibid., 1895. — -Studies in Evolution, New York, 1901. — The ventral integument of
Tribolites, Amer. Journ. Sci., 1902 (4), vol. xiii. — Lindstrom, G. Researches on the Visual Organs
of Trilobites. Svensk. Vet. Akad. Handl., 1902, vol. xxxiv,
C. Ontogeny : Barrcmde, J., vide supra, 1852. — Beecher, G. E., The Larval Stages of Trilobites.
Amer. Geologist, 1895, vol. xvi. —Matthew, G. F., Sur le developpement des premiers Trilobites.
Ann. Soc. Roy. Mai. de Belgique, 1889, vol. xxiii. — vide ante, 1882-93.
D. Systematic Position : Zittel, K. A., Handbuchder Palaeontologie, 1881-85, vol. iii. — Grundziige
der Pahiontologie, 1895. — Lang, A., Text-book of Comparative Anatomy, English Translation by
H. M. and M. Bernard. 1891. — Kingsley, J. S., The Classification of the Arthropoda. Amer.
Nat., 1894, vol. xxviii. — Bernard, H. M,, The Systematic Position of the Trilobites. Quar. Journ.
Geol. Soc, 1894-95, vols. 1., li. — The Zoological Position of the Trilobites. Science Progress,
1895, vol. iv. — Woodward, H., Some Points in the Life-History of the Crustacea in Early Palaeozoic
Times. Quar. Journ. Geol. Soc, 1895, vol. li, — Haeckel, E., Systematische Phylogenie der
wirbellosen Tiere (Invertebrata), 1896. — Beecher, G. E., Outline of a Natural Classification of the
Trilobites. Amer. Journ. Sci., 1897 (4), vol. iii.
E. Classification: Barrandc, J., vide stqyra, 1852. — Beecher, G. E., ante, 1897. — Brongniart,
A., ante, 1822. — Burmeister, II., ante, 1843. — Corda, A. J. G., and Hawle, J., ante, 1847. —
Haeckel, E., ante, 1896. — Dalman, J. W., Om Palaeaderna eller de sa kallade Trilobiterna
Stockholm, 1826. — Milne Edivards, H., Histoire naturelle des Crustaces, 1834-40. — Quenstedt,
F. A., Beitrage zur Kenntniss der Trilobiten. Wiegmann's Archiv fur Naturgesch. , 1837, vol. iii.
— Emmrich, H. F.,I>e Trilobitis. Dissertation, 1839. — Zur Naturgeschichte der Trilobiten, 1844. —
694 ARTHROPODA phylum vii
cheeks, which may he separate or united in front, and carry the compound sessile
eyes when pit'esent ; cephalic apipendages ptediform, consisting of five pairs of limbs,
all Uramous, and functioning as ambidatory and oral organs, except the simple
antennules, which are purely sensory. Upper lip forming a well-developed hypostoma ;
under lip fresent. Somites of the thorax movable upon one another, varying in
number from two to twenty -nine. Abdominal segments variable in number, and fused
to form a caudal shield. All segments, thoracic and abdominal, carry a pair of
jointed hiramous limbs. All limbs have their coxal elements forming gnathobases,
which become organs of manducation on the head. Respiration integumental and by
branchial fringes on the exopodites. Development proceeding from a protonauplius
form, the protaspis, by the p>rogressive addition of segments at successive moults.
The Trilobites constitute a group of extinct marine animals, and are
related to the stock of the higher modern Crustacea ; they are therefore to be
considered as very primitive Crustaceans. The subclass had its origin in pre-
Cambrian times. Trilobite remains are very abundant in the oldest known
fossiliferous strata, the Cambrian, where they exceed in number and diversity
all other forms of animal life. They continue to be very plentiful during the
Ordovician and Silurian, but decline in the Devonian, and the fcAV last sur-
vivors are found in the Carboniferous and Permian. Probably there have
been more than two thousand species described, distributed among nearly two
hundred genera. These numbers give an^idea of the amount of differentiation
and specialisation attained by Trilobites during Paleozoic times.
Carapace. — Trilobites were covered or pi'otected on the dorsal side by a
hard crust or shield, which is the only portion commonly preserved. Their
remains, even when fragmentary, are recognisable by the form and structure of
this shield. It is divided longitudinally by two dorsal furrows, or grooves,
into three portions or regions, and on this account the name Trilobite was
first given. The central part formed the axis of the animal, and contained the
principal organs, as the viscera, heart and chain of ganglia. Transversely the
shield is divided into (1) a head portion called the cephalon ; (2) a series of
joints or segments, forming the thorax ; and (3) a tail-piece or pygidium,
forming the abdomen.
The test seldom exceeds one millimetre in thickness, and consists of thin
laminae of carbonaceous and phosphatic compounds of calcium, some of which
were originally chitinous substances. The laminae are frequently traversed
Goldfuss, A., Systematische Ubersicht der Trilobiteu imd Besehreibung einiger neueii Arten
derselbeu. Neues Jalirb. fiir Mineral, 1843. — M'Cui/, F., On the Classification of some British
Fossil Crustacea, with Notices of new Forms in the University Collection at Cambridge. Ann.
Mag. Nat. Hist., 1849 (2), vol. iv. — Chapman, E. J., Some Remarks on the Classification of the
Trilobites as influenced by Stratigraphic Relations : with Outlines of a new Grouping of these
Forms. Trans. Roy. Soc. Canada, 1889, vol. vii. — GUrich, G., Versuch einer Neueinteilung der
Trilobiten. Centralbl. Mineral. Geol. Pal., 1907. — Jaekel, 0., tjber die Agnostiden. Zeitschr.
Deutsch. Geol. Ges., 1909, vol. Ixi. — Pompeckj, J. F., tJber Calymmene, Brougniart. Neues Jahrb.,
1898, vol. i. — Raymond, P. E., Notes on Parallelism among the Asajihidae. Trans. Roy. Soc.
Canada, 1912 (3), vol. v. — Reed, F. R. C, Notes on the Evolution of the genus Clieirurus.
(Jeol. Mag., 1896 (4), vol. iv.—Idem, Blind Trilobites. Ibid., 1898, vol. v.— Idem, On the British
species of Conocoryphe. Ibid., 1900, vol. vii. — Idem, On some Wenlock species of Lichas. Ibid.,
1903, vol. X., and (5), 1907, vol. iv.—Idem, The Classification of the Phacopidae. Ibid., 1905,
vol. ii. — Idem, Notes on the genus Lichas. Quart. Journ. Geol. Soc, 1902, vol. Iviii. — Idem, On
the genus Trinucleus. Geol. Mag., 1912 (5), vol. ix. — Wedekind, II., Klassifikatiou der Phaco-
f)iden. Zeitschr. Deutsch. Geol. Ges., 1911, vol. Ixiii.
F. Bibliogi-aphy : Voydcs, A. W., A Classed and Annotated Bibliography of the Palaeozoic
Crustacea. Cal. Acad. Sci. Occas. Papers, iv., 1893. Supplement in Proc. Cal. Acad., 1895, vol.^v.
SUBCLASS I
TRILOBITA
695
by minute pores, which give a punctate appearance to the test, and which are
sometimes large, as in Homalonotus and related forms.
The carapace is somewhat arched or convex, generally elongate-oval in
form, and usually rounded at both ends. The length is almost invariably
greater than the width. Very often the same species shows a broad form,
as well as a relatively larger, narrower one. The former was considered i by
Barrande as representing the female, and the latter the male individual. The
carapace is often ornamented with spines, teeth and knobs. These may be of
the nature of surface ornaments, or in the case of spines, may be produced by
growths from the genal angles, the ends of the segments of the thorax and
pygidium, or the spiniform extension of the pygidial termination.
The carapace does not often terminate at the margin as a simple lamellar
plate, but is turned under, and forms a reflexed margin, or doublure, which is
parallel to the outer edge, but is separated from the upper surface by a narrow,
partially included space. This produces the hollow spines from the ends of
the segments, from the genal angles and from the pygidium. In rare instances,
the spines are solid.
The axial lobe, or middle part, is defined by two longitudinal dorsal furrows
extending the whole length of the thorax, and also over more or less of the
cephalon and pygidium.
The ])leura are the two lateral areas on each side of the axis. Thus, there
are pleural cephalic, thoracic and pygidial regions. The name pleuron (in
the singular), or pleura, is especially applied to the extensions from the axial
portion of each free segment.
The Cephalon. — The cephalon, or cephalic shield (Fig. 1337), includes all
that part of the carapace in front of the thorax. It comprises the hypostoma,
epistoma, the free cheeks bearing
the eyes, the fixed cheeks, and the
glabella ; it is generally semicircular
in form, and is joined along its
posterior margin to the thorax.
The postero - lateral margins, or
genal angles, are frequently drawn
out into spines. Usually there is
an occipital furrow extending across
the cephalon parallel to the posterior
margin, and defining the occipital
ring or segment.
The ■ glabella is the axial portion
of the cephalon, and is defined by
the primary dorsal furrows (Fig.
1337). It shows typically three
oblique or transverse furrows in
addition to the occipital ring, mark-
ing the limits of the original five consolidated segments, and corresponding to
the paired appendages of the ventral side. Sometimes the positions of the
muscular fulcra are also indicated on the dorsal surface, by short furrows, or by
shallow pits. The glabella may constitute nearly the whole of the cephalon,
as in Dciphon or Aeglina, or it may be narrow, as in Harpes and Enrycare. In
some cases it does not extend over half the length of the cephalon, as in Harpes
It, Genal spines ; gl, Glabella ; If,
Frontal lobe ; 1^43, Side lobes ; 1-3,
Side furrows of glabella ; so, Neck
furrow ; A, Neck ring ; (S, Facial
suture ; oc. Visual surface of the eyes ;
p, Palpebral lobe.
696
AETHROPODA
PHYLUM VII
The hypostoma,^ or labrum,
Crustaceans, and consists of a
A
Hypostoinas. *A, Corydocephalus jialniatus.
C, Ericfinurus intercostatus, side and front views
fafter Novak). BB, Anterior edge ; M, Middle
furrow ; E, Posterior furrow of tlie middle por-
tion ; P, Posterior- edt;e ; L, Lateral edge ; y, Pos-
terior wing.
and Aulacopleura, but it may extend to the frontal border, as in Placofaria or
Ceraurus, or even beyond, as in Pliacops, Ampyx and ConoUchas. The entire
portion of the glabella which lies in front of the anterior lateral furrows, and
which is often somewhat enlarged laterally, is called the frontal lobe. Some-
times the limitation between the glabella and fixed cheeks is scarcely defined,
as in Illaenus and Dipleura. Most frequently, however, three pairs of grooves
can be distinguished in front of the neck furrow, marking the pentamerous
division of the glabella and the five pairs of appendages attached to the
cephalon. Sometimes the lateral furrows are continuous across the glabella,
or again, they may be directed obliquely (Triarthrus), or even form longi-
tudinal grooves (ConoUchas).
is homologous to the upper lip of other
separate plate attached by an articulating
surface or line to the reflexed border of
the cephalic shield (Fig. 1338).
In front of the hypostoma is a rostral
area sometimes partly occupied by a
separ-ate plate, the epistoma (lUaemis,
Calymene).
The fixed cheeks are lateral extensions
from the glabella, to which they are
firmly joined, forming the centx'al portion
of the cephalon. They may occupy more
than two -thirds of the cephalon, as in
Conocoryphe, or may become greatly reduced, as in Lichas and Proetus. The
cranidium consists of the glabella and the fixed cheeks.
The free cheeks carry the compound eyes, and are separated from the
cranidium by a suture. They may form (a) a continuous ventral plate, as in
Harpes, Jgnostus, Cryptolithus, etc. ; they may include {h) a greater or lesser
portion of the dorsal surface, being either entii-ely separated by the cranidium,
or (c) meeting, and (d) sometimes coalescing in front. They are widely
separated in Ptychoparia, in juxtaposition in Asaphus, and continuous in
Dalmanifes.
The genal angles are the posterior lateral angles of the cephalon. They
may be rounded, as in Illaenus, angular, as in Goldius, or spiniform, as in
Cryptolithus and Dalmanites. They belong either to the fixed cheeks, as in
Dahnanites, or to the free cheeks, as in Illaenus, Goldius and Proetus.
The character of the cheeks is especially influenced by the facial sutures
separating the free cheeks from the rest of the cephalon. They appear
as sharply defined lines beginning either at the posterior margin, or
near the genal angles, or on the lateral margins, and extend to the eyes,
thence around the inner margin of the visual areas, then turn anteriorly, and
either unite in passing around the front of the glabella or remain separate, in
which case the sutures terminate in the anterior margin. The position of the
facial sutures thus determines the relative size of the fixed and free cheeks.
After the death of the animal, or after moulting, the cephalic shield frequently
fell into pieces, dividing along these sutures.
In most Trilobites, the existence of eyes has been demonstrated, though
^ Brijgger, W. C, Uber die Ausbilduiig des Hypostouies bei einigen skandiuavisclieu Asapliideu.
Bihang K. Svensk. Vet. Akad. Handl., 1886, vol. xi.
SUBCLASS I TRILOBITA 697
they appear absent altogether in some genera {Co')iocoryphe, Agnostus), and are
so imperfectly shown in others that for a long time they remained unrecognised
{Agraulos, Sao, Ellipsocephalus, etc.). The eyes are compound, and are elevated
above the free cheeks. The adjoining area of the fixed cheeks is also drawn
upwards, thus forming the palpebral lobe. The visual areas of the eyes are
borne by the free cheeks. The shape of this area is extremely variable, but
together with the palpebral lobe it generally forms a truncated, conical or
semilunar elevation, of which the laterally directed, convex side is occupied
by the visual surface (Phacops, Asaphus). It may likewise have a circular or oval
form, and very little convexity above the general surface. The eyes may be
quite small, as in Encrinurus and Trimerocephalus ; large and prominent, as in
Phacops, Dalmanites and Proetus ; or very large, as in Aeglina, in some species
of which nearly the entire area of the free cheeks is faceted, and the visual
surface extends around the entire outer borders of the cephalon. In many of
the primitive genera the eyes are situated at the distal ends of raised lines, or
eye lines, extending outward from near the forward end of the glabella.
As regards their structure, the compound eyes of Trilobites are recognised
as of two kinds. In the first, the holochroal, the visual area is covered with a
continuous horny integument, or cornea, which is either smooth and externally
gives no idea of its compound nature, or granular, on account of the facets
beneath. The lenses of the ommatidia are often visible by translucence. The
second type of structure, the schizochroal, is confined to the single family
Phacopidae. In this, the visual area is made up of small, round or polygonal
openings for the separate facets of the cornea, between which is an interstitial
test or sclera. The size of the facets varies from more than 0'5 mm. in some
of the Phacopidae, to from 6-14 facets in the width of 1 mm. in other Trilobites.
The number and arrangement of the facets also vary greatly according to the
genus. Trimerocephalus volhorthi shows only 14 facets, while species of Phacops
may possess from 200-300, and Dalmanites hausmanni has 600. Among the
holochroal eyes, the number of facets is much greater ; in Goldius palifcr it is
estimated at 4000, in Ogygites nohilis at 12,000, and in Caphyra radians as high as
15,000. Usually the facets are arranged in regular, alternating, vertical rows,
or quincuncially.
Certain genera show visual organs of an entirely different type, which can
be best regarded as simple eyes, and correlated with the ocelli of many Crus-
taceans. Thus, the genera Harpes and Tretaspis present from one to three
simple elevations or granules on the fixed cheeks, at the ends of eye-lines,
while the ordinary compound eyes on the free cheeks are absent.
The Thorax. — In contrast to the undivided cranidium, the thorax consists
of a series of short, transverse, articulating segments, which difter in number
with the genus and species. Every thoracic segment is divided by the dorsal
furrows into a middle portion (axis, tergum) and two lateral divisions {pleura,
epimera). The axial portions are firmly anchylosed with the pleura, and are
generally strongly convex, with the posterior margin incurved. Anteriorly
they bear an extension below the general surface, and separated by a furrow.
This forms a surface of articulation along which the segments are movable, and
is covered by the edge of the segment immediately in front, so that it is chiefly
visible in coiled or disarticulated specimens. Barrande distinguished two
types of pleura : (1) furrowed pleura (j)lhre a sillon), which have a diagonal
furrow on the upper surface, running posteriorly from the anterior edge near
698
ARTHROPODA
PHYLUM VII
the axis, and towards the free extremity; and (2) ridged pleura {jplhvre a
hourrelet), having a longitudinal ridge or narrow fold. These characters vary-
considerably, and are sometimes obscure. In a small number of genera
(Illaemis, Nileus) the pleura are perfectly smooth.
All pleura show a distal or lateral, and a proximal or inner portion. The
latter extends from the axis to the fulcrum or bend, i.e. to a place where the
pleura bend more or less abruptly downward, and also generally toward the
rear. The distal portion, beginning at the fulcrum, may continue of equal
thickness and be rounded or obtuse at the extremity, or it may decrease in
size and terminate in a spine.
The number of thoracic segments differs exceedingly among different
genera. The smallest number, two, occurs in Agnostus. The largest number
so far observed, twenty-nine, is found in some species of Harpes. A variation
is to be noted even among the species of a single genus, hence this character
is not of general application for purposes of classification. For example.
Fig. 1339.
Pygidiuni of Oiiygiocaris huchi (Brongt.).
Ordovician, Wales.
Fig. 1340.
Pygidium of Goldius umbellifer (Beyr.).
Devonian ; Bohemia.
there are species of Ampyx and Aeglina with five to six thoracic segments,
Phillipsia with nine to fifteen, Cheirurus with ten to twelve, Cyphaspis with ten
to seventeen, ElUpsocephahis with ten to fourteen, and Paradoxides with sixteen
to twenty. In general, there seems to be a sort of mutual relationship
between the number of thoracic segments and the size of the pygidium.
When the latter is large, the thoracic segments are usually few ; but if small,
the number of thoracic segments is large.
The Pygidium. — The abdomen of Trilobites is commonly known as the
pygidium (Fig. 1339), though sometimes styled the caudal shield or plate. It
consists of a single piece, with an arched upper surface, upon which may be
distinguished regularly a median axis and two lateral parts, or pleural lobes,
marked more or less distinctly by transverse furrows. Sometimes it bears
considerable resemblance to the cephalic shield {Agnostus, Eodiscm). The
pygidium evidently originated from the anchylosis of a number of similar
segments. The potential segmentation is often so strongly marked that it is
very difficult to recognise the dividing line between the thorax and pygidium,
except in disarticulated specimens. Sometimes the evidences of segmentation
disappear entirely or are but faintly indicated on the lower side. When
segmentation along the axial and lateral lobes is weak, the pygidium difl'ers
considerably in appearance from the thorax.
The axis may extend as far as the posterior end of the pygidium, or to
SUBCLASS I TRILOBITA 699
any part of the length, but is sometimes reduced to a short rudiment (Goklius,
Fig. 1340), or it may be even entirely obscured (Nileus). The number of
axial segments normally corresponds to the number of pygidial, and varies
between two and twenty-eight. On the lateral lobes, all or at least a part of
the pleura may also be seen, being continued from the axis as ribs separated
by furrows. In these cases, the furrowed and the ribbed pleura can usually be
distinguished, but not infrequently they have entirely disappeared as surface
features. Many of the Cambrian Trilobites are conspicuous for their small
pygidium and elongated thorax.
The outline of the pygidium is most frequently semicircular, parabolic or
elliptical ; more rarely it is triangular or trapezoidal. The margin is entire,
less commonly dentate or spiny. The border, as in the case of the cephalon
and the pleura of the segments, has a reflexed margin, or doublure, which in
some genera attains considerable width.
The Ventral Side. — The ventral side of Trilobites is commonly inaccessible
for purposes of observation, since, as a rule, it is so firmly attached to the
rock that the organs, even though present, cannot be exposed by the ordinary
methods. Furthermore the appendages and ventral structures are so thin
and delicate that the most favourable conditions are necessary for their pre-
servation. For this reason, great uncertainty has prevailed regarding the
presence and character of the legs and various appendages. After a careful
preparation of their inferior side, by far the larger number of Trilobites show
only the vacant hollow space beneath the dorsal shell, and the hypostoma
attached to the reflexed margin of the cephalic shield. This common condition
of the fossils led Burmeister, in 1843, to the assumption that all organs on
the lower side, as in Phyllopods, were originally soft and fleshy. Previous
to this, however, Linnaeus, in 1759, described what appeared to be antennae,
and Eichwald, in 1825, announced both antennae and legs. Altogether the
early literature down to 1870 contains quite a number of claimants for this
discovery. Most of the evidence is manifestly 'erroneous, and the two or
three cases which bear some semblance of validity are too obscure to be of
any scientific value.
Billings, in 1870, published the description and figure of an unusually
well-preserved Isotelus gigas from the Trenton Limestone of Ottawa, Canada.
The ventral side of the specimen showed eight pairs of jointed legs on each
side of a median furrow. Soon after. Woodward described an antenna or
pediform cephalic appendage, lying beside the hypostoma of another individual
of the same species. Through the investigations of Walcott (1875-94) on
Ceraurus and Calymene, by means of transverse and longitudinal sections
of enrolled specimens, a number of problems have been settled as to the
characters of the ventral
side. It is now known '^-^^^^^^^^^ >^
that Trilobites possessed #^ i^r^^^^^^^^^^^^^^g-^^^^..- 5"?'
a thin, external, ventral J 4> m ^ ^^^^^^^^^^^^^^^^^^^""?^N^
membrane attached to the ^^^^^ p o ^^
retlexecl margin OI the jiedian vertical section of Ceraurus i^leurexantheimis Green, c,
cephalon, thoracic segments Cephalon with hypostoma below ; 111, Mouth; v, Ventral membrane;
1 .,. -r , (', Intestinal canal ;?)!/, Pyaidium (after Walcott).
and pygidium. It was sup-
ported by transverse processes which became thickened with age, and to
these the legs were attached.
700
ARTHROPODA
PHYLUM VII
The alimentary canal, discovered by Beyrich and Volborth, begins at
the mouth and then curves over backward beneath the glabella, and extends
parallel with the dorsal test to its termination in the anal opening at the
posterior end of the pygidiura (Fig. 1341).
Most of the recent advances in the knowledge of Trilobite structure have
come from the study of numerous very perfectly preserved specimens of
Fig. 1342.
Trmrthrus hecki Green. Utiea Slialu (Oi(lo\'ician) ; Rome, New York. A, Dorsal, and B, Ventral aspect,
2/i (after Ueeuher).
IViarthnis hecki Green, from the Utica Shale (Ordovician), near Eome, New
York. Undoubted antennae in this form were discovered by Valiant, and first
announced by Matthew in 1893. Subsequently a series of papers was
published by Beecher on the detailed structure of this Trilobite, Avhich is now
the best known of any species, and necessarily forms the basis of much of the
following summary of ventral organs.
In the median line anteriorly, there is first the hypostoma or upper lip, at
the end of which, and opening obliquely backward, is the mouth (Walcott, in
Calyrmw). In Triarihrus the lower lip, or metastoma, is a convex arcuate
plate, just posterior to the extremity of the hypostoma. At the angles on
either side are two small elevations, or lappets.
SUBCLASS 1
TRILOBITA
701
Paired Appendages. — All segments of the cranidium, thorax and pygidium,
except the anal segment, carry appendages, all of which are biramous save the
anterior pair. The anterior
antennae, or antennules, are
attached at the sides of the
hypostoma, and consist of a
simple, many-jointed flagel-
lum (Fig. " 1342). The
caudal rami of the Cambrian
genus Neolenus (Fig. 1343)
are long, slender, jointed
and attached to the last
segment of the pygidium.
The typical Trilobite
leg has two branches arising
from a basal joint, or coxo-
podife, which is prolonged
into a gnathobase. The
inner branch, or endopodite,
has typically six joints.
The outer branch, or exo-
podite, has a long proximal joint, with a distal multiarticulate portion, or
the proximal joint may be flat and elongate, forming the entire exopodite,
as in Neolenus (Fig. 1343). Long setae extend posteriorly, and on the distal
portion they are so crowded as to make a conspicuous fringe, imparting a
characteristic appearance to the leg.
Besides the antennules, the cephalon bears four pairs of pediform biramous
appendages, with large gnathobases functioning as manducatory organs. Of
ti>
134a.
Middle Cambrian
Neolenus serratus Rominger.
B.C. Microphotograph showing elongate setiferous exopodite.
(after Walcott).
Burgess Pass,
Fig. 1344.
Triarthrus hccki Green, a, Restored tlioracic limbs in transverse
section of the animal ; h, Section across anterior portion of pygidium ;
c, Section across posterior portion of pygidium (after Beecher).
Fig. 134.5.
Triarthrus hccki Green.
Dorsal view of second thoracic
leg, with and without setae and
without Kuatliobase. en, Endo-
podite ; ex, Exopodite (after
Beecher).
these the first may be correlated with the posterior antennae of higher Crustacea.
In structure and function they are true mouth appendages, like the second
pair of nauplius limbs. The second pair, corresponding to the mandibles of
higher forms, and the third and fourth, corresponding to maxillae, have the
same structure as the first, with large gnathobases and fringed exopodites.
The thoracic and abdominal limbs are of the same biramous type. The endo-
702
ARTHROPODA
PHYLUM VII
podites are jointed, crawling legs ; posteriorly, especially on the pygidium,
the joints become flattened and leaf -like, cai'rying tufts of setae, and being
adapted for swimming.
The exopodites are fringed along their posterior edges with narrow,
oblique lamellar elements becoming filiform at the ends, thus converting the
limb into a swimming organ, and probably also serving respiratory functions
(Figs. 1343, 1346).
Habits. — In the absence of any closely allied recent forms, it is difficult to
reach definite conclusions respecting the manner of life of Trilobites, except
A B
Fio. 1346.
Crypiolithus fensellatus Green. Utica Shale (Ordo^ician) ; Rome, New York. A, Left half of pygidium and
three thoracic segments, with test removed, and showing fringes of the exopodites. B, Ventral aspect of sani(\
a, Endopodite ; h, Exopodite. 'O/i (after Beeclier).
such as are based upon their organisation and mode of occurrence. They were
undoubted marine animals, since their remains are found only in salt-water
deposits, associated with brachiopods, cephalopods, crinoids, and other typical
oceanic forms. Some species are plentiful in calcareous or argillo-calcareous
deposits, with thick-shelled brachiopods, gastropods and reef-building corals,
which evidently did not live at any considerable depth. Other forms appear
to have been bottom crawlers, frequenting either muddy or sandy bottoms ;
and again, others like Crijptolithus, lived partly buried in the soft mud. On
the other hand, many species indicate, from the absence of visual organs, a
comparatively deep-water habitat. The structure of the appendages of many
was probably such as to permit of both swimming and
crawling, as in a number of families of modern Crustacea,
and they were therefore restricted neither to the shore
nor to the bottom. This doubtless explains the occur-
rence of the same species in very difi^erent sediments.
Foiver of Enrollment. — The bodies of most Trilobites
were capable of being rolled up completely like many
of the Isopods (Fig. 1347). In the enrolled condition
the margin of the pygidium is closely applied to the
doublure of the cephalon, thus entirely concealing the
ventral side of the body. The thoracic segments over-
lap, and admit of more or less motion upon one anothei'. The pleura also
Fio. l;;47
Foerste.
Calymcne ineeki
Ordovician ; Cincinnati, Ohio,
Enrolled specimen.
SUBCLASS I
TRILOBITA
703
imbricate, and their fulcra are provided with facets upon which the fulcra of
adjacent segments impinge. The ends of the pleura thus protect the ventral
surface along the sides, when the animal is enrolled. Some forms appear to
have possessed the power only to a limited degree. In these, the creature is
usually found extended, and the facets on the fulcra are either rudimentary
or absent.
Ontogeny. — Minute spherical or ovoid fossils associated with Trilobites
have been described as possible Trilobite eggs, but nothing is known, of
course, of the embryonic stages of the animals themselves. The smallest and
most primitive organisms which have been detected, and traced by means of a
series of specimens through successive changes into adult Trilobites, are little
discoid or ovate bodies not more than 1 mm. in length. This first larval form
has been named the profaspis, and has been found to be the typical larval form
characteristic of all Trilobites. It is believed to approximate the protonauplius
form, or the theoretical, primitive, ancestral, larval form of the Crustacea.
The simple characters possessed by the protaspis are the following, as
drawn from the study of this stage in all the principal groups of Trilobites : —
Dorsal shield minute, not more than 0'4 to 1 mm. in length; circular or ovate in
form ; axis distinct, more or less strongly anniilated, limited by longitudinal grooves ;
head portion predominating ; axis of cranidium with five annnlations ; abdominal
portion usually less than one-third the length of the shield ; axis with from one to
several annulations ; pleural portion smooth or grooved ; eyes, tvhen present, anterior,
marginal or subnmrginal ;• free cheeks, when visible, narrow and margined.
The changes taking place during the growth of an individual are chiefly
the following : — Elongation of the body through the gradual addition of the
free thoracic segments ; development of the pygidium ; translation of the
eyes, when present ; modifications in the glabella ; growth of the free cheeks ;
and final assumption of the mature specific characters of pygidium and
ornamentation.
In a classification of the stages of development, the protaspis has the rank
of a phylembryo, and corresponds in value to the protoconch of cephalopods,
the px'odissoconch of pelecypods, and the protegulum of brachiopods. In its
geological history and the metamorphoses it undergoes to produce the perfect
Trilobite, accurate information can be gained as to what the primitive char-
acters are, and the relative values of other features acquired during the long
existence of the class.
Of the developmental stages after the protaspis, the nepionic may be con-
A B
A B
Fig. 134S.
Ptyclioparia kingi MprW.
Cambrian. A, Protaspis en-
lareerl. B, Adult reduced.
Fi(i. 1349.
.Sao hirsuta Barr. Cambrian.
A, Protaspis enlarged. B, Adult
reduced.
Fig. 1350.
Triarthrus becJci Green.
Ordovician. A, Protaspis en-
larged. B, Adult reduced.
sidered as including the animal when the cephalon and pygidium are distinct,
and the thorax incomplete. There would thus be as many nepionic stages as
there are thoracic segments. The neanic stages would be represented by the
animal with all parts complete, but with the average growth incomplete.
704
ARTHROPODA
PHYLUM VII
Final progressive growth and development of the individual would fall under
the ephebic stage. Lastly, general evidences of senility would be interpreted
as belonging to the gerontic stage.
Morphogeny. — During the protaspis stage, several moults take place before
13ol.
I'lXiitus parviusculus Hall.
Ordovician. A, Protaspis
iimch enlarged. B, Adult
slightly enlarged.
'-Y,-.'
Fin. 1352.
Acidas2)is tuherculata
Conrad. Devonian. A,
Protaspis enlarged. B,
Adult reduced.
Fig. 13")3.
Dahnanitina socialis (Barr.).
Ordovician. A, Protaspis en-
larged. B, Adult reduced.
(Figs. 1348-1353 after Beecher.)
I
the complete separation of the pygidium or the introduction of thoracic seg-
ments. These bring about various changes, namely, the stronger annulation
of the axis, the appearance of the free cheeks on the dorsal side, and develop-
ment of the pygidium by the introduction of new appendages and segments,
as indicated by the additional grooves on the axis and limb. In the earliest,
or Cambrian genera, the protaspis stage is by far the simplest expression of
this period to be found. In the higher and later genera, the process of
acceleration or earlier inheritance has pushed forward certain characters until
they appear in the protaspis, thus making it more and more complex.
Taking the early protaspis stages in Solenopleura, Liostracus or Pfychoparia,
it is found that they agree exactly with the foregoing diagnosis in its most
^ j> c elementary sense. Since they are the
chai'acters shared in common by all larvae
at this stage, they are taken as primitive,
and accorded that value in dealing with
adult forms possessing homologous features.
Therefore, any Trilobite with a large elon-
gate cephalon, eyes rudimentary or absent,
free cheeks ventral or marginal, and glabella
long, cylindrical, and with five annulations,
would naturally be placed near the begin-
ning of any genetic series, or as belonging
to a very primitive stock.
Next must be considered the progressive
Cambrian • skrey addition of characters during the geological
"iopmlnHSBanfndVr'''""''''''^^^^ ^^"^^^'^ °^ ^^^ protaspis, and the ontogeny
of the individual during its growth from
the larval to its mature condition. It has been shown by Beecher that
there is an exact correlation to be made between the geological and zoological
succession of first larval stages and adult forms, and therefore both may be
reviewed together.
The first important structures not especially noticeable in all stages of the
protaspis are the free cheeks, which usually manifest themselves in the meta-
or para-protaspis stages, though sometimes even later. Since they bear the
visual areas of the eyes, when such are present, their appearance on the dorsal
Fio. 13.04.
.Sao hirsuta Barrande.
Bohemia,
of de
SUBCLASS I
TEILOBITA
705
shield is practically simultaneous with these organs, and before the eyes have
travelled over the margin, the free cheeks must be wholly ventral in position.
AVhen first discernible, they are very narrow, and in Ptychoparia and Sao,
include the genal angles. In Dalmanites and Cheirurus, however, the genal
angles are borne on the fixed cheeks.
Since the free cheeks are ventral in the earliest larval stages of all but the
highest Trilobites, and as this is an adult feature among a number of genera,
which on other grounds are very primitive, this is taken as generally indicative
of a very low rank. The genera Harpcs, Agnostus, Cryptolithus and their allies
agree in this respect, and constitute the Hypoparia.
The remaining genera of Trilobites present two distinct types of head
structure, dependent upon the extent and character of the free cheeks. In
both, the free cheeks make up an essential part of the dorsal crust of the
cephalon, being continued on the ventral side only as a doublure or infolding
of the edge, similar to that of the free edge of the cranidium, the ends of the
thoracic pleura, and the margin of the pygidium. They may be separated
only by the cranidium, as in Ptychoparia ; by the cranidium and separate
A n c D
Fig. 1355.
Ontogeny of Sao hirsuta Barr. (Pinsthoparia) A, Protaspis. B, Cephalon of nepionio individual. C, Cephalon of
later nepionio individual having eight free segments. D, Cephalon of adult (from Beechei-, after Barrande).
epistomal and rostral plate, as in lUaenus and Homalonofus ; or they may be
united and continuous in front, as in Aeglina and Dalmanites. One type of
structure is distinguished by having the free cheeks include the genal angles,
thus cutting off more or less of the pleura of the occipital segment. The
genera belonging to this group constitute the second order — the Opisthopiaria.
The third and last type of structure includes forms in which the pleura of the
occipital segment extend the full width of the base of the cephalon, embracing
the genal angles. The free cheeks are therefore separated from the cranidium
by sutures cutting the lateral margins of the cephalon in front of the genal
angles. Genera having this structure are here placed in the order Proparia.
The characters still to be noticed have chiefly family and generic values,
A r. c D
FlQ. 1356.
Ontogeny of DalmanUina socialis (Haw-.). {Pivparia) A, Piotasi)is. B, Cephalon of Individual of three free
segments. C, Cephalon of one with seven free segments. D, Ceijlialon of adult (from Beecher, after BaiTande).
and are of great assistance both in determining the place of a family in an
order and the rank and genetic position of a genus in a family.
There is very satisfactory evidence that the eyes have migrated from the
ventral side, first forward toward the margin, and then backward oVer the
cephalon to their adult position. The most primitive larvae should therefore
VOL. I 2 z
706 ARTHROPODA phylum vii
present no evidence of eyes on the dorsal shield. Just such conditions are
fulfilled in the youngest larvae of Ptychoparia, Solenopleura and Liostracus.
The eye-line is present in the later larval and adolescent stages of these genera,
and persists to the adult condition. In Sao it has been pushed forward to the
earliest protaspis, and is also found in the two known larval stages of Triar-
thrus. Sao retains the eye-line throughout life, but in Triarthnis the adult has
no trace of it. A study of the genera of Trilobites shows that this is a very
archaic feature, chiefly characteristic of Cambrian genera, and only appearing
in the primitive genera of higher and later groups. It first develops in the
later larval stages of certain genera (Ptychoparia, etc.) ; next in the early larval
stages (Sao) ; then disappears from the adult stages {Triarthnis) ; and finally
is pushed out of the ontogeny (Dalmanites).
In Ptychoparia, Solenopleura, Liostracus, Sao and Triarthrus, the eyes are
first visible on the margin of the dorsal shield after the protaspis stages have
been passed through, and later than the appearance of the eye-lines ; but in
Pro'etus, Acidaspis, Ceratarges and Dalmanites, through acceleration, they are
present in all the protaspis stages, and persist to the mature or ephebic condi-
tion, moving in from the margin to near the sides of the glabella. Progression
in these characters may be expressed, and in so far taken for general applica-
tion among adult forms to indicate rank, as follows: — (1) Absence of eyes;
(2) eye-lines ; (3) eye-lines and marginal eyes ; (4) marginal eyes ; (5) sub-
marginal eyes ; (6) eyes near the pleura of the neck segment.
The changes in the glabella are equally important and interesting.
Throughout the larval stages the axis of the cranidium shows distinctly by
the annulations that it is composed of five fused segments, indicating the
presence of as many paired appendages on the ventral side. In its simplest
and most primitive state it expands in front, joining and forming the anterior
margin of the head (larval Ptychoparia and Sao). During later growth it
becomes rounded in front, and terminates within the margin. In higher
genera, through acceleration, it is rounded and well defined in front, even in
the earliest larval stages, and often ends within the margin (larval Triarthrus
and Acidaspis). From these few simple types of pentamerous glabellae, all
the diverse forms among species of various genera have been derived, through
changes affecting any or all of the lobes. The modifications usually consist in
the progressive obsolescence of the anterior annulations, finally producing a
smooth glabella, as in Illaenus and Niohe. The neck segment is the most per-
sistent of all, and is rarely obscured. The third or mandibular segment is
frequently marked by two entirely separate lateral lobes, as in Acidaspis, Cono-
lichas, Chasmops, etc. Likewise, the fourth annulation carrying the first pair
of maxillae is often similarly modified in the same genera, also in all the
Proetidae, and in Cheirurus, Crotalocephalus, Sphaevexochus, Ampyx, Harpes, etc.
Here, again, among adult forms, the stages of progressive differentiation may
be taken as indicating the relative rank of the genera.
The comparative areal growth of the free cheeks is expressed by the
gradual moving of the facial suture toward the axis. As the free cheeks
become larger the fixed cheeks become smaller. In the most primitive pro-
taspis stages, and in Agnostus, Harpes and Cryptolithus, the dorsal surface of the
cephalon is wholly occupied by the axis and fixed cheeks, while in the higher
genera the area of the fixed cheeks becomes reduced until, as in Stygina and
Phillipsia, they form a mere border to the glabella. Therefore the ratio
SUBCLASS I TRILOBITA 707
between the fixed and free cheeks furnishes another means of assisting in the
determination of rank.
The pleura from the segments of the glabella are occasionally visible, as
in the young of Elliptocephala, but usually the pleura of the neck segments are
the first and only ones to be distinguished on the cephalon, the others being
so completely coalesced as to lose all traces of their individuality. The pleura
of the pygidium appear soon after the earliest protaspis stage, and in some
genera [Sao, Dalmanites) are even more strongly marked than in the adult
state, and much resemble separate segments. The growth of the pygidium is
very considerable through the protaspis stage. At first it is less than one-
third the length of the dorsal shield, but by successive addition of segments it
soon becomes nearly one-half as long. In some genera it is completed before
the appearance of the free thoracic segments, all of which are added during the
nepionic stages. An interpretation of these facts, to apply in valuing adult
characters, would indicate that a very few segments, both in the thorax and
pygidium, may be evidence of arrested development or suppression. On the
other hand, the apparently unlimited multiplication of thoracic and especially of
abdominal segments in some genera is also to be considered as a primitive char-
acter expressive of an annelidan style of growth. Genera like Asaphus, Phacops,
etc., having a constant number of thoracic segments accompanied by other char-
acters of a high order, undoubtedly represent the typical Trilobite structure.
These analyses and correlations clearly show that thei-e are characters
appearing in the adults, of higher and later genera, which successively make
their appearance in the protaspis stage, sometimes to the exclusion or modifica-
tion of structures present in the more primitive larvae. Thus the larvae of
Dalmanites or Proetus, with their prominent eyes and glabella distinctly
terminated and rounded in front, have characters which do not appear in the
larval stages of ancient genera, but which may appear in their adult stages.
Evidently such modifications have been acquired by the action of the law of
earlier inheritance or tachygenesis, as it was called by Hyatt.
Position in the Zoological System. — Since Trilobites have been made the sub-
ject of special study, they have been commonly classed with the Crustacea, and
placed near the Phyllopods by most observers. Quite a number of naturalists,
however, still divorce the Trilobites and Limuloids from the Crustacea, and
ally them with the Arachnids. Leaving aside the question of the homologies
of Limulus, it is a fact that Trilobites show the clearest evidence of primitive
Crustacean affinities, in their protonauplius larval form, their hypostoma and
metastoma, the five pairs of cephalic appendages, the slender jointed antennules,
the biramous character of all the other limbs, and their original phyllopodiform
structure. They difter from Limulus, not only in most of these respects, but
also in not having an operculum. From Limuhis and all other Arthropods
they are distinguished by having compound eyes on free cheek-pieces, which
apparently represent the pleura of a head segment that is otherwise lost,
except possibly in some forms of stalked eyes and in the cephalic neuromeres
of later forms. The most recent discussions as to the affinities of Trilobites
are to be found in the papers by Bernard, Kingsley, Woodward and Beecher,
where, from the facts presented, the relationships of these animals with the
Crustacea follow as a necessary corollary.
As to the rank of the Trilobites in a classificatory scheme, there is also
much diversity of opinion. They have been long regarded as an order of
708 ARTHROPODA phylum vii
Crustaceans, but any attempt to include them in this way under higher groups,
such as the Entomostraca, Malacostraca or Merostomata, results in such broad
generalities and looseness of definition as to render these divisions of little
value. The present state of knowledge of Trilobite structure and develop-
ment is in favour of assigning them nothing short of the rank of a subclass.
In nearly every particular, the Trilobite is very primitive, and closely
agrees with a theoretical Crustacean ancestor. Its affinities are with the
known subclasses of the group, especially their lower orders, but its position
is not intermediate. The more primitive characters may be summarised as
follows : — (1) They are all free marine animals; (2) they have a definite con-
figuration ; (3) the larva is a protonauplius-like form ; (4) the body and
abdomen are richly segmented, and the number of segments is variable ; (5)
the head is typically pentamerous ; (6) the thorax and abdomen are always
distinct, the number of segments in each being variable ; (7) all segments
except the anal bear paired appendages ; (8) all appendages except antennules
are biramous ; and (10) the coxal elements of all limbs form gnathobases,
which become organs of manducation on the head. Walcott has recently
discovered (1912) the appendages of the Cambrian trilobitic genus Neolenus
and those of other Crustaceans, which indicate that the Trilobite is a
Crustacean intermediate in structural organisation between the Branchiopoda
and the Merostomata.
Classification. — Barrande gives a complete r6sum6 of the classifications
applied to Trilobites down to 1850, and shows in a very satisfactory manner
the weak points of each, furnishing strong reasons as to why they are un-
natural and therefore untenable. The underlying principles of these early
attempts at a classification are here briefly summarised. (1) The first classifi-
cation of Trilobites was advanced by Brongniart in 1822, in which all the
forms previously known as Entomolithus paradoxus were shown to belong to five
distinct genera. (2) Dalman, 1826, made two groups, based upon the presence
or absence of eyes. (3) Quenstedt, 1837, recognised the number of thoracic
segments and the structure of the eyes as of the greatest importance. (4)
Milne Edwards, 1840, considered the power of enrollment as of prime value.
(5) Goldfuss, 1843, established three groups depending on the presence or
absence of eyes and their structure. (6) Burmeister, 1843, accepted the two
divisions of Milne Edwards, and laid stress on the nature of the pleura and the
size of the pygidium. (7) Emmrich's first scheme, 1839, was founded on the
shape of the pleura, the presence or absence of eyes and their structure. (8)
The later classification of the same author, published in 1844, depended on
whether the abdomen was composed of fused or free segments, and the minor
divisions were based chiefly on the structure of the eyes and the facial suture.
(9) Corda, 1847, placed all Trilobites in two groups, one having an entire
pygidial margin, and the other with the pygidium lobed or denticulate. (10)
M'Coy, 1849, took the presence or absence of a facet on the pleura for a
divisional character. As this is an indication of the relative power of enrol-
ment, it does not diff"er matei'ially from the schemes of Milne Edwards and
Burmeister. Zittel, in a review brought down to 1885, includes in addition
the schemes of (11) Barrande, 1850, and (12) Salter, 1864, and remarks that
the basis of Barrande's general grouping, namely, the structure of -the pleura,
has neither a high physiological nor a morphological significance. Both
Barrande and Salter recognise nearly the same families, with slight differences,
SUBCLASS I
TRILOBITA
709
and the latter adopts a division into two lines, based on the number of body-
rings and size of the pygidium. These include and are themselves included
in four groups, founded on the presence and form of the facial suture and the
structure of the eyes. (13) Chapman, in 1889, proposed four suborders or
primary groups based purely upon arbitrary features of general structure and
configuration, especially the form of the glabella, whether wide, conical or
enlarged. (14) Haeckel, in 1896, divided the Trilobites into two orders
based upon the presence or absence of a functional pygidium.
The classification here followed is essentially that prepared by Beecher for
the first edition of this treatise, but with some amplification and modification,
made possible by the recent work of Reed, Clarke, Jaekel, Walcott and others.
Beecher's classification, although not universally accepted, has proved superior
to any previously proposed, and forms the basis for most of the modern
investigation of the group.
Order 1. HYPOPARIA Beecher.
Free cheeks forming a continuous marginal ventral plate of the cejihalon, and in
some forms also extending over the dorsal side at the genal angles. Siiture ventral,
marginal or snlmarginal. Compound paired eyes absent ; simple eyes may occur on each
fixed cheek, singly or in pairs.
Even in the higher genera of this order, the suture is frequently imnoticed, but can
be seen in all well-preserved specimens. In Gryptolithus and Harpes it follows the edge
of the cephalon, and separates the dorsal from the ventral plate of the pitted brim.
Since eye-spots occur on the fixed cheeks in the young of Gryptolithus and adult
Harpes, it is probable that this character is a primitive one in the order, and has
been lost in Agnostus, Eodiscus, Ampyx and Dionide.
The ontogeny of higher genera shows that the true eyes and free cheeks are first
developed ventrally, appearing later at the marginal, and then on the dorsal side of
Fio. 1357.
Cepliala of //(/yiojiana. A, Agnostus. B, Eodiscus. C, Harpes. D, Crypiolithus. E, Ampyx (after Beecher).
the cephalon. Therefore the Agnostidae, Cryptolithidae, and Harpedidae have, in
this respect, a very primitive head structure, characteristic of the early larval forms
of higher families. Other secondary features show that this order, though the most
primitive in many respects, is more specialised than either of the others, except in
their highest genera. The characters referred to are the glabella and pygidium. Very
few species show the primitive segmentation of the glabella, it being usually smooth
and inflated and resembling in its specialisation such higher genera as Proiitus,
Asaphus and Lichas. The pygidium often fails to indicate its true number of
segments. Many species of Agnostus and Eodiscus show no segments either on the
axial or pleural lobes of the pygidium. Gryptolithus and others may have a numerously
annulated axis and fewer grooves on the pleural portions. The number of ajipendages
corresponds to the axial divisions. The multiplication of segments in the laygidium,
and their consequent crowding, make them quite rudimentary.
710
ARTHEOPODA
PHYLUM VII
Family 1. Agnostidae M'Coy.
Hypo2Jaria with head and abdomen shields similar; free cheeks not visible from the
dorsal side. Thorax xvith two segments. Cambrian and Ordovician.
Subfamily A. Condylopyginae Raymond.
Agnostidae with many-lobed shields, long glabella ivhich expands totvard the front,
and long and broad axial lobe on pygidium..
Condylopyge Corda. Anterior lobe of glabella broad. Pygidium
with three pairs of middle - lobes, and a broad end -lobe. Middle
Cambrian ; Europe and North America.
Pleuroctenium Corda (Fig. 1358). Similar to Condylopyge, but
with anterior lobe of glabella flattened, and crossed by radiating
grooves. Cambrian ; Europe.
Diplagnostus Jaekel. Anterior middle-lobe divided. Axial lobe
of pygidium pointed behind. Cambrian ; Europe.
Peronopsis Corda. Anterior middle lobe of glabella simple, not
wider than the part behind. Accessory lobes present at base of
glabella. Middle Cambrian ; Europe and North America.
Subfamily B. Arthrorachinae Raymond.
Agnostidae with middle lobe of glabella short and simple; small accessory lobes
present at base of glabella.
Arthrorachis Corda. Ordovician ; Europe and North America.
Hypagnostus Jaekel. Axial lobe of pygidium narrow, pointed behind.
Subfamily C. Agnostinae Jaekel.
Agnostidae toith both shields sculptured. Middle lobe of cephalon long, narrowed
toward the front. Accessory lobes always present.
Agnostus Brongniart (Figs. 1357, A ; 1359). Surface
smooth ; accessory lobes simple. Cambrian ; Europe and
North America.
Ptychagnostus Jaekel. Surface wrinkled or otherwise
ornamented. Accessory lobes double. Cambrian ; Europe
and North America.
Subfamily D. Phalacrominae Corda.
Fig. 135S.
Pleuroctenium
rjranulatum (Barr.).
Cambrian ; Skrey,
Bohfiinia. 5/j (after
Barrande).
Fig. ]:;5'.i.
Agnostus pisiformis (Linn.).
Cambrian ; Andiarnm, Sweden.
Complete individnal, and frag-
ment of limestone witli detaelied
cephala and pygidia.
Agnostidae with shields scarcely lobed.
Lejopyge Corda. Middle lobe of cephalon and pygidium Ijarely indicated-
Ordovician ; Europe.
Phalacroma Corda. Cephalon and pygidium without lobes. Cambrian and
Ordovician ; Europe and North America.
Family 2. Eodiscidae Raymond.
Hypoparia of small size ; free cheeks not visible from the dorsal side ; thorax of three
segments ; pygidium annulated. Cambrian.
SUBCLASS I
TRILOBITA
711
Eodiscus Matthew (Microdiscus Salter non Emmons) (Fig. 1357, B). Glabella short,
occipital ring spined. Lower and Middle Cambrian ; Europe and North America.
Goniodiscus Raymond. Glabella long, occipital ring obtusely pointed. Type,
Microdiscus lobatus Hall. Lower Cambrian ; North America.
Family 3. Shumardiidae Lake.
Hypoparia similar to the Agnostidae in size and in structure of the cephalon, but
with small, stronyly segmented pygidium, and six segments in the thorax.
Shthmardia Billings. Glabella proniinent, expanding toward the front. Lower
Ordovician ; Europe and North America.
Family 4. Harpedidae Corda.
Hypoparia loith very large head shield and small pygidium. Free cheeks ventral,
sutitre marginal. Tliorax with numero^is segments {seventeen to twenty-nine). Cephalon
with hroad pitted hrim. Ordovician to Devonian.
The broad hippocrepian pitted hvhn of the Harpedidae has its counterpart in
Gryptolithus and Dionide, although less well developed in those
genera. The head is also relatively longer and larger, both
features being decidedly larval. The functional visual spots or
ocelli, situated on the fixed cheeks, are found only in this
family and in Tretaspis arid in the young of Gryptolithus. Thu
great number of thoracic segments is another primitive
character, and the cephalon is larger than the thorax and
pygidium.
Harpes Goldfuss (Fig. 1357, G). Hypostoma somewhat
pentagonal, angular in outline. Silurian and Devonian ;
Europe and North America.
Eoharpes Raymond {Harpina Novak) (Fig. 1360). Hypostoma
oval in outline. Ordovician ; Europe and North America.
Fig. 1360.
Eoharpes ungula (Stern-
berg). Ordovician ;
Bohemia, l/i (after Bar-
lande).
Family 5. Trinucleidae Emmrich (Gryptolithidae Angelin).
Hypoparia with large cephalon and small pygidium. Free
cheeks ventral, carrying the gcnal spines. Gephalon with a pitted,
hrim. TJwracic segments few {five or «?";<■). Ordovician.
Gryptolithus Green {Trinucleus Murch.^mrs) (Figs. 1346, 1357,
D ; 1361). Central portion of cephalon divided by the dorsal
furrows into three prominent portions. No ocelli in adult.
Ordovician ; Europe and North America.
Trinucleus Murch. (restr.). Glabella obovate, with two pairs
;ryptoiithus (jMfussi ^f ^^^^ glabellar furrows. Pits on brim set in deep radiating
furrows; no ocelli or eye-lines. Ordovician; Europe and N orth
America. Type T. fimbriatus Murch.
Tretaspis M'Coy. Glabella spherical in front, conical behind, with two pairs of
strong glabellar furrows ; ocelli and eye-lines present. Ordovician ; Europe and
North America.
Dionide Barrande. Similar to Gryptolithus, but with an irregularly pitted border
and a large pygidium. Ordovician ; Europe.
Fig. 1361.
(Barr.). Ordovician (Etage
D) ; Wesela, Bohemia.
X i/i.
712
ARTHROPODA
PHYLUM Til
Family 6. Raphiophoridae Angeliu.
Hijimparia with large trilobed cephalon without brim, small, wide 'pygidium, and
few thoracic segments. Small free cheeks
visible on the dorsal surface. Glabella,
produced in front of the cephalon as a spine.
Ordoviciaii and Silurian.
Fin. 1362.
Ampi/x nasutus
(Dalnian). Or-
dovieian ; Pul-
kowa, Russia.
X v.-
Raphiophorus Angelin.
Glabella obo-
Five
vate, with an abrupt apical spine,
thoracic segments. Europe.
ylm292/x Dalman (Figs. 1357, J?; 1362,
1363). Glabella oval, terminating in a
round spine. Six thoracic
Europe and North America.
Lojichodomas Angelin. Glabellar spine long and prismatic in section. Europe and
North America.
Fig. 1363.
Ampyx portlocki Barrande.
Ordovician (Etage D) ; Leiskow,
Bohemia, x i/i (after Barrande).
segments.
Order 2. OPISTHOPARIA Beecher.
Free cheeks generally separate, cdivays bearing the genal angles. Facial sutures
extending forward from the posterior part of the cephalon within the genal angles, and
cutting the anterior margin separately, or more rarely uniting in front of the glabella.
Qompound paired holochroal eyes on free cheeks, and tvell developed in all but the most
primitive family.
The families which are here i')laced under this order lend themselves quite readily
to an arrangement based uj^on the characters successively appearing in the ontogeny of
any of the higher forms. Thus Sao, Ptychoparia and other genera of the Olenidae
Fig. 1364.
Cephala of the Ojns^/tojxiria. A, Atops. B, Conocoryphe. C, Ptychoparia. D, Olenus. E, Asaphus.
F, lUaenus. G, Proiitus. H, Goklius. I, Lichas. J, Acidas2ns (after Beecher).
have first a protaspis stage only comparable in the structure of the cephalon with the
genera of the preceding order. Therefore this stage does not enter into consideration
in an arrangement of the families of the Opisthoj^aria. In the later stages, however,
there is a direct agreement of structure with the lower genera of this order. The
nepionic Sao, with two thoracic segments (Fig. 1355, B), has a head structure agi'eeiug
in essential features with that in Atops or Conocoryphe (Figs. 1364, A, B). A later
nepionic stage, with eight thoracic segments (Fig. 1355, G) agrees closely with the
adult Ptychoparia or Olenus (Fig. 1364, C, D). These facts clearly indicate that the
family Conocoryphidae should be put at the base of this extensive order. Moreover,
as Ptychoparia and Olenus are more primitive and simpler genera than Sao, they, as
SUBCLASS I
TEILOBITA
713
typifying the family Olenidae, govern its position, which accordingly would be after
the Conocoryjjhidae.
Differences in the position of the eyes, the relative size of the free and fixed cheeks,
and the degree of specialisation of the glabella have a definite order in the ontogeny of
any Trilobite, and furnish characters of taxonomic value in arranging the families
jjlaced under the Opisthoparia (see Fig. 1364).
Family 1. Conocoryphidae Angelin.
Opistho2Mria with free cheeks very narrow, forming the lateral margins of the
cephalon, and bearing the genal spines. Eye-lines are present, but neither ocelli nor
compound eyes. Thorax with from fourteen to seventeen segments. Pygidium small.
Cambrian.
The genera comprised under this family present a number of very primitive
characters, such as are displayed only in the larval stages of higher forms. The free
cheeks are narrow and marginal, and may be compared with those in the nej)ionic
stages of Sao and Ptychoparia. Eyes have not been detected, but the presence of an
eye-line suggests their possible existence. The variations in the glabella are very
marked, and are as great as those which in higher forms attain some importance as
family characteristics.
So far as known, all the larval forms in the other families of the Opisthoparia
agree in having the narrow marginal free
cheeks, bearing the genal angles. The
eye-line is present in most of the adult
Olenidae, and in the early stages of all so
far as known, so that the general average
of characters in the Conocoryphidae re-
presents the main larval features through-
out the other families.
Conocoryphe Corda (Figs. 1364, B ;
1365, 1366). The glabella is convex,
tapering toward the front. Anterior
border of cephalon marked by a broad
and deep furrow. Cambrian ; Europe and
North America.
Gtenocephalus Corda. Similar to Cono-
coryphe, but with a lobe in front of the
glabella. Cambrian ; Europe and North
America.
Fig. 13GG.
Ceplialonof C'oiio-
coryphe sulzeri
Schlotheim.
Fio. 1365.
Conocoryphe sulzeri Schloth.
Without the free cheeks. Cam-
-r-, /T-i. -.^y^. A -.«^w^ briaii (Etage C) ; Giiietz,
^ioj9S Emmons (Figs. 1364, .4; 1367). Buhemia. i/i-
Glabella long, and does not taper. Thorax
of seventeen segments. Pygidium small. Lower Cambrian ; North America.
Fig. 1367.
Cephalon oiAto^s
trilineatus Em-
mons.
Family 2. Mesonacidae Walcott (Olenellidae Moberg).
Opisthoparia with large cephalon and small, simple pygidium. Facial sutures in
a state of sijmphysis and usually not to be distinguished. Eyes large, the palpebral lobes
extending to the glabella. Glabella narrow, sometimes tapering toward the front.
Thorax of numerous segments {thirteen to tioenty-seven). Lower Cambrian.
This family is considered by Walcott to have developed in pre-Cambrian time from some
annelid-like ancestor by the gradual combination of segments to form the cephalon and
pygidium. A compact, strong pygidium, made up of many segments, does not occur in this
family, nor among any of the simplest forms of Lower Cambrian Trilobites. The Middle
714
ARTHROPODA
PHYLUM VII
Cambrian Paradoxides is thought to have been descended from Callavia, through Holmia
and Wanneria.
Mesonacis Walcott. Tliorax long and tapering, the third segment enlarged, and
the pleura extended as long spines. The fifteenth segment has a large spine on the
axial lobe. Ten segments behind the great spine.
Europe and North America.
Ellvptocephala Emmons. Like Mesonacis, but
without the enlarged third segment, and with long
spines on the axial lobes of the last five segments.
Eastern North America. E. asaphoides Emmons.
Paedeumias Walcott. Like Mesonacis, but
with rudimentary thoracic segments and pygidium
posterior to the fifteenth segment. North America.
Olenellus Hall. Like Mesonacis, but without
segments liack of the fifteenth, the great spine of
which is usually considered as a pygidium.
Europe and North America.
Olenelloides Peach. Adult is essentially like a
larval form of Olenellus, as indicated by the large
cephalon and narrow thorax. Europe.
Holmia Matthew (Fig. 1368). Thorax with
sixteen segments, the pleura of which end in
rounded spines. Europe and America.
Wanneria Walcott. Similar to Holmia, but
with l^roader spines on the pleura of the thoracic
segments, and with a spine on the fifteenth seg-
ment. North America.
Callavia Matthew. Similar to Holmia, but
with narrower glabella, and broader spines on the
pleura of the thoracic segments. Europe and
North America.
Peachella Walcott. Cephalon with blunt, tumid
genal spines ; elongate, narrow glabella ; small eyes
and marked convexity. Eastern Nevada.
Family 3. P aradoxidae Emmrich.
Opisthoimria loith large cephalon, small free cheeks,
long narroiv eyes, the palpebral lobes not reaching
the glabella in the adult. Thorax long, with numer-
ous segments {seventeen to twenty-
three). Pygidium small and
simple. Cambrian.
Holmia Vjenilfi Linuarson. Cambrian ;
Ringsaker, Norway. Left half of glabella
removed, exposing hypostoma beneath, s/^
(after Holm).
Paradoxides Brongniart (Figs.
1369, 1370). Glabella enlarging
toAvard the front. Middle Cam-
brian ; Europe, Eastern North
America and Australia.
Fio. 1370.
Family 4. Olenidae Bunneister. Paradoxides (cf.
„ ,„„, young of P. r«:/?af"x
Ornsthoparia xoith short and Corda.) = Hydr,,-
Paradoxides hohemicus Barr. Cam- . ■, , , ,, -,• cevhalus cami'< Barr.
l)rian (Etagc C) ; Ginetz, Bohemia, i/a- '"'*'*^ cephalon, small pygidtum, Cambrian ; Bohemia.
SUBCLASS I
TRILOBITA
715
small free cheeks, and narrovj glabella. Eye-lines present, eyes small. Tliorax of from
twelve to twenty-two segments. Cambrian and Ordovician.
Olenus Da]man (Figs. 1364, I) ; 1371). Glabella only moderately convex, rounded
in front. Upjier Cambrian and Ordovician ; Enrojae.
Eurycare Angelin (Fig. 1372). Ceplialon very sbort and wide, eyes far a^iart.
Genal spines long and incurved. Cambrian ; EiU'oi^e.
Fig. 1374.
Pi«-1371. Fio.1372. Fio.lSTS. A^dacoplcurakonincU
Olcnnstruneatus Briinn. Eurycare hrevicmidn Any:. Sao hirsuta (Barr). Barr. Silurian (Etage
Cambrian ; Andraruni, Cambrian ; Andrarum, Sweden Cambrian (Etage C) ; D) ; Knclielberg, near
Sweden (after Angelin). (after Angelin). Skrey, Bohemia. Prague. Bohemia.
Peltura Milne Edwards. Glabella wide, extending nearly to the front of the
cephalon. Eyes small, close to tbe front of the glabella. Pygidium small, with short
spines. Upper Cambrian ; Europe and North America.
Ptychoparia Corda (Figs. 1348, 1364, G). Glabella convex and narrow, short,
furrowed. Pygidium large. Cambrian ; Europe, Asia and North America,
Sao Barrande (Figs. 1349, 1354, 1355, 1373).
Glabella strongly convex. Thorax of seventeen seg-
ments. Pygidium very small. Surface granulose.
Cambrian ; Bohemia.
Euloma Angelin. Glabella convex, short, with
prominent side lobes, similar to those of Calymene.
Pygidium short and wide. Ordovician ; Europe.
Aulacopleura Corda {Arethusina Barrande) (Fig.
1374). Glabella short, small, with basal lobes. Thorax
of twenty-two segments. Pygidium small. Silurian ;
Bohemia.
Triarthrus Green (Figs. 1342, 1344-1345, 1350,
137^). Lacks eye-lines. Glabella low and broad. The
facial sutures cut the genal angles. This genus is note-
worthy on account of the wealth of information that has
been gained concerning the appendages, antennae and
other parts in wonderfully preserved remains. Ordovi-
cian ; Euroj)e and America,.
Bathynotus Hall. Eyes long and narrow. Axial
lobe wide. Thorax of thirteen segments. Lower Cam-
brian ; America.
Family 5. Solenopleuridae
Angelin.
Fig. 1375.
Triarthr'iis hecki Green. Ordo-
vician ; Rome, Xew York. Specimen
showing antennae and legs. 8/2
(after Beecher).
Opistlioparia with free cheeks small and widely
separated in front, glabella short, convex, tapering toward the front, eyes small.
Pygidium short, of few segments. Cambrian and Ordovician.
716
ARTHEOPODA
PHYLUM VII
Solenopleura Angelin. Eye-lines present. Cambrian ; Europe, Asia, and North
America.
Hystricurus Raymond. Eye-lines absent. Ordovician ; North America.
;v^:«-.'y-''^u
Vk.. lliTO.
Neolenus serratus (Roiuingei). Burgess shale (Middle Cambrian) ; Burgess Pass, British Columbia,
portion of an individual showing thoracic legs and caudal rami, x 3/j (after Walcott).
Posterior
Fig. 1377.
Neolenua serratus (Rominger). Burgess shale (Middle Cam-
brian) ; British Columbia. Group of thoracic and abdonnnal
legs, showing basal joint or coxopodite, and six-jointed leg
with three terminal claws, x Vl (=ifter WalcottV
Family 6. Oryctocephalidae
Beecher.
Opisthoparia with large cephalon
and smaller 2Jygidium, 2J(ilpebral lobes
long and connected with the glabella.
Pygidium of six to nine segments,
lohich end in spines. Cambrian.
Oryctocephabis Walcott. Glabellar
furrows represented by deep pits wliicL.
■ire connected across the top of the
glabella by shallow fixrrows. Middle
Cambrian ; North America and Asia.
Zacanthoides Walcott. Glabellar
furrows not deep, intergenal spines
present, thorax spinose. Middle
Cambrian ; North America.
Olenoides Meek. Pygidium larger
and with shorter spines, and eyes
smaller than in Zacanthoides. Cam-
brian ; America.
Neolenus Matthew (Figs. 1343,
1376, 1377). Like Olenoides, but
the furrow on each pleuron of the
thorax is diagonal instead of being
straight. Cambrian ; America.
SUBCLASS I
TRILOBITA
17
Family 7. Ceratopygidae Raymond.
Opisthoparia with sub-equal cephalon and pygidium, long, nearly amooth glabella.
Pygidium with long spines at the sides. Cambrian and Ordovician.
Geratopyge Corda. Glabella long, narrow, with, basal lobes. Pygidium with long
splines sjiringing from the pleural lobes at the second annulation. Basal Ordovician ;
Europe and North America.
Habella with
Pig. 137'. ».
FAlipsocephalun h.offi
Scliloth. Cambrian
(Etage C) ; Ginetz,
Boliemia.
Albertella Walcott (Fig. 1378). Eyes long,
three pairs of furrows. Pleura of third segment of thorax
■ extended into spines. Cambrian ; North America and Asia.
Family 8. Ellipsoce-
phalidae Matthew.
Opisthoparia with
narrow free cheeks, small
eyes, smooth, unfurrov)ed
glabella, twelve to sixteen
thoracic segments, and small
pygidiuvi. Cambrian.
Ellipsocephalus Zenker
(Fig. 1379). Dorsal fur-
rows of the cephalon deep,
cheeks are very narrow.
Cephalon with a narrow,
raised border. Cambrian ;
Europe and North
America.
Agraulos Corda.
Glabella faintly outlined,
cephalon without concave
or rimmed border. Cam-
brian; Europe and
America.
Stremiella Matthew,
cephalon. Lower Cambrian ; America.
Family 9. Remopleuridae Corda.
Opisthoparia with large, faintly furrowed glabella, which has a tongue-like anterior
projection. Eyes very large, extending nearly around the glabella. Thorax of eleven to
thirteen segments. Pygidium small. Ordovician.
Bemopleurides Portlock. Pygidium wider than long, with two j^airs of short
spines. Ordovician ; Europe and America.
Gaphyra Barrande (Fig. 1380). Pygidium long and flat. Genal spines and
pleura of thorax flattened. Ordovician ; Europe and North America.
Fig. 137S.
Alhertdla hdcnae Walcott. Lower Cambrian :
Powell County, Montana (after Walcott).
Fig. 1380.
CapTiyra radians
Barr. Ordovician
( Etage D) ; Konigsliof,
Boliemia. Vi (after
Barrande).
Similar to Agraulos, but with a narrow rim around the
Family 10. Bathyuridae Walcott.
Opisthoparia with cephalon and pygidium usually nearly equal in size. Glabella
long, cylindrical, reaching nearly to the anterior margin. Eyes large and close to the
glabella. TJiorax of nine segments. Pygidium more or less strongly ribbed. Middle
Cambrian to Ordovician.
718
ARTHROPODA
PHYLUM VII
Bathyurus Billings (Fig. 1381).
Glabellar furrows faint or absent. Pygidiuui
with four pairs of smooth ribs, and a long, pro-
minent axial lobe. Ordovician ; North America,
including Beekmantown beds of Newfoundland.
Petigurus Raymond. Cephalon like Bath-
yurus. Pygidium with nodose ribs and strongly
annulated axial lobe. Ordovician ; Canada and
Ireland.
Bathyuriscus Meek. Glabellar furrows
deeper, eyes further forward, and pygidium
larger than in Bathyurus. Middle Cambrian ;
North America and Asia.
Bathyurellus Billings. Glabella low, smooth,
pointed in front. Cephalon and pygidium
with broad concave borders. Ordovician ; North
America.
Asaphidae Burmeister.
Family 11.
Ofisthoparia with large., sub -equal haul and
Fig. 13S1. abdomen shields, inominent eyes, eight segments in
Bnthyurnsiunfiispinus Waicoti. Black River the thorax, and toith a median vertical suture in
KoS"^ ' ^'''^'°'^' ^•^'- "" ''' ^*^"" the doublure of the cephalon. Middle Cambrian
to Ordovician.
Facial suture
Subfamily A. Ogygiocarinae Raymond.
Asaphidae with hijpostoma rounded or pointed behind.
Ogygiocaris Angelin {Ogygia auct. non Brong.) (Fig. 1339). Pygidium with flat,
furrowed ribs. Axial lobe very narrow,
marginal in front of
glabella. Ordovician ;
Eiu'ope.
Ogygopsis Wal-
cott (Fig. 1382).
Similar to Ogygio-
caris, but with eye-
lines, and eyes small
and far apart. Middle
Camljrian ; British
Columbia.
Mega laspis Ange-
lin (Fig. 13 83).
Glabella short,
cephalon and pygi-
dium nearly smooth
and sometimes
pointed. The facial
sutures meet in a
point far forwaid of
the glabella. Ordovi-
cian ; Europe, Asia,
and rarely North
America.
■^
S^'
Fig. 1382. i
OgygupsiSjldotzi (Rotiiiiigcr). Miilille Cam-
brian ; Mount Stepliuu, British Cohinibia.
i/i (after Walcott).
Megalaspis extenuata Aug. Ordo-
viciau ; ijast Gotlaiidj Sweden,
i/i (after Angelin).
SUBCLASS
TEILOBITA
719
Asaphellus Callaway. Similar to Megalaspis, but with longer and flatter glabella,
and shorter shields. Tremadoc ; Europe. Lower Ordovician ; North America.
Hemigyraspis Raymond. Similar to Asaphellus, but with facial suture marginal
in front. Tremadoc ; Europe. Lower Ordovician ; North America.
Sympliysurus Goldfuss. Cephalon and pygidium short, sub-hemispherical, without
concave border. Axial lobe narrow. Lower Ordovician ; Europe and America.
Nileus Dalman. Similar to Symphysurus, but with broad axial lobe and very
large eyes. Ordovician ; Europe and North America.
Subfamily B. Asaphinae Raymond.
Asaiihidae ivith hypostoma bifurcated.
AsaphiijS Brongniart (Figs. 1364, E ; 1384). Cephalon and pygidium short and
(^%
Fig. 13S4.
Asaphus expansus (Linn.). Ordovician ; Pulkowa, near St. Petersburg, Russia, i/i (after .Salter).
wide, glabella prominent, expanding forward, and reaching
the anterior margin, which is without concave border.
Axial lobe of i:)ygidium ringed, pleural lobes smooth.
Ordovician ; Europe and Asia.
Onchometopiis Schmidt. Similar to Asaphus, but the
glabella only obscurely defined, axial lobe rather wide, and
pygidium smooth. Ordovician; Europe and North America.
Basilicus Salter. Pygidium strongly ribbed, glabella
convex, prominent, facial suture marginal in front. Ordo-
vician ; Europe and North America.
Ogygites Tromelin and Lebesconte {Ogygia Brongniart)
(Fig. 1385). Similar to Basilicus, but glabella less pro-
minent, and sutures meeting in a point in front of glabella.
Ordovician ; Europe and North America.
PtAjchopyge Angelin. Glabella short, facial sutures well
inside the margin, pygidium not ribbed, concave borders
wide, and doublure very broad. Ordovician ; Europe.
Isotelus Dekay. Cejihalon and pygidium smooth, with
wide depressed borders. Axial lobe of thorax wide. Ordo-
vician ; rare in Europe, abundant in North America.
Family 12. Illaenidae Corda.
, Opisthoparia with large, convex cephalic and abdominal
shields which are nearly smooth and without concave border.
Epistomal plate large, hypostoma convex, ovoid. TJiorax of
eight to ten segments, tuith smooth pleura. Pygidium smooth,
with short axial lobe. Ordovician and Silurian.
Illaenus Dalman (Figs. 1364, F ; 1386). Axial lobe
Fio. 13S5.
Oyygites guettardi (Brong.).
Ordovician ; Angers, France.
Mechanically deformed indi-
vidual (after Brongniart).
720
ARTHROPODA
PHYLUM VII
about one-tliird the total width. Ordovician and Silurian ; Europe, Asia and North
America.
A B "" ^
1380.
A, lllacnus dalmani Volb. Ordovician ; Pulkowa, near
St. Petersburg, Russia. B, C, I. crassicauda Dalman.
Ordovician ; Dalekarlien, Sweden (after Holm).
Bumastus Murchison. Axial lobe very wide ; cephalon
and pygidium smooth. Ordovician and Silurian ; Europe
and Nortli America.
Thaleops Conrad. Glaljella rather well defined ;^eyes nikeioccphaius winvesotenns
small and elevated. Ordovician and Silurian; North Owen. Upper Cambrian ;^Wiscon-
America.
Fig. 13S7.
sin. A, Cranidiuui.
(after Hall).
B, Pygidium
Family 13. Dikelocephalidae Miller.
Opisthoparia loith large cephalon and pygidium, glabella marked by faint furroivs
which extend across it. Eyes large. Pygidium with short axial lobe, and usually a
pair of flat spines. Upj)er Cambrian and Lower Ordovician.
Dikelocephalus Owen (Fig. 1387). Spines on pygidium far apart, short and
broad. Complete specimens are known of D. lodensis and D. crassimarginatus.
Upper Cambrian ; North America.
Dikelocephalina Brogger. Spines close together at the posterior end of pygidium.
Lower Ordovician ; Europe.
Family 14. Goldildae Raymond (Bronteidae Angelin^).
Opisthoparia with eyes close to the glabella and to the posterior margin of the
cephalon. Glabella muck expanded toward the front. Thorax with ten segments.
Pygidium larger than the cephalon, with short axial lobe. Ordovician to Devonian.
Goldius de Koninck {Brontes Goldfuss) (Figs. 1340, 1364, H; 1388). Pygidium
with radiating ribs extending from the end
of the axial lobe to the margin. Ordovician
to Devonian ; Europe and America.
Thysanopeltis Corda. Like Goldius, but
with small spines along the jiosterior margin
of the pygidium. Devonian ; Europe and
North America.
Bronteopsis Nicholson and Etheridge.
Cephalon like Goldius ; pygidium with
longer axial lobe, behind which is a longi-
tudinal ridge. The ribs on the pleural lobes do not radiate from a centre as in
Goldius, and they die out before reachiug the margin. Ordovician ; Europe.
1 The family name " Bronteidae " cannot be retained, as de Kouinck's term Goldius has
priority over Bronteus Goldfuss, a term which was substituted for Brontes of the same author on
finding that the latter appellation was preoccupied.
Fiii. 13S8.
Goldius palifer (Beyr.). Cephalon. Devonian
(Et. F) ; Konieprus, Bohemia (after Barrande). ; t
SUBCLASS I
TEILOBITA
721
Family 15. Proetidae Corda.
Small Opistho'paria ivith cephalon and pygidium nearly equal, free cheeks large, eyes
long, and close to the glabella. Thorax with eight to ten segments. Ordovician to
Permian.
Proetus Steininger (Figs. 1351, 1364, G ; 1389)
furrows. Pygidium smaller than cephalon.
Ordovician to Carboniferous ; Europe,
Asia and America.
Gyphaspis Burmeister. Similar to
Proetus, but with a strongly elevated
ridge which surrounds the glabella out-
side the dorsal furrows. Glabella with
prominent basal lobes. Ordovician to
Devonian ; Europe and America.
Haploconus Eaymond. Similar to
Gijphaspis, but without the basal lobes on
the glabella. Type, Bathyurus smithi
Billings. Ordovician ; North America.
Phillipsia Portlock (Fig. 1390).
Similar to Proetus, but with large pygi-
dium, and basal lobes on glabella
Glabella witliout deep lateral
Fk;. 1390.
Fig. 1389.
rroetus , bohemims Corila.
This Silurian (Et. E) ; Konieprus,
. -1 1 • Bohemia (after Barrande).
genus survived all other trilobites, but
became extinct with the close of the Permian. Carboniferous and Permian ;
Europe and America.
PhiUipsin gernmulifera
Phill. Lower Carboni-
ferous ; Kildare, Ire-
land.
Aeglina Barrande (Fig. 1391).
A l: ( •
Family 16. Aeglinidae Pictet.
Opisthoparia with large glabella and. eyes which occupy nearly the whole area of the
free cheeks.
This genus has the glabella strongly convex,
prominent, smooth ; fixed cheeks suppressed ;
eyes very large ; thoracic segments five or six ;
pleura grooved ; pygidium large, with short axis.
Ordovician ; Europe.
Family 17. Lichadidae Corda.
Opisthoparia with large cephalon and pygi-
dium, the glabella greatly modified by the peculiar
development of the lateral furrows. Thorax with
nine or ten segments. Pygidium with short
axial lobe, and the pleural lobes modified in
various ivays. Ordovician to Devonian.
Fig. 1301.
Aeglina iiHaca Barr. Ordovician (Etage D) ;
Vosek, Bohemia. A, Nat. size. B, C, enlarged
(after Barrande).
Lichas Dalman (Figs. 1364, /; 1392).
The glabella is broad, with axial furrows which
do not reach the neck furrow. Occipital lobes are present. Pygidium flat, with
the pleural lobes divided by furrows into two pairs of lobes with short free ends, and
a median flattened lobe. Ordovician and Silurian ; Europe and America.
Amphilichas Raymond {Platymetopus Schmidt). Glabella large, divided longi-
tudinally into three lobes by a pair of axial furrows which join the neck ring.
Ordovician ; Europe and America.
Gonjdocephalus Corda (Figs. 1338, A; 1393). Glabella with three pairs of side lobes,
VOL. I 3 A
722
ARTHROPODA
PHYLUM VII
the central lobe narrow.
Pio. 1392.
Lichas laciniatiis Wahlb.
Silurian ; Sweden (after
Angeliii).
Corydocephalus
Hall and Clarke.
New York.
ptyonurun
Silurian ;
Pygidium small, the pleural lobes crossed by two narrow,
prominent ribs which end in spines.
Ordovician and Silurian ; Europe
and North America.
HoplolicJias Dames (Fig. 1394).
Cephalon trilobed, the central lobe
produced in front, and not depressed
at the back as in Gonolichas. Occipital
lobes present. Ordovician to De-
vonian ; Europe.
Geratarges Giirich (Fig. 1395).
Glabella with two curved spines in
front, and pygidium with numerous
spines. Devonian ; Europe.
Geratolichas Hall and Clarke
(Fig. 1396). Cephalon with two
pairs of long, curved spines on the
axial portion. Devonian ; North
America.
Terataspis Hall. Glabella bulbous,
strongly pustulose. Devonian ; North
America.
Fig. 1395.
Ceratarges armatus
(Goldfuss). Devonian ;
Germany (after Beyrich).
Fig. 1394
Hoploliclias schmidti Dames.
Ordovician ; Germany (after
Dames).
Fig. 1396.
Family 18. Odontopleuridae
Burmeister.
Geratolichas gryps Hall
and Clarke. Devonian ; New
York (after Hall and Clarke).
twelve segments. Pygidium small.
Ordovician to Devonian.
Opisnioparia with large free
cheeks, small eyes. Thorax of eight to
All parts of the crust are usually very spinose.
In this family, as well as in the Lichadidae, is to
be found the highest expression of differentiation and
specialisation among the Opisthoparia. The primitive
pentamerous lobation of the axis of the cranidium is
entirely obscured, and is only clearly seen in the pro-
taspis and early nepionic stages. These two families
are very closely related, the chief differences being
noted in the size and character of the pygidium, and
the ribbed or grooved pleura. The Lichades are
generally much larger and flatter, but the smaller and
spinose forms of Geratarges and Geratolichas approach
quite near some of the Acidaspidae.
Odontopleura Emmrich. Occipital ring smooth or
with a median tubercle. Ordovician and Silurian ;
EurojDe and America.
Ascidaspis Murchison (Figs. 1352, 1364, J).
Occipital ring with a single median spine. Ordovician
and Silurian ; Europe and America.
Geratocephala Warder (Fig. 1397). Occipital ring
with two long, nearly straight, divergent sj)ines.
Ordovician and Silurian ; Europe and North America.
Dicranurus Conrad. Occipital ring with two long spirally recurved
Devonian ; Europe and North America.
Fig. 1397.
Ceratopephala dufrenoyi (Barr.). Sil-
urian (Etage E) ; St. Ivan, BoJiemia
(after Barrande).
spines
SUBCLASS I
TRILOBITA
723
Ancryopyge Clarke. Margin of pygidium with twelve very long, slender, curved
spines. Devonian ; North America.
SelenopelUs Corda. Thorax with very long spines extending from the pleura ;
pygidium aspinose. Ordovician ; Europe.
Glaphurus Eaymond. Thorax with twelve segments. Pygidium very small and
aspinose. Ordovician ; North America.
Order 3. PROPARIA Beecher.
Free cheeks not hearing the genal angles. Facial sutures extending from the lateral
margins of the cephalon in front of the genal angles, inward and forward, cutting the
anterior margin separately, or smiting in front of the glabella. Compound paired eyes
scarcely developed or sometimes absent in the most primitive family ; ^vell developed and
schizochroal in the highest family.
This is the only order of Trilobites which apparently begins during the known
Paleozoic, and unlike the other orders, had no pre-Cambrian existence. The earliest
Fig. 1398.
Cephala of the Proparia. A, Placoparia. B, Enerinurus. C, Calymem. D, Dipleura. E, Cheirnrm.
F, Dalmanitina. G, Dalmanites. H, Chasmop,'<. I, Phacopidella. J, Phncops (after Beecher).
forms of Proparia were initiated at the close of the Cambrian and dawn of the
Ordovician. The greatest generic differentiation of the group was early attained ;
during the Silurian and Devonian a rapid decline ensued, and only one or two
genera survived into the beginning of the Carboniferous.
Among the Opisthoparia, it seems clear that the Conocoryphidae formed the
natural base or most primitive family in the order, and is distinguished by the
narrow marginal free cheeks and absence of well-developed eyes. It is of great
interest and importance to be able to note that under the Proparia there is a similar
primitive family having characters in common with the other, but still clearly
belonging to the higher order. Placoparia, Areia and Dindymene constitute a group
of apparently blind Trilobites with narrow marginal free cheeks, and present in
general the appearance of Atops, Conocoryphe, Gtenocephalus, and other members of the
Conocoryphidae.
Family 1. Encrinuridae Angelin.
Proparia with narrow free cheeks; either blind, or with small eyes. Pygidium
composed of many segments, the pleural ribs usually less in number than the rings on the
axial lobe, and usually ending in spines. Ordovician and Silurian.
Encrinurus Emmrich {Cromus Barrande) (Figs. 1338, B, G ; 1398, B ; 1399, 1400).
Cephalon tuberculated, glabella prominent, free cheeks separated in front by a small
724
AETHROPODA
PHYLUM VII
epistomal plate ; eyes small, elevated on conical prominences ; thoracic segments
eleven : pygidium elongate, triangular. Ordo-
vician and Silurian ; Europe, Asia, and America.
Gybcle Loven. Similar to Encrinurus, but
with the ribs of the pygidium turning back
sliarply, parallel to the axis. Ordovician and
Silurian ; Euroiie and America.
Encrinurus punc
tatus Emmrieh. Sil
urian ; Gotland.
Calymenidae Milne Edwards.
Fig. 1400.
Fig 13'^t9
Encrinnrus hohemicns
(Barrande). Silurian tti -i o
(Etage E) : Loehkow, l^amily 2.
Bohemia. ...
Propana with thirteen segments, the hypo-
stonm notched hehind, and attached to an epistomal plate. Free cheeks narrow, the
facial sutures cutting the
margin almost exactly:\in
the genal angles. Ordovician
to Devonian.
Calymene Brongniart
(Figs. 1398, G; 1401).
Glabella prominent, strongly
lobed, with two or three
pairs of lateral furrows.
Ordovician to Devonian ;
Europe, Asia and America.
Pharostoma Corda.
Glabella prominent, very narrow at the front, with
two pairs of glabellar furrows. Long genal spines
present. Ordovician ; Europe.
Homalonotus Koenig. Axial lobe wide, cephalon
short and trilobate in front, cheeks forming high
mounds crowned by the eyes. Silurian ; Europe
and Nova Scotia.
Trimerus Green (Fig. 1402). Cephalon longer
than in the preceding, not trilobate in front, free
cheeks narrow. Silurian and Devonian ; woild-wide
distribution.
Dipleura Green (Fig. 1398, D). Axial lobe wide.
Pygidium smooth. Devonian ; Europe and America.
Fig. 1401.
Calymene meeki Foerste.
Ordovician ; Cincinnati, Ohio.
Family 3. Oheiruridae Salter.
Fig. 1402.
Trimerus clelphiitocephalus Grfien.
Silurian ; Lockport, New York.
Proparia with small free cheeks, whose anterior ends
are separated by the glabella. Pygiditim small with
pleura ending in spines. Thorax with nine to eighteen segments. Ordovician to Devonian.
Subfamily A. Cheirurinae Raymond.
Oheiruridae with eleven segments in the thorax {rarely nine to thirteen), and four
segments in the pygidium.
Cheirurus Beyrich (Figs. 1398, E ; 1403). Glabella smooth, more than one-third
the total width of the ceplialon ; pygidium with six or seven sub-equal spines.
Ordovician and Silurian ; Europe, Australia and America.
Geraurus Green (Fig. 1341). Glabella pustulose, one-third or less the total width
of the cephalon ; pygidium very small, with the first pair of sj^ines very long, the
others short or absent. Ordovician ; Eurojje, Asia, and America.
SUBCLASS I
TRILOBITA
725
Grotalocephalns Salter. Similar to Cheirurus but with furrows extending all
across the glabella. Silurian and Devonian ; Europe.
Sphaerexochus Beyrich. (Fig. 1404). Glabella globular, cheeks small. Ordovician
and Silurian ; Europe and America.
Pseudos2)haerexochus Schmidt.
Glabella tumid, tapering forward.
Pygidium with subequal spines.
Ordovician ; Europe and America.
Nieszkoivskia Schmidt. Glabella
tumid or prolonged into a spine
behind. Pygidium with two pairs of
spines. Ordovician ; Eurojje and
America.
Fifi. 1403.
Cheirurus insi(jnis Beyr. Sil-
urian (Etage E); Kozolup, Bo-
hemia. Vl (after Barrande).
Fio. 1404.
Sphaerexochus mirus
Beyrich. Silurian;
Listice, Bolieiiiia. x l/i
(after Barrande).
Fig. 1405.
Cephalon of Pliomera fischeri
(Eichvvald). Ordovician ; Pulkowa,
Russia.
Subfamily B. Pliomerinae Raymond.
Gheiruridae loith fifteen to nineteen segments in the thorax; jyygidium hemisphericy
ivith five flat segments.
Pliomera Angelin (Amphion Pander) (Fig. 1405). Glabella expanding forward,
with two small median lobes on the front. Border of the cephalon denticulate.
Ordovician ; Europe.
Pliomerops Raymond. Similar to Pliomera, but the glabella has parallel sides,
and lacks the two small lobes at the front. Ordovician ; Europe and America.
Placoparia Corda (Fig. 1398, A). Free cheeks are narrow; eyes absent.
Ordovician ; Europe.
Subfamily C. Deiphoninae Raymond.
Gheiruridae mth a part of the glabella bulbous.
Beiphon Barrande. (Fig. 1406). Glabella globular,
without lateral furrows. Free cheeks minute. Silurian ;
Europe and North America.
Staurocephalus Barrande. Glabella with two pairs
of glabellar lobes behind the bulbous portion. Cephalon
with a denticulate border, and pygidium similar to that
of Pliomera. Silurian ; Europe and North America.
Sphaerocoryphe Angelin. Glabella with one pair of
lobes behind the bulbous portion. Ordovician and
Silurian ; Europe and North America.
Fig. 1406.
Deiphon forhesi Barr.
(Etage E) ; St. Iwan,
(after Bariande).
Silurian
Bohemia
tcith large facets, schizochroal.
Family 4. Phacopidae Corda.
Proparia with rather large free checks, eyes large,
Thorax with eleven segments. Ordovician to Devonian.
726
AETHROPODA
PHYLUM VII
Subfamily A. Ualmanitinae Reed.
Phacopidae with more or less modified pentamcrous segmentation of the glabella, and
usually ivith large cranidia and fijgidia.
Dalmanitina Reed (Figs. 1353; 1356;
1398, i'^; 1407). Pentamerism of head well
marked, lobes of glabella distinct ; genal angles
rounded or with short spines. Pygidium
with few segments, rarely more than ten.
Ordovician and
Silurian ; Europe.
Dalmanites Bar-
rande (Figs. 1337 ;
1398, G; 1408).'
Frontal lobe of gla-
bella detached. Pygi-
dium strongly mucro-
nate, with twelve to
Devonian ; Europe and
. Fig. U07.
Dalmanitina xodaUs (Bair.). Ordovician (Etage
D) ; Wesela, near Prague, Bohemia. Cephalon, i/]
sixteen segments. Silurian and
America.
Asteropyge Corda (Gryphaeus Green). Pygidium with five
pairs of marginal spines, and sometimes a terminal spine.
Devonian ; Europe and America.
Proholium ffihlert. Cephalon with a snout-like anterior
prolongation. Devonian ; Europe and America.
Subfamily B. Phacopinae Reed.
Fig. 1408.
Phacopidae loith qlahallar furrows nearly or quite obsolete, . , . ,
. -'. 7, 7 7 7 -'J- Dalmanites limulurus
and pygidium small and rounded. (Green). Silurian ; Lockport,
New York (after Hall).
Phacopidella Reed {Acaste Goldfuss) (Figs. 1398, J; 1409).
Glabella with three pairs of ,^^5?^^^ faintly defined
Ordovician and Silurian ; /!(F^-'''''^^™|k Europe.
Phacops Emmrich (Figs. ^fe^/W
furrows, except occasionally ^^^'^'^..^^^M the last pair, obsolete. Silurian
and Devonian ; world - wide te=^?^^3^?=^ distribution.
lateral furrows.
Fio. 1409.
Phacopidella downin giae
(Murch.). Silurian ; Lud-
low, England (after Salter).
Fio. 1410.,
Phacops latifrons
Bronn. Devonian ;
Gerolstein, Eifel
District, Germany.
Fig. 1411.
Phacops stcrnhergi Barr.
Devonian (Etage G) ; Hostin.
Bohemia (after Barrande).
Trimerocephalus M'Coy. Eyes small and far forward. Devonian ; Europe.
SUBCLASS I TRILOBITA '727
Subfamily C. Pterygometopinae Reed.
Rather small Phacopidae, the cephalon with more or less modified pentamerous
lobation, and the pygidiuvi less triangular and with fewer seg-
ments than in most of the Dalmanitinae.
Pterygometopus Schmidt (Fig. 1412). Glabella with three
pairs of lateral furrows. Ordovician ; Europe and North
America.
Ghasmops M'Coy (Fig. 1398, H). Second pair of glabellar
lobes absent, or represented by tubercles. Ordovician; Europe. (j)l\m!)T'^'^ oi\\oy\cf^n\
Monoraicos Schmidt. Second and third pairs of glabellar iswos, Esthonia (after
furrows represented by pits. Ordovician ; Europe.
Fir,. 1412.
Schmidt).
Geological Range and Distribution of Trilobites.
Trilobites are the only large division of the Arthropoda which has become extinct.
Even in the earliest Cambrian they bear evidence of great antiquity, — in their
diversified form, larval modifications, polymerous head and caudal shields. These
features show that Trilobite phylogeny must extend far back into pre-Cambrian
times, and it is probable that primitive Branchiopods, of a type corresponding to the
modern Apus, were developed even earlier. The views of Bernard and Walcott
regarding the origin of Trilobites and higher Crustacea from a primitive Apus-lika
ancestral stock are mentioned a few pages farther on under the head of Branchiopoda.
Concerning the habits of Cambrian Trilobites Dr. Walcott has suggested that the
adult animals probably crawled about the sea-bottom and did not swim freely in the
water to the extent that it would be necessary to see the bottom. Their habits must
have been very much like those of Limulus when in search of food. That the
creatures burrowed and pushed their way through the mud and soft sands is proven
by the trails and burrows made by them, some of which we now designate as
Protichnites.
The maximum development of Trilobites occurred in the Cambrian and Ordovician,
after which they steadily waned both in niunbers and variety. The genera of the
Conocoryphidae, Eodiscidae, Mesonacidae, Paradoxidae, Oryctocephalidae and Ellipso-
cephalidae, are wholly restricted to the Cambrian, and here also are found nearly all
the Olenidae and Agnostidae, only scattering representatives of which survive into
the Ordovician. The Asaphidae are more characteristic of the Ordovician, and the
Cryptolithidae, Shumardiidae, Remopleuridae, Bathyuridae and Aeglinidae are
restricted to it. The Raphiophoridae, Goldiidae, Harpedidae, Encrinuridae, and
Illaenidae flourished in the Ordovician and Silurian, while the Proetidae, Lichadidae,
Odontopleuridae and Phacopidae attained their greatest development in the Silurian
and Lower and Middle Devonian.
The later Devonian witnesses a decline in the number of families present, and with
the close of this era, the class practically became extinct, since only five genera of
one family, the Proetidae, are met with in the Carboniferous, and the single genus
Phillipsia alone persists as late as the Permian.
As regards their geograj^hical distribution, some genera are of cosmopolitan occur-
rence : such as Agnostus, Gonocoryphe, Ptychoparia, Paradoxides, Gryptolithus, lUaenus,
Proetus, Phillipsia, Acidaspis, Lichas, Galymene, Homalonotus, Gheirurus, Phacops,
Dalmanites, and others. The majority of forms, however, are extremely limited in
distribution, so that a large number of genera found in Sweden, Bohemia, England
and North America are unknown outside of certain very restricted areas ; and the
total number of species common to both sides of the Atlantic is very small.
A remarkable contrast is observable between the older Paleozoic Trilobites of the
728
ARTHROPODA
THYLUM VII
northern parts of Europe, and those of the middle and southern portions. While the
majority of northern genera and sjiecies are common to Great Britain, Scandinavia
and Russia, the forms of the central European provinces (Bohemia, Thuringia, Fichtel-
berg, the Hartz, Belgium, Brittany, Northern Spain, Portugal, the Pyrenees, the Alps
and Sardinia) are so dissimilar as to stand in closer relationships with the North
American than with the first-named Trilobite fauna. Of the 350 species found in
Norway and Sweden, and of the 275 species in Bohemia, only six are common to
both provinces, and it is doubtful if these are really identical.
The first of the accompanying taljles shows the range and relative development of
the orders and the subclass ; the second represents the vertical range of the several
families of Trilobites.
TABLE I
Diagram Constructed by Beecher showing Relative Development
OF THE Orders of Trilobites
Permian.
Carboniferous.
Devonian.
Silurian.
Ordovician.
Cambrian.
Pre-Cambrian.
[Table
SUBCLASS I
TRILOBITA
729
Table showing Vertical Range of Trilobites
Orders and Families.
q 3
a
So
1:20
S
'3
5
o
g
in
s
o
o
S
a
3
XI
u
C3
O
0^
Order 1. Hypoparia
Familv 1 Acnostidae
2. Eodiscidae .
3. Shumardiidae
4. Harpedidae
5. Trimicleidae
6. Rapliiophoridae .
Order 2. Opisthoparia
Familv 1. Conofiorvnhidae
2. Mesonacidae
3. Paradoxidae
4. Olenidae
5. SolenopleTiridae .
6. Oryctocephalidae
7. Ceratopygidae
8. Ellipsocephalidae
9. Remopleuridae .
10. Bathyuridae
11. Asaphidae .
12. Illaenidae .
13. Dikelocepbalidae
14. Goldiidae .
15. Proetidae .
16. Aeglinidae .
17. Lichadidae .
18. Odontopleuridae .
_..
i
Order 3. Proparia
Family 1. Encrinuridae ....
2. Calymenidae ....
3. Cheiruridae ....
4. Phacopidae
— .
j
Total Number of Families .
7
9
8
22
11
8
3
1
[The foregoing chapter on Trilobites has been revised by Dr. Percy E. Raymond, of the
Museum of Comparative Zoology at Cambridge, Mass. Some notes on Cambrian genera,
together with two or three figures illustrating the same, have been contributed by Dr. C. D.
Walcott. — Editor.]
730 ARTHROPODA phylum vii
Subclass B. EUCRUSTACEA Kingsley/ (Crustacea proper.)
Crustacea having typically two pairs of antenniform preoral appendages and at
least three pairs of pastoral appendages acting as jaws.
In the Crustacea proper the appendages of the head-region are as follows :
the first and second pairs are preoral and are known respectively as antenmiles
and antennae; the third pair, placed on either side of the mouth, are the
mandibles ; the fourth pair, maxillulae, and fifth pair, maxillae (the two pairs
sometimes known as first and second maxillae), are secondary jaws. The
appendages behind these vary in character, some being walking or swimming
feet, while from one to three pairs may be subsidiary to the maxillae in
feeding, in which case they are called maxillipeds.
Regarding the evolution of the subclass, Bernard has reached the conclusion
'
Strabops ' '
Sidney
Amiella
Aglaspis
Molaria
Emeraldella -
Habelia
H
canchoiha
Yphoia
Nathorstia
••Mauella
Belitna .
/
Waptia
^Naraoia
Bidentia
^Hymenocaris
, Opabinia
Theoretical Evolution of Cambrian Crustacea from the Branchiopoda
(according to Walcott").
that all Eucrustacea are descended from a browsing carnivorous annelid with
its first five segments (head) bent so that its mouth faced ventrally and
posteriorly, and using its parapodia for pushing food into its mouth. The
modern representative of this hypothetical crustacean-annelid, according to
Bernard, is Apus. In the Burgess shale (Middle Cambrian) crustacean
fauna of British Columbia occur certain annelids, like Canadia spinosa Walcott,
which have the head bent down so that the mouth faces posteriorly, and in
1 Literature : Gerstaecker, A. and 0)-tmann, A. E., Crustacea, in Bronn's Klassen und Ordnungen
des Thierreichs, vol. v., 1866-1901.— Ca^maw, IT', T., Crustacea, in Lankester's Treatise on Zoology,
pt. vii., fasc. 3, 1909.
- Walcott, C. D., Middle Cambrian Brauchiopoda, Malacostraca, Trilobita, and Merostomata.
Smithson. Misc. Coll., 1912, vol. Ivii., no. 6.
SUBCLASS II EUCRUSTACEA— BRANCHIOPODA 731
the opinion of their describer may have been derived from the same general
type of animal as the accompanying crustaceans.
The preceding diagram, which is taken from Walcott, illustrates that
author's views as to the relations of Cambrian crustaceans to a theoretical
ancestral stock which for convenience is correlated with ^|ms-like forms.
From this primitive stock it is assumed that the Branchiopoda Avere derived,
and from them three distinct branches were developed prior to, or during,
Cambrian time. According to this view Trilobita are direct descendants of
Branchiopoda, and in turn gave rise to the line leading through the orders
Aglaspina, Limulava and Eurypterida to the Xiphosura. The structure and
probable habits of Trilobites lead Walcott to the opinion that these were
mud-burrowing animals more or less allied to Limulus. The Phyllocarida
and Ostracoda are assumed by the same author to have been derived from
the Branchiopoda, but on different lines of descent from that of the Trilobites
and the orders grouped under the Merostomata.
The Eucrustacea are frequently divided into Eniomostraca and Malacostraca,
but the first of these groups is not a homogeneous assemblage ; it is rather a
repository in which have been placed all forms not members of the Malacostraca.
The Eucrustacea are here divided into the superorders BrancJiiopoda, Ostracoda,
Copepoda, Cirripedia and Malacostraca.
Superorder 1. BRANCHIOPODA Latreille.^
Eucrustacea in which the carapace may form a dorsal shield or a bivalve shell or
may he entirely absent ; the number of body segments and appendages varies greatly ;
the appendages of the body are rarely pediform, generally foliaceous and lohed.
Under the Branchiopods are embraced very differently formed Crustaceans
of large and small size, living mostly in fresh water or salt lakes, and
possessing little else in common than the leaf- like form of leg. The
segmentation of the body in the larger forms is very distinct, but in the
water fleas (Cladocera) it is usually quite incomplete. The number of body-
segments varies considerably among different genera. In the strongly
segmented forms the body is elongated and protected in front by a flat or
shield-shaped dorsal carapace {Apus), or it is naked (Branchipus). In the
Cladocera and Estheriidae, which are enclosed in a bivalve shell, the body is
'■ Literature: A. Recent Forms. -r-G'ra6e ^. , Bemerkungen iiber die Pliyllopoden, etc. Wieg-
laaun's Archiv fiir Naturgescli., 1853-1865, vols, xix., xxi. — Claus, C, Papers on Branchipus
and Apixs, in Abhandl. Gesellsch. Wiss. Giittingen, 1873, vol. xviii., and Arbeit. Zool. Inst. Wien,
1886, vol. vi. — Weismann, F. L. A., Zur Naturgeschiclite der Daphniden. Zeitschr. Wisseusch.
Zool., 1876-80, vols, xxvii., xxxiii. — Lankester, E. R., Several papers on Limulus, Apus, etc.,
in Quart. Journ. Microsc. Soc, 1881, vol. xxi. — Packard, A. S., Monograph of the Phyllopod
Crustacea of North America, 12th Ann. Rept. U.S. Geogr. and Geol. Surv. Terr., 1883.— «S^ars, G. 0.,
Fauna Norvegiae. I. Phyllocarida and Phyllopoda, 1896. — Bernard, H. M., The Apodidae. Nature
series, London, 1892.
B. Fossil Forms. — Jones, T. R., On Fossil Estheriae and their distribution. Quar. Journ.
Geo!. Soc, 1863, vol. xix.— Monograph of the Fossil Estheriae. Palaeontogr. Soc, 1862. — 5th
and 7th Repts. Comm. British Assoc Adv. Sci. on Fossil Pliyllopoda, 1887-89.— Geol. Mag.,
Sept. 1890, Feb. 1891, Dec. 1893, July 1894.— Trans. GeoL Soc Glasgow, 1890, vol. ix.—
Clarke, J. M., New Devonian Phyllopods. Amer. Journ. Sci., 1882, vol. xxiii. — Hall, J., and
Clarke, J. M., Palaeontology of New York, 1888, vol. vii. — Bernard, H. M., Fossil Apodidae.
Nat. Sci., 1897, vol. xi. — Schuchert, C, On the fossil Phyllopod genera Dipeltis and Protocaris.
Proc U.S. Nat. Mus., 1897, vol. xix.— Clarke, J. M., Estheria in Devonian of New York and
Carboniferous of Ohio. Rept. N.Y. State Paleontologist, 1900.— irfewi. Notes on Paleozoic Crus-
taceans. 51th Ann. Rept. N.Y. State Mus., 1902, vol. i.— Walcott, C. D., Middle Cambrian
Branchiopoda, Malacostraca, etc. Smithson Misc. Coll., 1912, vol. Ivii., no. 6.
732
ARTHEOPODA
PHYLUM VII
laterally compressed, shortened, and often indistinctly segmented. The head
is sharply demarcated from the rest of the body, and is usually provided with
two large eyes sometimes coalesced, in addition to which there is often a
a small unpaired eye. The upper lip is very large, the mandibles have no
palps, and the maxillae are reduced or absent.
The body-limbs are usually foliaceous and lobed on the outer and inner
margins. They vary in number from four to more than sixty pairs, and
usually all carry gill-plates. The posterior part of the body is without
limbs and usually ends in a caudal f urea, the rami of which may be filiform,
flattened or claw -like. All Branchiopods have the sexes 'distinct. The
males are often much less numerous than the females, and the latter
reproduce largely by parthenogenesis.
The classification of the Branchiopoda here given differs from that
commonly adopted, in that the term Phyllopoda (Latreille, 1802) is not
employed for an ordinal division including several groups which are dis-
tinguished from the Cladocera chiefly by the greater number of somites and
appendages and by the prevalence of metamorphosis in development. Instead,
these groups of the old division Phyllopoda are more properly assigned the
rank of independent orders, all three being sharply contrasted from one
another as well as from a fourth order, Cladocera. Phyllopods in the old
sense, therefore, are equivalent to the orders Anostraca, Notostraca and
Conchostraca, as here recognised. The substitution of the term Phyllopoda
for Branchiopoda, in the usage of Glaus and some writers following him is
contrary to the rule.^
Order 1. ANOSTRACA Sars.
Head distinct, carapace absent, paired eyes pedunculate; thorax with eleven to
nineteen pairs of trunk -limbs, none post - genital ; f ureal rami
unsegmented, rod-like or flattened.
Branchipodites Woodward. Similar to the Recent Branchi-
pus. Oligocene of Bembridge, Isle of Wight. B. vectensis
Woodw.
Opabinia, Leanchoilia, Yohoia (Fig, 1413), Bidentia Walcott.
Middle Cambrian ; British Columbia.
Order 2. NOTOSTRACA Sars.
Carapace forming a dorsal shield ex-
tending over the anterior segments ; paired ■
eyes sessile; antennae vestigial; trunk -
limbs forty to sixty-three pairs, of ivhich
ttventy-nine to fifty-two are post-genital ;
furcal rami multiarticulate.
Fig. 1413.
Yohoia tenuis WaUtott.
Middle Cambrian ; Britisli
Columbia. Dorsal view,
X2/i.
Protocar is Walcott (Fig. 1414). This
is the oldest representative of the Apus-
type, and exhibits a remarkable similarity
to A2)us in its univalve carapace, multi-
segmented abdomen, and single pair of
Lower Cambrian ; Vermont.
Pig. 1414.
Prolocaris marshi Walcott.
Lower Cambrian ; Georgia,
Vermont, x %.
caudal spines
1 Unfortunately some writers, following Glaus, have transposed the names Branchiopoda and
Phyllopoda, applying the latter to the superorder and the former to one of its divisions, but this
use is not sanctioned either by priority or by universal custom.
SUBCLASS II
EUCRUSTACEA— BEANCHIOPODA
733
Ribeiria Sliarpe ; Ribeirella Shubert and Waagen. These names have been applied
to arched, univalved bodies with strong beaks, muscular scars and sub-cardinal ridge.
They occur in the early Ordovician of Europe and America, and are doubtfully
assigned to a position among the Ajjodidae.
Apus Latreille. Trias to Recent. Lepidurus Leach. Recent. These genera,
included in the family Apodidae, comprise the largest known forms of Branchiopods,
some sjjecies of Ajms having a length of 70 mm. The imder-mentioned Cambrian
Notostracans are placed in separate families by Walcott.
Naraoia (Fig. 1415), Burgessia and Waptia Walcott (Fig. 1416). Middle
Cambrian ; Britisli Columbia.
Anomalocaris Whiteaves. This name has been aj^plied to bodies from the
Pig. 1415.
Naraoia covipacta Walcptt. Middle Cambrian ;
British Columbia. Dorsal view, x -/i.
Fu.. 1410.
Waptia Jieldensis Wal-
cott. Middle Cambrian ;
British Columbia. Dorsal
view of flattened specimen,
Cambrian of British Columbia which have been comjjared to the segmented abdomen
of a Branchioj)od, each segment bearing a pair of lamellate appendages. Although
the objects abound where found, nothing is known of the carapace, nor is there any
evidence of the surface markings which characterise most Crustacean shields. Their
affinities are doubtful.
Euchasma, Eopteria and Ischyrina Billings ; Technophorus Miller. These names
have been applied to remains from the Ordovician of North America, regarded by
their describers as Pelecypods, but undoubtedly of Crustacean nature. Their reference
to the Notostraca is uncertain.
Order 3. CONCHOSTRACA Sars.
Carapace hivalved, enclosing the tvhole body ; antennae ivell developed, biramotis,
natatory ; paired eyes sessile, coalescent. Body-limbs ten to twenty-seven pairs, of ivhich
none to sixteen are post-genital, and the first one or two in the male form clasping organs.
Fnrcal rami claw-like.
734
AETHROPODA
PHYLUM VII
Family 1. Lininadiidae Baird.
Family characters the same as above given for the order.
Estheria Eiijipel (Figs. 1417, 1418).
united by a straight tootliless margin.
Shell composed of two thin rounded valves,
External surface concentrically ridged or
Fig. 1417.
Estheria minuta Alberti. Lettenkohle Dolo-
mite ; Sinsheim, Baden. A, i/j. B, 6/j. C,
Portion of the exterior, 50/j.
FlO. 141S.
Estheria sp. indet. Lower barren
Coal Measures ; CarroUton, Oliio.
Umbonal portion showing muscular
or nuclear node, i3/j.
striated, and between the ridges are more or less regularly interlacing or branching
striae. The latter character serves to distinguish this genus from Posidonomya among
Pelecypods. The beaks are not sharply defined, and the primitive portions sometimes
bear a strong ocular or muscular node.
The genus Estheria has numerous fossil representatives, being first met with in the
Devonian, and occurring mostly in brackish and shore deposits. It abounds in the
productive Coal Measures, in the Permian, Trias (Lettenkohlenmergel) and 'W^ealden,
and has been found in the Pleistocene clays of Canada.
Leaia Jones (Fig. 1419). CarajDace marked by one or two diagonal ridges
Fio. 1419. ■
A, Leaia teidyi Jones. Coal Measures ; Potts vi He,
Pennsylvania. B, Lcdia haentschiana Geinitz. Coal
Measures ; Neunkirclien, near Saarbriicken (after
Golden berg).
Fig. 1420.
Schizodiscus capsa Clarke.
Hamilton ; Centerfleld, New
York. 2/j.
which run from the anterior end of tlie dorsal margin toward the lower margin.
Carboniferous ; Europe and North America.
EstherieUa Weiss. Carapace as in Estheria, but with radial riblets crossing the
concentric striae. Permian ; Russia. Buntersandstein ; Saxony.
Schizodiscus Clarke (Fig. 1420), Carapace peltate, with a straight hinge which
is in the major axis of the shield. Each valve nearly a semicircle ; surface marked
with concentric ridges. Middle Devonian ; New York.
Lepeditta Matthew. Cambrian ; North America.
SUBCLASS II
EUCRUSTACEA— OSTRACODA
735
Family 2. Bradoriidae Matthew.
Carapace bivalvcd, membranaceous, calcareo-corneus in composition, not completely
separated hut prohahly often fused along the cardinal edge; free margins of valves
slightly gaping ; main muscle spot close to antero-cardinal angle just behind and beneath
the ocular tubercle.
The members of this family have hitherto been considered as Cambrian Ostracoda, but
recent studies have shown them to be Branchiopoda. The genera listed below embrace
several distinct types of structure, and will in part be referred to other families in the course
of study.
Beyrichona Matthew (Fig. 1421, A, B). Valves subtriangular with a broad
undefined depression in the dorsal slope, limited in front by a short node-like ridge.
A B
Fig. 1421
A, Beyrichona tinea Jlatthew,
Beyrichona papilio Matthew.
Cambrian of New Brunswick.
X 4/i. B,
X •*/!. Middle
Fig. 1422.
A, Hipponicharion clavatiim Matthew.
X Vi- -B, Aluta enyo (VValcott). X 8/j.
Middle Cambrian of New Brunswick and
China.
Hipponicharion Matthew (Fig. 1422, A). Valves semi-elliptical with two
prominent marginal ridges and an inconspicuous central ridge near hinge line.
Pohjphyma Groom. Valves semicircular with numerous rather variable tubercules.
Bradoria, Escasona, Aluta Matthew (Fig. 1422, B). (?) Isoxys Walcott.
Order 4. CLADOCERA Milne Edwards.
Carapace bivalved, generally enclosing body but leaving head free; paired eyes sessile,
coalesced ; antennae large, forming swimming organs ; four to six pairs of body-limbs ;
f ureal rami claw-like.
The egg-cases (ephippia) of Cladocera have been recognised in Glacial de2:)0sits in
Germany. Lynceites ornatus Goldenberg, from the Carboniferous, is a very doubtful
representative of this order.
Superorder 2. COPEPODA Milne Edwards.
Eucrustacea without a distinct carapace, but with one or two of the anterior
somites coalesced with the head. Paired eyes usually absent. Antennules and
antennae usually well developed ; typically six pairs of biramous body-limbs. Caudal
furca present.
The Copepoda are without known representatives in the fossil state.
Superorder 3. OSTRACODA Latreille.^
Small, indistinctly segmented Crustacea completely enclosed in a horny or calcareous
bivalve shell. Not more than seven pairs of appendages present — two of antennae,
1 Literature : Bosquet, J., Description des Entomostraces fossiles de la craie de Maestricht.
736 ARTHEOPODA phylum vii
one of mandibles, two of maxillae, and two pairs of feet. Abdomen short and
rudimentary.
As a rule only the bivalved shell of the Ostracoda is found fossil, and since
the classification is based principally upon characters presented by the
appendages, the relations of recent to fossil forms cannot be made out with
certainty, especially as the form and ornamentation of the shell are largely
independent of the internal organisation.
The valves are closed by a subcentral adductor muscle, the attachment of
which is marked on their inner sides by a tubercle, pit, or a number of small
spots. The shell is compact in structure, commonly from 0"5 mm. to 4 mm.
in length, although sometimes exceeding 20 mm. The outer surface may be
smooth and glossy, or granulose, pitted, reticulose, striate, hirsute, or other-
wise marked, the effect being often quite ornamental. The two valves may
be of equal size (Beyrichia), or more or less unequal, with either the right or
left valve overlapping at the ventral border only (Leperditia), or at the dorsal
border as well (Bairdia), or in some cases overlapping all round (Cytherella).
Most commonly the outline is ovate or reniform ; in many cases, however,
one or both ends may be pointed or drawn out in the form of a beak ; and
when the dorsum is straight, the ends may join it angularly. Although
usually convex, the ventral margin is sometimes straight or gently concave.
It is sometimes impossible to distinguish between anterior and posterior
extremities, but as a rule the posterior half is somewhat thicker than the
anterior, even though of equal or of less height. The hinge -line may be
straight or arcuate, the hinge itself being generally simple, although among
the Cytheridae hinge teeth and corresponding sockets are often developed.
There are commonly a small median and two larger lateral eyes ; the position
Mem. Soc. Roy. Sci. Lk'ge, 1847, vol. iv. — -Description de.s Entomostraces fossiles des terrains
tertiaires de la France et de la Belgique. Mem. Couroun. Acad. Roy. Belg., 1850, vol. xxiv.- —
Monographic des crustaces fossiles du terrain cretace du Duche de Limburg. Mem. Commiss. Carte
geol. Nederlande. Haarlem, 1854. — Reuss, A. E.. Die fossilen Entomostracen des osterreichisclien
Tertiiirbeckens. Haid. naturw. Abhandl., 1850, vol. iii., pt. 1. — Die Foraminifereu mid Entomo-
stracen des Kreidemergels von Lemberg. Ibid, iv., pt. 1, 1851. — Jones, T. M., A Monograph of
the Entomostraca of the Cretaceous Formation of England. Palaeont. Soc, 1849. — Idem, and
Hinde, G. J., A Supplemental Monograph of the Cretaceous Entomostraca of England and Ireland.
Ibid., 1890. — Jones, T. R., A Monograph of the Tertiary Entomostraca of England. Ibid., 1857.
— Idem, and Sherborne, G. I)., A Supplemental Monograph of the Tertiary Entomostraca of
England. Ibid., 1889. — Jones, T. R., and Kirkby, J. IF., Notes on Palaeozoic bivalved Entomostraca,
Nos. 1-32. Ann. Mag. Nat. Hist, 1855-95. — Egger, 0., Die Ostracoden der Miociinschichten bei
Ortenburg. Neues Jahrb., 1858. — Speyer, 0. W. C, Die fossilen Ostracoden aus den Casseler
Tertiiirbildungen. Cassel Jahresber., 1863, vol. xiii. — Brady, G. S., Orosskey, H. W., and
Robertson, D., A Monograph of the Post-Tertiary Entomostraca of Scotland. Palaeont. Soc, 1874.
— Jones, T. R., Kirkby, J. W., and Brady, G. S., A Monograph of the British Fossil bivalved
Entomostraca from the Carboniferous Formations. Ibid., 1874, 1884. — Jones, T. A., and HoU,
H. B., Notes on Palaeozoic bivalved Entomostraca. Ann. Mag. Nat. Hist., 1869, ser. 4, vol. iii. —
Brady, G. S., and Norman, A. M., A Monograjih of the marine and fresh-water Ostracoda of the
North Atlantic, etc. Sci. Trans. Roy. Dublin Soc, 1889-96, vols, iv., v. — Lienenklaus, E.,
Monographie der Ostracoden des nordwestdeutschen Tcrtiiirs. Zeitschr. Deutsch. Geol. Ges., 1894,
vol. xlvi. — Jones, T. R., and Kirkby, J. W., On Carboniferous Ostracoda from Ireland. Sci.
Trans. Roy. Dublin Soc, 1896, vol. vi. — LIrich, E. 0., The Lower Silurian Ostracoda of Minnesota.
Geol. Minn., Palaeont., vol. iii., pt. 2, 1897. — Shcrburn, C. I)., The literature of fossil Ostracods.
Nat. Sci., 1897, vol. x. — Lienenklaus, E., Die Tertiiir-Ostrakoden des mittleren Norddeutschlands.
Zeitschr. Deutsch. Geol. Ges. 1900, vol. Iii. — Idem, Die Ostrakoden des Mainzer Tertiiirbeckens.
Ber. Senckenberg Nat. Ges. Frankfurt, 1905. — Matthew, G. F., Ostracoda of the basal Cambrian
Rocks in Cape Breton. Canad. Rec. Sci., 1902, vol. viii. — Chapman, F., Some Silurian Ostracoda
and Phyllocarida. Proc Roy. Soc. Victoria, 1904, n. s. vol. xvii. — Ulrich, E. 0., and Bassler,
R. S., New American Paleozoic Ostracoda, pts. ii. and iii. Proc. U. S. Nat. Mus., 1906, 1908,
vols. XXX., XXXV. — Miocene Ostx-acoda. Maryland Geol. Surv., Miocene Vol., 1904.
SUBCLASS 11
EUCRUSTACEA— OSTRACODA
737
of the latter being often indicated on the exterior of the valves by a small
" eye tubercle," or ocular spot.
Save for one or two families (Cypridae) Ostracods are almost wholly
restricted to marine or brackish water. They are gregarious, and occur in
vast hordes swimming near the surface or creeping over the bottom, preferring
usually shallow depths. Their remains abound in nearly all the principal
formations, and they are often important rock-builders. The identification of
fossil Ostracods is very difficult on account of their similarity of form and
ornamentation, and usually minute size ; and they cannot be well intercalated
among the recent series for reasons already given. Sars has arranged the
living forms into four divisions, Podocopa, Platycopa, Mi/odocopa and Cladocopa,
but assembling the families into higher groups is not attempted here, and
only the more repx'esentative genera can be noticed.
Family 1. Leperditiidae Jones.
Thick-shelled Ostracoda, mostly of considerable size. Valves smooth and glossy, of
very compact structure, and in general regularly convex ; hinge-line straight; anterior
and posterior ends oUiquely truncated or rounded, and neither gaping nor excised.
Shell sub-oblong with an oblique backward
dorsal edge straight, generally angular at the
Valves unequal, the right larger and over-
Leperditia Rouavxlt (Fig. 1423).
swing, from 2 mm. to 22 mm. long;
extremities ; ventral outline rounded,
lapping ventral edge of
the left. Surface often
corneous in apjjearance,
smooth, and eye tubercle
generally present on
the antero-dorsal
quarter. A large
rounded sub - central
muscular imprint pre-
sent on interior. Ordo-
vician to Carboniferous.
Leper ditella Ulrich. Similar to above, but the left instead of right valve is the
larger, and has a groove within its ventral border for receiving the simple edge of
the right valve. Eye tubercle wanting. Length 1 mm. to 3 mm. Ordovician.
Isochilina Jones (Fig. 1424). Like Leperditia except that the valves do not over-
lap but are equal in every respect. Ordovician and Silurian.
Aparchites Jones. Shell not over 3 mm. in length, equivalve, sub-ovate or
oblong ; ventral edge thickened, often bevelled. Ordovician and Silurian.
Schmidtella Ulrich. Ordovician. Paraparchites Ulrich and Bassler. Carboni-
ferous ; North America.
Fig. U-23.
Leperditia hisingeri Schmidt. Silurian ;
Wisby, Gotland, i/i-
Fir.. 1424.
Isochilina gigantea Roenier.
Silurian eriatic ; Lyck, East
Prussia. 2/3 (after F. Roemer).
Family 2. Beyrichiidae Jones.
Small equivalve Ostracoda tuith a long straight hinge. Shells vertically sulcated and
more or less lohate, varying from forms having a simple median depression to others in
which the surface of the valves is raised into numerous low lobes, ridges or nodes.
Primitiella Ulr. (Fig. 1425, a). Valves with a broad, undefined mesial depression
in the dorsal slope. Ordovician to Devonian.
VOL. I 3 B
738
ARTHROPODA
PHYLUM VII
Primitia Jones and Holl (Fig. 1425, b). Has well-marked subcentral pit or
sulcus, with furrow extending to the hinge line. Ordovician to Permian.
Dicranella Ulr. (Fig. 1425, d). Like Primitia but has horn-like process on one
or both sides of the sulcus. Ordovician.
Aechmina J. and H. (Fig. 1425, c). Sulcus is replaced by a single, horn-like
process. Ordovician to ]\Iississij)pian.
Ulrichia Jones. Ordovician to Mississippian. Synafhe, Beyrichiopsis, Beijrichiella
Jones and Kirkby. Carboniferous.
Eurycliilina Ulr. (Fig. 1425, g). Like Primitia but ventral margin provided
with a wide, frill-like border. Ordovician and Silurian.
JoneseUa Ulr. (Fig. 1425, /). Valves subovate with a ci;rved ridge on the
posterior two-thirds. Ordovician and Silurian.
Fig. 14-25.
Paleozoic Ostr<Koda. a, Primitiellu unicornis Uli-. x i^/i- ''> Pi'imitia fincinnatieiisis Miller, x i-*/i. c,
AechmiTM marginata Ulr. X I'l/j. d, Dicranella bicornis Ulr. x ii^/i. e, Ctenobolhina ciliata Emmons, x s/j.
/, Jonesella crepidifurmis Ulr. x '^-/i. g, Eurychilina reticulata Vlr. x 'O/i. /(, Halliella IdbrosaXSlr. x i'*/!.
i, Kloedenia centricornis Ulr. and Bass, x I'l/j. j, Tetradella qiiadrilirata H. and W. x i3/j. fc^ Ceratopsis
chambersi Miller, x i2/j. l^ Kloedenella iurgida Ulr. and Bass, x I'l/i. in, Kirkbya tnibqxifulrata Ulr. x ^-i/i.
n, Beynchia clavata Kal. x i-i/i. o, Drcpanella crasHnoda Ulr. x i"/]. p, Dilobcfla typa Ulr. x i^/i.
Bollia Jones and Holl. Valves with a central looped or horseshoe-shaped ridge.
Ordovician to Mississippian.
Tetradella Ulr. (Fig. 1425, j). Valves marked l)y four more or less curved
vertical ridges united ventrally. Ordovician and Silurian.
Geratofsis Ulr. (Fig. 1425, k). Has a horn-like process arising from the ex-
tremity of the jjosterior ridge. Ordovician and Silurian.
Gtenoholbina (Fig. 1425, e), Drepanella (Fig. 1425, o), Halliella Ulr. (Fig. 1425,
h). Ordovician to Devonian.
Beyrichia M'Coy (Fig. 1425, n). Valve has three lobes or nodes with the central
one the smallest. Ordovician to Devonian.
Kloedenia Jones and Holl (Fig. 1425, i) ; Kloedenella Ulr. and Bass. (Fig.
1425, Z). Silurian and Devonian. Dilobella Vlr. {Fig. IA25, p). Ordovician. Hollina,
Jonesina, Treposella Ulr. and Bass. Devonian to Carboniferous.
The following genera, doubtfully referred here, should perhaiJs be regarded as
Paleozoic Cytheridae :
Kirkhya Jones (Fig. 1425, m). Devonian to Permian. Moorea J. and K.
Ordovician to Permian. Strepula J. and H. Silurian and Devonian. Macronotella
Ulr. Ordovician,
SUBCLASS II
EUCRUSTACEA— OSTRACODA
739
Family 3. Oytheridae Zenker.
Minute shells of generally elongate-oval, reniform or sub-qioadrate outline, and of
dense structure. Surface smooth, imnctate, nodulose, striate or spinose ; hinge generally
denticulated, the right valve with
two teeth in most eases, and the left
with corresfonding pits.
Fossil species of this family are
very numerous iu the marine deposits
of the Cretaceous and Tertiary. The
resemblance between Gytherc and the
Devonian genus Strepula is so decided
as to indicate relationship.
Gythere Miiller (Fig. 1426, a).
Shell reniform or subquadrate, Valves of fossil Ostracoda. «, Cytlwe basslcri Ulr. X H/i.
,, -J J. ■ 4- J. r ^1 Cytheropteron nodot:u)ii Uli'. and Bass, x i''/]. c, Cytheridea
usually widest m tront ; SUrtace perarcuata Ulr. x i-i/i. rf, Pachydomella tumida Ulr. x l^/j.
variously ornamented • hinse teetll ^tXestulebcrismuellcriana(ham.). X •*"/!. f, OctonaHa stiginata
strong, placed one at each end of
a horizontal bar which fits into a corresponding furrow and sockets of the left valve.
Permian to Recent.
Gythereis Jones (Fig. 1427). Like Cy there but connecting bar of the hinge is
wanting. Cretaceous to Recent.
Cytheridea Bosq. (Fig. 1426, c). Differs from Gythere in having hinge beset with
Fli;. 1420.
Fio. 1427.
Cythereis qimdrilatera Roemer. Gault ; Folkestone, England, x 25/j (after T. Rupert Jones).
row of small teeth in right valve, often interrupted in the middle, and with corre-
sponding pits in the left valve. Jurassic to Recent.
Cytherideis Jones. Shell more or less triangular ; hinge simple. Cretaceous to
Recent.
Carbonia Jones. Carboniferous. Gijtheropteron (Fig. 1426, 6), Xestoleheris (Fig.
1426, e) and Pseudocythere Sars. Tertiary to Recent.
Family 4. Thlipsuridae Jones.
Reniform or ovate inequivalve shells, less than 2 mm. in length, the margin of one
valve overlapping that of the other more or less completely ; dorsal margin arcuate,
ventral sometimes straight or slightly sinuate. Siorface with two or more definite pits.
Tldipsura Jones and Holl. Valve generally with three pits, one posterior and two
in the anterior half. No ornament. Silurian and Devonian.
Octonaria Jones (Fig. 1426, /). Differs from the last in having the surface of
valves raised into a thin spiral or annular ridge which in the more typical forms is
8-shaped. Silurian and Devonian.
Phreatura J. and K. Posterior end of shell strongly compressed and marked by
a shallow semicircular pit ; a similar but smaller pit is present at the anterior
extremity. Carboniferous.
740
ARTHROPODA
PHYLUM VII
Family 5. Cypridae Zenker.
Minute, mostly reniform or elongate-ovate, corneous or corneo-calcareous shells, ivith
thin, someivhat unequcd valves, one overlapping the other either ventrally or dorsally or
both.
Recent Cypridae are chiefly fresh-water inhabitants, but this is true in a lesser
degree of the fossil forms. All the Paleozoic representatives are marine, excepting
perhaps certain Carboniferous species. Fossil remains are extraordinarily profuse in
certain deposits, and the family is an important rock-builder.
Palaeocijpris Brongt. Shell 0*5 mm. long, sub-ovate, smaller posteriorly than in
front ; surface granulose and finely hirsute in dorsal region. Carboniferous.
Gypris Miiller (Fig. 1428). Shell reniform or oval, thin, translucent, smooth or
A hirsute, often j^^mctate ; hinge edentulous, somewhat
thickened ; ventral margin often sinuate. Tertiary to
Recent.
Fig. 1428.
Cyi->ris faba Desm. Miocene;
Oeningen, Switzerland. A, Dorsal, and
B, Lateral view, is/j (after Bosquet).
C, Valves composing fresh-water lime-
stone at Nordlingen.
Fig. 1429.
Cypridea waldensis
Sowb. Wealden ; Ober-
Isirchen, Hanover. 15/^.
Fig. 1430.
Bn.inlia curta M'Coy.
Ijow er Carboniferous ;
Ireland. 15/j (after
Kirkby).
Cypridea Bosq. (Fig. 1429). Like Gypris, but with a small hook-like projection
at the antero-ventral angle. Purbeck and Wealden.
Bairdia M'Coy (Fig. 1430). Shell sub- triangular or rhomboidal, with the
greatest height near the middle, generally smooth, both extremities narrowly rounded
or pointed. Dorsal margin more or less strongly convex ; hinge formed by over-
lapping edge of left valve. Ordovician to Recent ; maximum in Carboniferous.
Bythocypris Brady. Shell smooth, reniform, ovate or elliptical ; left valve over-
lapping the smaller right valve usually on both dorsal and ventral margins.
Typically Recent, but a number of Paleozoic forms have also been assigned to this
genus.
Macrocypris Brady. Similar to the last, but generally more elongate, posteriorly
more acuminate, and the right valve larger than the left. Ordovician and Silurian ;
also Jurassic to Recent.
Pontocypris Sars. Like Bythocypris, except that the shell is very delicate, and
the hinge is simple without overlap. Silurian, Carboniferous, Pleistocene and Recent.
Fig. 1431.
Cytherclla conipressa
(Miinst.). Oligocene ;
Riippelmonde, Belgium.
22/i (after Bosquet).
Family 6. Oytherellidae Sars.
Family characters chiefly displayed by soft parts. Shell minute,
incquivalve, thicJc, calcareous, not notched anteriorly.
Gytherella Jones (Fig. 1431). Shell oblong or sub -ovate,
compressed in front ; surface generally smooth, but sometimes
undulating and marked Avith pits and granules. Contact margin
of the larger right valve grooved for reception of flange -like
edge of smaller left valve. Ordovician to Recent.
Gytherellina Jones and Holl. Silurian. (?) Pachydomella
Ulrich (Fig. 1426, d) ; Bosquetia Brady. Recent.
SUBCLASS II
EUCRUSTACEA—OSTRACODA
741
Family 7. Entomidae Jones.
Shells relatively short, strongly convex, reniform, ovate or rounded quadrate, suh-
equivalve, luith a more or less loell-marked depression near the middle of dorsal region.
Surface sculpture concentric or radiate.
Entomis Jones (Figs. 1432, 1433).
slightly curved sub-naedian vertical
furrow extending to the hinge line ;
in front of furrow occasionally a
rounded tubercle. Surface marked
generally with raised, concentric,
transverse or longitudinal lines.
Ordovician to Carboniferous ; very
profuse in Devonian.
Entomidella Jones. Like En-
tomis, but with furrow extending
entirely across the valves to ventral
edge. Ordovician and Silurian.
Elpe Barr. Shell reniform, 3
mm. to 7 mm. long, with depres-
sion just behind the middle of the
dorsal slope ; posterior half sometimes strongly inflated
Ordovician and Silurian.
Shell sub-ovate or fabiform ; valves with a
A B
Fio. 1432.
Entomis pelagica Barr.
Lower Devonian (F) ;
Konieprus, Bohemia.
Fig. 1433.
Entomis serrato-striuta (Sandb.).
Upper Devonian ; Weilburg,
Nassau. A, Fragment of matrix,
Vi- B, Ventral and lateral aspects,
s/j. C, Impression of valve, 9/i.
Delicate radial ornament.
Family 8. Cypridinidae Sars.
Shells equivalve sub-elliptical to ohlong, convex, smooth or punctate, and sometimes
ribbed, especially in posterior half. Anterior end ivith a notch and hook-like hood over-
Tianging an opening left between edges of valves for protrusion of the lower antennae ;
posterior extremity freqxhently acuminate.
Gypridina Milne Edw. (Fig. 1434). Shell generally acuminate, oviform, rarely
Fig. 1434.
Cypridina primaeva (de
Kon.). Coal Measures ; Braid-
wood, England. •>/, (after
Jones, Kirkby and Brady).
Fm. 1435.
Cypridella v.yrightii J. K. and B. Lower
Carbonifennis ;( Corlv, Ireland. ^/i (after
Jones, Kirkby and Brady).
Fig. 1436.
Cyprella chrysalidea (de
Kon.). Lower Carboni-
ferous ; Cork, Ireland.
*li (after Jones, Kirkby
and Brady).
oblong ; antero-dorsal edge projecting beak-like over the strongly defined notch ;
muscle spot large, sub-central, often visible on exterior. Ordovician to Recent.
Gypridinella J. K. and B. Like Gypridina, but having the antero-ventral region
projecting somewhat prow-like and generally beyond the hook. Carboniferous.
Gypridellina J. K. and B. Differs from the last in having a tubercle or lump
above the centre of the valve. Carboniferous.
Gypridella de Kon. (Fig. 1435). Like Gypridellina, except that it has a curved
sulcus behind the tubercle. Carboniferous.
Gyprella de Koninck (Fig. 1436). Shell much as in the last, but annulate.
Carboniferous.
Sulcuna, Rhombina J. K. and B. ; Gypresis, Cyprosina Jones. Paleozoic.
742 ARTHEOPODA phylum vii
Family 9. Entomoconchidae.
Shell sub-globose, more or less inequivalve ; anterior edge truncate and with central
portion of margin inturned so as to leave a simple or sinuate slit. Beak not developed.
Entomoconchus M'Coy ; Offa Jones, Kirkby and Brady. Carboniferous.
Geological Range of the Ostracoda.
Numerous supposed Ostracoda (Bradoria, Beyrichona, etc.) have been described
from the Cambrian, but all of these now prove to be Brancliioi^ods. The earliest
undoubted Ostracoda are indicated by a few species of Leperclitia found in the
Beekniantown beds (Lower Ordovician) of Tennessee. During the Middle and
Upj)er Ordovician these Crustaceans flourished greatly, and form excellent horizon
markers. The prevailing Ordovician and Silurian types belong to the Leperditiidae
and Beyrichiidae, although toward the close of the Silurian numerous Cypridae make
their apjjearance.
Devonian Ostracoda are less numerous, but manifest essentially the same types as
in the earlier periods. Here, however, the larger Leperditiidae are entirely wanting.
Although many small species of archaic genera persist in the Carboniferous, the aspect
of the fauna is changed by the strong development of Cypridinidae. Thereafter
Ostracods are but sj)arsely represented until the Cretaceous, when certain genera,
especially Gythere, develop a surprising variety of species. Little difference can be
detected between Tertiary Ostracods aud their modern descendants, although on
account of the facilities for studying the anatomy of the soft parts it has been possible
to distinguish many more genera among the living forms.
[The above revision of the groups Branchiopoda and Ostracoda has been prepared by
Dr. R. S. Bassler. — Editor.]
Superorder 4. OIKRIFEDIA Burmeister. Barnacles.^
Sessile, mostly hermaphroditic animals, enclosed in a membranous mantle which
is often covered with calcareous plates. Body attached by the anterior extremity of the
1 Literature : A. Recent Forms : — Thompson, J. V., Zoological Researches and Illustrations.
1. Cork, 1830. — Discovery of the Metamorphosis in the Lepades, etc. Phil. Trans. Roy. Soc, pt.
2, 1835. — Burineistcr, H., Beitriige zur Naturgeschichte der Raukenfiissler. Berlin, 1834. — Martin-
Saint-Ange, G. J., Memoire sur I'organisation des Cirripedes. Mem. Savans llltrang., Acad. Sci.,
Paris, 1835, vol. vi. — ■Daricin, C, A Monograph of the Sub-Class Cirripedia. Ray Soc, 1851-54,
vols, i., ii. — lloek, P. P. C, Report on the Cirripedia. Rept. Challenger Exped., Zool., viii., x.,
1883-84. — Anrivillius, G. W. »S'., Stndien iiber Cirripeden. Svensk. Vetensk. Akad. Handl. . 1893,
vol. xxvi., no. 7. — Groom, T. T., On the Early Develoi)ment of the Cirripedia. Phil. Trans. Roy.
Soc, 1894, vol. clxxxv. — Hansen, H. J., Phyllopoda and Cirripedia. Plankton Expedition, 1895.
— Gruvel, A., Monographic des Cirrhipedes. Paris, 1905.
B. Fossil Forms. — Sowerby, J., aud J. de C, The Mineral Couchology of Great Britain.
London, 1812-30. — Roemer, F. A. Die Versteineruugen des uorddeutscheu Kreidegebirges. Hanover,
1840-41. — Darwin, C, A Monogi\iph of the Fossil Lepadidae of Great Britain. Palaeont. Soc,
1851. — A Monograph of the Fossil Balauidae aud Verrucidae of Great Britain. Ibid., 1855. —
Bosquet, J., Monographic des Crustaces fossiles du terrain cretace du Duche de Limbourg. Mem.
Comraiss. Carte geol. Nederlande, 1854. — Notice sur quelques Cirripedes recemment deconverts
dans les terrains cretaces du Duche de Limbourg. Haarlem, 1857. — Reuss, A. E., Ueber fossile
Lepadiden. Sitzungsber. Akad. Wiss. Wien, 1864, vol. xlix. — Woodward, H., On Turrilepas, etc
Quar. Journ. Geol. Soc, 1865, vol. xxi. — Barrande, J., Systcme Siliirien du centre de la Boheme,
I. Suppl., 1872. — Segnenza, G., Ricerche palaeoutologiche intorno di Cirripedi terziarii della Pi-oviucia
di Messina, Pts. i., ii. , Naples, 1873-76. Marsson, J., Die Cirripeden und Ostracoden der weissen
Schreibkreide der Insel iRtigen. Mittheil. naturw. "Ver. Neu-Vorpommeru und Riigen, 1880, vol.
xii. — Zittel, K. A., Bemerkungen iiber eiuige fossilcn Lepaditen aus deni lithographischen Schiefer
und der oberen Kriede. Sitzungsber. Bayer. Akad. Wiss., 1884, vol. xiv. — Fuber, C. L., Remarks
SUBCLASS II EUCRUSTACEA— CIREIPEDIA 743
head ; obscurely, and at times not at all segmented ; posterior portion with at most
six pairs of biramous legs or cirri, which, however, may be fewer in number or
altogether absent.
The typical and best known Cirripedes {Bala7iidae, Lepadidae) differ so
widely from all other Crustacea in their external form, solid calcareous shells,
slightly developed respiratory and sensory organs, and especially in their
hermaphroditic sexual apparatus, that until 1830 they were commonly classed
with the Mollusca. About this time J. V. Thompson and Burmeister showed
that these Cirripedes pass through a nauplius stage, and that directly before
attachment both Balanus and Lepas undergo a C^pm-stage, thus showing very
clearly their relation to the Eucrustacea.
All Cirripedes are marine animals. Those with calcareous shells attach
themselves to stones, wood, moUusks, crabs, corals and sea plants, and often
cover rocky coasts in myriad numbers. Some, genera {Coronula, _ Chelonobia)
attach themselves to whales and turtles ; some (Pyrgoma, Falaeocreusia)
become embedded in corals, and others bore into shells of mollusks or
lead a parasitic existence on Decapods or within the shells of other Cirripedes.
Most Barnacles inhabit shallow water, but certain genera occur at great
depths, from 1900 to 2000 fathoms (Scalpellum, Verruca). Many of the
living families are naked, and naturally only those possessing shells
(Thoracica) have left fossil remains, although some of the tubular cavities in
molluscan shells may . have been perforated by naked Cirripedes. Fossil
forms occur sparingly in the older strata, and do not become abundant until
near the close of the Tertiary.
Order 1. THORACICA Darwin.
Body indistinctly segmented, and enclosed in a membranous mantle in which calcare-
ous plates are usually developed. Six pairs of cirri present. Mostly hermaphroditic,
sometimes with complemental males.
The relations of the first two of the following families to the other members of
the order are conjectural.
Family 1. Lepidocoleidae Clarke.
Body covered with two vertical columns of overlapping plates, those of one series
alternating -with those of the other. Terminal or caudal plate axial. Basal or cephalic
portion of the body with a ventral curvature. Apices of the plates on the dorsal margin.
No accessory plates.
Lepidocoleus Faber (Fig. 1437). Elongate, blade-shaped ; dorsal edge the thicker,
ventral edge sharper and linear. The two series of plates make a complete enclosure,
oil some Fossils of the Cincinnati Group. Journ. Cincin. Soc. N<at. Sci., 1887, vol. ix. — Ball, J.,
and Clarke, J. M.. Palaeontology of New York, 1888, vol. \n.— Clarke, J. M., Notes on certain
Fossil Barnacles. Amer. Geol., 1896, vol. xvii. — Matthew, G. F., On occurrence of Cirripedes in the
Cambrian. Trans. N. Y. AcacL Sci., 1896, vol. xv.— Logan, IT. N., Cirripeds from Cretaceous of
Kansas. Kansas Univ. Quar. 1897, vol. \i. — Woodward, H., Cirripedes from the Trimmingham
Chalk in Norfolk. Geol. Mag. 1906, dec. 5, vol. \\\.—Idem, on the genus Loricula. Ibid., 1908,
vol. v.— Z)e Alessandri, G., Studi monografici sui Cirripedi fossili d' Italia. Palaeontogr. Ital.,
1906, vol. xii. — Idem, Osservazioni sopra alcuni Cirripedi fossili della Fraucia. Atti Soc. Ital.
Nat., Milano, 1907, vol. xlv. — Reed, F. R. C, Structure of Turrilepas and its allies. Roy. Soc.
Edinb., 1909, vol. xlvi. — ir^Y/igrs, T. H., The Cirripede genus Scalpellum. Geol. Mag. 1910,
dec. 5, vol. vil— Idem, The Cirripede Brachylepas cretacea H. Woodward. Ibid., 1912, vol. ix.
744
AETHROPODA
PHYLUM VII
being interlocked on the dorsal edge, but are only in apposition on the ventral
edge, where they were undoubtedly capable of dehiscence for
the protrusion of the appendages. This is the most primitive
genus of the group. Ordovician to Devonian.
Family 2. Turrilepadidae Clarke.
Body ivith four to six vertical columns of triangular plates,
two of the columns being small, accessory and sometimes much
modified in shape. Gaiidal plate patelliform, axial.
Turrilepas Woodw. (Plumulites a b
Barr.) (Fig. 1438). Body elongate-
Silurian ; Rociiester, New conical with four to six columns of
lork. Jjorsal, lateral and
ventral views. large triangular overlapping scales,
some of which are keeled in the
middle. Besides having concentric striae, the surface may be
radially lined or punctated. Cambrian (?) to Upper Devonian.
Strobilepis Clarke. Composed of four columns of over-
lapping plates, two of which are of large and eqnal size.
Of the other two intervening columns, one consists of a
few very small plates, and the other is modified into a series
of grooved sj^ines which appear to overlap one another at
their bases, and to lie opposite the column of small plates,
Fid. 1437.
Lepidocolcns Hnrhi Clarke.
Fig. 143S.
Caudal extremity terminated by a circular, conical, axial England. A, Compiet
plate, against the sides of which lies the first plate in each putes,' enlarged '(after'
column. Middle Devonian.
TurriUpas imghtianus de
Koninck. Silurian ; Dudley,
,e indi-
Isolated
Wood-
ward).
Family 3. Lepadidae Darwin. (Goose Barnacles).
Shell pedunculated, composed mainly of the paired terga and scuta, the impaired
carina, and a variable number of small calcareous plates, some of which cover the
flexible peduncle ; others take part in the capitulum. The calcareous plates are never
fused.
Archaeolepas Zittel (Fig. 1439). Peduncle flattened, the two principal surfaces
FlO. 1439.
Archaeolepas • redten-
hachcri (Opp.). Litlio-
graphic Stone ; Ke!-
heim, Bavaria. Vi- 'i
Carina ; li, Rostrum ;
S, Scutum ; T, Tergum.
Fl(i. 1440.
A, Loricula laevisHma Zitt.
Senonian ; Dulinen, West-
phalia. Vi- B, C, Loru-uta
syriaca Dames. Cenomanian ;
Lebanon. Vi 'I'l'l "h-
Fig. 1441.
Scalfiellum gallicum
Hebert. Upper Cretace-
ous ; Meudon, near Paris.
2/, (after Hubert).
with four to six, the narrow sides with two columns of small scales. The capitulum
is composed of triangular scuta, two large trapezoidal terga, a short unpaired carina,
and a minute rostrum. Upper Jura to Lower Cretaceous.
Loricula Sowb. (Fig. 1440). Peduncle squamous. Capitulum with two scuta,
two terga, four lateralia and a very narrow carina. Cretaceous.
SUBCLASS II
EUCRUSTACEA— CIRRIPEDIA
745
Pollicipes Leach (Polylepas Blainv.). Capitulum composed of numerous (eighteen
to one hundred) plates, among which the scuta, terga, rostrum and carina are dis-
ci u
Fig. 1442.
Capituhim of Scalpellum fossulum Darwin.
Upper Cretaceous ; Norwich, B^ngland. s/j.
C, Carina ; L, Laterale superius (upper latus) ;
R, Rostrum ; S, Scutum ; T, Tergum ; cl,
Carino -.latus ; il, Infra - median latus ; rl,
Rostral latus ; sc, Sub-carina ; sr, Sub-rostrum
(after Darwin).
Fig. 1443.
Scalpellum fossidumDavvim.
Upper Cretaceous ; England.
Carina much enlarged (after
Darwin).
Fig. 1444.
Lepas anatifera Linn.
Recent; Mediterranean. C,
Carina ; P, Peduncle ; S,
Scutum ; T, Tergum.
Lateralia generally in two columns. Peduncle mem-
UpiJer Jura to Recent. Doubtfully recorded from
tinguishable by their size,
branous with minute scales,
the Silurian.
Squama, Stramentum Logan. Upj)er Cretaceous (Niobrara) ; Kansas.
Scalpellum Leach (Figs. 1441-1443). Capitulum with twelve to fifteen pieces.
Terga and scuta much larger than in Pollicipes and of
very characteristic form. Carina narrow, long, with
arched surface. Peduncle covered with fine scales,
rarely naked. Cretaceous to Recent, and doubtfully
recorded from the Silurian.
LejMS Linn. (Fig. 1444). Peduncle naked.
Capitulum consisting of only two very large tri-
angular scuta, two small terga, and a single carina.
Pliocene and Recent.
Poecilasma Darwin. Capitulum consisting of Fig. 1445.
three, five or seven pieces. Carina extending only to BrachyUpas naissanti (Hebert) (=
base of the terga, the latter sometimes wanting. ^r1utS,s"ttSmr'^ScxS-
Scuta sub-oval. Tertiary and Recent, ;, upper latus ; f, tergum ;c, carina ; t.s
imbricating plates. Vi (after W ithers).
Family 4. Brachylepadidae H. Woodward,
Shell sessile, loith a large number of plates, the arrangement of which indicates a
transition from the Lepadidae towards the Balanidae.
The single known genus Brachylepas H. Woodward (Fig. 1445) occurs in the
Upper Senonian of England and the continent of Europe.
746
ARTHROPODA
PHYLUM VII
Family 5. Verrucidae Darwin.
Shells sessile and composed of six pieces. Of the scuta and terga only those of one
side are free the others being fused ivith the rostrum or carina.
The solitary genus Verruca Schum., ranges from the Cretaceous to Recent.
Family 6. Balanidae Darwin. (Acorn Barnacles).
Shell ohtusehj conical, circular or oval in cross section, with broad, often calcareous
and cellular base; composed of foiir to ten ^'- compartments" more or less completely fused
at their sides, and tivo pairs of free terga and scuta
which close the upper aperture like an operculum.
Of the lateral plates which compose the crown-
shaped immovable test, two are designated as carina
Pic. 1440.
Diagram of the shell of Balanus. B,
Basis ; C, Carina ; CL, Carino - lateral
oompartinent ; L, Lateral compartment ;
It, Rostrum ; KL, Rostro-lateral com-
partment. Eacli valve or " compart-
ment " consists of a central ' ' paries " (p)
flanked by " alae " (ri) or "radii " (/■).
... OG
Fig. 1447.
Scutini) and tergum of Bakmus. A, External aspect of tergum,
showing "spur" below and "beak" above. £', Internal view of
scutum, showing muscular scar {li). C, Internal view of tergum
(after Darwin).
and rostrum, the pieces lying between and occurring in pairs being called lateralia. If
^ J, additional plates are inserted
among the lateralia, they are
termed according to their position
rostro- or carino - lateralia. The
scuta and terga lie free on the
Irnck of the animal, and in fossil
forms are generally lost. They
have a very characteristic form,
and hence are of great systematic
imiJortance. Since among fossil
species, however, only the mar-
ginal plates are for the most part
preserved, the determination of
their structural characters is often
quite uncertain.
Balanus Lister (Figs. 1446-
1449). Shell low, conical or
cylindrical, composed of six pieces. Opercular plates sub-triangular ; base membranous
or calcareous. Eocene to Recent.
Protobalanus Whitf. Affinities doubtful. Composed of twelve jslates, of which
the carina is the largest ; rostrum small, lateralia in five pairs, fused only near the
base. Middle Devonian.
Acasta Leach. Sliell composed of six solid pieces. Base calcareous, cuii-.sha])ed ;
epizoic on Sponges and Alcj^onarians. Pliocene and Recent.
Fig. 1448.
Balanus coneavus Broun. Crag; Sutton, England. .1, Shell.
iJ, Tergum. r, Scutum. Vi (after Darwin).
SUBCLASS II
EUCRUSTACEA— CIERIPEDIA
74:
Pyrgoma Leach {Creusia Blainv.). Shell formed of a single piece. Base cui3-
shaped or sub- cylindrical ; epizoic on Corals. Lower Devonian (?). Tertiary and
Recent.
Palaeocreusia Clarke (Fig. 1450). Affinities doubtful. Shell in one jiiece, with
a deep cylindrical base ; ejjizoic on corals. Lower Devonian.
Coronula Lara. Composed of six lateralia, with thin, deeply folded walls dividing
(?**
'PA
Fio. 1449.
Balanus pictus Miinst. Miocene ; Dischingen, Wiirtemberg.
Pio. 1450.
Palaeocreusia devoniea Clarke.
Embedded in Farositc>:. Middle De-
vonian (Onondaga limestone) ; Le
Roy, New York.
the interior space into chambers which open at the lower side of the shell. Base
membranous ; epizoic on whales. Pliocene to Recent.
Ghthamalus Ranz. (Euraphia Conrad). Shell depressed, composed of six pieces.
Base membranous. Cretaceous, Miocene and Recent.
Pachylasma Darwin. Shell in the young with eight pieces, which afterwards become
six, or by coalescence of the lateralia are apparently reduced to four. Base calcareous.
Pliocene to Recent.
Superorder 5. MALACOSTRACA Latreille.
Eucmstacea having, in Recent forms, typically fourteen (^rarely fifteen) body-
somites besides the telson. All the somites (except the fifteenth) bear appendages
which are differentiated into two groups, a thoracic of eight and an abdominal of
six pairs.
The classification of the Malacostraca has undergone considerable modifi-
cations at the hands of zoologists within recent years, and further research is
necessary before some of the fossil forms can be assigned to their proper
places in the newer arrangements.
The basis of the new classification is the recognition of the fact that what
has been called the " caridoid facies " is a common inheritance from the
primitive stock of the Malacostraca (possibly excepting the Phyllocarida),
and does not imply close affinity between the various groups presenting it.
The chief characters that go to make up this facies are the stalked eyes, the
scale-like exopodite of the antenna, the thoracic carapace, the natatory
exopodites of the thoracic limbs, the large and ventrally flexed abdomen,
and the " tail-fan " formed by the uropods and telson. The group " Schizo-
poda " has long served as a receptacle for primitive forms possessing these
characters, and its dismemberment into the three orders, Anaspidacea,
Mysidacea and Euphausiacea, is attended by the inconvenience that the
characters distinguishing these orders are but rarely to be discovered in
fossils.
748 ARTHROPODA phylum vii
Following is the scheme of classification here adopted : —
Series I. Leptostraca.
Division A. Phyllocarida.
Order Nebaliacea.
Series II. Eumalacostraca.
Division A. Syncarida.
Order Anaspidacea.
Division B. Peracarida.
Order 1. Mysidacea.
„ 2. Cumacea.
,, 3. Tanaidacea.
„ 4. Isopoda.
5. Amphipoda
5)
Division C. Eucarida.
Order 1. Euphausiacea.
„ 2. Decapoda.
Division D. Hoplocarida.
Order Stomatopoda.
Series I. LEPTOSTRACA Glaus.
Division A. PHYLLOCARIDA Packard.'
Order 1. NEBALIACEA Caiman.
Abdomen of seven somites (in the Recent forms), the last of which is without
appendages, and a telson hearing a pair of movable f ureal rami. Carapace present,
1 Literature : Salter, J. W. , On some new Fossil Crustacea, etc. Quar. Journ. Geol. Soc, 1856-62,
vols, xii., xix. — -On New Silurian Crustacea. Ann. Mag. Nat. Hist., 1860, vol. v. — Hall, J.,
Palaeontology of New York, 18,59, vol. iii.— 16th Ann. Kept. N.Y. State Cabinet Nat. Hist., 1863.
— Woodward, //., On a new Genus of Phyllopodous Crustacea. Quar. Journ. Geol. Soc, 1866,
vol. .xxii.— Geol. Mag., 1872, 1882, 1885.— C'/«)fs, C, Ueber den Ban und die systeniatische
Stellung von Nebalia. Zeitschr. wissenscli. Zool., 1873, vol. xxii. — tJber den Organismus der
Nebaliden. Arb. zool. Inst. Wien, 1888, vol. viii. — Barrande, J., Systeme Silurien du centre de
la Bohenie, I. Suppl., 1872. — Etheridge, R., On Dithyrocaris andAntluapalaemon in Scotland. Quart.
Journ. Geol. Soc, 1879, vol. xxxv. — Whitfield, li. P., Notice of new Forms of Fossil Crustacea,
etc. Amer. Journ. Sci., 1880, vol. xix. — Clarke, J. J/., New Phyllopod Crustacea from the
Devonian. Amer. Journ. Sci., 1882, vol. xxiii. — New Discoveries in Devonian Crustacea. Ibid., 1883,
vol. XXV. — Ueber deutsche oberdevonische Crustaceeu. Neues Jahrb., 1884, vol. i. — On the
Structure of the Carapace in Rhinocaris, etc. Amer. Nat., 1893, vol. xxvii. — 14tli Rept. State
Geol. N.Y. I., 1898. — Beecher, G. E., Ceratiocarida, from the Upper Devonian Measures. 2nd Geol.
Surv. Penn. Rept. PPP, 1884. — Tdem, Revision of the Pliyllocarida from the Chemung and Waverly
Groups of Pennsylvania. Quar. Journ. Geol. Soc, 1902, vol. Iviii. — Tones, T. li., and Woodioard,
H., Various Papers in Geol. Mag., 1884-94, and Reports l-12of Comm. on. Fossil Phyllopoda, Brit.
Assoc. Adv. Sci., 1883 95. — Nurdk, 0., Remarques sur le genre Aristozoe. Sitzungsber. bohm.
SUBCLASS II EUCEUSTACEA— PHYLLOCARIDA 749
with a movably articulated rostral plate. Eyes pedunculate ; thoracic limbs foliaceous ;
no brood-plates (oostegites) ; first four pairs of abdominal limbs biramous, last two
piairs reduced.
This definition is based on the characters of the Recent genus Nebalia
(Fig. 1452) and its allies, which Packard first grouped together under the
name Phyllocarida with the fossils described below. Many of the fossils,
however, show important differences from the Recent genera {e.g. in the
number of abdominal somites) which may eventually require the establishment
of new orders if they are to be retained within the division of Phyllocarida.
Cephalic appendages have not been satisfactorily determined in any fossil
species, although traces of them have been noticed in a few genera (Cryptozoe,
Ceratiocaris, Bhinocaris). In the absence of contrary evidence there is reason
to suppose that the appendages of the head, thorax and abdomen were
after the type of Nebalia, since there is close correspondence in the form of
carapace, rostrum and abdomen. Owing to the non-preservation of limbs,
distinctions within the group are based principally on diff'erences in the
structure of the carapace, and in number of body - segments. Several
fossil genera (Echinocaris, Bhinocaris, Mesothyra) bear
a distinct optic node or pit, suggesting a sessile
simple eye in contradistinction to the stalked facetted
eye of Nebalia. In these genera, also, large cuspidate
masticatory organs (Fig. 1451) have been found,
which were apparently attached only by means of
muscles ; these are compared by H. Woodward with
the gastric teeth of the lobster. From the Middle
Cambrian of British Columbia Walcott has described
wonderfully preserved specimens of Phyllocarida
(new species of Hymenocaris, etc.) showing append- fig. 1451.
ages, which will probably repay more detailed Gastric teeth of EcUnocans
, • , • punctata Hall. Hamilton :
investigation. Pratfs Fails, New York. %.
Suborder A. NEBALIINA Clarke.
Carapace folded, univalved and rostrate.
Family 1. Nebaliidae Baird.
Cephalic appendages five, thoracic eight, abdominal eight, terminating in two caudal
spines. No metamorphosis; development direct.
Nebalia Leacli (Fig. 1452). Represented by a few marine species inhabiting
shallow waters. Paranehalia and NebaUopsis are also Recent and marine.
Akad. Wissens., 1885. — Ibid., 1886. — On Occurrence of a New Form of Discinocaris in Bohemia.
Geol. Mag., 1892, dec. 3, vol. ix. — Sars, G. 0., Report on the Phyllocarida (Leptostraca). Kept,
Challenger Expedition, 1887, vol. xix. — Hall, J. and Clarke, J. AL, Palaeontology of New York,
1888, vol. vii. — Whitfield, R. P., New Genus of Phyllocaridae. Bull. Airier. Mus. Nat. Hist.,
1896, vol. V\n.^Jones, T. R., and Woodvxt7-d, H., Monograph of the British Palaeozoic Pliyllopoda
(Phyllocarida, Packard), Part iii. Palaeontogr. Soc, 1898. — Clarke, J. M., Some Devonic and
Siluric Phyllocarida from New York. 54th Ann. Kept. N.Y. State Mus., 1900 (1902). — Tr«/co«,
C. B., Middle Cambrian BranchioiDoda, Malacostraca, Trilobita and Merostomata. Smithson,
Misc. Coll. 1912, vol. Ivii. No. 6.
750
ARTHROPODA
PHYLUM VII
Suborder B. HYMENOCARINA Clarke.
Nebalia-like forms toith folded univalved carapace; rostrum wanting (1).
Family 1. Hymenocaridae Salter.
Body with eight to nine thoracic and abdominal seginents, and six caudal spines in
three fairs.
Hymenocaris Salter (Fig. 1453). Carapace narrow in front, very broad posteriorly,
convex ; surface smooth or faintly lined. Cambrian ; Wales and British Columbia.
Fig. 1452.
Nebalia geoffruyi M. Bdw. Recent ; Mediterranean. «/i.
Fig. 1453.
Hymenocaris vennicauda Salter.
Uppei' Cambrian ; Dolgelly, Wales.
i/i (after Salter).
Several peculiar genera described by Walcott under the names of Hurdia, Tuzoia,
Odaraict, Fieldia and Garnarvonia, from the Middle Cambrian of British Columbia,
are doubtfully referred to this family.
Suborder C. CERATIOCARINA Clarke.
Carapace bivalved, with a median symphysis and a free rostrum.
Family 1. Ceratiocaridae Salter.
Carapace pod-shaped, smooth and without eye-nodes.
Geratiocaris M'Coy {Entomocaris Whitf.) (Fig. 1454). Valves of carapace elongate,
sub-ovate or sub-quadrate,
^^ narrow in front, sub-
VX* truncate, but not in-
j Bi^^ curved behind. Surface
without nodes or carinae.
''tt Antennae (?) obscure; suj)-
posed gastric teeth large,
cuspidate. Rostrum
lanceolate. Body seg-
ments fourteen or more.
Fig. 1454. four to sBvcn extending
Cemtiocaris papiUo Salter. Ordovician ; Ijanark- lieyond the carapace, SOme
sliiie. rt, Traces of antennules (?); m, Toothed plates, f flipiii witli nh^pnrp
possibly the mandibles ; r, Rostral J.late. l/j (after °^ U^e^n A\ llil ODhCUre
H. Woodward). branchial ajjpendages
(uropods). Telson long,
spinose on the edges ; two lateral appendages or cercopods. Abundant in Ordovician
and Silurian ; Europe and North America.
SUBCLASS II
EUCRUSTACEA— PHYLLOCARIDA
751
Cardiolites Nicli. Supposed tracks of Geratiocaris (?). Silurian ; Scotland.
Garyocaris Salter. Carapace smootli, narrow, sub-acute in front, thick. Abdomen
unknown- ; caudal plate with three spines. Cambrian ; Wales.
Physocaris Salter. Carapace bladder-shaped, pointed in front, bivalved (?), smooth.
Abdomen smooth ; telson longer than the cercopods. Silurian.
Lingulocaris, Saccocaris Salter. Very imperfect remains of Crustacean bodies.
Lingula Flags ; Wales.
Acanthocaris Peach. Carapace small, with a blunt snout in front ; surface smooth.
Body segments numerous, seven exposed beyond the carapace. Telson long ; cercopods
short or rudimentary. Lower Carboniferous ; Scotland.
Xijthidiocaris Jones and Woodw. (emend.). Known only by its long curved blade-
like telson. Silurian (Ludlow) ; England. (A", ensis Salter.)
Gryptozoe Packard. Carapace smooth, broadly rounded in front ; imperfectly
known. Coal Measures ; Illinois. (C. problematicus Packard). Probably congeneric
with the Carboniferous species named Geratiocaris oretonensis and C. truncata Woodw.,
in which traces of four cephalic appendages have been found.
Golpocaris Meek. Carapace smooth, with deep anterior marginal sinus and sharp
extremity. Caudal plate with three .spines. Lower Carboniferous ; Kentucky.
Strigocaris Vogdes (Solenocaris Meek). Carapace narrow and elongate, with
longitudinally striated surface ; very imperfectly known.
Lower Carboniferous ; Kentucky.
Nothozoe Barrande. Doubtfully assigned here. Ordovi-
cian ; Bohemia.
Phasganocaris Noviik., Known only from the abdomen
and telson. Last segment long, cylindrical, with strong
articulation. Telson articulated to the cercopods by dee]>
sockets ; edges spinose. Surface scaly. Lower Devonian ;
Bohemia.
Macrocaris Miller. Carapace valves very narrow in
front, broad behind, strongly lineate. Body segments
numerous. Lower Carboniferous ; Kentucky.
Family 2. Echinocaridae Clarke.
Garapace elongate or oval, with nodes {r)iuscular or seg-
mental) in the cejyhalic region, one of which in each valve
may he ocular hut hears no optic pit; one or more lateral
,i,u,,, carinae usually present.
•^Uii/j^^ A free rostrum has been
observed in some genera.
Echinocaris Whitf.
(Figs. 1451, 1455). Hinge
short, carapace sub - oval,
broad in front, not in-
curved behind, no postero-
lateral spinules ; a single
sigmoid carina on each valve, sometimes a small
accessory ridge near the hinge. Surface punctate
and pustulose, no longitudinal striations. Of the
body segnifints, six are ex^aosed and bear small
spines on their surface and posterior margins.
icarishorrijiiiata Clarke, cheimmg Telson and cercopods are spines of imequal size.
Alfred, New York Vi (after M^rl^qi^ a^^ TT^..^,. n^,.«,.,-o,. • xr^,.fL A».o^i.a
Fig. 1455.
Echinocaris punctata (Hall).
Hamilton Group; Pratt's Falls,
New York, i/i (after Beecher).
Fig. 1456.
I'ephr
Group ;
Clarke).
Middle and Upper Devonian ; North America.
752 AETHROPODA phylum vii
Pephricaris Clarke (Fig. 1456). Carapace as in the last, but without the lateral
carinae. Margins provided with a single row of long recurving spines. Three or
four abdominal segments protrude beyond the carapace, the last two having a single
pair of long sjiines. Ujiper Devonian ; New York.
Aristozoe Barr. (Bactrojms Barr.). Carapace with cephalic node well developed,
but without lateral carinae. But one abdominal segment known, and this is very-
long, cylindrical, with an intricate hinge at the articulation with the caudal spines.
Telson a long spine with a row of spinules on each lateral edge. Novak has shown
that of Barrande's three species, Aristozoe regina, Bactropus longipes and Geratiocaris
dehilis, the first rej^resents the carapace, the second the last abdominal segment, and
the third the telson of one form, A. regina. Devonian ; Bohemia. Species referred
to the same genus have been described from the Cambrian of North America and
Devonian of Germany and Russia.
Orozoe and Callizoe Barrande are presumably allied to Aristozoe, Silurian ;
Bohemia. Zonozoe Barr. and Solenocaris Young are not Crustaceans.
Eleutherocaris Clarke. Carapace elongate-subc^uadrate, truncate in front, incurved
behind ; rostrate (?). Broad, obscure nodes in the cephalic region ; lateral carinae
single, anterior and very short. Body segments unknown ; caudal plate with a
slender telson and cercopods of equal length. Surface of all known parts more or less
strongly tuberculated. Upper Devonian ; New York.
Ptychocaris Novak. Valves elongate-subquadrate, posterior margin sloping or
slightly incurved. Ceijhalic region with a cluster of small nodes in front, and two
larger nodes behind. Lateral region with a single long sigmoid carina. Surface
striated with raised longitudinal lines. Abdomen and tail unknown. Lower
Devonian ; Bohemia.
Elymocaris Beecher. Surface of carapace evenly convex, smooth, without lateral
carina ; hinge line long ; posterior margin convex ; cephalic
nodes obscure ; rostrum not observed. Abdomen with two ex-
posed segments ; caudal plate short, with broad convex, rapidly
tapering telson and two cercopods, setigerous on their inner
margins. Middle Devonian ; New York. Upper Devonian ;
Pennsylvania.
Tropidocaris Beecher (Fig. 1457). Carapace with truncate
posterior margins ; ocular node well defined, other cephalic
nodes obscure ; rostrum narrow and ridged ; surface of valves
Fi(i. 1457. with several strong longitudinal carinae. Abdomen with two
Trojndocans hicarmata exposed segments, which are sub -cylindrical and without
Beecher. Chemung . . "^
Group ; Warren, Penn. spinules. Upper Devonian and Lower Carboniferous ; Penn-
Carapace and rostrum, i/i qvlvania
(after Hall and Clarke). syivania.
Emmelezoe Jones and Woodw. Valves of carapace elongate,
narrow, and with distinct ocular node ; other cephalic nodes wanting. Surface with
fine longitudinal raised striae. Abdomen unkno-wii. Sihtrian.
Suborder D. RHINOCARINA Clarke.
Carapace with a free rostrum and narroio median dorsal plate separated from the
valves by a straight or slightly curving hinge at each side. Ocular nodes clearly defined,
with a distinct optic pit at the summit.
Family 1. Rhinocaridae Clarke.
Valves articulated by interlocking at the single point ivhere they come in contact.
Abdominal segments two to three. Posterior margin of carapace concave and spined.
SUBCLASS II
EUCRUSTACEA— PHYLLOCAEIDA
753
Rhinocaris Clarke (Fig. 1458). Carapace smooth, with fine raised longitudinal
striae ; divergent, branching furrows radiating backward from the eyes. Lateral
carina very faint. Abdomen with two or three free segments, the last much longer
than the others ; all diagonally striated or chevroned. Caudal plate with a broad
Fig. 1458.
Rhinocaris columbina Clarke. Ham-
ilton Group ; Canandaigua Lake, New
York. .-1, E, Dorsal and lateral views of
animal. B, D, Same of rostrum, en-
larged. C, Median plate, enlarged.
Fig. 1459 bis.
Mesothyra oceatii Hall. Portage Group
(Upper Devonian) ; Ithaca, New York. A,
Eye. B, Hinge of right valve, i/j.
Fig. 1459.
Mesothyra oceani HaU. Upper Devonian; New
York. Reconstruction of carapace and abdomen.
1/2 (after Hall and Clarke).
telson and two long and slender cercopods fimbriated on their margins. Middle
Devonian ; New York.
Mesothyra Hall and Clarke (Fig. 1459). Carapace large, valves distinctly inter-
locking at point of contact. Lateral carinae strong, crenulated at the summit.
Abdomen with two broad, exposed segments. Telson shorter than the cercopods,
the latter setigerous. Upper Devonian ; New York.
Dithyrocaris Scouler {Argas Scouler). Very similar in aspect to Mesothyra,
with the junction line of the valves overlapped by a (free ?) rugose ridge or narrow
interstitial plate. Rostrum not observed. Devonian and Carboniferous ; Scotland.
Rachura Scudder, known only from the abdomen and telson, is probably allied to
Dithyrocaris. Carboniferous ; Illinois.
Chaenocaris Jones and W. Carapace valves with a very strong lateral ridge and
without posterior spine. Carboniferous ; Scotland and Belgium.
VOL. I
3 c
754
ARTHROPODA
THYLUM VII
Suborder E. DISCINOCARINA Clarke.
Sub-circular or oval shields with a triangular rostrum filling an anterior notch.
Surface ornamented with raised- concentric lines. Substance chitinous.
Family 1. Discinocaridae AVoodward.
Test convex, sometimes mesially ridged ; in a single piece.
Discinocaris Woodw. Shield sub-circular, rostral notch and rostrum angular.
Abdominal segments and caudal spines have been referred to this
genus by Jones and Woodward. Silurian ; Great Britain,
Bohemia.
Aspidocaris Reuss. Similar to Disrinocaris. Raibl Beds
(UpiJer Trias) ; Hallstadt.
Dipterocaris Clarke (Fig. 1460). Shield with a deep posterior
notch, sliorter than the anterior or rostral notch. Sides of shield
sloping. Silurian ; Scotland. Ui^per Devonian ; New York.
Fig. 14(50.
Diptfivcaris ivtustus
d'Aich. and Verii. Pe-
vonian ; Eifel. i/j.
Peltocaris Salter.
Abdomen unknown.
Family 2. Peltocaridae Salter.
notch and plate.
A numbei'
Shields mesially sutured.
Circular shields with a rounded rostral
Ordovician ; Great Britain.
Apityrhopsis Barr. (Fig. 1461). Like Peltocaris, but with the
rostral notch angular. Silurian ; Bohemia and Great Britain.
Pinnocaris Etheridge. Similar to Dipterocaris, but bivalved.
Ordovician ; Scotland. (P. lapirorthi Etheridge jun.)
Fki. 1461.
AptyrhopsU j)7'i))i«.s
Addendum. '^arr. ordovician (D) ;
Branik, Bulipniia. l/i
„ . . ^ ,. . _,. - ,„,-,> (af'tei- Bai'Kin(]e).
ot generic names, sucJi as vardiocaris (rig. 1462),
Ellipsocaris, Pltoladocaris Woodward, and Sputhiocaris Clarke,
have l^een applied to Devonian fossils whicli closely resemble the
Silurian Discinocaris, of whose Crustacean nature there seems to
be 110 doubt. Some of these l)odies, however (Garcliocaris), have
been found in the living chamber of Goniatites {G. intumescens),
and have undoubtedly served as opercula or aptychi of these
Cejahalopods ; of others the nature is not fully understood.
Lisgocaris Clarke is not a Crustacean ; Gryptocaris Barrande is
})robably the operculum of a Hyolithoid ; Myocaris Salter is
stated to be a Pelecypod ; Proricaris Baily was founded on
parts of Geratiocaris ; Grescentilla and Pterocaris Barrande are
doubtfully Crustacean.
Fia. 1462.
Vardiocaris (Anajiti/-
rhns?) rocmeri Woodw.
Upper Devonian ;
Blidesheini, Eifel. Vi-
Series 11. EUMALACOSTRACA Grobben.
Abdomen of six somites, all of which may hear appendages, and a telson ivhich
never bears movable furcal rami. Thoracic limbs rarely all similar, fi/picalhj
pediform.
The remains of Crustacea presenting the primitive " caridoid fades," as
described above, occur in the Carboniferous, and it may be that the Eumala-
costraca had their origin in that epoch. If certain Devonian fossils are
SUBCLASS II
EUCRUSTACEA— SYNCARIDA
755
correctly assigned to the Isopoda, however, the origin of the series must
have been considerably earlier.
Vlll
Division A. SYNCARIDA Packard.'
Order. ANASPIDACEA Caiman.
Carapace absent. First thoracic somite fused with the head, or defined therefrom
by a groove. Eyes pednncidate or
sessile. Thoracic legs typically toith
exopodites ; no oostegites. Uropods and
telson forming a tail-fan.
The name Syn-
carida was applied
by Packard to a
group of Carboni-
ferous and Per-
mian Crustacea of
which the affinities
long remained ob-
scure.
Fig. 1463.
Anaspides tasmaniae Thomson.
The dis-
covery, in the
fresh waters of
Tasmania and
Australia, of living forms with similar characters has thrown a new light on
A - S
Recent ; Tasmanm. Male, 3/,. c.gr, "Cervical
^n-oove " ; ii, viii, Second and eighth thoracic somites ; 1, 6, First and sixth ab-
dominal somitea (after Caiman).
Fig. 14G4
Palaeocaris typus Meek and Worthen. Coal Measures ; Illinois. A, Restoration of body, omitting eyes, 4/^.
B, Telson and uropods, 6/j (after Packard).
the subject, and reinvestigation of some of the fossils has only emphasised
their close agreement with the Recent Anaspides (Fig. 1463) and its allies.
Of the fossil genera, Palaeocaris Meek and Worthen (Praeanaspides
1 Literature : Jordan, H. , and Meyer, H. von, Crustacean der Steinkohlenforniation von
Saarbriicken. Palaeontogr. , 1854, vol. iv. — Brocchi, P., Note sur un Crustace, etc. Bull. Soc.
Geol. France, 1880, ser. 3, vol. \m.— Packard, A. S., On the Syncarida, etc. Mem. Nat. Acad.
Sci. Washington, 1886, vol. iii. — Thovison, G. M., On a freshwater Schizopod from Tasmania.
Trans. Linn. Soc. London (2) Zool., vi., 1894. — Caiman, W. T., On the Genus Anaspides, etc.
Trans. Roy. Soc. Edinburgh, 1896, vol. xxxviii., pt. iv. — On Pleurocaris, etc. Geol. Mag.,
1911, dee. 5, vol. viii. — Fritsch, A., Fauna der Gaskohle, 1901, vol. iv., Heft 3, Crustacea, etc,
— Woodivard, H., Some Coal-measure Crustaceans, etc. Geol. Mag., 1908, dec. 5, vol. v. —
Sayce, 0. A., On Koonunga cursor, etc. Trans. Linn. Soc. London (2) Zool., xi., 1908. —
Smith, G., On the Auaspidacea, living and fossil. Quart. Journ. Microsc. Sci., 1909, vol. liii.
756
ARTHROPODA
PHYLUM VII
Woodward) (Fig. 1464), from the Coal Measures of England and North
America, is now the most completely known. It resembles Anaspides in
general form, in the segmentation of the body, the pedunculated eyes, the
characters of antennules, antennae, and even of the minute mouth-parts^ the
exopodites of the thoracic legs, and the form of the tail-fan. The only
important difference between the two, apart from the delicate lamellar gills
which could hardly be looked for in a fossil, is the presence in I'alaeocaris of
a wedge-shaped first thoracic somite, which, in Anaspides, is fused with the
head.
Uronedes Bronn (Gampsonyx Jordan and v. Meyer) (Fig. 1465), from the
Lower Permian of Saarbriicken, resembles Falaeocaris,
but has one of the anterior pairs of legs enlarged and
armed with spines. Acanthotelson
Meek and Worthen, and Pleurocaris
Caiman, from the Coal Measures of
Illinois and of England respectively,
have the first thoracic somite fused
with the head and may perhaps have
no thoracic exopodites. These exo-
podites are also stated to be absent in
Gasocaris Fritsch, from the Permian
Gaskohle of Bohemia. Falaeorchestia
Zittel (Fig. 1466) and Nedotelson
Fio. 1460 PaiMorcMstm paraiieia Brocchi, are less Completely known,
Uronedes fimhrtatus (Fntsch). Coal Meas- i i p n • ^ ^ • ■
(Jordan). Rothlie- iires ; Lisek, near Beiann, and are doubtfully included in this
gendes ; Lebach, Saxony. Bohemia. i/j (after
i/j. Fritsch). group.
Fig. 1466.
Division B. PERACARIDA Caiman.
Carapace, when present, leaving at least four of the thoracic somites distinct ;
first thoracic somite always fused with the head. Eyes pedxincidate or sessile.
Oostegites attached to some or all of the thoracic limbs in the female, forming a brood-
pouch.
Of the orders included in this division, two, the Cumacea and Tanaidacea,
are unrepresented in the fossil state.
Order 1. MYSIDACEA Boas.^
The caridoid fades is retained. The carapace extends over the greater p)(^'>'t of
the thoracic region, hut does not coalesce dorsally with more than three of the thoracic
somites.
Among the caridoid forms known from Carboniferous rocks, Pygocephalus
Huxley, from the English Coal Measures, has recently been shown by
^ Literature: Sars, G. 0., Report on the Schizopoda. Scient. Results Challenger Exped.,
Zool., xiii., 1885. — Salter, J. ]V., Higlier Crustacea from British Coal Measures. Quart. Journ.
Geol. See, 1861, vol. xvii. — Etheridge, R., Occurrence of Anthrapalaemon in Carboniferous of
Scotland. Ibid., 1877, vol. xxxiii. — Ortmann, A. E., The Systematic position of Crangopsis, etc.
Anier. Journ. Sci., 1897, ser. 4, vol. iv. — Woodioard, //., On i\\& gewns Pygocephabts, etc. Geol.
Mag., 1907, ilec. 5, vol. iv. — Peach, B. N., Monograph on Higher Crustacea of Carboniferous Rocks
of Scotland. Mem. Geol. Surv. Great Britain, 1908.
SUBCLASS II
EUCRUSTACEA— PERACARIDA
757
H. Woodward to possess a brood-poiicb formed of overlapping oostegites;
and may therefore be referred, with little doubt, to the Mysidacea.
Crangopsis Salter, from the Lower Carboniferous
of Scotland and the base of the Waverly in
Kentucky is placed here by Ortmann, since it
has the jDOsterior thoracic somites distinct beneath
the carapace. Anthrapalaemon Salter (Fig. 1467),
Pseudogalathea, Tealliocaris, and Palaemysis Peach,
all from the Carboniferous, have also been referred
to this order.
Order 4. ISOPODA Latreille.^
Body usually broad and depressed. Carapace
absent; first thoracic somite, rarely also the second,
fused with the head. Abdomen short, the last somite
almost always coalesced with the telson. Eyes sessile.
Thoracic limbs without exopodites. Abdominal limbs
lamellar, branchial. , „ , ' '•,■,,„ ,, w
' Anthnipalneinon gractlis M. ana W.
Of the earlier fossils that have been referred ^°^l fl^^^j^^^^v^^^r
to this order, Oxyuropoda Carpenter and Swain
(Fig. 1468), from the Devonian of Ireland,
has the strongest claim to be regarded
as an Isopod. Its appearance earlier
1 Literature : A. On Recent Forms. — Beddard,
F. E. , Report on the Isopoda. Sci. Results Challenger
Exped., Zool., xi., IS85.— Hansen, H. J., Isopoden,
Cumaceen and Stomatopoden der Plankton-Expedition.
Ergebn. Planktou-Exped., ii., 1895.— /(fe?», On the
Family Sphaeroniidae. Quart. Journ. Micrpsc. Sci.,
1905, n.s. vol. xlix. — Miers, E. J., Revision of the
Idoteidae. Journ. Linn. Soc. London, 1883, vol. xvi.
— Richardson, H. , Monograph on the Isopods of North
America. Bull. U.S. Nat. Mus., 1905, vol. liv.~
Sars, G. 0., An account of the Crustacea of Norway,
vol. ii. Isopoda. Bergen, 1896-99.
B. On Fossil Forms. — Amnion, L. von, Beitrag zur
Kenntniss der fossilen Asseln. Sitzuugsber. Bayer.
Akad. Wiss., \^%2.~Andree, A'., Zur Kenntniss der
Crustaceen-Gattung A rthroiileura Jordan. Palaeontogr.,
1910, vol. W\\.— Carter, J., On fossil Isopods. Geol.
Mag., 1889, dec. 3, vol. vlSdwards, H. Milne, Sur
deux crustaces fossiles. Ann. Sci. Nat. Zool., 1843,
ser. 2, vol. xx. — Idem, On Archaeoniscus. Ann. Mag.
Nat. Hist., 1844, ser. 2, vol. xin.—Kunth, A.,
Crustaceen von Solenhofen. Zeitschr. Deutsch. Geol.
Ges., 1870, vol. x\\\.— Meyer, H. von, Ueber Palaeo-
niscus obtusus. Palaeontogr., 1858, vol. v. — Racovitza,
E. G., and Sevastos, R., Proidotea haugi, n.g., n.sp.,
etc. Arch. Zool. Exper. Paris, 1910, ser. 5, vol. vi.—
Renus, M., tjber Palaeosphaeroma uhligi, etc. Beitr.
Palaont. Geol. Osterr. - Ungarn, 1903, vol. xv.—
Woodward, H., Several papers in Trans. Woolhope
OxvuropoM im^nJcsC^v and Swain. Upper Field Club, 1870 ; Geol. Mag 1870 dec 1, vol. vii. ;
Old Red Sandstone ; Kiltorcan, Ireland, a, 1890, dec. 3, vol. vu. ; 1898, dec. 4, vol. \.~Jdem,
Portion of antenna; c, Chela (?) ; o, Eye; p, On Squilla, etc. Quart. Journ. Geol. Soc, 1879, vol.
Segment of body-limb ; « Uropod ; 1-7, xxxv.—Carpewto' G*. .ff., and ;S!wm(,, /., A Devonian
Thoracc segments; 1. -VI., Abdommal segments. /^ •• ^";'^ t-i a „i iqhq ,^.1 v^,-;;
i/i (after Carpenter and Swain). Isopod. Proc. Roy. Irish Acad., 1908, vol. xxvii.
Fig. 1408.
758
ARTHROPODA
PHYLUM VII
than the primitive caridoid forms may, however, justify some suspicion as
to its affinities. Praearcturus Woodward, from the Old Red Sandstone of
Herefordshire, has very slender claims to be admitted into
this order, and the same may be said of Amphipeltis Salter
(Devonian of Nova Scotia), and Arthropleura Jordan (Coal
Measures).
Undoubted Isopods appear in Secondary rocks, Urda
Miinster (Fig. 1469), from the Kimmeridgian of Solenhofen,
has some very peculiar characters in which it approaches
the males of the Recent Gnathia, differing, however, in the
large size of the eyes. Cyclosphaeroma Woodward, from the
Great Oolite and Purbeck, resembles in general form some
Recent members of the family SiDhaeromidae, as do also
Archaeoniscus Milne Edwards (Fig. 1470), from the English
Purbeck and Eosphaeroma Woodward (Fig. 1471), from the
Eocene and Miocene. Palaega Woodward (Fig. 1472),
Cenomanian and Oligocene, has a general resemblance to
the Recent Aega and allied genera. Proidotea Racovitza and Sevastos, from
A: A
ttJl
Fig. 1469.
Urda rostrata Munst.
Litliographie Stone ;
Solenhofen, Bavaria.
Vi (after Knntli)-
Fio. 1470.
A, ArclMconiscus brodei
M. Edw. Purbeck ; Vale
of Wardour, Wiltshire. 3/j
(after Woodward). B, Frag-
ment of matrix, i/i (after
Quenstedt).
Fio. 1471.
A, Eusphaeroma bro7igniarti
M. Edw. Middle Oligocene ;
Butte de Chaumont, near
Paris, s/i (after Woodward).
B, Fragment of matrix, i/j
(.after Quenstedt).
I)6...j;u:v
Fig. 1472.
I'alapija scrobiculatn (v.
Animon). Lower Oligo-
cene ; Hiiring, Tyrol, an.
Antennae ; o, Eyes ; jfi,
Uropod ; I-VII, Thoracic
segments ; 1-6, Abdominal
segments.
the Oligocene of Roumania, is closely allied to the Recent Mesidotea in the
tribe Valvifera.
Order 5. AMPHIPODA Latreille.i
Body usually compressed laterally. Carapace absent ; first thoracic somite, more
' Literature : Jlale, C. S., Catalogue of the .4inphipo(la in the Britis'h Museum, 1862. — Sars,
V,.
SUBCLASS II EUCRUSTACEA— EUCARIDA 759
rarely also the second, fused with the head. Abdomen short, ventrally flexed, the
last somite usually distinct. Eyes sessile. Thoracic limbs loithout exopodites, the
basal segments usually lamellar, carrying gills. Abdominal
appendages divided into two sets, the last three pairs directed
backwards, styliform.
Although various Paleozoic fossils from the Silurian ^^^ ^^.^
{Necrogammarus Woodward) and later rocks have been aa,n,narm oeninge.n^u
referred to this order, it is only in the Tertiary that Heer Miocpne ; oenin-
ci PI e " ^ 5?*""' Baden. 2/^.
undoiibted Amphipods appear, bome oi these, from the
Miocene, are referred to the Recent genus Gamriiarus Fabricius (Fig. 1473),
from which Palaeogammarus Zaddach, found in Baltic amber, is doubtfully
distinct.
Division C. EUCARIDA Caiman.
Carapace coalesced dorsally vnth all the thoracic somites. Eyes pedunculate.
No oosiegites.
Order 1. BUPHAUSIACBA Boas.'
Caridoid forms in which none of the thoracic appendages are specialised as
maxillipeds and the gills are in a single series attached to the bases of the thoracic
limbs.
Anthracophausia from the Calciferous Sandstone of Scotland is descrilied
by Peach as belonging to this group, but the points of resemblance are very
slight.
Order 2. DBCAPODA Latreille.'
The caridoid fades may be retained or may be very greatly modified. The first
three pairs of thoracic limbs are specialised as maxillipeds and one or more of the
(t. 0., An account of the Crustacea of Norway, vol. i., Ainijliipoda, Christiana, 1890-95. — Stebhing,
T. li. R., Report on the Amphipoda. Scient. Results Challenger Exped., Zool. , 1888, vol. xxix.
— Idein, Ganimaridea, in Das Tierreich, 1906, vol. xxi. — Zaddach, <•., Ein Aiiiphipod im Bernstein.
Hclniften physik.-cikononi. Ges. Konigsberg, 1864, vol. v.
^ For literature references see under the head of Mysidacea.
- Literature: A. On Recent Forms. — Alcock; A., Materials for a careinological fauna of India,
nos. 1-6. .Journ. Asiatic Soc. Bengal, 1895-1900, vols. Ixiv., Ixv., Ixvii.-lxix. — Idem, Catalogues
of Calcutta Museum, 1899-1910. — Bate, C. S. Report on the Crustacea Macrura. Scient. Results
Challenger Exped., Zool., 1888, vol. xxiv. — Boa.s, J.E. V., Studier over Decapoderues Slaegtskabs-
forhold. Dansk. Vidensk. Selsk. Skr., 1880, ser. 6, vol. i. — Borradaile, L. A., Classification of
Decapod Crustaceans. Ann. Mag. Nat. Hist., 1907, ser. 7, vol. xix. — Bouvier, E. L., Sur I'origine
homarienne des Crabes. Bull. Soc. Philomath., Paris, 1896, ser. 8, vol. viii. — Faxon, IF., Revision
of the Astacidae. Mem. Mns. Comp. Zool., Cambridge, 1885, vol. x. — Idem, Stalk-eyed Crustacea.
Albatross Reports, xv. Op. cit., 1895, vol. xviii. — Henderson, .T. R., Report on the Anomura.
Scient. Results Challenger Exped., Zool., 1888, vol. xxvii. — Herrick, F. //., The American Lobster.
Bull. U.S. Fish Comm., 1895, and Bull. Bureau Fisheries, 1911, vol. xxix.—IIti.dei/, T. II., On the
Classification and Distribution of the Crayfishes. Proc. Zool. Soc, London, 1878. — Ortmann,
A. E., Die Decapoden-Krebse des Strassburger Museums. Zool. Jahrb. Abth. Syst., 1890-94,
vols, v.-vii. — Idem, Das System der Decapoden-KreTise. Oj). cit., 1896, vol. xi. — Miers, E. J.,
Report on the Brachyura. Sci. Results Challenger Exped., 1886, vol. xvii.
B. On Fossil Forms. — Bell, T., Monograph of the fossil Malacostracous Crustacea of Great
Britain. Paleontogr. Soc, 1857-62. — Bittner, A., Brachyuren des vicentischen Tertiiirgebirges.
Denkschr. Akad. Wiss., Wien, 1877-83, vols, xxxiv., xlvi. — Carter, J., On Orithojisis bonneyi.
Geol. Mag., 1872, dec. 1, vol. ix.^Idem, Contribution to the imlaeontology of the Decapod Cru.stacea
of England. Quart. Journ. Geol. Soc, 1898, vol. liv. — Cushman, J. A., Fossil Crabs of the Gay
Head Miocene. Amer. Nat., 1905, vol. xxxix. — Efcdlvn, A., Description des crustaces fossiles.
760
ARTHROPODA
PHYLUM VII
following pairs are usually chelate. The gills are typically in several series attached
to the bases of the thoracic limbs and to the lateral wall of the thorax.
Although undoubted Decapods have not been recognised in formations
earlier than the Trias, it is probable that some of the caridoid forms known
from the Carboniferous may be the forerunners of this large and varied order.
Pig. 1474.
Penaeus meyeri Oppel. Upper Jura (Litliograpliic Stone) ;
Solenhofen. 1/2.
Suborder A. NATANTIA Boas.
Body usually compressed, rostrum compressed and serrated. First somite of
abdomen not much smaller than the others. Legs slender, sometimes with evopodites ;
any one of the first three pairs may he enlarged. Abdominal appendages well developed,
used for swimming.
Of the three tribes which compose this suborder, the Penaeidea and Stenopidea
agree in having the first three pairs of legs chelate (with a few exceptions in the
Penaeidea), and the side-plates of the second abdominal somite not expanded ; they
differ in that the third pair of
legs is much larger than the
first in the Stenopidea, but not
in the Penaeidea. The Caridea
never have the third pair of
legs chelate, and have the
side -plates of the second ab-
dominal somite expanded to
overlap those of the somites
in front and beliind.
The Penaeidea are some-
what doubtfully represented
in the Trias, but a long series of fossils from the Solenhofen Lithographic Stone can
be referred with certainty to this tribe. Some of these are included in the Recent
genus Penaeus Fabricius (Fig. 1474), while Acanthochirus Oppel, Bylg'ia, Drobna and
Dusa Miinster are extinct genera.
The Stenopidea comprise a small number of Recent forms which show some
Bull. Soc. Geol. France, 1859, ser. 2, vol. xvi. — Fritsch, A., Uber die Caliauassen der bdhmischeu
Kreide. Abhandl. Bolim. Ges. Wiss., 1868, vol. liv. — Knebel, W. von. Die Eryonjden des oberen
Weissen Jura von Siiddeutsclilaud. Arch. Biontol., 1907, vol. ii. — Lijrenthey, E., Uber die Brachy-
iiren der paliiont. Sanimlung des Bayer. Staates Termeszet Filzetek, Budapest, 1898, vol. xxi. —
Idem, Beitriige zur Decapodenfauna des ungarischen Tertiiii-s. Math.-naturw. Ber. aus Ungarn,
1898, 1903, vols, xiv., xviii. — Idem, Falaontol. Studien Uber tertiiiren Decapoden. Op. cit., 1907,
vol. xxi. — Idem, Beitriige zur tertiaren Decapodenfauna Sai-diuiens nnd Agyptens. Op. cit., 1908,
1909, vols, xxiv., XXV. — Mark, W. von der, Fossile Fische, Krebse und Pflanzen aus der Kreide.
Palaeontogr., 1863, vol. xi. — Idem, and Schluter, C, Neue Fische und Krebse aus der Kreide von
Westphalen. Op. cit., 1868, vol. xv. — Meyer, H. von, Neue Gattungen fossiler Krebse. Stuttgart,
1840. — Moericke, W., Die Crustaceen der Stramberger Schichten. Palaeontogr., 1897, Supplem.
vol. ii. — Oppel, A., Ueber jurassische Crustaceen. Palaeont. Mittheil. Mus. Bayer. Staates, 1862,
vol. ii. — Ortmann, A. E., On Limiparus in the Upper Cretaceous of Dakota. Anier. Journ. Sci.,
1897, ser. 4, vol. iv. — Pilshry, H. A., Crustacea of the Cretaceous formation of New Jersey.
Proc. Acad. Nat. Sci. Pliilad., 1901, vol. iii. — Hathbnn, M. J., Descriptions of fossil crabs from
California. Proc. U.S. Nat. Mus., 1908, vol. xxxv. — Schluter, C, Die Macruren-Decapoden
Westphalens. Zeitsclir. Deutsch. Geol. Ges., 1862. vol. xiv. — Idem, Kreide- und Tertiiir-Krebse des
nordlichen Deutschlands. Op. cit., 1879, vol. xxxi. — Idem, Podocrates im Senon von
Braunschweig. Op. cit., 1899, vol. Ii. — Stimpson, IT. , Fossil Crab from Gay Head. Journ.
Boston Soc. Nat. Hist., 1863, vol. vii. — Tribolet, M., Descriptions des cru.stacees dii terrain
neocomien. Bull. Soc. Geol. France, 1874-75, ser. 3, vols, ii., iii. — Mliitfield, B. P., American
si3ec\es oi' Iloploparia. Bull. Anier. Mus. Nat. Hist., 1907, vol. xxiii. — Winkler, T. C, Etudes sur
les genres Peinphix, Glyj}haeu, etc. Arch. Mus. Teyler, 1883, ser. 2, vol. \. — Woodward, H.,
Macrurous Crustacea, etc. Quart. Journ. Geol. Soc, 1872-76, vols, xxix., xxxii.
SUBCLASS II
EUCRUSTACEA— EUCARIDA
761
affinities with the Reptantia. The extinct genus Aegcr (Fig. 1475), which has
representatives in the Trias and also in the Solenhofen Lithographic Stone, agrees
with the Recent genera in having the third pair of legs chelate and much larger
than the first. It is, in all probability, a primitive member of this tribe.
Representatives of the Caridea are not known with certainty earlier than the
Kimmeridgian, though some Carboniferous fossils have been described as having the
enlarged side-j)lates of the second abdominal somite, whicli are characteristic of this
tribe. In the Solenhofen Stone numerous genera occur, some of which, such as TJdora
Miinster, and Udorella Oppe], have exopodites on the thoracic legs, a primitive
character suggesting affinity with the Recent family Acanthephyridae. Other
Solenhofen genera, in which these exopodites appear to be wanting, are Blaculla,
Fig. 1475.
Aeger tipularius (Schloth.). Upper Jura (Lithographic Stone) ; Eiehstadt, Bavaria. 2/.,.
Hefriga and Elder Miinster. The Recent deep-sea genus Oplophorus i\Iilne Edwards
(Acanthejihyridae) has been identified, with considerable probability, in the Upper
Cretaceous of Westphalia. Some Caridea are found in frosh-water Tertiary deposits,
as for example Homely s von Meyer, from the Miocene of Oeningen ; but it is
impossible to say what relation they bear to the groups of Recent Caridea that have a
fresh -water habitat.
Suborder B. REPTANTIA Boas.
Body often depressed, rostrum often absent, small and depressed if present. First
somite of abdomen distinctly smaller than the others. Leys stout, without exopodites,
the first jMir usually much larger than the others. First five pairs of abdominal
appendccges commonly small, not used for swimming.
§ 1. Palinura.
This section consists of lobster-like forms w4th the rostrum very small or often
absent, with the carapace fused at the sides with the epistome, and the exopodite of
the uropods not divided by a distinct suture. It includes two tribes (1) the Eryonidea
and (2) the Scyllaridea (or Loricata).
The Eryonidea comprise, among living forms, only a small number of genera
such as Polycheles Heller, and JFillemoesia Grote, which have chelae on the first four or
1
762
ARTHROPODA
PHYLUM VTI
on all five pairs of legs. All are blind and inliabit only the deep sea. The fossil
genera, however, include forms that lived in shallow water and probably possessed
eyes. The earliest is Tetrachela Eeuss, from the Upper Trias of Raibl. Eryon
Vie. 14Tti.
Erymi ■iinijiiiiqn'U!< (.St-lilotli.)- Litliograpliie Stone ; Solenhofeii, Bav.aria.
Vo.
Desmarest (Fig. 1476), of which finely preserved specimens ai'e found in the Upper
Jurassic Solenhofen Stone, ranges from the Lias (perliaps the Trias) to the Neocomian.
Tlie Scyllaridea, which are distinguished, among other characters, by having the
Fi(i. 1477.
Mecncliirus luniiiiiiiiiiiis (fichloth.). Ijithographic Stout' ; Eichstadt, Bavaria. i/.,.
first pair of legs imperfectly chelate, include the Spiny Lobsters {Falinuridae)
and their allies. The earlier forms should j^robably all be referred to the
extinct family Glypliaeidae, of which, the first representatives occur in the Trias.
Pemfhix von Meyer (Fig. 1478) occurs in the Muschelkalk. Lithogaster and
GUjphaea von Meyer (Fig. 1479) range fi'om Trias to Cretaceous. Pseudogly^ilucn
SUBCLASS II
EUCRUSTACEA— EUCARIDA
763
Oppel is Jurassic. Scwpheus and Preatya Woodward are Liassic. Mecochirus Kef.
(Fig. 1477) is found in tlie Middle and Upper Jura, and Meyeria M'Coy, in the
, . Neocomian. All of these have a more or less
distinct rostrum and the antennae moderately
developed.
PaUnurina Miinster, from the Lower Lias and
Solenhofen Stone, appears to be a member of the
Pali)iuridae, a family which has the rostrum sup-
pressed and the antennae very stout. Podocrates
Geinitz, from Upper Cretaceous and Eocene is
hardly to be distinguished from the Recent Linu-
parus Gray. Cancrinus Miinster, from Solenhofen,
which has the antennae short and very broad,
perhaps leads toward the ScyUaridae, in which the
antennae form liroad flattened plates. Scyllaridia
Pit;. 1478.
Pe.mphix aueurii Desm. Muschfilkalk ; Crailsheim,
Wiirtemberg. i/i-
Pi(i. U7'.i.
Glyphaea fenuiit Oppel. Lithographic Stone ;
Eichstiidt, Bavaria. A, Side-view, i/i- -'5, Rostral
region enlarged, a, a", First and second pairs oi'
antennae ; o, Eye ; s, Antennal scale ; M, Base of
second pair of antennae.
Bell is found in the Gault and London Clay, while the Recent Scyllarus Fabr. first
appears in the Chalk.
§ 2. AsTACURA. Lobsters and Crayfishes.
This section comprises only the tribe Nephropsidea (Astacidea) including the true
Lobsters and Crayfishes. In these, the rostrum is of moderate size, the carapace is
free from the epistome, and the exopodite of the uropods is divided by a suture.
The first three pairs of legs are chelate and the first pair is greatly enlarged.
The earliest member of this group is Eryma v. Meyer (Fig. 1480), found in the
Lias, and also occurring, together with Pseudoastacus, Stenochirus and Etallonia Oppel,
in the Solenhofen limestone. Isolated chelae of Magila (Fig. 1481) are abundant
throughout the Jura. Enoplochjtia M'Coy; Nyniphaeops Schlilter; Oncoparia Bosquet;
764
ARTHEOPODA
PHYLUM VII
Palaeasfacus Bell; and Hoidoixma M'Coy, occur in the Upper Cretaceous of Westplialia,
Bohemia and England, the last-named genus also occurring in the Tertiary. More
doulitfuUy, the Recent
genera ■which include the
Lobster,^ the Crayfish of
Europe, and the Norway
Fir.. 1481. Lobster (iVep/iroj3s of Leach),
Magiu snprajurensi.t have been stated to occur
(Quenstedt). Upper Jura; j ^^ Upper Cre-
Chela. taceous.
Fig. 1480.
Eryma leptodactylina (Germ.). Litho-
graphic Stone
(after Oppel).
Fio. 1482.
CaUiana!!sa archiaci M. Echv. Turonian ; Montdragon,
Var (after Mihie Edwards).
Fif!. 1483.
Callimiaxsa untiqua Otto. Turonian ; Turnau, Bohemia.
Right chela.
§ 3. Anomura.
This section includes forms which have the abdomen generally soft or bent upon
itself, with reduced side-plates and tail-fan. They are rare as fossils. The tribe
Galatkeidea is represented only by chelae from the Upiaer Cretaceous of Denmark,
referred to the Recent Galathea Fabr. Of the tribe Thalassinidea, the Recent
genus Gallianassa Leach (Figs. 1482, 1483) is known from the Kimineridgian, as
well as from the Cretaceous and Tertiary. Thcdassina Latreille is Tertiary and
Recent. The tribe Paguridea, including the Hermit-crabs and their allies, is very
doubtfully rejwesented in the Eocene of Hungary by chelae referi'ed to the Recent
Pagurus Fabr. The Hippidea are unknown in the fossil state.
§ 4. Brachyura. True Crabs.
The true Crabs have the abdomen small, bent under the thorax, and without a
tail-fan ; the carapace fused with the epistome at the sides and nearly always in the
middle line in front ; the third maxillipeds more or less broad and flattened, covering
the other mouth-parts.
^ The generic name Ilomarus Mihie Edw. is most commonly used for the Lobster, and Astacus
Fahr. for the Crayfish. Some writers, however, employ Astacvs Fabr. for the Lobster, and
Hotavuihiiis Leach for the European Crayfish. The questions of nomenclature involved cannot suit-
ably be discussed here, but reference may be made to a recent ruling (1910) of the International
Commission on Zoological Nomenclature.
SUBCLASS II
EUCEUSTACEA— EUCARIDA
765
The Dromiacea take the lowest place among the tribes composing this section
differing from the more specialised Brachyura in retaining many primitive characters.
Thus, the last somite of the abdomen often retains vestiges of uropods, the first
abdominal somite of the female has a pair of appendages, the fossettes for the reception
of the antennules are less clearly defined, and the gills are more numerous.
Among the Recent Dromiacea, again, the family Homolodromiidae is the most
primitive, its members, which inhabit the deep sea, presenting many features which
A
D
1484.
.(, Prosopoii marginatum, v. Meyer. Upper .Juni (e) ; Oerlinger Valley, l-So.
near Ulm. 3/2. B, P. personatwm. Upper Juiii (y) ; Weissiugen, Wurtem- Dromiopsis rugosa
berg. Rostrum enlarged. C, P. aculeutu in. v. Meym: .Same locality as ^4. (Schloth.). Uppermost Cre-
-D, P. pustulatuvi Quenst. Same locality as A. taceous ; Faxoe, Denmark.
link them with the Lobsters of the tribe Nephropsidea. It is therefore of special
interest to find, as Bouvier has shown, that the earliest fossil Brachyura, forming the
extinct family Prosoponidae, are allied, by the form of the carapace and the disposition
of the grooves upon it, tq the existing Homolodromiidae. In the majority of cases
the carapace alone is preserved, but portions of the abdomen and limbs are known in
Protocarcinus (Palaemachus) Woodward, from the Forest Marble (Bathonian) of
England. The genns Prosopon von Meyer (Fig. 1484) is of even earlier date,
appearing in the Bajocian and persisting to the Neocomian. Later forms approach
more specialised Recent types, such as Hotnolopsis Bell from the Gault, leading towards
the Homolidae ; and Dromiopsis Reuss (Fig. 1485), leading towards the Dromiidae.
The Tertiary Dromilites Milne Edwards, is scarcely different from the Recent Dromia.
The tribe Oxystomata is characterised by the form of the mouth-frame, which is
triangular and produced to the front of the head between the eyes. The earliest
examj^le of the tribe is Mithraciies Gould,
from the Lower Greensand. Palaeocorystes
Bell (Fig. 1486), ranges from the Gault
to the Eocene. Eucorystes and Necrocar-
cinus Bell (Fig. 1487), are found in the
Gault and Upper Greensand. The precise
relations of these to modern families are
doubtful. The Recent Calajypa and
Matuta Fabr., however, are known from
Eocene and later deposits.
The remarkable family Raninidae,
distinguished by the unusual form of the
chelae and by the elongate carapace,
which is broader in front than behind, is known as early as the Cenomanian chalk,
and its representatives are not rare in the Tertiary. Raniella and Raninoides
Milne Edwards, are Cretaceous genera. Of the few Recent genera, Ranina Lamarck
(Fig. 1488) is known from the Eocene.
The tribe Brachygnatha, in whicli the mouth-frame is quadrate, includes the great
majority of the Brachyura. It is divided into two subtribes, the Oxyrhyncha and
Brachyrhyncha.
Fig. 1486.
Palaeocorystes stokesi
(Mantell). Upper
Greensand ; Cam-
bridge, England.
Fig. 1487.
Necrocarcinus trlcarinatus
Bell. Greensand ; Cam-
bridge, England (after Bell).
766
ARTHROPODA
PHYLUM VII
The Oxyrhyncha have the carapace narrowed in front and produced into a more
or less distinct rostrum. Fossil forms are few and generally rather small.
Fio. 1488.
A, B, Ranina marestiana Ki'mis {=R. lidli Schafh.)- Eocene ; Kressenberg, Bavaria. Ventral and
dorsal view.s. C, Chela of 7.'. houilleana M. Bdw. Eocene ; Biarritz, Prance. 1/2-
Micromaia Bittner (Fig. 1489), and Microthorax
MicroiiMia tuhercvlata
Bittner. Eocene ; San
Giovanni Illarione, Italy.
(After Bittner.)
lateral. Since, however, i
they are not separated in
the more recent systems of
classification.
The Catometopous
families are not well repre-
sented among fossils. Litho-
pliylax Milne Edwards,
from the Upper Cretaceous,
is an early and somewhat
doubtful form. GnUnopsif^
and Coeloma Milne Edwards
(Fig. 1490) ; Liforicola
Woodward ; and Palaeo-
grapsus Bittner, are known
from the Eocene and Oligo-
cene. The Recen.t Gecar-
Noetling, are Eocene and
Miocene forms respectively.
The Recent Lambrus Leach
is known from the Eocene,
and Maia Lamarck from
the Pliocene.
The subtribe BracJiy-
ihyncha includes a large
number of families which
are often divided into two
groups: (1) the Gyclome-
topa, with the carapace
broad and arcuate in
front ; and (2) the Gatome-
fopa, in which the carapace
is more or less quadri-
t is impossible to distinguish the two groups sharply,
Fig. 1490.
Coehiiiia vigil M. Edw. Eocene :
Laverda, Italy.
Fio. 1491.
Ijobocarciiius paulino viierti-mhergicus v. Meyer.
Mokkatam, near Cairo, Egypt. Male.
Eocene ;
SUBCLASS II
EUCRUSTACEA— EUCAEIDA
767
cinus Leach, is stated to occur in the fresh-water Miocene deposits of Oeningen.
Archaeoplax Stimpson is found in the Miocene of Gay Head, Massachusetts.
The Cyclometopous families have many representatives in the Tertiary and a few
in the Cretaceous. The earliest are of Cenomanian age, inchiding Efyus Mantell and.
Fr(!. 1492.
XaiUhopsis krexsaibergmxis v. .Mpvcv. Eocene ; Kressenberg, Ba\-aiin. Male, ventral and dorsal aspects, 1/2.
doubtfully, the Recent Xantho Leach. Tifanocarcinus and Palaeucarpilius Milne
Edwards, appear in the Upper Cretaceous. The Recent Panopens Milne Edwards, is
said to date back to the Cretaceous. In the Eocene are found Harpartocardnus Milne
Edwards; LoSocamwMS Reuss (Fig. 1491) ; .ra?i</io|;s?:s M'Coy (Figs. 1492, 1493) ; and
Neptocarcinus and Carcinocarcinns Lorenthey. The Recent genera Cancer Linn. ;
Atercjidis de Haan ; and Etisus Mihie Edwards, are recorded from the Upper Eocene,
Pig. 1493.
Xanthopsis hruckmamii v. Meyer. Eocene ; Sonthofen,
Bavaria. Ventral view of female, Vi-
Fig. 1494.
J 'aammocarcinus iLericarti (Desm.). Middle Meeressand
(Miocene) ; Le Gue-a-Tresmes, France (afteri A. Milne
Edwards).
although the demonstration of their precise identity with Recent forms is not in all
cases satisfactory.
The easily recognised Swimming-crabs of the family Portunidac are certainly
represented as early as the Eocene by such forms as Psammocar cinus Milne Edwards
(Fig. 1494); Portunites B&\\; and the Recent iVepiwMfs de Haan. The River-crabs
\potamonidae) are said to be represented in the fresh-water Miocene of Oeningen by
the Recent genus Potamon Savigny {Thelphusa Latreille).
768
ARTHROPODA
PHYLUM VII
Division D. HOPLOCARIDA Caiman.
Order 1. STOMATOPODA Latreille.i
Carapace small, leaving at least four of the thoracic somites distinct and wn-
covered; with a movable rostral plate anteriorly. Eyes pedunculate. Eyes and
antennules home on movable segments of the head. First five pairs of thoracic limbs
sub-chelate, the second pair very large. Abdomen large and depressed, ending in a
tail-fan. First five pairs of abdominal appendages carrying tufted gills.
The existing Stomatopods form a very homogeneous group, within which
onljT^ one family (Squillidae) can be recognised, while many of the genera are
separated by comparatively slight differences. Representative forms are
Squilla Fabr. ; Lysiosquilla and Pseudosquilla Dana ; Gonodactyhis Latreille ; and
Coronida Brooks. Modern Stomatopods are exclusively marine, the adults
generally inhabiting burrows
in the sand or mud of the sea-
bottom in shallow water, chiefly
in the tropics, but extend-
ing also 50 degrees on either
side of the equator. Many
species seem never to wander
far from their burrows, into
which they retreat with great
rapidity when alarmed. The
larval stages, on the other
hand, are exclusively pelagic,
of glass-like transparency, and
occur in great numbers in the
plankton of the warmer seas.
All the Stomatopods appear
to be of active, predatory
habits. They range in size
approximately from 38 to
Fig. 1495. 340 mm.
Sculda pennata Mnnst. Upper Jura ; Bavaria, yl, £, Dorsal The existence of Stoma-
views, Vi and 3/i. C, Ventral aspect, s/i- «, e, First and second f^nnds; in PnlpnymV timps la
pairs of antennae (after Kunth). topoUS in raieOZOlC timCS IS
still doubtful. Necroscilla
Woodward, from the English Coal Measures, is based on a fragment of the
abdomen and telson. Perimerturns Peach, from the Carboniferous of
Scotland, shows several features, such as the massiveness of the abdomen and
the movable rostral plate, that suggest an affinity with this order. In the
Kimmeridgian of Solenhofen undoubted Stomatopods occur, some of which
are even referred to the Eecent genus Squilla Fabr. (also known from
1 Literatiu'e : Munster, G. Graf zu, Beitrage zur Petrefaktenkiuide. Parts iii. and v., 1840-
1842. — Mark, W. von der, and Schlutcr, C, Neiie Fische uud Krebse aus der Kreide von Westphalen.
Palaeontogr., 1868, vol. xv. — Kunth, A., Uber wenig bekannte Crustaceen von Solenhofen.
Zeitschr. Deutsch. Geol. Ges., 1870, vol. xxii. — Woodward, II., Contributions to the knowledge of
fossil Crustacea. Quart. Journ. Geol. Soc, 1879, vol. xxxv. — Brooks, W. A'., Report on the
Stomatopoda. Scient. Results Challenger Exped., Zool., 1886, vol. xvi. — Miers, E. J. On the
Squillidae. Ann. Mag. Nat. Hist., 1880, ser. 5, vol. v.
CLASS II ARACHNIDA 769
Cretaceous and Tertiary deposits). Sculda Miinster (Eeckur Miinst. ; Buria
Giebel) (Fig. 1495), also from the Solenhofen beds, differs considerably from
Recent forms. It is of interest to note that larvae of Stomatopods belonging
to what is known as the Erichtlms type have been recognised in the Cretaceous
of the Lebanon.
[With the underuoted exceptions this revision of the Eucrustacea has been prepared for the
present treatise by Dr. \V. T. Caiman, of the British Museum of Natural History. The
systematic account of the Branchiopoda and Ostracoda has been revised by Dr. R. S. Bassler,
of the United States National iMuseum, and that of the Phyllocarida by Dr. John M. Clarke,
State Geologist and Director of tlie New York State Museum at Albany. — Editoe.]
Class 2. ARACHNIDA.
Arthropods in which the branchial folds function as gills or as lungs, or heroine
metamorphosed into air-tuhes (tracheae) penetrating the body. The body is divided
into two regions, cephalothorax and abdomen, the line between the two passing behind
the sixth pair of appendages. Cephalothoracic segments usually coalesced, those of
the abdomen either free or fused. Frequently a piost-anal spine is present. Antennae
lacking ; genital openings upon the first abdominal somite ; midgut long ; spermatozoa
motile ; development without nauplius or zoea stages.
The affinities of the Recent Limulus and its extinct Xiphosurous allies
with the group represented by Scorpions, Spiders, etc., was pointed out by
Straus-Diirckheim as long ago as 1829, and additional reasons for removing
the Merostoraes from association with Crustacea were brought forward at a
later period by various writers, among whom may be mentioned Henri and
Alphonse Milne -Edwards, Dohrn, Lankester, van Beneden, Kingsley, Laurie,
Clarke and Ruedemann. Kingsley, in discussing the relations between
Limulus and the Crustacea on the one hand, and the Arachnida on the other,
has indicated the following points of agreement: (1) a branchial respii'ation ;
(2) absence of malpighian tubes ; (3) absence of salivary glands ; (4) absence
of embryonic envelopes ; and (5) presence of compound eyes. He has also
shown 28 points in which Limulus and the Arachnids agree, and in which
both differ from the other " Tracheates " (Myriapoda and Insecta).
The following points of likeness are considered as of special importance
for justifying the association of Merostomata with the Arachnida :
(1) The numerical homologies of segments and appendages; (2) the exact
homologies existing in the respiratory organs ; (3) the fact that the cephalo-
thoracic appendages are pediform, the basal joints serving as jaws ; (4) the
presence of true nephridia opening in the base of the third or fifth pair of
appendages or in both ; (5) genital openings in the seventh (or more probably
eighth) segment of the body ; (6) extreme length of the midgut ; (7) presence
of an internal structure, the entosternite ; (8) inclusion of the ventral nerve
cord and its nerves in the external artery and its branches ; (9) the close
similarities in the central nervous system.
The Arachnida form a more diverse class than the Insecta, and display
nearly as much differentiation among themselves in structure, size and habit
as do the Crustacea. The larger and more complex forms have a fixed and
constant number of segments, and in all Arachnida, as in Insecta and the
higher Crustacea, it is possible to analyse the body into twenty-one
VOL. I 3 D
770
AETHROPODA
PHYLUM VII
segments (or somites). Some of these, however, may be suppressed during
the ontogeny, not all of them persisting to the adult stage, or else becoming
fused in various ways.
The body segments of Arachnida are grouped together in higher aggregates
or categories, called " tagmata " by Lankester (or expressed more simply as
" regions "), of which three are usually distinguishable. These regions are :
(1) the prosoma, often termed also the " cephalothorax " ; (2) the mesosoma,
also called by some writers the "thorax" or " preabdomen " ; and (3) the
A B
nana
stern urn
-■3
en I la I
aperi:ulum
--- 3
Vn
'3
mala
aculeus.
Fin. 1496.
Duthus vccitarms Amoreux, a ty]iical OM-World Scorpion. A, Dorsal, and B, VRntral view.
i/;i (after Kraepelin).
metasoma (another name for the " postabdomen " or " tail " of earlier writers.
Fig. 1496). The first of these regions includes all of the segments in front
of the genital pore, usually six in number. The second, or mesosoma, begins
with the somite bearing the genital pore, and ends with the last somite which
bears free appendages, typically six segments in all. The third region, or
metasoma, consists usually of six segments, none of which bear appendages,
excepting that the terminal one often has attached to it a postanal "telson,"
which may be considered as in the nature of an appendage. The latter takes
in Scorpions the form of the sting, in Xiphosures and Eurypterids that of the
spine. Among Merostomes, where the body is sometimes sharply divided
functionally into two regions only (" cei:)halothorax " and "abdomen" as
CLASS II ARACHNIDA 771
they are then commonly called), the metasoma together with the mesosoma
make up the abdomen. The abdominal segments, although usually distinct,
are sometimes coalesced or fused.
Arachnids have the sexes distinct, and do not reproduce asexually or,
so far as known, parthenogenetically. As a rule there is little external
difference between male and female, except for a very frequent disparity
in size and an occasional modification of some of the appendages. In several
genera of Eurypterids two forms of opercular appendages of sexual significance
have been recognised, and, by analogy with Lmiulus, the more primitive of
these is assigned to the male, the more elaborate to the female. From this
it appears that, in Eurijpterus at least, the adult males are smaller than the
females, as is true of Limulus also. Mites, Scorpions and Pedipalps are
viviparous, but all other members of the class lay eggs.
Primitive Arachnids appear to have been altogether marine, and to have
breathed by gill-books borne on appendages. During or after Silurian times,
when their descendants acquired a terrestrial habitat and changed from
water-breathing to air-breathing, the gill-books sank into the body and
became lung-books or were replaced by tracheae. Eeference may be had to
the recently published works by Gaskell on The Origin of the Vertebrates (1908),
and Patten on The Evolution of the Vertehrates and their Kin (1912), for an
extended discussion of the so-called Arachnid theory of the origin of
vertebrates.
The Arachnida are divided into two subclasses, Merostomata and Enibolo-
branchiata. The chief distinguishing character of the former of these groups
is that the gills are patent and exposed, and (in living representatives)
malpighian tubules are absent. It is to be noted that both these features
are associated with aquatic life.
Subclass A. MEROSTOMATA Dana (emend. Woodward).^
(Syn. Gigantostraca Haeckel ; Delobranchiata Lankester.)
Six pairs of ambulator ij limbs about the mouth, the foremost of which terminates
in chelicerae. The rest serve as organs of locomotion, and their coxal joints for
prehension and mastication. Behind the mouth is a single or paired metastoma.
Frosoma {" cephalothorax") depressed, with usually a pair each of median ocelli and
laterally placed kidney-shajyed comptound eyes. Respiration by means of lamellar
branchiae borne on the apipendages of all, or all but one of the first six post-cephalic
segments, which collectively form the mesosoma. In Limulus there are no salivary
glands, no malpighian tubules, and no embryonic membranes {^^ amnion") are found
in development.
Concerning the origin of the subclass, it is to be noted that the early
appearance and later atrophy of the abdominal appendages is clearly a
feature that points to a common ancestor for the Scorpion and Merostomes
^ The best bibliographies of Merostomata, including also historical reviews of the group, are to
be found in the following memoirs : — Woodward, IL, A Monograph of the British Fossil Crustacea
of the Order Merostomata. Palaeont. Soc, 1866-78, pp. 21-30. — Packard, A. S., On the Car-
boniferous Xiphosurous Fauna of North America. Mem. Nat. Acad. Sci., 1885, vol. iii. pp. 153-6.
— Clarke, J. M., and Ruedemann, R., The Eurypterida of New York. Mem. 14, N.Y. State
Museum, 1912, p. 438.
772 AETHROPODA phylum vii
*
having such appendages. Also it is to be inferred that the cephalothorax
in the embryo of the Scorpion retains ancestral features, from the facts that
its length corresponds to about six abdominal segments and it equals the
latter in width.
A comparison of the larvae of all three, Eurypterids, Limulus and the
Scorpion, shows that the two last-named have lost the primitive form of the
abdomen by acceleration ; that of Limulus being much broadened, that of
the Scorpion abruptly contracted to the tail or postabdomen, while the
Eurypterids have best preserved the original gradual and uniform contraction.
The carapaces, of Eurypterids and the Scorpion have most nearly retained
the original proportions and form of the common ancestor. Of the cephalo-
thoracic appendages the chelicerae are alike in all three groups and obviously
ancestral in their form ; the remaining legs have taken quite different courses
of adaptation, the Scorpions having developed the powerful chelate pedipalps,
the Eurypterids the swimming legs, while those of Limulus have remained
relatively undifferentiated.
These and other facts tend to support the inference that neither Limulus
nor the Scorpions are derivable from Eurypterids, but that all three, while
related, have early separated ; and that the Eurypterids are still nearest in
their general aspect to the early common ancestor. The appearance of
Eurypterids in the Cambrian with the essential characters of the group is
in accordance with their larval aspect, while the early separation of Scorpions
from the primitive stock is evinced by the occurrence of typical Scorpions in
the Silurian, and by the fact that in the Carboniferous they show a greater
diversity of form than they do to-day. On the other hand the similarity of
the ancient Palaeophonus nuntius to Recent forms is conclusive evidence that
the Scorpions have been very " persistent types " and had developed their
typical characters much earlier than the Silurian. There is no reason to
doubt that, as there are Eurypterids in the Cambrian, the Scorpions also
reach back to that era, and the diversion from the common ancestor must
have already been inaugurated in early Cambrian time.
As to what this common ancestor was we have no clue. Surely the
Trilobites, which are true primitive Crustacea, are not ancestrally or other-
wise closely related to Merostomes, and the latter even in the Cambrian are
far removed from any possible synthetic ancestors, as is shown by their very
definite number of segments and the arrangement of their appendages. We
must search, therefore, for still more primitive Arthropods than the Crustacea
as ancestors of Merostomes and ilrachnids generally. In support of this view
Clarke and Ruedemann point to the absence of anything in the ontogeny of
the Eurypterids that would suggest a crustacean nauplius stage, the admitted
absence of all crustacean characters in the adult forms, and the equal absence
of all crustacean features in the ontogenies of Limulus and the Scorpion.
Order 1. XIPHOSURA Gronovius.i
Body, in mature types, distinctly trilohed longitudinally. Cephalothorax large,
semicircular, the compound eyes, when present, laterally situated, and ocelli near the
^ Literature : Hoeven, J. van dei\ Recherclies sur lliistoire iiaturelle et ranatoniie des Limules.
Leydeii, 1838. — Minister, G. Oraf zu, Beitriige zur Petrefaktenkunde. Parts i., iii., 1840. —
Gegenhaur, C, Anatomische Untersuchuugen eiiies Limixlus. Abliaudl. iiaturf. Ges. Halle, 18.58.
CLASS ir ARACHNIDA— XIPHOSURA 773
centre in front. First pair of appendages chelicerate. Metastoma with two small
accessory 2)Iates. Abdomen tvith seven to ten segments, which are dorsally free or
coalesced ; the six anterior ones provided with lamellar appendages on the under side.
Telson long, ensiform, movable.
Family 1. Oyclidae Packard.
Cephcdothorax small, orbictdar, discoidal or convex, calcareous or chitinous,
bounded by a distinct border. Cephalic appendages nearly as in embryonic Limulus.
Cyclus de Kon. (Fig. 1497). Known almost solely by the orbicular
cephalothorax with its imperfectly preserved appendages, which seem to be
simple swimming legs. Their enlarged joints cover the
ventral surface of the carapace everywhere except in
the centre, which is occupied by a V-shaped plate,
towards the pointed extremity of which all the basal
joints of the limbs converge. Coal Measures ; Great
Britain, Illinois and Missouri.
Family 2. Belinuridae Packard.
■ Body limnloid in^ general aspect. Cephalotltorax F'*'- ^^'•^'•■
rounded, with long, slender genal spines; its appendages as coafMeasm^'fSm Creek;
in larval Limulus. Abdomen with the segments in vart n'inois. cephaioUiorax show-
, , 7 77 T 1 , 1 . 1 J- -77 7 n ^ ing traces of let;s and alimentary
or almost wliolly consolidated ; telson of variable length. canal, i/i-
Belinurus Konig (Fig. 1498). Cephalothorax hippocrepiform, its central
portion surrounded by a broad, flat marginal area, which at the genal angles
is produced into a long, slender spine. Abdomen with eight segments,
besides the much-elongated, slender telson ; seventh and eighth segments are
consolidated. Upper Old Red Sandstone and Coal Measures of Great Britain
and northern France {B. belkdus Konig ; B. reginae Baily). Also in Coal
Measures of Illinois (B. lacoei Packard).
— Baily, W. IL, Explanation of Sheet 137 of the Maps of the Geol. Surv. Scotland, 1859.—
Remarks on Beliuiirus. Ann. Mag. Nat. Hist., 1863, ser. 3, vol. xi. — Giebel, O. G., Limulus
Decheni. Zeitschr. gesammt. Naturw., 1863, vol. xxi. — Meek, F. B., and Worthen, A. H., Kept.
(tboI. Surv. III., 1868, vol. iii. — Woodivard, H., Notes on Neolimulus, Cyclus, Merostomata, etc.
Geol. Mag., 1869-94, dec. 1, vol. v. ; dec. 3, vols, vii., ix. ; dec. 4, vol. i. — Dohrn, A., Embryologie
und Morpliologie des Limulus. Jenaische Zeitschr., 1871, vol. vi. — Packard, A. S., Development
of Limulus. Mem. Boston Soc. Nat. Hist., 1872, vol. i. — Idem, Anatomy, Histology and
Embryology of Limulus. Anniv. Mem. Boston Spc. Nat. Hist., 1880. — Idem, Carboniferous
Xiphosurous Fauna of North America. Mem. Nat. Acad. Sci., 1885, vol. iii. — Van Beneden,
M. E., Systematic Position of King Crabs and Trilobites. Ann. Mag. Nat. Hist., 1872, ser. 4,
vol. ix. — Milne-Edwards, A., Recherches sur I'anatomie des Limules. Ann. Sci. Nat., 1873,
ser. 5, vol. xvii. — Lankester, E. R., Limulus an Arachnid. Quart. Journ. Microsc. Sci., 1881,
vol. xxi. — Peach, B. N., Further Researches among Crustacea and Arachnida. Trans. Roy. Soc.
Ediub., 1882, vol. xxx. — Williams, H. S., New Limuloid Crustacean from the Devonian. Amer.
Journ. Sci., 1885, ser. 3, vol. xxx. — Hall, J., and Clarke, J. M., Palaeontology of N.Y., 1888,
vol. vii. — Kishenouye, K., Development of Limulus. Journ. Coll. Sci. Tokyo, 1891, vol. v. —
Kingsley, J. S., Embryology of Limulus. Journ. Morphol., 1892-93, vols, vii., viii. — Fritsch,
A., Fauna der Gaskohle. Prague, 1901, vol. iv. — Clarke, J. M., Pseudoniscus in the Eurypterus
Beds of New York. Rept. N.Y. State Palaeont. for 1900. (54th Ann. Rept. N.Y. State Mus.),
1902. — Rogers, A. F., Some new American Species of Cyclus from the Coal Measures. Kansas
Univ. Sci. Bull., 1902, vol. i.. No. 10. — Stromer von Reichenbach, E., tJber Molukkenkrebse.
Zeitschr. Deutsch. Geol. Ges. Mouatsber., 1907, vol. lix. — Gaskell, W. B., Origin of the
Vertebrates, London, 1908. — Patten, W., Evolution of the Vertebrates and their Kin, 1912.
774
AETHEOPODA
PHYLUM VII
Presfwichia Woodw. (Euproiips Meek; Anthracopeltis Boulay) (Fig. 1499).
Differs from Belinurus in having seven coalesced abdominal segments, besides
a short and obtuse caudal
spine. Outline of ab-
domen subsemicircular,
central axis of body
segments narrow. Coal
Measures; England,
northern France, Russia
and Illinois. Type, P.
anthrax (Prestw.).
Protolimuliis Pack.
Cephalothorax relatively
large, subsemicircular.
with small appendages ;
PlfJ. 149S.
Belinurus reqinae Baily. ^"'- l'*'^^-
Coal Measures ; Queen's Prestwichia danac (Meek). Coal Meas- .
County, Ireland. Vi (after ures; MazonCreek,Grundy County, Illinois. itS geiial angles lesS prO-
Woodward). 2/ (aft,er Packard). ' J j xi, • .r, "1
duced than in the two
preceding genera. Abdomen with six segments besides a large, thick caudal
spine. Upper Devonian (Chemung Group) ; Pennsylvania. Type, Prot.
eriensis (Williams).
Prolimulns Fritsch. Cephalothorax ellipsoidal, broader than long, without
genal angles, and with relatively long appendages. Abdomen rounded,
shorter than the cephalothorax, with lamellar appendages. Telson slender
equalling one-half the total body length. Permian ; Bohemia. Type, P.
ivoodwardi Fritsch.
Family 3. Limulidae Zittel (King or Horseshoe Crabs).
(Syn. XiphosuridaG Pocock.)
Body longer than broad; cephalothorax arched dorsalhj, the central jwrtion
separated from the sides by longitudinal grooves; marginal area large and flat.
Abdomen composed of six consolidated segments forming a simple sub-triangidar
shield, and a long slender telson. Six p)airs of abdominal limbs, five of them, having
over a hundred p)airs of gill-leaves.
Limulus Miiller, restricted by Fabricius (Fig. 1500). Living species belong-
ing to this, the solitary genus of the family, occur on the eastern shores of North
and Central America and Asia. According to Pocock's classification {Ann.
Mag. Nat. Hist., 1902, ser. 7, vol. ix.), the foui- Asiatic species are referable
to two genera distinct from Limulus s.s. In all forms the four cephalothoracic
feet are chelate, the sixth pair is furnished with a whorl of plates used in
pushing the animal through the mud. Gills are borne upon the five posterior
pairs of abdominal appendages, the anterior pair being without gills, but
having the genital opening upon the posterior face.
The males are smaller than the females, aud are fxirther distinguished by the hooked, not
chelate, termination of the second, or second and third appendages, a chai-acter which they
acquire only at maturity. The young embryo of Limulus is without an elongated caudal
spine, and swims freely by means of its abdominal appendages. With its marked lateral
eyes, segmented abdomen and body divided into median and lateral regions by longitudinal
grooves, it presents considerable resemblance to a Trilobite, and the stage has in fact been
CLASS II
AEACHNIDA— XIPHOSUEA
775
called the Trilobite stage (Fig. 1500, B). After the first moult the caudal spine begins to
elongate, and at this stage, while tlie abdomen retains its segmented larval character, a true
affinity with the Paleozoic Frestwichia and Bclinurus is clearly revealed. The prevailing
modern view is that in Limulus we have a member of the Arachnida which retains its water-
breathing liabit, and, in the features of the abdominal appendages, some traces of the
characteristic structure of the primitive crustacean stock from which the Arachnida originally
sprang.
The genus first makes its appearance in the Trias, one small species being known from
tlie Buntersandstein of the Vosges, and another, L. viccnsis Bleicher, from the Keuper of
C, Limulus jiriscui
Miinst. Muschelkalk ;
Laineck, near Bay-
reutli. Vi-
B, Embryo of Limulus,
ill the so-called "Trilo-
bite stage." Lateral
eves faintly .shown.
(After Dohni.)
A, Limulus walchi Desm. Lithograjihic Stone; Solenhofen, Bavaria.
hitter showing several pairs of imi)erfectly preserved ambulatory limbs. On the carapace, covering the prosoma,
are seen impressions of the lateral eyes.
Fic. 1500.
Dorsal and ventral aspects, the
Lorraine. L. loalchi is abundant in the Lithographic Stone of Bavaria ; L. nathorsti and
L. woodivardi are Jurassic species from Sweden and England respectively ; L. syriacus
occurs in the Cretaceous of the Lebanon ; and L. decheni occurs in the Oligocene brown coal
of Teuchern, near Merseburg.^
Order 2. SYNXIPHOSURA Packard.
Body elongated ; cephalothorax semicircular with more or less distinctly defined
m.cdian axis, and no facial sutures. Compound eyes generally present, ocelli not
^ Biihm, J., tjber Limulus decheni Zincken. Jahrb. Preuss. Landesanst. Bergakad., 1905,
xxvi. One of these specimens described by Btilim represents doubtless the largest known
vol
Limulus.
776 AKTHROPODA phylum vii
observed except in NeoUmidm. Abdomen trUobed, its segments free, the pleura jlat
and extended, and usually terminating in lateral projections or spines.
With tlie exception of the Cambrian Aglaspis (Fig. 1501), all the genera belonging to this
order are of Silurian age, and are too imperfectly known as yet to permit a satisfactory
grouping into families, although several such have been ]iroposed by Packard. Zittel united
them, together -with certain genera of Xiphosura, in the family Hemiaspidae, which term is
retained, but employed in a restricted sense.
Suborder A. AGLASPINA Walcott.
Body elongate, transversely trilohed, more or less sharply divided into tioo regions
only. Cephalothorax with or without sessile eyes; on the ventral side it has an
epistoma and five pairs of movable appendages. Abdominal
segments all free, varying from seven (Aglaspis) to tiuelve
{Emeraldella) in addition to the caudal spine.
Family 1. Aglaspidae Clarke.
Cephalothorax moderately large, trilohed ; abdominal seg-
ments with distinct axis and pleurae ; telson long and spiniform.
Aglaspis Hall (Fig. 1501). Cephalothorax relatively
Fig. 1501. large, its trilobed central portion short and conate, in front
Aglaspis eatoni whitf. of which are two approximate compound eyes ; bounded
w?s^cOT^in"'%'r ' ^°'^'' o^^ ^^^ sides by a distinct border. Abdominal segments
described as seven in number, flat and blade -like, not
grooved on the pleura ; telson a long and somewhat obtuse spine. Cambrian;
Wisconsin.
Under this family also are included three genera from the Burgess shale
member of the Stephen formation (Middle Cambrian) of British Columbia,
described by Walcott under the names of Molaria, Ilahelia and Emeraldella.
They are remarkable for displaying well-jDreserved abdominal appendages.
Suborder B, BUNODOMORPHA, nomen novum.
This group contains only the family Hemiaspidae, as at present constituted.
It is a somewhat heterogeneous assemblage, but recognised as separated from
the Aglaspidae by more than family dift'erences.
Family 1. Hemiaspidae Zittel.
This family, in its restricted sense, may be provisionally maintained
pending further investigation of the rare and in some respects obscure forms
embraced by it. The original definition of this family is no longer applicable,
its limits having become narrowed by the removal of various genera to
other groups.
Neolimulus Woodw. Cephalothorax short and broad, crescentic, elevated
mesially, and bearing one or two pairs of ocelli. Compound eyes lateral and
connected with the genal angles by a suture. Abdomen very broad anteriorly,
not distinctly divided into two regions, all of its segments free, trilobed and
CLASS II
ARACHNIDA— SYNXIPHOSURA
N, p. f*
/ 1 1
at least nine in number
discovered. Axial portion of abdomen
backwards. This genus has been understood
as connecting the Xiphosura with the Synxi-
phosura. Silurian ; Scotland. Type, N.falcatus
Woodw.
Bunodes Eichw. [Exapinurus Nieszk.) (Fig.
1502). Cephalothorax semicircular, convex,
with radial furroAvs from the median portion.
Facial sutures obscure, converging from the
posterior to the anterior margin. According to
Patten's interpretation, a median ("parietal")
and a pair of lateral eyes are present, but no
genal spines. Abdomen divided into an an-
terior portion (mesosoma or " thorax ") consist-
ing of six trilobite-like segments having a broad
median axis and lamellar pleura with diagonal
pleural lines ; and a posterior portion (meta-
soma or " postabdomen ") of four narrow seg-
ments, besides a long and acuminate telson.
External surface of carapace and somites pus-
tulose. Silurian ; Oesel.
Hemiaspis Woodw. (Lmuloides Salter) (Fig.
1503). General form similar to that of Bunodes.
Cephalothorax one -half
as long as broad, with
several genal
central portion
fined,
ments
besides
telson,
tinctly
the telson not observed in any specimen thus far
rapidly from before
diminishing
regions
Fio. 1502.
Bunodes lunula, var. schrenki, Niesz.
Silurian ; Rootzikull, Oesel. Drawing
made from a plaster model, as restored by
Patten, "-/i. Pros, Prosonia ; M.<, Meso-
soma, following which are the four narrow
somites and telson constituting the meta-
sotna ; le, Lateral eye ; pe, Parietal eye.
(Supposed antennae omitted.)
spines ;
well de-
Postcephalic seg-
nine in number,
the acuminate
more or less dis-
divided into two
(mesosoma and
metasoma), subtriangular
in outline, and with a
broad median axis which
tapers gradually from before backwards. Pleura flat
and short, the lateral margins of the sixth divided into
two lobes, as if compound. Segments seven to nine
are narrower and longer than the preceding, their
combined length equalling that of the tail-spine.
Silurian ; Scotland.
Bunodella Matthew. Prosoma small, postcephalic segments seven in number,
tapering posteriorly. Axial portion of the body elevated ; telson not observed.
Silurian ; New Brunswick.
Pseudoniscus Nieszk. (Fig. 1504). Prosoma relatively large, convex,
hippocrepiform, probably eyeless and without facial sutures ; genal angles
extended into short spines ; surface obscurely marked with radial furrows.
Postcephalic portion ("abdomen") strongly trilobed and trilobitiform, with
Fig. 1503.
Hem iaspis Vniiuloides Woodw.
SiluriaTi ; Leintwardine, Eng-
land. Vi (after Woodward).
778
ARTHEOPODA
PHYLUM VII
gradually tapering median axis. Segments nine in number, besides a short
pointed telson, all with smooth surfaces. The first five segments with
obliquely grooved pleura ; sixth and seventh
partly conjoined on the pleura, and corre-
sponding axial parts of the segments narrow ;
eighth and ninth segments narrow, lanceolate,
and with increasing retral curvature. Average
total length of animal 2 "5 cm. Silurian;
Oesel and New York State (Salina Group).
j Orders. EURYPTBRIDA Burmeister.^
Body elongated, with a thin cldtinous epi-
dermal carapace ornamented by fine scale -like
markings. Frosoma with tiuo large, sometimes
facetted lateral eyes and a pair of median ocelli ;
on the ventral side with six pairs of appendages,
the foremost of which is preoral and chelicerate.
Mouth bordered posteriorly by a metastoma.
" Abdomen " consisting of thirteen free segments,
of which the anterior six belong to the mesosoma
and bear ventrally five pairs of broad, foliaceous
appendages, corresponding or comparable to the
operadum and branchial appendages of Limulus.
Fio. 1504. jL . ^-'^-^ - ^ -^ ,
PseudoniscuB rooseveiti Clarke. Complete ^^'^ mctasoma cmsists of SIX free, annular seg-
individual. Silurian (Salina Group); Monroe ments without appendages, together with a loug
County, New York. »/i (after Clarke). , , , _, 7 i> ' J
or spatutate telson.
This order, which is restricted wholly to the Paleozoic, embraces the largest
Arthroijods known, some of them {Pterygotus, Stylonurus) having attained a length
1 Literature: Dekay, J. E., On a Fossil Crustaceous Auimal. Ann. N.Y. Lye. Nat. Hist.,
1825, vol. i.—M'Coij, F., Some British Fossil Crustacea. Ann. Mag. Nat. Hist., 1849, ser. 2, vol.
iv. — Roemer, F., Ueber ein E.xemplar von Eurypterus. Palaeontogr. , 1851, vol. i. — Huxley, T. //.,
On Himantopterus. Quar. Journ. Geol. Soc, 1856, vol. xii. — Idem, and Salter, J. W., On Ptery-
gotus. Mem. Geol. Surv. United Kingd., 1859, vol. i.—Page, D., Advanced Text-Book of Geology,
1856 and ISb'd.—Nieskowski, J., De Euryptero remipede. Dorpat, 1858.— ^a^/, J., Palaeon-
tology of New York, 1859, vol. m.— Salter, J. W., Some Fossil Crustacea, etc. Quar. Journ. Geol.
Soc, 1862-63, vols, xviii., xix. — Woodward, H., Numerous papers in Geol. Mag., ser. 1, dec. 1,
vols, i., ix., and Quar. Journ. Geol. Soc, vols, xxi., xxiii., xxiv., x.xvii., xxviii., etc, 1864-72.
— Idem, Monograph of British Fossil Crustacea, Order Merostoniata. Palaeontogr. Soc, 1866-78.
—Grate, A. R., and Pitt, W. H., New Crustaceans from Water- Lime Group (Eusarcus, Ptery-
gotus, etc.). Bull. Burtalo Soc Nat. Sci., 1875, vol. m.^Pohlman, J., Fossils of the Water-Lime
Group. Ibid., 1881-84, vols, iv., v. — Peach, B. N., Further Researclies among Crustacea and
Arachnida. Trans. Roy. Soc. Edinb., 1882, vol. xxx.— Schmidt, F., Miscellanea Silurica. Mem.
Acad. Imp. Sci. St-Petersb., 1883, ser. 7, vol. xxxl—Hall, J., Note on Eurypteridae. 2nd Geol.
Survey Penn., Rept. PPP., 188^.— Idem, and Clarke, J. M., Palaeontology of New York State,
1888, vol. \\\.— Whiteave.s, J. F., Palaeozoic Fossils of Canada, 1884, vol. in.— Fraipont, J.,
Euryptc'Tides nouveaux du Devonien. Ann. Soc. Belg. Geol., 1889, vol. x\\\.—Clctypole, E. W.,
On Eurysoma, Careinosoma, etc Amer. Geol., 1890-94, vols, vi., xm.— Laurie, M., Eurypterid
Remains from Pentland Hills. Trans. Roy. Soc Edinb., 1892, vol. xxx\\\.—Idevi, On Eurypterida.
Nat. Sci., 1893, vol. \\\.—Idem, Anatomy and Relations of the Eurypteridae. Ibid., 1893, vol.
xxxvii., and Nat. Sci., 1893, vol. m.—Holvi, G., tjber Eurypterus Fischeri. Bull. Acad. Imp.
Sci. St-Petersb., 1896, ser. 5, vol. iv. ; also Memoires, 1898, ser. 8, vol. viii., and Geol. For. i
Stockholm Fiir., 1899, vol. x\\.— Semper, M., Gigantostraken des bohmischen Palaozoicum. Beitr.
Pal. u. Geol. Osterr.-Ung., 1898, vol. \\.—Beccher, C. E., Restoration of Stylonurus. Amer.
Journ. Sci., 1900, vol. x.—Idem, Eurypterid Remains from Missouri. Ibid., 1900, vol. xii., and
Geol. Mag. 1900, dec. 4, vol. viii. —^'ar^e, C. /., Eurypterid Fauna from the Salina Rept. N.Y.
CLASS II
ARACHNIDA— EURYPTERIDA
779
of nearly three metres. The presence of gills upon the branchial appendages shows
that the Eurypterids were aquatic, and the structure of their appendages indicates
tliat they were for the most part mud-crawlers, though some were good swimmers.
They are found associated
with cephalopods and tri-
lobites in the Cambrian
and Ordovician of North
America ; with cephalo-
pods and marine arthropods
(Phyllocarids and Ostra-
cods) in the Silurian ; with
Ostracophores and Arthro-
dires in the Devonian ; and
with land plants, scorpions,
insects, fishes, and fresh-
water amphibians in the
productive Coal Measures.
It is ajiparent, therefore,
that from being originally
marine forms, they became
gradually adapted to
brackish, and jiossibly even
fresh-water conditions.
The Eurypterids and
Xiphosures present a num-
l)er of points of common
resemblance. Both groups
have a prosoma comi^osed
of at least six fused seg-
ments, and bearing two
pairs of eyes, one pair
simple, the other com-
pound, on the dorsal sur-
face of the carapace. The
number and. position of
the appendages of the
prosoma in Eurypterids
are the same as in Limulus,
and the chelicerae are
similarly constructed in
both cases. The basal joints of all five pairs of legs in Eurypterids are toothed and
function in mastication ; similarly in Limulus all are spiny except the coxae of the
last j)air of legs. In both groups a similar process called the epicoxite is borne upon
the coxae. On the mesosoma the genital operculum and plate-like appendages with
branchial lamellae are similar in both groups. A striking difference between them,
however, is seen in the segments of the mesosoma and metasoma, the somites being all
free in Eurypterids, but in Limulus fused together. The resemblance between Euryp-
terids and Scorpions is none the less striking, both groups showing the same number
Fig. liiOo.
Eurypterus remipes Dekay. Bertie Waterliine (Silurian) ; Herlvimer
County, N.Y. Restoration of dorsal aspect. Va (after Clarice and
Ruedemann).
State Palaeont., 1903. — Schmidt, F., tJber Stylouurus von Osel. Bull. Acad. Imp. Sci. St-Petersb.,
1904, ser. 5, vol. xx. — Seemann, F., Zur Gigantostrakenlauna BcJlimens. Beitr. Pal. u. Geol.
Osterr.-Uug., 1906, vol. xix. — Pruvost, P., Crustaces du nord de la France. Ann. Soc. Geol.
Nord, 1911, vol. xl. — Clarke, J. M., and Ruedemann, R., Eurypterida of New York. Mem.
N.Y. State Mus. no. xiv., 1912.
780
AETHROPODA
PHYLUM VII
■^--O'
of segments in the three regions of the body, and the appendages of the prosonia
being identical in number and position.
The general form of the body in Enrypterids (Fig. 1505) is somewhat like that
of a Scorpion, Imt is relatively broader ami shorter. The prosoma or cephalolhorax
consists of six fused seg-
ments covered by a quadrate
carapace with its front
angles rounded. This beai-s
on its dorsal surface two
pairs of eyes — large kidney-
shaped lateral eyes, and
median ocelli. The com-
pound lateral eyes are
smooth in theEurypteridae,
facetted in the Pterygotidae.
As shown by Clarke and
Ruedemann, these facetted
eyes are identical in struc-
ture with those of Limulus.
On the ventral surface
of the prosoma (Fig. 1506)
are seen six pairs of appen-
dages, of which the first pair
(the chelicerae) are preoral
in position, and the remain-
ing five pairs are found at
the sides of the elongate
mouth, and are develojjed
as legs. These legs consist
typically of a basal joint
(coxa), the inner margin
of which (gnathobase) is
provided with teeth and
able to function in masti-
cation, much as in Limuhis
or Apu,s, whilst the distal
part of each appendage
served as an organ of loco-
motion. The ambulatory
part of the appendages is
usually six-jointed, and is
attached to a small, oval
"ej)icoxite" at its anterior angle exactly in the same fashion as in Limulus. The
fifth pair of legs is spineless and slender, probably serving as balancing organs.
The sixth pair is characterised in all members of the order by its greater size and
usually somewhat flattened form, as well as by its termination in an oval plate or
claw. This last pair is commonly termed the palette or paddle, and seems to have
had a swimming function, although it is probable that the animal used it also
for anchoring or burying itself in the mud.
Behind the prosoma are twelve free segments, plus the tail-spine, of which the
first six form the mesosoma, and the remainder the metasoma. On the ventral
surface the segments of the mesosoma bear pairs of plate-like appendages, each of
which slightly overrides the next succeeding one. These appendages bear on their
inner (posterioi-) surfaces the lamellar branchiae, which are oval in outline (Fig.
Enrypicrm fischerl Eichw. Silurian ; Island
iniliviilual, Vi (from Holm).
of Oesel. Female
CLASS II
AEACHNIDA— EURYPTEKIDA
781
1509), and in a general way are comijarable to the leaf -like external gills of Limulus.
The first and second segments of the mesosoma are covered on the ventral snrface
by the genital operculum., which consists of a pair of plates meeting in the middle
line and having a median lobe attached to them. The latter, from analogy with
Limulus, is undoubtedly genital in function, and varies in form in the same species,
correlating with sex.
Family 1. Eurypteridae Burmeister.
Body elongate, narrow in form to hroadlij expanded in the mesosomatic region.
Frosoma subquadrate to suhtriangvlar in outline, with rounded front angles ; telson
spiniform. Compound eyes smooth,
not facetted, generally near the
middle of the cephalic shield ; no
epistoma; chelicerae not extending
beyond the fronted margin of the
carapace. Sixth pair of legs
adapted for either sioimming or
crawling. Female genital append-
age composed of several lobes.
Certain genera which are here
included in this family {Eusarcus,
Stylonurus, etc.) present rather
wide departures from the type, and
in the recent classification proposed
by Lankester {Encydop. Brit.,
12th ed., article on Arachnida)
they are placed in sejiarate families.
Concerning genetic relations, much
new light has been gained through
study of the stages of development
of the principal genera, and by
comparison of them with the
primitive and much generalised
Strahops from the Cambrian.
This genus is one of the earliest
known Eurypterids, and is re-
garded by Clarke and Euedemann
as an actual progenitor of most
Silurian forms. According to
the authors just named the Euryp-
terids studied by them pass through a so-called Straho2}s-sta.ge during the course of
their nepionic development. It has also been shown by them that the ontogeny of
Euiypterids fully corresponds to that . of Limulus in lacking any indication of a
nauplius or zoea stage.
Strahops Beecher (Fig. 1507). Prosoma small, comparatively wider than
in Eurypterus, but the eyes further back, small, and very far apart ; body
somites not distinctly differentiated into two regions (mesosoma and
metasoma), twelve in number besides the short and blunt tail-spine. In view
of its generalised characters this genus is eminently fitted to serve as a
Fig. 1507.
Strabopfi thacheri Beecher. Potosi limestone (Upper Cambrian) ;
St. Franijois County, Mo. Restoration of dorsal aspect. 2/3
(after Clarke and Ruedemaun).
782
ARTHROPODA
PHYLUM VII
prototype from which later Eurypterids are descended. Cambrian (Potosi
limestone) ; Missouri.
Eurijpterus Dekay (Lepidoderma Reuss ; (?) Ctwipylocejjhalus Eichw.) (Figs.
1505, 1506, 1508). Body elongate, narrow, attaining sometimes a length of
1 m. Prosoma contained five or six times in total length of the body, depressed
convex, subquadrate, with rounded anterior angles. Anterior margin nearly
straight, posterior slightly concave. Eyes reniform, somewhat in front of the
middle ; between them and close to the axial line are two ocelli. The entire
prosoma bordered by a narrow marginal furrow, and the margin broadly
enfolded on the ventral side. In the middle of the lower side is the cleft-
shaped mouth, which is bordered laterally by the basal segments of the fifth
pair of legs, and posteriorly by the large oval metastoma. Ordovician
(Normanskill shale) to Permian ; Europe and North America.
The first pair of ap])endages was regarded by Woodward and Schmidt as filiform and
tactile. Laurie, Holm, Clarke and Ruedemann, and others, however, have shown that they
are chelicerate, and thus in accord with homologous structures in other members of the
family. The three succeeding appendages are six- or eight-jointed and covered with fine
spines. The fifth pair is eight-jointed, and longer than those in front of it. The posterior
pair is a powerful swimming-organ ; its great subquadrate basal joints enclose the metastoma,
and together with this, cover nearly one-half of the ventral side of the prosoma.
All of the body segments are free. The first six form the mesosoma, and together
collectively occupy about one-fourth of the body-length. They are short and broad, and
nearly uniform in shape ; but the second segment has lost its hard skeleton on the ventral
surface, and the first covers the greater part of the genital operculum. This first segment
joins the jjosterior margin of the prosoma
and consists of two lateral portions and
a median process. All six segments of
the mesosoma are moderately overlap-
ping on the ventral side, and each is
divided by a median suture or cleft into
two parts. After these follow the six
ring -like segments of the metasoma,
which diminish gradually in width pos-
teriorly, and the body is terminated by
a long, slender telson. The latter is
properly to be regarded as an appendage
of the twelfth segment, as indicated by
the position of the anus in relation to it.
Larval stages have the telson short,
thick and four-sided, witli dorsal, ventral
and two lateral edges, corresponding in
form to that of the primitive Strabops.
About twenty-five species of Em'yj)-
f.rrus are known, the largest being about
1 m. long. They are found for the most
part in argillaceous or sandy deposits
in transition strata between tlie Silurian
and Devonian of England, Gotland,
Oesel, Podolia, and in the Water-lime
Grou]) (Silurian) of New York. They
are rare in the Devonian, but occur
again more frequently in the Coal
Measures of Scotland, Silesia, Bohemia,
Saarbriicken, and Pennsylvania. The
last survivor is from the Permian of
Bussaco, Portugal, where it occurs in
association witli land plants {JValchin, Sphenopteris). Typo, E. re7)iipes Deka.y .
Onyc]iop)ierns Clarke and Ruedemann. Terminal claw (with joint) of sixth
leg developed into a propelling spine ; fifth pair undifferentiated. Silurian ;
Indiana. Type, Eurypterus kokomoensis Miller and Gurley.
Fio. 1508.
Eurypterus rem.iiies Dekay. Bertie AVaterlime (Silurian);
BuH'alo, N.Y. Ventral aspect of a young individual in
which tlie relatively large size and length of the paddles,
and abrupt contraction of the body posteriorly, are especi-
ally noteworthy, x 3/j (after Clarke).
CLASS ir
ARACHNIDA— EUEYPTERIDA
783
Tijlopterus Clarke and Kuedemann. Thick calcareo-chitinous integument,
with median divided knobs on tergites. Silurian ; Canada. Type, Eurypterus
hoylei Whiteaves.
Ecliinognathns Walcott. Imperfectly known. Cephalothoracic appendages
with numerous curved spines, indicating an animal of large size. Ordovician ;
New York.
Megalograptus Miller. Richmond beds (Lowermost Silurian) ; Ohio.
Known only by fragmentary remains.
Dolichopterus Hall. Sixth prosomatic appendage has the terminal claw
developed into an elliptical oar-plate. Waterlime (Upper-
most Silurian) ; New York. Silurian ; Oesel.
Eusarcus Grote and Pitt (Eurysoma and Carcinosoma
Claypole). Eurypterids with the six mesosomatic seg-
ments greatly expanded, the next following of the
metasoma being abruptly contracted. Prosoma subtri-
angular, compound eyes at apex in front ; metastoma
subtriangular. Second pair of legs the longest. Terminal
joint of the sixth prosomatic appendage not expanded.
General aspect of body scorpion -like. Ordovician and
Silurian ; New York, Indiana, and Pentland Hills, Scot-
land.
Anthraconedes Meek and Worthen. Like Eurypferus,
but with spines on the falcate posterior angles of the
abdominal segments. Coal Measures ; Illinois and
Pennsylvania.
Adelophthalmus Jordan and von Meyer. Comprises
eyeless Eurypterids. Coal Measures ; Saarbriicken.
? Eurypterella Matthew. Probably not a Eurypterid.
Devonian ; New Brunswick.
? Beltina Walcott. Probably not a Eurypterid.
Montana.
Slimonia Page (Himantopterus Salter) (Fig. 1509).
Body attaining a length of 60 cm., and width of 15 cm.
Prosoma subquadrate, with anterior marginal eyes and sumonia acuminata
median ocelli. Preoral appendages in the form of small ^-^^r'^:^
stout pincers, much like chelicerae in Limulus. Of the t.jon of ventiai aspect,
• J- X 1 1 i.u c i- • J-£ J ^ showing appendages of
five pau's of postoral appendages, the nrst is modmed to the prosoma i.— vi., geni-
form tactile organs. The first seven postcephalic seg- seiiXite"of"them'^osonia
ments much wider than the rest. The first two sternites \}^-~~ ^\h\-, metasoma
are represented by the genital plate and its posterior xix. Dotted areas of the
-...^ , IP T • lii • mesosoma are branchial
divisions ; the other nve are discontinuous plates bearing lameiiae showing through
branchial lamellae on their inner surface. The five ^llVfter'Li'iirier''"'^^"''"
posterior segments are long, narrow, and cylindrical.
Telson like that of Pterygofus, but produced into a longer spine. Only one
species known. Old Red Sandstone ; Scotland.
Stylonurus Page (Fig. 1510). Body similar in general proportions to
Pterygotus, and often exceeding 1 m. in length. Prosoma quadrate or sub-
pentagonal, its margins bent under. Eyes large, approximate, sometimes
supported by strong orbital ridges ; ocelli on the slope of a median ridge.
Preoral appendages chelicerate. The five pairs of postoral appendages
Algonkian ;
784
ARTHEOPODA
PHYLUM VII
increase in length from the first backward, the last pair enormously elongated,
being nine-jointed, extending almost to the end of the telson, and terminating
in a sharjD claw. The first two
pairs of legs frequently bear
paired leaf- life spines. Telson
long and slender. Silurian and
Devonian ; Scotland, Russia, New
York, and Pennsylvania.
Subgenus : Cienopterus Clarke
and Ruedemann. First three
pairs of legs with numerous paired
spines to each segment.
Tarsoptenis Clarke and Ruede-
mann. Silurian ; New York.
JDrepanopterus Laurie. Body
as in Sf'i/lonurus, but the pos-
terior legs much less elongated.
Silurian ; Scotland and Indiana.
Family 2. Pterygotidae
Lankester.
Body elongate, narrow. Pro-
soma semiellijdical to suhqnadro,te in
outline ; telson spiniform in Eugh-
miUeria ; spatulate and bilobed
peltate in all other genera. Com-
pound eyes facetted, marginal;
epistoma present; chelicerae sonie-
Sfy!onuruse.ceUlormn. Chemung-CatskiU Group (Upper ^^^'^^^ 9reatly extended. Last pair
Devonian) ; Pennsylvania. Restoration of dorsal aspect, of UqS olwaVS adapted tO SWiviminq.
V'^o (after Clarke and Ruedemann). ^ i .,77 • i
■ Female genital appendage simple.
Pterygotus Agassiz (Figs. 1511-1512). Eurypterids sometimes of gigantic
size, attaining a length of over 2 m. Prosoma semi-ovate, with anterior
marginal facetted eyes and median ocelli. The metastoma is a heart-shaped
plate attached along the middle line to the ventral wall of the prosoma,
between the bases of the last pair of legs, and extending outwards and
forwards so as to enclose the jaws in a kind of chamber. Epistoma a thin
plate, occupying the same position as the hypostoma in trilobites, and having
the preoral appendages attached close to its posterior border. The latter are
large pincers, probably prehensile in function; by Schmidt and Woodward
they are represented as many-jointed, but it is now known that they consist
of but three long joints. Behind the mouth are four pairs of slender Avalking
legs, followed by the large " swimming feet," which are similar to those in
Eurypterus, except that they are less broadly expanded at the tips. Telson
an oval plate, terminating in a slight projection. The species first referred
to this genus (P. prohlematicus Ag.) is imperfectly understood, and P. anglieus
Ag., which is well known, is generally accepted as the typical form of the
genus. Ordovician ; New York. Silurian ; Wales, Scotland, Sweden, Oesel,
Russia, New York, and Australia. Old Red Sandstone ; Scotland.
Fi<-i. 1510.
CLASS II
ARACHNIDA— EUEYPTERIDA
785
Erettopterns Huxley and Salter. Like Pterygotus, but with a bilobed
telson. Silurian ; Lanarkshire.
IlughmiUeria Sarle. Small animals with carapace as in Pterygotus, chelate
Fig. 1511.
Pteri/(jolus huffaloenns (Polilnian). Bertie Waterlinie (Silurian) ; Buflalo, Xew York. Restoration of
A, dorsal, and B, ventral aspect, i/ao O^'t'*'' Clarke and Ruedeniann).
appendages on short legs, and telson as in Euryptenis. Epistoma lyre-shaped,
flanked by lateral shields. Ordovician and Silurian ; New York.
Glyptoscorpius Peach. Body
attaining a length of 30 cm.
Surface covered with highly
developed scale-markings. The
animal is provided with a pair
of comb-like structures supposed
to resemble the pectines of
scorpions, and the legs end in a
double claw. Lower Carboni-
ferous • Scotland.
Hastimima White. Large forms having a pterygotoid hastate telson with
impressed median ventral plate. Carboniferous ; Brazil, Nova Scotia (?) and
Devonian of South Africa.
Fig. 1512.
Pfe.rygoiU!< buffaloensis (Polilnian). Bertie Waterlime (Silurian) ;
Buffalo, New York. The toothed anterior chela, i/o.
Order 4. LIMULAVA Walcott.
Body elongated. Prosoma with lateral or viarginal eyes ; on the ventral side
with five pairs of appendages, some of which are hiramous. Postcephalic portion
of body (mesosoma and metasoma) consisting of twelve segments, the anterior nine of
VOL. I 3 E
786 ARTHROPODA phylum vri
which bear gills ; the last has a central spatulate process that, combined with
swimmerets, forms a strong caudal Jin.
It is doubtful whether this group, which in the biramous jointed legs and
compound telson possesses crustacean features, belongs to the merostomes or
connects the latter with the crustaceans.
Walcott, from his discovery of jointed body appendages in Sidneyia, is
inclined to the view that this genus is transitional between trilobites and
Eurypterids. One family is recognised, the original diagnosis of which is
given as follows :
Family 1. Sidneyidae Walcott.
Cephalothorax small, without lobes, eyes marginal; ventral side with large
epistoma, five pairs of movable appendages, the gnathobases of the three j^osterior
pairs forming organs of manducation. Abdomen twelve-jointed, the three posterior
segments annular and narrow, the terminal one forming, with lateral swimmerets, a
fan-like tail ; nine anterior segments with a pair of branchial appendages on each ;
the three posterior segments without ventral appendages. Surface smooth, or
ornamented by narrow, irregular, fine imbricating ridges.
In this family are placed two genera, Sidneyia and Amiella Walcott, from
the Ogygopsis shale of the Stephen formation (Middle Cambrian), near Field,
in British Columbia, Canada. They are described and figured in Smithson.
Misc. Coll., 1911-12, vol. Ivii., nos. 2 and 6. Sidneyia inexpectans Walcott,
the type species, which attains a length of about 17 cm., is represented by
very fine material. The accompanying genus Amiella is less satisfactorily
preserved, and there are indications of its occurrence also in the Cambrian of
Yunnan, in Indo-China.
[The foregoing -chapter on the Merostomata has been revised for the present edition by
Dr. John M. Clarke, New York State Geologist,, and drawings for several new figures of
Euryjiterids have been kindly furnished by him and Dr. R. Ruedemann, of Albany. — Editor.]
Subclass B. EMBOLOBRANCHIATA Lankester.'
Arthropods with at least three preoral segments in the adult stage, xoith one pair of
preoral appendages called chelicerae, and five postoral pairs, the anteriormost of which
are the pedip)alpi. Chelicerae two- or three-jointed, retrovert or chelate. Pedipalpi
pediform, chekite or retrovert, typically six-jointed, legs typically seven-jointed. Head
fused with at least one thoracic segment, usually with the entire thorax, forming a
cephalothorax or prosoma. Genital opening on the first somite of the mesosoma.
Nephridia modAfied as coxal glands. Abdomen typically composed of twelve segments,
* Literature : Gomstock, J. H., The Spider Book. New York, 1912. — Fritsch, A., Palaozoische
Arachniden. Prague, 1904.— /^ocA, C. L., and Berendt, J. &, Die iui Bernstein befiudliclien
Crustaceen, Myriapoden, Arachniden und Apteren der Vorwelt. 'Berlin, 1854. — Lankestcr, E. R.,
Articles on Arachuida and Arthropoda in Encycl. Brit., 1911. — Laurie, M., On a Silurian Scorpion
from the Pentland Hills. Trans. Roy. Soc. Edinb., 1899, vol. x.x.xix. — Petrunkcvitch, A.,
Monograph of terrestrial Palaeozoic Arachnida of North America. Trans. Conn. Acad. Sei. (In
press.) — Pocock, R. /., Monograph of the terre.strial Carboniferous Arachnida of Great Britain.
Palaeontogr. Soc, 1911. — Scudder, S. H., Fo.ssil Spidens. Harvard Univ. Bull., 1882, vol. ii. —
Idem, Illustrations of the Carboniferous Arachnida of North America. Mem. Boston Soc. Nat.
Hist., 1890, vol. iv. — Idem, Index to the known fossil Insects of the World, including Myriapods
and Arachnids. Bull. U.S. Geol. Surv. No. 71, 1891. — Warhvrton, C, Chajiter on Embolo-
brancliiata in Cambridge Natural History. London, 1909. — ■Whitjicld, R. P., Fossil Scorpion
from the Silurian roJks of America. Bull. Amer. Mus. Nat. Hist., 1885, vol. i.
SUBCLASS II
EMBOLOBEANCHIATA
787
even ivhen external segmentation is subsequently lost. Anus on last abdominal segment.
Eyes, when "present, simple, variable in number. Respiration by lung-books or tracheae.
The subclass of Embolobranchiata includes .spiders, scorpions, mites, ticks, etc.,
and comprises in all thirteen orders. Of these four are entirely extinct, and of
those still living six have continued to exist since the Paleozoic, and only one is not
known to have fossil representatives. So far as the evidence of extinct forms goes,
the older members of the various orders seem to have resembled to a remarkable
degree those existing at the present day, and serve to illustrate the extreme antiquity
of living types of invertebrate animals. The majority of fossil sjiecies is known from
remains preserved in amber of Lower Oligocene age in eastern Prussia. The most
delicate jaarts, including the finest hairs and sjsiders' webs are to be found practically
unaltered within this transparent fossil resinous substance which exuded from ancient
Coniferous trees.
The order Scorpionida {Scorpiones) is the oldest among the Embolobranchiata
Fw. 1513.
Upper Silurian primitive Scorpions, ralaeophonns. A, P. nuntlus Thor. and Lindst. Ludlow series
^Clunian) ; Gotland. Restoration of dorsal aspect. % (after Pococlc). B, P. caledonicus Peacli. Ludlow
series (Clunian) ; Lanarkshire. Reconstruction of ventral aspect, in which the space for a genital operculum,
the pair of pectens, and the absence of any evidence of pulmonary stigmata are noticeable features, s/o (after
Pocock).
and bears witness to a common origin with the Eurypterida. Scorjiions are
characterised by having tliree -jointed chelate chelicerae and six -jointed chelate
pedipalpi ; the head is fused with the thorax ; the abdomen is comj)Osed of twelve
segments, the last five of which are annular and form the so-called postabdomen or
tail. At the end of this latter is a telson modified as a poison gland with sting.
On the ventral surface is found a characteristic pair of appendages, the " comb."
Lung-books are present in four pairs.
Silurian Scorpions are grouped together under the suborder Apoxtjpoda, which
contains a single family represented by the genera Palaeophonus Thorell (Fig. 1513)
ARTHROPODA
PHYLUM VII
and Proscorpius Whitfield. The former of these comj)rises three species occurring in
the Upper Silurian (Clunian) of Gotland and Lanarkshire, and the latter a single
one from the Bertie Waterlime of New Yoi'k. Pocock has suggested that the
supposed mesosomatic " sternites " of PalaeopJbonas are really broadly laminate
gill-bearing appendages, as they have been shown to be in Eurypterus. Similar
appendages occur also in Eobuthns, and it is inferred that respiratory lamellae lay
beneath them as they do in Limulus. Thus, the In-eathing organs in primitive
Scorpions were gills, and the animals are thought to have been aquatic, possibly
even marine. But in Carboniferous genera an important change has taken place,
in that the covering jjlates have closed over the lamellae of the gills, leaving only
slit-like openings called stigmata. Breathing in these forms took place by the
admission of air through the stigmata to lung-books. P. nuntius was blind.
Eoscorpius Meek and Worthen (Fig. 1514) ; Isobuthus Fritsch ; and Cyclophthahnus
Corda, are examples of Carboniferous Scorpions. Eoscorpius does not differ in any
important respect from living forms, and appears to have been quite as highly
organised. According to Fritsch the order Scorjiionida attained its acme during the
Carboniferous and subsequently declined. Imperfect remains have been found in the
Trias of Warwickshire, and a species of Tityus Koch occurs in Oligocene amber.
The order Pedipalpida (Whip-scorpions, etc.) has two-jointed retrovert chelicerae,
and six-jointed, retrovert or chelate, raptorial pedipalpi. The first pair of legs is
Fig. 1514.
Eoscorpius carhonarius Meek and Wortli. Coal Measures ;
Mazou Creek, Illinois. A, Dorsal aspect of soma, Vi- -B, Pecten
or "comb," enlar.ned.
«S^^ Fio. lol5.
Ge/rallnura hohemica (Kusta).
Coal Measures ; Rakonitz, Bohemia,
i/i (after Kusta).
very long and modified as tactile organs. Coxae of second pair of legs placed behind
those of the pedipalpi, while the small coxae of the first pair are widely separate
and situated above and external to tlie former. Abdomen segmented, movably jointed
to the cephalothorax ; last two or three segments small, annular, either with or with-
out a segmented whip. To this order belong Geralinura (Fig. 1515) and GraeopJionus
Scudder, from the Carboniferous ; Stenarthron Haase, from the Upper Jurassic Litho-
graphic Stone of Bavaria ; and Phrynus Latreille, which occurs Tertiary and Recent.
The order Palpigradi is constituted by the single Recent genus Koenenia Grassi,
found in southern Italy, Sicily, and Texas. It has no fossil representatives.
The extinct order Kustarachnida is represented by a single family, comprising
SUBCLASS II
EMBOLOBRANCHIATA
789
the solitary genus Kustarachne Scudder (Fig. 1516), of wliicli three Carboniferous
species have been described. Chelicerae not observed ; pedipalpi chelate, their
coxae fused solidly together ; ab-
domen segmented, pediculate, the
terminal segment annuliform ; legs
long and slender.
The order Solpugida (Solifugae)
has the head fused with the first
thoracic segment, all the remaining
thoracic segments being free. Cheli-
cerae chelate : pedipalpi pediform ;
abdomen segmented ; respiration by
means of tracheae ; trochanters two-
jointed ; coxae and trochanters of
the fourth pair of legs with a row
of characteristic " maleoli." Proto-
solpiiga Petrunk. (Fig. 1517) is
known from the
Fig. 1516.
Fi<^ lai;
r roti.isolpuga carhonaria Pet-
runk. Coal Measures ; Mazou
Creek, Illinois, i/i (after Pet-
runkevitch).
Kiistanichne tenuipes
Carboniferous. Scudder. Coal Measures;
,, , „ 1 i • 1 Mazon Creek, Illinois.
Modern forms are sulitropical. 3/.,(afterPetrunkevitch).
The order Ricinulei or Podo-
(jonida, is represented in the'^nodern fauna by two tropical genera, and includes also
a few Carboniferous forms. Head and thorax fused, forming a cephalothorax, in
front of which is 'a movable plate called the " cucullus." Abdomen composed of
nine segments, but so , united with the cephalothorax that the first and second
abdominal segments are not visible. The three hindmost segments are small, annular,
forming a short " tail."
Chelicerae are two-
jointed, chelate; pedi-
palpi chelate ; tro-
chanter of first and
second pairs of legs
two-jointed ; the third
pair of legs in the
male is modified as a
copulatory apparatus ;
eyes absent in both
sexes. Polyochera
Scudder (Fig. 1518);
and Gurculioides
Buckland are Carboni-
ferous examples.
The order Pseudoscorpionida also known as Chernefidea or Chelonetni (False
Scorpions), is chiefly Recent, with no fossil representatives older than the Tertiary.
In this group the head is fused with the thorax, the abdomen is segmented and
broadly joined to the cephalothorax. Chelicerae chelate, with openings on the
movable finger for the ducts of the spinning glands ; pedipalpi chelate. The Recent
genus Chelifer Geotfr. (Fig. 1519) occurs also fossil in Baltic amber.
The order Araneida or Araneae (Spiders) has numerous fossil representatives,
the earliest of which appear in the Carboniferous. Head and thorax fused ;
chelicerae two-jointed, retrovert ; pedipalpi pediform, their terminal joint in the
male modified as a copulatory organ ; abdomen segmented only in the most primitive
suborder, anteriorly constricted and movably united with the cephalothorax ; usually
six spinnerets present on the abdomen, but their number may vary between two
Fio. 151S.
I'lilyoi'hera iwui alata Scud. Coal Measures ;
Mazon Creek, Illinois. <*/2 (after Petrunke-
viteli).
Fig. 1519.
Chelifer hemprichi Menge.
Oligoceiie; Baltic amber, y/i.
790
ARTHROPODA
PHYLUM VII
and eight
Arthrohjcosa Harger (Fig. 1520), and Profolycosa Roemer (Fig. 1521), are
Carboniferous examples, but tlie majority of forms are known from Oligocene amber
found on the shores of tlie Baltic in East Prussia. Mizalia Koch (Fig. 1522) is an
Fig. 1520.
Arthrnlycosa antlqxia Harger. Coal 'Measures :
Mazon Creek, Illinois, i/i (after Petrunkevitch).
Fig. 1521.
I'rofolycof:a aiitlira-
cophila Roemer.
Coal Measures;
Myslowitz, Sile.sia.
(after F. Roemer).
Fig. 1522.
Mizalia rostrata Koch and
Berendt. Oligocene ; Baltic
amber. 3/j.
Fig. 1523.
Attoides eresifonnis Brongt.
Oligocene ; Aix in Provence.
lo/i (after Brongniart).
Fig. 1524.
Thorn isus oeninijensis
Heer. Freshwater Mio-
cene ; Oeningen, Baden.
"/i (after Heer).
example from the latter locality; Attoides Brongt. (Fig. 1523) occurs in the fresh-
water Oligocene marls of Aix in Provence, and Thomisus Walck. (Fig. 1524) in
similar deposits of Miocene age at Oeningen, Baden. The Upj)er Oligocene lignites
of Rott, near Bonn, Ger-
many, and the Miocene fresh-
water strata of Florissant,
Colorado, have also yielded
remains of this order. Among
Eocene localities, from which
fossil Spiders have been ob-
tained, should be mentioned
the Green River beds of
Wyoming, and the strata at
Quesnel, British Columbia.
The known sj^ecies of fossil
Spiders aggregate about 250.
Tlie order Anthraco-
con fined to the
FlO. 1525.
Anthrai-oiHitrtiis I'oelkeUauus
Karsch. Coal Measures ; Neu-
rode, Silesia. Dorsal aspect,
i/i (after Karsch).
Fig. 1526.
respects intermediate l^etween them.
Eoplirynvs pri'stvicii (Buokland). ynor+i ic
Coal Measures ; Coalbrookdale, Bng- '^'^'- ^-^
land. Dorsal aspect, showing ten Palcozoic, and is IJerhapS
tergal segments of the hind- body. i. t i ji -d t i
Vi (after Woodward). ' ancestral to tlie Pedipalps
and Oi^iliones, being in some
Its distinguishing characters are as follows :
suBPHYLUM II MYRIAPODA 791
head fused with the thorax ; abdomen segmented, apparently broadly joined to the
cephalothorax ; between the tergites and sternites one or two rows of pleural
Rclerites ; anus with an operculum which represents the tergite of the eleventh
segment ; chelicerae not known ; pedijialiDi short, pediform ; legs seven-jointed with
movable coxae apparently articulated to a sternum. Anthracomartus Kartsch (Fig.
1525); Brachypyge and Eophrynus Woodward (Fig. 1526) ; Alaiocercus and Trigono-
tarbus Pocock ; and Kreischeria Geinitz are Carboniferous genera.
The order Haptopoda is also confined to the Paleozoic. Head fused with the
thorax ; abdomen segmented, broadly joined to the cephalothorax ; pedipalpi short,
pediform ; pleura soft, without sclerites ; tarsus of the first pair of legs seven-jointed.
Flesiosiro Pocock, from the Carboniferous of England, is the solitary known genus.
The order Phalangiotarbi, like the two preceding orders, is Paleozoic, Head
fused with the thorax ; abdomen broadly joined to the cephalothorax, segmented,
with soft pleura devoid of sclerites ;
several anterior tergites very short, with a ^#^
thickened posterior edge ; anus with an ^^
operculum, representing the tergite of the y/^
twelfth segment ; chelicerae not observed ; exZESa^ZTT^M^^^^
pedipalpi short, pediform. Phalangiotarbus II--*^^^^K»^v?'^'---^
Haase ; Geratarhus Scudder ; and Arclii- ^'^=^^^^^^^^^^^^^^^023^^^
tarbus{ = Geraphnjnus) Scudder (Fig. 1527) ; ^^^^^^^^<^/^\j<^»^i^^^T/^~^^
Opiliotarbus Vocock ; Discotarbus V&iixxnk.^ pr?^^^^^g>-r ^^^.>.
etc., are Carboniferous. I.; rrr~~7^ j \ "^-^-^^i
The order Phalangida or Opiliones n W^ZTji Vi
(Harvest -spiders) has many fossil repre- ^>Jw~-+v x"-
sentatives, most of which are preserved in ^^5^ ^X '
Oligocene amljer. Head fused with the ^5b ''xj^
thorax ; abdomen broadly joined with the Fig. 1527.
cephalothorax, segmented, the anal oper- ArcTiUarhus roUimlatus Scudder (=GeraphrymLS
..iilniii rM^rec;ATitinCT tbp tertritp nf the tenth co)-ho?ia/n<s Scudder). Coal Measures ; Mazon Creek,
cuium rtpiesenting tne lergu-e oi ine lenin jm^^ig^ under surface, i/i (after Petrunkevitch).
segment. Chelicerae three-jointed, chelate ;
pedipalpi pediform ; coxae of the first, often also of the second and third pairs of legs
with maxillary lobes ; one pair of tracheae. Nemastomoicles Thevenin ; Dinopilio
Fritsch ; and Protopilio Petrunk., all from the Carboniferous, are referred to this
order. The first-named of these, however {Nemastomoides claveris Thevenin), may
possiblj^ lielong to the Anthracomarti.
The order Acarina, Acari, or Rhynchosfomi (Mites, Ticks, etc.) comprises degenerate
Arachnids in which the abdomen is usually not segmented and is either broadly
joined to the cephalothorax or completely fused with it. Coxae of pedipalpi fused
together ; coxae of legs widely separate, without maxillary lobes. Numerous fossil
representatives are known from Oligocene amber and Tertiary freshwater deposits,
the majority of species being referable to Recent genera. Through the Opiliones this
order appears to be connected with the Spiders.
SuBPHYLUM B. Myriapoda Latreille.^
Tracheate Arthropods with distinctly separated head bearing a single pair of
antennae, and a soma composed of numerous {at least twelve) fairly similar segments
1 Literature: Fritsch, A., Faiuia der Gaskolile, vol. iv. Prague, 1899-1901.— Griimell, F.,
Quateruary Myriapods aud Insects of California. Univ. of Cal. Publ., Dept. Geol., 1908, vol. v.—
Koch, G. L., Die Myriapoden. Regensburg, 1847.— /toc/t, C. L., and Berendt, J. C, Die im
Bernstein Ijetiudliclien Crustaceen, Myriapoden, Arachniden uud Apteren der Vorwelt. Berlin,
792 ARTHROPODA phylum vii
which are never divided into fagmata ; there are two or three imirs of mouth ajijyendages ,
and numerous pairs of legs.
The time-honoured division of Myriapods into the orders commonly known
as Centii^edes and Millipedes {Ghiloj^oda and Diplopoda), plus the more recently
established groups of Pauropoda and Symphijla, which latter have no fossil repre-
sentatives, has of late years been abandoned. The prevailing modern view is to
regard the above-mentioned groups of tracheate Arthroj)ods as independent classes of
the phylum ; and the reason for this is found in the recognition of closer athnities
Ijetween the Chilopoda (Centipedes) and the Hexapoda (Insects), on the one hand, than
between the Chilopoda and Diplojooda on the other. According to the modern system
the older fossil Millijiedes, which are embraced in the extinct orders Protosyngnatha
and Archipolypoda of Scudder, fall within the limits of the class Diplopoda.
For practical purposes, however, it will be convenient to retain the designation
Myriapoda in a general sense, it being a familiar term, and the number of fossil
forms with which the paleontologist has to deal being comparatively limited. The
groujjs of which Centijiedes and Millipedes are the most important members are here
treated as classes, conformal)ly to the view which assigns them equal rank with the
exclusively Recent Pauropoda and Symphyla. Among the latter, certain genera
agree exactly in the numerical segmentation of the body with an isopod, a thysanuran,
and a primitive arachnid. This would lead to the inference, as pointed out by
G. H. CarjDenter, that " all the Arthropodan classes must be derived from ancestors
with a definite number of segments, and the development of a large number of
somites in such* forms as Julus, Geophilus, and Apus must be regarded as a secondary
condition."
Class 1. DIPLOPODA Gervais (CMo(7m«Aa Latreille). (Millipedes).
Trunk homonomously segmented, segments usually numerous and not flattened, of a
variable number (from 12 to 150), and the majority of them fused pairioise, each tergite
bearing two pairs of legs. Head with one pair of short, seven-jointed antennae, one pxiir
of mandibles, and one or two pairs of maxillae. No compound eyes, but numerous ocelli
usually present.
The anterior three or four segments of the soma are free, with a single pair of
legs to each segment. The anterior pair, or both pairs of legs corresj^onding to the
seventh tergite are usually modified as copulatory organs
(gonoi^ods), but in one order (Oniscomorpha) it is the
posterior pair of legs that is thus modified. A pair of
genital openings is present at the base of the legs of the
second segment. Resj^iration takes place by means of either
tufted or tube-like tracheae with spiracles at the base of
the legs.
Recent Diplopoda are divided into eight orders. At
Fio. 1528. least five of the modern families have Tertiary representa-
Jalusan.tiquiM'iieydw. Upper tives, especially in amljer. Among Tertiary examj)les may
S!G™?y^''4.^°"' "'"" l^e mentioned the following: JuUs Linn. (Fig. 1528);
Graspedosoma Leach ; Euzonus Mewge ; Polyxenus Latreille;
1854. — Peach, B. N., On some new Myriapods from the Palaeozoic rocks of Scotland.' Proc. Phys.
Soc. Edinb., 1899, vol. xiv; — Pocock, R. I., Articles on Centipedes and Millipedes in Encycl. Brit.,
1911. — Scuddci; S. JI., On Carboniferous Myriapods. Mem. Boston Soc. Nat. Hist., 1873-90,
vols, ii.-iv. — Idem, Index to the known fossil Insects of the World, including Myriapods and
Arachnids. Bull. U.S. Geol. Surv., No. 71, 1891. — Cockerell, T. D. A., Catalogue of the generic
names based on American Insects and Arachnids from the Tertiary rocks, with indications of the
type species. Bull. Amer. Mus. Nat. Hist., 1908, 1909, vol. xxvi!
SUBPHYLUM II
MYRIAPODA
793
and Fhryssonotiis Scudder {Lophonohis Menge). A species of Julus (J. telluster
Sciidder) occurs in the Green River Eocene of Wyoming, and another in the Miocene
freshwater beds of Florissant, Colorado.
The older fossil forms are referable to the two extinct orders of Scudder, Proto-
syngnatha and Archipolyj^oda. The former of these approaches closely to the Recent
order Pencillata, and is represented by the Carboniferous genus Palaeocampa Meek
and Wortlien. The second of these orders comprises three families, of which the
Archidesmidae resembles the Recent Polydesmidae. Archidesmus Peach (Fig. 1529) ;
Fig. 1529.
Archidcsmus maenicoU Peacli. Lower Old Red Sand-
stone ; Forfar.shire, Scotland. Vl (after Peacli).
Fio. 1530.
Euphohcria nrmigera Meek and Worth. Coal
Measures ; Mazoii Creek, Illinois, i/j.
and Kam'pecaris Page, from tlie Old Red Sandstone of Scotland, are examples. The
family Euphoberiidae shows some resemblance to the Julidae of the present fauna,
Ijut the dorsal scuta are more or less distinctly divided into two portions corresponding
with the pairs of legs. < Among Carboniferous genera belonging to this family may
be mentioned tlie following : Acantlierpestes and Euphoheria Meek and Worthen
(Fig. 1530); Amynilispes and Eileticus Scudder. Acantlierpestes is regarded by
Scudder as probably amphibious, and attains the relatively enormous length of
20 cm. {A. giganteus Baldwin). Tlie family Archiulidae is represented in the
Carboniferous by Trichiulus and Archiulus Scudder, and Xylobius Dawson. One
Mesozoic species, Jidopsis cretacea Heer, from the supposed Cretaceous of Greenland,
is of doubtful ordinal position, but may belong to the Archipolypoda.
Class 2. CHILOPODA Latreille. (Centipedes).
Body more or less flattened dorso-ventrally, composed of <c variable number of
segments {from 18 to 176), with a single piair of legs to each segment. One pair of
segmented antennae, the joints being at least fourteen in number, one pair of mandibles
and tuw pairs of maxillae. First pair of somatic appendages modified as porverful
maxillipeds with poison glands emerging on the terminal claw (toxognaths). Last j)air
of appendages {those borne by the antepenultimate segment) modified as copulatory organs.
Unpaired genital apertiire on the penultimate segment. Eyes variable in number, simple
or compoihnd {Scutigera), often wanting. Respiration by means of tracheae with either
paired spiracles in the pleural membranes or single spiracles in the median dorsal line.
Recent Chilopoda are divided into five orders, three of which have Tertiary
representatives, especially in amber, and in the freshwater deposits of Aix in Provence.
The following true Chilopod genera are known from the Tertiary : Cermatia Rossi ;
Scolopendra Linn. ; Lithobius and Geophilus Leach. The older fossil remains cannot be
positively referred to any of the five existing orders. By Scudder they were assigned
to two extinct families, named by him Gerascutigeridae and Eoscolopendridae.
The former of these includes tlie genus Latzelia Scudder, and the latter the genera
Palenarthrus and Ilyodes Scudder, all from the Coal Measures of Illinois.
[The text for the preceding chapters on Embolobranchiata and Myriapoda has been reA'ised
by Dr. Alexander Petrunkevitch, of Yale University. — Ebitou.]
794 ARTHEOPODA phylum vii
SuBPHYLUM C. Insecta (Hexapoda). Insects.^
Trarheate Arthropods loitli body at maturity consisting of a distinct head, thorax
and abdomen. Head provided loith one pair of antennae, one of mandibles, and two of
maxillae. Thorax composed of three segments, each supplied with a pair of legs, and the
second and third segments also usually carrying a pair of wings on their dorsal surfaces
in the adult stcde. Abdom.en composed of several {commonly ten) distinct segments, and
usually without leg-like appendages. Development usually throthgh metamorphic stages.
No undoubted remains of Insecta are known from strata older than the
Carboniferous, but in the Coal ]\Ieasures and Permian a considerable variety of
winged forms has been detected, in Ijoth Europe and North America. These earlier
Insects appear to be more generalised than are the post- Paleozoic forms, and the
majority are referred by Handlirscli to orders distinct from those occurring in Mesozoic
and later formations. But one order, the Blattoidea, seems to have survived from
Paleozoic times onward to our own day. The primitive extinct order Palaeodictyop-
tera is regarded as the ancestral stock which gave rise to the other Paleozoic orders,
and from the latter in turn have originated the modern Insect groups.
Although it is clear that strangely differentiated forms occurred among the
different Insect groups as early as the Carboniferous, yet it has been conclusively
shown that this differentiation had little dej^th, and that it is only through Mesozoic
and later descendants that we have any clue to a wide separation of the original
Paleozoic forms. Among the latter, the neuration of the wings, though diversified,
had yet a far greater homogeneity than is found now, or than existed during Mesozoic
time, from the Trias onward. The fore wings of whatever type were as diaphanous as
the hind, and could never (as in most of their descendants) properly be called tegmina.
The wings of the Protodonata of Brongniart had indeed a superficial resemblance
to those of living Odonata in shape, reticulation, and sweep of the veins. But in
fundamental neuration they were altogether different, and no trace is to be discovered
of those characteristic features of the Odonata, such as the nodus, triangle and
pterostigma, which apj^ear fully elaborated in the Mesozoic species.
" The wings, broadly speaking, may be said to be three-margined. The margin
that is anterior when the wings are extended is called the costa, and the edge tliat is
then most distant from the body is the outer margin, while the limit that lies along
the body when the wings are closed is the inner margin.
"The only great order of insects provided with a single pair of wings is the Diptera,
and in these the metathorax possesses, instead of wings, a pair of little capitate
bodies called halteres or poisers. In the great order Coleoptera, or beetles, the
anterior wings are rejilaced by a jiair of horny sheaths that close together over the
back of the insect, concealing the hind wings, so that the beetle looks like a wingless
insect ; in other four-winged insects it is usually the front wings that are most useful,
in flight. In the Orthoptera the front wings also differ in consistence from the
other pair over which they lie in repose, and are called the tegmina." (Sharp,
Cambridge Natural History, vol. v.)
^ The most complete bililiograpliies are to be found in various well-known publications on fossil
Insects by S. H. Scudder, and in the work by A. Handlirsch, Die fossileu Insekten, Leipzig,
1906-8. See also Handlirscli s Revision of American Paleozoic Insects, in Proc. U. S. Nat. Mus. ,
1906, vol. xxix. For important recent contributions one should consult the writings of Agnus,
Bode, Bolton, Brnes, Burr, Cockerell, Dainpf, Enderlein, Leriche, Melandrr, Meunier, Olfers,
Pruvost, Reis, Rohwer, Schlechtendal, Sellards, Shelford, Ulnier, Wickham, and others.
The most elal)orate descriptions of the insect faiuia of Commeutry are contained in the follow-
ing memoirs : — Brongniart, C, Recherches pour servir a I'histoire des insectes des temps primaires,
etc. Saint-Etienne, 1893. — Meunier, F., Nouvelles recherches sur quelques insectes dii terrain
houiller de Commentry (AUier). Annales de Paleont. , vols, iv., vi., 1906-12.
SUBPHYLUM III INSECT A 795
Among the Orthopterous Insects of the British series of Carboniferous rocks are
a number of forms allied to cockroaches, and nodules of the same age contain wings of
Palaeodictyopterous and allied Insects, some of them showing colour bands (Brodiea).
At Comm entry (Allier), France, is found the richest deposit of Carboniferous Insects
in the world, and this fauna has been ably investigated by Charles Brongniart
(1893) and later writers. Very numerous fossil remains are known from different
Mesozoic and Cenozoic horizons. The Insects found in the English and German
Lias are for the most part small and insignificant, but there are known a moderate-
sized dragonfly, and also a few Coleoptera. Various remains occur also in the Stones-
field Slate, Purbeck, Wealden, Bagshot Beds (Upper Eocene), and Bembridge Beds
(Oligocene) of England. Insects are well represented in the Lithographic Stone
(Kimmeridgian) of Bavaria ; in freshwater Oligocene deposits of Aix in Provence,
and especially in Baltic amber of the same age from East Prussia ; in the Miocene
brown coal of Rott near Bonn ; in the Miocene lacustrine deposits of Oeningen,
Baden, on Lake Constance ; and in similar deposits of Florissant, Colorado, also
of Miocene age. Many Insects also come from the Miocene deposits of Radoboj
in Croatia, and from the Indusial limestone of Lower Miocene age from Offenbach.
There is considerable reason to supjjose tliat Insects were more numerous in species
during Tertiary times than they are at the present day.
In the system here adopted the winged or wingless condition is made the basis
for dividing Insects into two classes, Pterygogenea and Apterygogenea. The former
of these comprises forty orders, thirteen of which are entirely extinct. The lowly
organised class of apterous Insects comprises four orders, three of which have Tertiary
rejjresentatives as well as Recent, and the remaining order is without known fossil
representatives.
If the opinion of Lankester and Bcirner, that the primitive Insects have a special
affinity with the Isopoda, be accepted, the discovery of Oxyuropoda in the Devonian
of County Kilkenny, Ireland, becomes of particular interest (see ante, p. 757). In
the view of G. H. Carpenter, a more general relationship between Insects and
Crustacea seems probable, so that this Devonian Isopod genus and the lowly organised
Pterygote order of Palaeodictyoptera must be regarded as having each advanced along
difterent lines of specialisation from their common ancestors. The common stock
from Avliich both Crustacea and Insecta are descended must surely have been Arthro-
pods with undifteren tinted trunk-segments, yet on the whole, resembling primitive
Crustaceans in structure, and possibly not very remote from Trilobites.
Class 1. PTERYGOGENEA Brauer.
Insects normally winged in the adult, or secondarily wingless, with faceted eyes, and
abdomen usually with nine or ten distinct segments.
t Order 1. PALAEODICTYOPTERA Goldenberg.
Head moderately large, rounded, ivith simple antennae, mouth parts adapted for
biting, and well-developed jaws. Two pears of wings, subequal in size, of similar form
and frimitive venation, incapable of being folded backward over the abdomen ; sometimes
a rudimentary third pair present on the first thoracic segment. Abdomen consisting of
ten nearly homonomous segments which often exhibit pleural lobes. Terminal segment
often with much elongated cerci. Thoracic legs similar.
In tliis order the wing structure is very primitive (Fig. 1531), corresponding
t This sign is used throughout the following pages to indicate that the systematic group referred
to is extinct.
796
ARTHROPODA
PHYLUM VII
very nearly to tlie liypothetical type. The cross-veins are numerous and more or
less irregular ; tlie anal lobe is not separated by a fold ; the anal veins are always
well developed, more or less branched,
C and curved regularly backward to the
SC posterior margin ; and there is no
anal fold nor fan - like plaitings.
Larvae are similar to the imago.
The Palaeodictyoptera are best
regarded as a generalised group of
very primitive organisation, and as
the probable progenitors of all winged
Pjq_ 1531 Ijisects. They are restricted to the
Diagram of the neuration of a primitive insect wing, one Paleozoic, and OCCUr in various
of the Palaeodictyoptera. The principal longitudinal veins "PupniiPaTi ond ISTnT-th ATnericnn
are connected by a network of cross -veins, c, Costa ; sc, -CiUropean anci l^Ortn Ameiican
Subcosta; r, Radius; rs, liadial sector; m, Media; ru, localities. There are al>OUt 120
Cubitus; a, Anal veins or nervures (after Handlirscli)- i ■ l^ ■ ■. c t ■ ^
known species, the majority ot which
are European, and about one-fourth of this number l)eing found in the Carboniferous
of the United States and Canada. Six species are known from the Pottsville, ten
from the Kanawha and Little River groups, eleven from the Allegheny, one from the
Conemaugh, and the remainder of American forms from the Productive Coal Measures.
Many of these Insects attain considerable size. The following named families have
been distinguished :
Dictyoneuridae, of which the genus Stenodictya Brongn. (Fig. 1532) is an example.
'^^^^;^^m£^^^^^'''^'^' /is^^
f^j^A^Sdiif^
Fig. 1533.
EkiblepPns da7ilelsi 'H.a\ii.\l. Coal Measures ;
Stenodictya lohatn Brongn. Stephanian (Upper Carboni- Mazon Creek, Illinois. The antennae, ocelli
ferous) ; Commcntry, Allier, France^ Tlie antennae, ocelli and and tarsi are reconstructed. -/x ' (after
tarsi are reconstructed, "/s (after Ilandlirsch).
Handlirsch).
Peromapteridae, Megaptilidae, Hypermegethidae, Mecynopteridae, Syntonopteridae,
Lithomantidae, Lycocercidae, Homoijiteridae, Homothetidae, Heolidae, Breyeriidae,
Fouqueidae, Grapliiptilidae, Sjiilapteridae, Lampioptilidae, Polycreagridae, Eublejitidae
(represented by Euhlejptus) (Fig. 1533), Metropatoridae, Paoliidae, Stygnidae, Aenigma-
todidae, and Synarmogidae.
t Order 2. MIXOTERMITOIDEA Handlirsch.
Wings with broadly rounded apical border, their venation resembling that of the
Palaeodictyoptera, hid more highly specialised.
SUBPHYLUM III
mSECTA
797
This order is probably an early aberrant offshoot of the preceding group, and is
known from two genera. Mixotermes Sterzel (Fig, 1534) occurs in tlie Coal Measures of
ca
Fig. 1534.
Mixotervies lugnucnsis Sterzel. Coal Measures;
Lugau, Saxony. Fore wing. 2/i (after Hand-
lirscli).
Recula parva Sclilecliten. Coal
Measures ; Wettin, Saxony. Fore
wing, '■^/i (after HaniUirsch).
Saxony, and Geroneura Matthew in tbe Little River group (approximately equivalent
to the Kanawha series) of New Brunswick.
t Order 3. RECULOIDBA Handlirsch.
An early aberrant offshoot of the Palaeodictyoptera, loith peculiarly specialised iving
neuration, and approaching in some respiects to the Proforthoptera and Protoblattoidea.
This order was proposed in a j)rovisional sense to include tlie single genus Eecula
Handlirsch (Fig. 1535), from the Coal Measures of Saxony.
t Order 4. PROTORTHOPTERA Handlirsch.
Wing pairs of unequal size, capable of being folded backward over the abdomen, and
with more complicated venation than in the preceding types, approaching in some respects
Fig. 1536.
Spanindera ambvlans Handl. Coal
Measures ; Mazon Creek, Illinois, i/i
(after Handlirsch).
1537.
Oi'.dischia wUUamsoni Brongn. Stephanian ;
Commentry, France. A forerunner of true Locus-
toids, witli long antennae and hind legs adapted
for springing. % (reconstructed by Handlirsch).
that of the modern Locnstidae. Hind wings similar to the front pair, but with larger anal
area, marked off by a fold. Antennae long and slender ; mouth parts strong, adapted
for biting. Prothorax often elongated or saddle-shaped, legs similar in form, the third
798
ARTHROPODA
PHYLUM VII
pail- sometimes elongated and adapted for springing ; cerci short or of moderate size ;
abdominal segments without lateral lobes. Females of some species with a well-developed
ovipositor.
This Paleozoic group is apparently intermediate in position between the Palaeo-
dictyoptera and Orthoptera proj^er. There are upwards of ninety known species,
about twenty of which occur in the Coal Measures of North America, and forty in
the Permian of Kansas. The following named families have been distinguished :
Spanioderidae, of which the genus Spaniodera Haudl. (Fig. 1536) is an example,-
Ischnoneuridae, Cnemidolestidae, Prototettigidae, Homalophlebidae, ProtokoUariidae,
Schuchertiellidae, Pachytylopsidae, Caloneuridae, Stenaropodidae, Oediscliiidae (with
well-developed jumping legs as shown in Oedischia Brongu.) (Fig. 1537), Omalidae,
Geraridae, Sthenaroceridae, Apithanidae, Cacurgidae, and Narkemidae.
Order 5. ORTHOPTERA Olivier.
Mouth parts well developed, mandihulate} Wings unequal., capable of being folded
backwards over the abdomen. Fore wings coriaceous, ivith numerous cross-veins, and the
principal longitudinal veins, with most of their branches, directed totvards the outer
margin. Hind wings thinner, delicately veined, with a large, plicated anal area.
Prothorax saddle-shapied ; hind legs generally saltatorial.
The Orthoptera are Insects of comparatively large size. The largest of existing
Insects are included within this order, and none of its members is so small as are
many minute representatives of other orders. Modern forms include grasshoppers,
locusts, green grasshoppers, katydids, and crickets.
/^^^
Suborder A. LOCUSTOIDEA Leach. (Locusts and Crickets).
Cubital area in the fore wings of the male {in most modern forms) modified into
stridulating organs; anterior tibiae loith auditory organ ; tarsi three- or four-jointed ;
antennae long and slender, consisting of
more than thirty segments; female almost
alioays with well developed ovipositor.
The earliest known members of this
suborder are found in the Lias of
Europe, and belong to the extinct
families of Locustopsidae and Elcanidae
(the latter typified by the genus Elcana
Giebel) (Fig. 1538). Apparently no
stridulating organs were developed, but
in the Elcanidae lamellar ajipendages
have been observed on the posterior
tibiae, by means of which the insects were probably able to ambulate on the surface
of the water or liquid mud after the manner of some living Tridactylidae and
Gryllidae. The Jura of Europe has yielded some true Locustidae (Green Grass-
hojipers) and Gryllidae (Crickets) with stridulating organs, and the families Tri-
dactylidae and Gryllotalpidae make their appearance in the early Tertiary. Remains
•• By tlie term niandibulate or " orthopteroiil " mouth is meant one in which the mandibles, or
maxillae, or both, are fitted for biting, crushing, or grasping food ; while the term suctorial implies
that some of the mouth parts are of a tubular form or are protrusible as a proboscis, wliich assists,
or protects, a more minute and delicate sucking apparatus.
Fig. 153S.
Elcana, geinUzi Hear. $ Upper Lias ; Dobbertin in
Mecklenburg. A true Locustoid, the cerci, tarsi ami
ocelli partly restored. 10/3 (after Handlirseli).
SUBPHTLUM III
INSECTA
799
of crickets are known from the Green Eiver Ecoene of Wyoming, and
are found also, with locusts, in the Miocene lacustrine beds of
Florissant, Colorado. Various European species are known of Bry-
madusa Stein. (Fig. 1539), and Gnjilas Linn. (Fig. 1540).
Fio. 1539.
Drymadusa speciosa (Heer). Miocene ; Oeningen, Baden, ^/i.
Suborder B. ACRIDIOIDEA Handlirsch.
Fig. 1540.
Gryllus mncrocercus
Germar. Lower Oli-
gocene; Baltic
amber. 3/., (after
Germar).
(Grasshojopers).
Stridulating organs sitnated in the hind femora and a modified longitudinal vein of
the fore ivings. Auditory organ on the side of the first abdominal segment. Antennae
short, composed of less than thirty segments. Tarsi short, three-jointed. No exserted
ovipositor in the female.
Fio. 1541. *
Tyrbuki russelU Seudder. Miocene lake
beds ; Florissant, Colorado. 3/^ (after
Seudder).
This is a grouj) of com-
paratively late origin, and is
derived in all probability from
the Locustopsidae or similar
locustoid ancestors. Grass-
hoppers are known from the
Green Eiver Eocene of Wyom-
ing, and from the freshwater
Miocene of Florissant, Colorado,
and elsewhere. Tyrbula (Fig.
1541) and Nanthacia Seudder,
etc., are examples.
Fio. 154:2.
Chresmoda obscura Germar. Lithographic Stone (LTpper Jura) ;
Solenhofen, BaAaria. 4/^ (after Handlirsch).
Order 6. PHASMOIDEA Leach. (Walking-sticks, Leaf Insects, etc.)
Body usually long and slender, mouth parts ortliopteroid, fore ivings rarely well
developed, iijithout stridulating organ, and loithout visible demarcation between the
cubital and anal areas. Hind ivings with large, folded anal lobe ; hind legs not
saltatorial, usually long and slender like the other pairs. Gerci short, genital appendages
of the female not prominent, tarsi five-jointed.
Here is placed the Upper Jurassic genus Chresmoda Germar (Fig. 1542), which.
800
ARTHROPODA
PHYLUM VII
as indicated liy tlae structure of its legs, proljably lived on the surface of tlie water
as do modern Gerridae. True terrestrial Phasmoidea occur rarely in Baltic amber
and in tlie Miocene lake beds of Florissant, Colorado. An example from the latter
locality is Agathemera reclusa Scudder.
Order 7. DBRMAPTERA De Geer. (Ear- wigs, etc.)
Flat-hodied running Insects ivith prognathous, orthopteroid mouth parts ; antennae
sim])k, consisting of from ten to thirty segments. Fore ivings, when present, very feebly
developed, and forming short, coriaceous tegmina.
Hind wings longitudinally and transversely plicated in
a complex fashion, consisting almost wliolly of the
highly specialised anal lobe. Legs similar, with three-
jointed tarsi ; cerci chelate.
This is a specialised order, which makes its first
appearance in the Tertiary of Europe and North
America. Labiduromma Scudder (Fig. 1543) is repre-
sented in the freshwater Miocene of Florissant, Colo-
rado, by about a dozen species. Forficula Linn,
ranges from the Eocene to Recent.
Fig. 1o43.
Lahiduromma exsnlatum Scudder.
Miocene lake beds ; Florissant, Colo-
rado. "Ji (after Scudder).
Order 8. DIPLOGLOSSATA de Saussure.
Includes the apterous, parasitical family Hemime-
ridae, living in Africa, unknown in the fossil state.
Order 9. THYSANOPTBRA Haliday. (Physopoda auct.).
Small terrestrial Insects with asymmetrical, hypognathous, suctorial movtJi. ptO'^i'ts,
short antennae, slender wings which are fringed when present, hit are often rudimentary
or wanting. Legs similar, tarsi ivith one or tivo joints, termi-
nated by a vesicular structure ; cerci reduced ; genital appendages
of the female forming a terebra.
Several genera occur in the Oligocene and Miocene of
Europe, and three in the Green River beds (Middle Eocene)
along the White River in western Colorado. Thrips Linn. ;
and Palaeothrips Scudder (Fig. 1544) are examples.
Fifi. 1544.
t Order 10. PROTOBLATTOIDEA Handlirsch. iWaco<;mi,«/ossiZisScuddeT.
' Green River beds (Eocene) ;
., ,, . Utah. r2/j (after Scudder).
Insects usually attaining considerable size. Head not con-
cealed beneath the prothorax, with orthopteroid mouth parts, and simple, numerously
jointed antennae. Fore wings usually with multifurcate principal veins and numerous
cross-veins ; subcosta well marked ; anal area distinctly limited by a. furrow, anal veins
mostly recurved. Hind wings ivith a distinct, enlarged, and folded anal lobe. Wings
capable of being folded over the abdomen, and the forward pair overlapping the hinder.
Legs non-saltatorial, the first pair sometimes robust and raptorial. Abdomen rarely
slender, generally more or less flattened ; cerci distinct ; female sometimes with a short
ovipositor.
This is an exclusively Paleozoic order, intermediate in jxisitiun lietween the
SUBPHYLUM III
INSECTA
801
Palaeodictyoptera and the true cockroaches and soothsayers (Blattoidea and Mantoidea)
of later date. The less specialised members of this order are very similar to those of
the parallel group Protorthoptera.
The Protoblattoidea are well represented in the Carboniferous and Permian of
Europe and North America by the following named families :
Stenoneuridae, Protophasmidae (typified by the genus ProtopJmsvia Brongn.)
(Fig. 1545), Eoblattidae, Oryctoblattinidae, Aetophlebidae, Cheliphlebidae, Eucaenidae
Fig. 1645. ,
Prolophasnia dumabi Brongn. Stephanian ;
Commoiitry, France. Antennae, ocelli, tarsi and
cerci restored from analogy. ■'/<j (after Hand-
lirsch).
Fio. 1546.
Eucaenus ovalis Scudder. Coal Measures ; Mazon
Creek, Illinois. Antennae, ocelli and tarsi recon-
structed, -i/y (after Handlirsch).
(typified by the genus Eucaemis Scudder) (Fig. 1546), Gerapompidae, Adiphlebidae,
Anthracothremmidae, and (?) Cnemidolestidae.
Order 11. BLATTOIDEA Handlirsch. (Cockroaches^).
Head deflexed, often entirely concealed from above by the large shield-like pronotum ;
with orthopteroid moufh parts and long, numerously jointed antennae. Leqs similar,
with five-jointed tarsi and long coxae. Fore wings or tegmina more coriaceous than the
hinder pair, and more frequently preserved ; they are capable of overlapping above the
abdomen ; their subcostae are more or less reduced, and the anal area is distinctly
separated by a cm-ved furrow. Hind wings with an enlarged, folded anal lobe.
Abdomen short and broad, provided with cerci, but ivithout visible female genital
appendages.
This order includes the majority of Paleozoic Insects, upwards of 300 species
being known from North American strata, a still larger number from European rocks
and a few from the Carboniferous of India. About 80 Jurassic species have been
described, half as many Tertiary, and we are acquainted with about 1200 Recent
species. In the most primitive family, tlie Archimylacridae, which includes more
than one-third of the American Paleozoic si^ecies, the neuration still resembles in the
main the Palaeodictyopteroid type. Highly characteristic of this family is the
condition of the long subcosta or mediastinal vein of the tegmina, which sends off a
large number of branches to the costal margin, either pectinate or arranged in groups,
but never issuing ray-like from the base of the wing.
1 Scudder, S. H., Revision of the American fossil Cockroaches. Bull. U.S. Geol. Surv., no. 124,
1895. — Schlechienclal, D. von, Uber die Karbon-Iusekten unci Spinneu von Wettin. Leipzic, 1913.
VOL. I 3 F
802
ARTHEOPODA
PHYLUM VII
From this generalised stock have probably been derived a numl)er of more
specialised families, also limited to the Paleozoic (Upper Productive Coal Measures
and Permian), among ■which may
\.Anal Veins
MediaslinaL
Scapular -
E:rtemomedicax
-Jtnal Furrow
Interiwmedian
be mentioned the following :
Spiloblattinidae, with smooth
fenestrated spaces between the bor-
dered longitudinal veins of the
tegmina ; Mylacridae, with the sub-
costal branches given otf from a
common point of origin at the base
(Fig. 1548, G); Poroblattinidae
and Neorthroblattinidae, with a
very short subcosta ; Mesoblatti-
nidae, with the subcosta forming
only a callous at the base of the
anterior border ; Pseudomylacridae,
Dictyomylacridae, Neomylacridae,
Pteridomylacridae, Idiomylacridae,
Diechoblattinidae, and Protere-
niidae.
Tertiary cockroaches are all
referable to modern families, and
are probably descended, at least for
the greater jjart, from the Mesoblattinidae, a family which is abundantly rej^resented
in Jurassic rocks. Many larval forms and even egg packets of cockroaches are found
Fig. Ii47.
Neuration of one of the tegmina of a Paleozoic Cockroacli
Asemohlatta mazona (Scud.), from the Coal Measures of Illinois.
The veins are named at the bnse of the tegmen, and the areas
are marked along the margin, -/i (alter Scudder).
Fui. 1548.
Types of fore wings in Paleozoic Cockroaches, "j-^. A, Priiriitive Archimylacrid. V,, Jlore highly specialised
Archimlyacrid. (\ Mylacris, typifying the Mylacridae. Nervures are marked as in Fig. 1531.
fossil. Specific determinations are often difficult, no two individuals being exactly
alike, and difterences often existing between the right and left wings of the same
individual.
SUBPHYLUM III
INSECTA
803
Illustrations of the tegniina of typical Paleozoic cockroaches are shown in
Figs. 1547 and 1548. Among North American examples may be mentioned
Adeloblatta (Fig. 1549) and Asevwhlatta (Fig. 1547) Hand-
lirsch, both from the Coal Measures of Illinois ; Phyloblatta
and Bradyblatta Handlirsch, from the Permian of "West
Virginia ; Etohlattina and Sinlohlattina Scudder, from the
Carboniferous and Permian respectively.
Order 12. MANTOIDBA Handlirsch.
(Soothsayers or Praying Insects).
Head exsarted- hut deflexed, nut covered by the protliorax,
lohich is elongate and variously formed, but never disk-like.
Mouth parts and antennae as in the Blattoidea. First pair
of leys largely develofed, raptorial, the coxae elongate and
free ; second and third fair of legs simple and similar ; the
tarsi five-jointed, without a pad between the claws ; a pair of
jointed cerci near the extremity of the body. Tegmina less
highly specialised than in the Blattoidea, subcosta well de-
veloped, anal area not so distinct.
(Scud.). Coal Measures ; Mazon
The earliest members of this order are the extinct Creek, Illinois. 2/j (after
Palaeomantidae from the Upper Permian of Russia. Higher
types, such as the extinct Haglidae and Geinitziidae, appear in tlie Lower and Upper
Lias respectively, of England and Germany. The latter family contains the single
genus Geinitzia Handlirsch (Fig. 1550), represented by three
species. Comparatively few Tertiary forms are known, but
in the modern fauna the Mantidae are an extensive family,
showing extreme variety in the shape of the body, and
characterised by the very remarkable front legs.
I »
Fig. 154'J.
A de.lohlatta columhiana
SC. 2-
CUy
Fig. 1550.
Geinitzia schlieffeni (Gein.). Upper Lias ; Dobbertin in
Mecklenburg, o/o (after HainUirsch).
Fig. 1551.
I'arotermes insignis Scudder
Miocene lake beds ; Florissant,
Colorado, ^/j.
Order 13. ISOPTERA BruUe. (Termites or White Ants).
Social terrestrial Insects. Head not concealed, with orthopteroid mouth parts, and
simple antennae consisting of from nine to thirty-one joints. Wing pairs elongate and
similar, anal area reduced, and, owing to a suture near the base of the luings, the
latter are deciduous. Legs similar, the body terminated by a pair of short cerci,
ovipositor concealed. Wingless individuals {workers, or sexually reduced males and
females) are polymorphous.
True Termites or White Ants appear first in the Eocene, and are represented in
Tertiary formations by about forty species. In the modern fauna upwards of 350
804
ARTHROPODA
PHYLUM VII
species are known. Parotermes Scudder (Fig. 1551); Eutermes Heer; and Hodotermes
Hagen occur in the Miocene lake beds of Florissant, Colorado.
Order 14. CORRODBNTIA Burmeister^ (Cojjeo g n atha Endevlein).
(Book Lice).
Minute terrestrial Insects ivith specialised ortliofteroid mouth ])arts, filiform or hair-
like antennae, and two pairs of unequal membranous xoings which are capable of being
folded backward, with reduced cross-veins. Hind wings smaller,
\ /* without folded anal lobe ; ne^iration highly specialised. Legs
homonomous, with two- or three-jointed tarsi. Prothorax small ;
cerci reduced, ovipositor not prominent.
Fig. 1552.
A number of sjjecies belonging in j)art to extinct and in
part to still living genera is known from Baltic amber (Lower
Oligocene of East Prussia), and from Sicilian amber of Upper
Miocene age. A very remarkable form with hard, chitinous
Sphaeropsocus icuenovii ^ings, and interesting from a phylogenetic standpoint, is
Hagen. Oligocene amber ; Sphaeropsocus Hagen (Fig. 1552), preserved in Baltic amber.
Hagen)! ^^^^'"^ ^^ The fifteenth order Mallophaga Nitsche, including parasitic
Bird Lice or Biting Lice, witli reduced mouth parts, and the
sixteenth order Siphunculata Meinert ( = Anoplura Enderlein), which is allied to the
Mallophaga but has suctorial mouth parts, comprise modern ectoparasitical Insects,
and are not known to be represented in the fossil state.
Order 17. COLEOPTERA Linnaeus. (Beetles).
Terrestrial or aquatic Insects with orthopteroid biting mouth parts and generally
multiarticulate antennae. Four ivings are present ; the upper pair shell-like in con-
sistency, and forming cases (elytra) which meet
together along the median dorsal line, so as to
sheathe completely the delicate membranoiis hind
pair. Legs generally homonomous or the third
pair modified for swimming or leaping. Abdo-
men sessile, without cerci or prominent ovipositor ;
the number of visible segments more or less re-
duced.
Over 350 species of rather primitive Cole-
optera have been found in Mesozoic strata, the
largest number being from the Uijper Jura.
The majority of these cannot be positively
assigned to Recent families, although it is
certain that many of these were represented as
early as the Mesozoic. On the other hand,
most of the Tertiary Coleoptera belong to exist-
ing families, and comprise nearly 2300 species.
This, however, is a small number in comparison to something like 200,000 described
species of Recent beetles.
The principal families which are repi'esented in the fossil state are the Carabidae,
to whicli belongs the cursorial beetle Tauredon Handl. (Fig. 1553); Elateridae ;
BujDrestidae ; Dytiscidae, etc. The Strepsiptera of Kirby may be considered as a
^ Enderlein, G., Die fossileu Copeognatheii iind ilne Phylogeuie. Palaeontogr., 1911, vol. Iviii.
Fm. 1553.
Tauredun horni Handl. Lithographic Stoni^
(Upper Jura) ; Bavaria. 5/3 (after Haiidlirsch.)
SUBPHYLUM III
INSECTA
805
highly specialised parasitical group of Coleoptera. In North America, the division of
tlie Khynchophora is represented in the Cretaceous of Greenland by two genera
{Archiorhynchus Heer and Gurcidiojms Hand!.), and much more abundantly in the
Fio. 1.554.
Cyphon vetustus
Giebel. Purbeck ;
Vale of Wardour,
England. 6/1 (after
Brodie).
Cerylonopsls slriatii
(Brodie). Purbeck ;
Vale of Wardour,
England.
Brodie).
8/1 (after
Fig. 1556.
Paltorhyiichus rectirostris
Soudder. Miocene lake beds ;
Florissant, Colorado, s/i-
Fig. 1557.
Apion refrenatum Scudder.
Miocene lake beds ; Floris-
sant, Colorado. 12/j.
freshwater Miocene of Florissant, Colorado. The divisions Heteromera, Phytophaga,
Laniellicornia, Serricornia, Clavicornia and Adephaga are also fairly well represented
at the latter locality. Two English and two American species are shown in Figs.
1554-1557.
Order 18. HYMBNOPTERA Linnaeus.^ (Ants, Bees, Wasps, etc.).
Terrestrial Insects with a free head having ivell-developed mandibles ; the first and
second maxillae are often elongated, and form in the higher groups a tubular proboscis
adapted for sucJdng. Antennae generally long and multiarticulate. Thorax and first
abdominal segments fused, the rest of the abdomen generally well separated hy a con-
striction. Legs usually homonomous, with five-jointed tarsi ; cerci not distinct ; genital
Fig. 1558.
Atocus defessus Scudder. Miocene lake
beds ; Florissant, Colorado. 2/^.
Fto. 1559
Pseudosirejo schroeteri Germ. Litho-
graphic Stone ; Solenhofen, Bavaria. Vl
(after Oppenheim).
appendages of the female forming either a more or less pronounced terebra or a sting.
Four wings of membranous consistency and a reduced number of veins ; the front pair
larger than the hind, which are always smaller and rarely fold up in repose. Wingless
forms frequent.
The earliest members of this order are of Jurassic age, and it is probable that some
^ Mayr, G., Die Ameisen ties baltischen Bernsteius, Schriften der phys.-okon. Ge.s. Konigs-
berg, 1868. — Mem, Studien iilier die Radoboj-Formiciden. Jalirb. geol. Reichsaiist. Wien, 1868,
vol^ x\ii. — Wheeler, IV. M., Ants. New York, 1910.
806
ARTHROPODA
PHYLUM VII
primitive types of the suborder Symphyta were already in existence during the Mesozoic,
although the most primitive saw-flies (Lydidae or Pamphilidae) are not known from
rocks older than tlie Tertiary. About 2900 Recent species of saw-flies are known,
several are preserved in Baltic amber, and fifty or more have been described from
Tertiary strata in Europe and North America. Of this number thirty-three occur
exclusively in the Miocene lake beds of Florissant. Here belong
the genera Dineura and Taxonus Dahlb. ; Tenthredo Linn.; and
Atocus Scudder (Fig. 1558). A group of more highly specialised
Siricid-like Insects, constituting the extinct family Pseudo-
siricidae {Pseudosirex Weyenb.) (Fig. 1559) is rather abundant in
Jurassic formations of Eurojie, l>eing accompanied by forerunners
of the next higher suborder, Apocrita. A great expansion of
the order took place during tlie Cretaceous, contemporaneously
with the rise of Angiosperms.
Nearly all of the principal modern families are represented
in the Mid-Tertiary formations, as for instance true saw-flies of
the family Tenthredinidae ; Siricidae ; various subfamilies of the
parasitic Ichneumonidae ; small Cynipidae or gall-flies; Sphecidae;
Vesjjidae or Avasps ; Formicidae or ants (Fig. 1560); and Apidae
m'^rt ^'"'^*''^' ''^^ ^^^^^^ 01" bees. Ants are exceedingly abundant in the Miocene lake
beds of Florissant, Colorado, thouvsands of individuals liaving been
obtained, and true wasps and bees are also present in large numbers. About
5000 species and sub-species of ants belonging to the modern fauna have been
described, as compared with about only 300 Tertiary species.
Fill. 15G0.
P7-ion.omyrmex longipes
Mayr. Lower Oligocene;
t Order 19. HADENTOMOIDBA Handlirsch.
This order, comprising a single family and genus, is evidently derived from the
Palaeodictyoptera, and shows sjiecialisation in the reduced venation of the homonomous
wings. The small Carboniferous genus Hadentomum Handl. (Fig. 1561) is perliaps
transitional to the next following order.
Order 20. EMBIOIDEA Kusnezow
(Oligoneura Borner).
Terrestrial Insects luith prognathous orthopteroid
mouth parts, homonomous free thoracic segments,
apterous or with homonomous wings showing re-
duced, venation. Antennae multiarticulate ; cerci
present ; first pair of legs with a spinning apparatus.
Modern Embiidae are one of the smallest
families of Insects, not more than sixty species
being known from all parts of the world, and
the group being an obscure one. They are small
and feeble Insects, and, as indicated by their
wide distribution, are to be looked upon as the
remnants of a once flourishing stock. A few
fossil remains have been found in Baltic amber and
in the Miocene lake beds of Florissant, Colorado.
Fic. 15()1.
ITiulentomum amcricaniim Ilaniil.
Measures; Illinois. ^Yo (after Hand
Coal
lirscli).
SUBPHTLUM III
INSECTA
807
i- Order 21. SYPHAROPTBROIDBA Handlirsch.
Body slender, of small size, loith homononious segments and tico pairs of Jiomonornoiis
loiiigs in v:hich the medial and cubital veins are greatly reduced.
This order, erected to contain the single genus Sypharoptera Handl. (Fig. 1562),
Tio. 1502.
Syphnroptern pneuma Ilandl. Coal Measures ; Mazon Creek, Illinois, ^/j (after Handlirsch).
is probably to be regaMed as a highly specialised lateral aberrant offshoot of the
Palaeodictyoptera. It is confined to the Upper Carboniferous.
t Order 22. HAPALOPTEROIDEA Handlirsch.
Like the last, this order is prol)ably a specialised derivative from the Palaeo-
dictyoptera, and appears to be related to primitive types of the next succeeding order.
' cu
Fi(i. 15(33.
Ilapaloptera gracilis Handl. Coal Measures; Tremont, Penna. s/i (after Handlirsch).
In the Carboniferous genus Hapakrptera Handl. (Fig. 1563), the wings have the
media and cubitus reduced, and the sector radii well developed.
808
ARTHROPODA
PHYLUM VII
Order 23. PERLARIA Handlirsch {Plecoptera Burmeistei).
Amphibious Insects unth prognathotis orthopieroid mouth parts and long multi-
articulate antennae. Body segments very nearly homonomous, legs fairly similar, and
wings with a rather specialised venation, generally shoioing
^„^s»^'^^^'''^^^S!^^^^^:^,i^^^,^^ a few cross-veins. Hind wings often with a conspicuous
folded anal lobe ; cerci usually well-developed ; tarsi three-
jointed ; females toithout a prominent terebra.
Fid. 1564. From tlie Permian of Russia and North America
Leiictm gracilis Pictet. Lower are known a number of Insect remains wliicli appear to
OliETOcene ; Baltic amber, ••/i (after ^ ^ ^ J_^ • j i ^ i • i j. •
Pictet). belong to this order, but whose precise relations are
difficult to determine. A few undoulited representatives
of the order, such as Mesonemura, Mesoleucfra and Platyperla Brauer, occur in the
Middle Jura of Siberia, and several genera, including Perla Geoffr., and Leuctra
Steph. (Fig. 1564) are preserved in Baltic amber.
t Order 24. PROTEPHEMEROIDBA Handlirsch.
Amphibious Insects of Palaeodictyopteran aspect. JVings homonomous, with a very
primitive venation and numerous cross-veins, but also showing intercalary veins extending
longitudinally. Thorax and abdomen, with very
nearly homonomous segments ; legs similar ; cerci
long.
Here is j)laced the solitary genus Triplosoba
Handl. { = Blanchardia Broiign.) (Fig. 1565) from
the Upper Coal Measures (Stephanian) of Com-
mentry, France. It is regarded as a connecting
link between the Palaeodictyoptera and true
Ephemeridae or may-flies belonging to the next
order.
Order 25. PLECTOPTERA Packard
{Agnatha auct.). (May-Hies).
Fio. 1565.
Triplosoha ind chcU a (BroDgn.). Stephan-
ian ; Comnientry, France. Vi Oifter
, ., , . . Brongniart).
Delicate amphibious Insects with atrophied ortho-
pteroid mouth parts, short antennae, and four membranous wings having both intercalary
and cross-veining ; the hinder pair in all Recent and many fossil
species more or less reduced and sometimes wanting. Antennae
short, with two basal joints and an apical needle-like segment.
Ocular organs large, often divided. Prothorax small, legs slender,
the first 2yair elongated, antenniform ; tarsi more or less reduced ;
cerci slender, very elongate; last segment often filiform. Larvae
loith respiratory abdominal legs.
This order is well represented in the Permian, Jurassic,
and Tertiary deposits of Europe and North America. The
older forms differ from existing Ephemerids in having the hind
Fir, 15G6 wings equal in size to tlie front pair, and in having more com-
Cronicus anomalus pHcated venation. Later and more highly specialised forms
(Pictet). Lower oiigo- have reduced venation. Nearly 300 species of may -flies are
cene ; Baltic amber,
(after Pictet)
^/a
known in the modern fauna, but these probably represent, as
SUBPHYLUM III
INSECTA
809
Scudder suggested, the lingering fragments of an expiring group. The genera
Gronicus Eaton (Fig. 1566); Palingenia Burm. ; Baetis Leach; and Ephemera Linn.
occur in Baltic amber, and the last-named is found also in the Miocene lake beds of
Florissant, Colorado.
t Order 26. PROTODONATA Brongniart.
Mostly very large Insects tvith large eyes and heavy jaws ; segments of the thorax
unequal; legs stout, homonomous. Wings suheqital, horizontally expanded and with a
Fig. 1567.
Meganenra monyi Brongn. Stei)lianian (Upper Productive Coal Measures) ; Commentry (Alliw), France.
i/e (afti'r lii'ougniart).
finely reticulated venation ; the hinder pair somewhat dilated totvards the base, ivithout
folds. Nodus, pterostigma, wing triangle, quadrangle, reduction of the anal vein, and
other characteristic wing structures of the trice Odonata are not developed in this order.
Sector radii and media probably not crossed. Abdomen slender.
This group is of transitional character between the Palaeodictyoptera and the true
Odonata or dragon-flies. Its geological range is from the Coal Measures to the Trias,
and the several genera belonging to it are grouped under the families Protagrionidae,
Meganeuridae and Paralogidae. In all, less than a dozen species are known, only
three of which are North American. These last are referred to the genera Paralogus
Scudder, typified by P. aeschnoides from the Coal Measures of Rhode Island ; Palaeo-
therates Handlirsch, from the corresponding horizon in Pennsylvania ; and Tupus
Sellards, from the Permian of Kansas. The gigantic Meganeura Brongn. (Fig. 1567),
from the Upper Coal Measures (Stephanian) of Commentry, France, measured over
75 cm. across the extended wings.
810
ARTHROPODA
PHYLUM VII
Order 27. ODONATA Fabricius.^ (Dragon-flies).
Elongate Insects with very mobile head and large eyes, highly specialised orthopteroid
mouth parts and small, inconspicuous antennae terminating in a bristle. Thorax
highly specialised ; legs similar, all placed more anteriorly than the wings. The wings
are elongate, equal or suhequal in size and similar in texture, membranous, finely
reticulated, with a nodus, pterostigma, more or less developed triangular areas, and
especially characterised by
/ the crossing of the anterior
) branches of the medial vein
by the radial sector. Abdo-
men slender and elongate,
consisting of ten segments
and a pair of terminal
caliper-like processes (cerci) ;
females sometimes with a,
terebra. The earlier stages
of life are aquatic ; the
mouth of the nymph develops
a peculiar structure 'called
the " mask."
True Odonata appear
first in the Lower Lias, and
are present throughout the
Mesozoic and Tertiary.
Most of the Jurassic types
l)elong to the suborder
Anisozygoptera, which is
represented in the modern
fauna by but a single
species. The more advanced
ZTarsopMehia eriinia Hagen. Lithograpliic Stone (Kimiueridsian) ; suborders, Zygoptera and
Biclistadt, Bavaria. An Upper .Jurassic dragon-fly witli long, forwardly Anisoptera became domi-
directed legs. 5/.^ (after Handlirsch). ' \, ^ .
nant durmg the Tertiary,
and comprise at the present day upwards of 1000 and 1300 sj)ecies respectively.
In the Anisozygoptera the wings are subequal and the nodal region resembles that
of the next succeeding suborder, but triangles are not formed by the cubitus and
cross-veins. Here belong the extinct families Diasatommidae ; Heterophlebiidae ;
Tarsophlebiidae (typified by the genus Tarsophlebia Hagen, Fig. 1568); Steno-
phlebiidae and Isophlebiidae.
In the Anisoptera the hind wings are considerably broader than the front pair,
the nodal region is generally situated in the middle of the costal margin and the
triangle formed by the cubitus and two cross-veins is Avell developed. A single
species belonging to the genus Gomphoides Selys is known from the English Lias, and
a number of allied genera, such as Nannogomphus and Mesuropetala Handl. ;
Protolindenia and Gymatophlebia (Fig. 1569) Deichmiiller ; Aeschnidium Westwood,
etc., occur in the Upper Jura. In Tertiary strata the families Gomphidae, Aeschnidae
and Libellulidae are represented by about sixty siaecies. As an example of Tertiary
Anisoptera may be mentioned Btenogomphus carletuni Scudder, from the Eocene strata
of Roan Mountain, Colorado.
^ Kirby, W. F., Syiiouyniic Catalogue of Neuroiitera Odonata, with an apiiemlix of fossil
species. London, l?>^Q.—Muttkoivski, H. aA., Catalogue of the Odonata of North America. Bull.
Pulilic Museum of Milwaukee, 1910, vol. i.
SUBPHYLUM III
INSECTA
811
In the suborder Zygoptera the wings are equal, no triangle is formed by the
cubitus and cross-veins, and the nodal region is situated very near the base of the
wings. Half a dozen species are known from the Ujiper Jura, and a considerably
larger number, mostly belonging to the family Agrionidae, occur in the Oligocene and
Miocene of Europe and North America. Dysac/rion Scudder is represented by a few
species in the Green River Eocene of Wyoming, and several species closely related
Fio. 1569.
Cymatophlebia longialata (Germar),
Litliographic Stone ; SolbAhofen,
Bavaria, '^fi.
Fio. 1570.
Argia alieiia (Scudder). Miocene lake beds ; Florissant,
Colorado. 3/j.
to living forms are known from the IMiocene lake beds of Florissant, Colorado.
Here also occurs Argia aliena (Scud.) (Fig. 1570), together with representatives of
several related forms, such as Melanagrion Cock. ; Lithagrion Scud. ; and Hesperagrion
Calvert. The most interesting dragon-fly from this locality, however, is Phenacolestes
Cockerel!, which has been made the subject of special investigation by P. P. Calvert
{Proc. Acad. Nat. Sci. Philacl, May 1913).
Order 28. MEGALOPTERA Latreille. (Alder-flies).
Head with prognathous orthopteroid mouth parts and multiarticulate antennae.
Four membranous wings of moderate size, meeting in repose over the hack at an
angle ; the hinder pair slightly the smaller ; anal area plicate. Venation of a some-
what archaic type, the nervures and transverse veinlets being moderately numerous,
and forming irregularly disposed cells. Segments of the thorax nearly equal, legs
homonomous, loith five -jointed tarsi; cerci usually
reduced, ovipositor not prominent. Larvae of acpiatic
habits, 2}ossessed of branchiae and legs, but no spiracles,
and with mandibles formed for biting, armed ivith strong
teeth.
Fio. 1571.
This group has a long geological history, extending f,,^^^,;^^^,, ^,;,„, pjetet. Lower
from the Lower Trias onward to the present day, and is oligocene ; Baltic amber. ■*/:) (after
proljably descended from Palaeodictyopteroid ancestors. ^^'^^'^ ''
The genera Ghauliodites Heer, and Triadosialis Handlirsch occur in the Lower Trias
(Bunter) of Germany, and an undoubted larval form, Mormolucoides articulatus
Hitchcock, is not uncommon in the Upper Trias of Turner's Falls, ]\Lassachusetts.
In this latter a head, or thorax, of three segments, and an abdomen of nine segments
812
ARTHEOPODA
PHYLUM VII
are recognisable. Ghaidiodes Latreille (Fig. 1571), an interesting form, is preserved
in Baltic amber of Lower Oligocene age.
Order 29. RAPHIDIOIDEA Handlirsch. (Snake-flies).
Terrestrial Insects with prognathoits orthopteroid mouth parts and long, multi-
articulate antennae. Head large, abdomen slender, prothorax greatly prolonged and
very mobile. Wings similar, membranous, of nearly equal size ; venation 'more highly
specialised than in the Megaloptera, with a prominent pterostigma ; anal veins forming
several irregular cells, of moderate size, and never fan-shaped in arrangement. Legs
similar, with Jive-jointed tarsi; no cerci ; females with an elongate exserted ovipositor.
Larvae of terrestrial habits, without abdominal legs and furnished loith mouth parts
adapted for biting.
Only two Recent genera are known, Raphidia Burm., and Inocellia Schneid.,
comprising in the aggregate about forty species. The former of these occurs fossil in
Baltic amber of Lower Oligocene age, and botli genera are represented in the Miocene
lake beds of Florissant, Colorado, by a few species. Megaraphidia elegans Cock, also
occurs at the last-named locality. It is to l)e inferred, however, that the group is
of pre-Tertiary origin, inasmuch as the modern genera are peculiar to the Palearctic
and Nearctic regions.
Order 30. NEUROPTERA Linnaeus. (Lacewing-flies, Ant-lions, etc.).
Usually slender, often very small Insects of terrestrial habits, with orthopteroid
mouth parts and generally long and multiarticulate antennae. Wings membranous,
subequal in size, with much reticulation, and longitudinal veins giving, off numerous
branches towards the margin, some of them distally forked ; anal area not defined, loith
few irregular veins; pterostigma seldom developed. Legs similar, with five -jointed
tarsi, front pair sometimes ra,ptorial ; abdomen without cerci or terebra. Larvae either
aquatic and provided with respiratory abdominal legs, or terrestrial ; in both cases with
mandibles and maxillae co-adapted to form spear-like organs that are suctorial in function.
In the emended sense this order includes only a limited number of sjjecies, of
which about 1300 are Recent, less than 30 are Cenozoic, and a small number are
Fig. 1572.
Prolieinerohius prodrcmius Hand). Upper Lias ;
Dobbertin in Mecklenburg, s/j (reconstructed by
Handlirsch).
Brongniartiella inconditissima Handl.
Lithographic Stone ; Solenhofen, Bavaria.
2/3 (after Handlirsch).
Mesozoic, most of the latter being from the Upper Lias. The group is of ancient
lineage, and is undoubtedly derived from Palaeodictyopteroid ancestors. The oldest
and most primitive family, that of the Prohemerobiidae, is represented in the Lias
SUBPHYLUM III
INSECTA
813
and Upper Jura by twenty-two species, some of whicli attain considerable size. The
genera Prohemerobius (Fig. 1572) and Archegetes Handl. ; and Brongniartiella Meunier
(Fig. 1573) are examples.
Other families of Neuropterous Insects which are restricted to the Mesozoic, such
as the Epigambridae, Sqlenoptilidae, Nymphitidae, Kalligrammidae and Mesochryso-
pidae, show a certain apj)roximation to Tertiary and modern forms. Members of the
now flourishing Osmylidae, Sisyridae, Nymphidae, Hemerobiidae, Coniopterygidae,
Chrysopidae, Nemopteridae and Myrmeleonidae have been recorded from Tertiary
rocks. The genera Osmyhis Latr. ; Osmy-
lidia Cockerell ; Bothromicromus, Tribo-
chrysa and Palaeochrysa Scudder are
represented in the North American Mio-
cene. The last-named genus is represented
by four species at the Florissant locality,
and Tribochrysa by one. A single species
each of Polystoechotes Burm., and Halter
Rambixr, has also been described from the
same locality.
t Order 31. MEGASECOPTERA
Brongniart.
Insects ivith slender body, the segments
of which are very similar, long antennae
and cerci, and homonomous legs. Wing
fairs equal, horizontally expanded, venation
specialised in that there is a reduced number
of branches and cross-veins.
This is an exclusively Paleozoic group,
derived from the Palaeodictyoptera, and
probably the progenitor of the next suc-
ceeding order. Here belong the families
Diaphonopteridae, Corydaloididae, Cam-
pyloj)teridae, Mischopteridae (typified by
the genus Mischoptera, Brongn.) (Fig. 1574), Raphidiopsidae and Prochoropteridae
Fu!. 1574.
Mischoptera voodivardi Brongn, Steplianian (Upper
Coal Measures) ; Commentry, France. Ocelli and
tarsi restored, i/.j (after Handlirsch).
Order 32. PANORPATAE Brauer {Mecaptera auct.). (Scorpion-flies).
Terrestrial Insects ivith orthopteroid mouth parts and long, multiarticidate antennae.
Prothorax smaller than the remaining segments; legs similar, ivith five-jointed tarsi;
abdomen slender, with short cerci and
large genital appendages in the male.
Wings equal, membranous, without en-
larged anal lobe, and with a limited
member of secondary branches and cross-
veins.
This order, which is now in a state
of decline, is abundantly rejaresented
in the Lias and Upper Jura of Europe.
Most of the fossil species belong to the
family Orthophlebiidae, of which the genera Orthophlebia Westw., and Neorthophlebia
Handl. (Fig. 1575) are exanqdes. True Panorpidae and Bittacidae occur in the
Fig. 1575.
NeorthophleMa macuUpennis Handl. Upper Lias ; Dob-
bertin in Mecklenburg. 5/i (after Handlirsch).
814
ARTHROPODA
PHYLUM VII
Tertiary of Europe and Nortli America. Representatives of the families Meropidae
and t Eobanksiidae, tlie latter typified by EobanJcsia Cockerell, are also known from
the Florissant lake beds. About 100 Recent species of Scorpion-flies are known.
Order 33. TRICHOPTERA Kirby (Phryganoidea Stephens).
Moderate-sized, water-frequenting Insects with long, multiarticiUate antennae v.nd
reduced or obsolete mandibles, but well-developed maxillae. Wings membranous, unequal,
more or less clothed ivith hair, nervures dividing at very acute angles; the front p)air
ivith longitudinal veins moderately branched, very few cross-veins, specialised anal area,
and often a pterostigma ; the liind pair generally
ivith an enlarged and plicated anal lobe. Pro-
thorax small, legs similar, with five-jointed tarsi
and prominent spu,rs ; cerci reduced, terebra
wanting. Larvae aquatic, with well - developed
mandibles, and as a rule providing themselves with
Cij;-^ cases or tubes formed of extraneous matter.
FK'- 1570. Some half - dozen genera comprising fifteen
Nccrotauiius iiitermedhis HaiuU. Upper species of primitive Caddis-flies are known from
Lias ; Dobbertin m Mecklenburg. «/i (alter \ . '■ i i ■ ,
Handlirsdi). Mesozoic rocks, most 01 them belonging to the
extinct family Necrotauliidae. Necrotaulius
Handl. (Fig. 1576); and Trichopteridium Geinitz are examples from the Upper Lias
of Germany. About 1400 Recent and 200 Tertiary species have been recorded,
of which 24 occur in the Miocene lake beds of Florissant, Colorado. At this
locality remains in the imago state are extremely abundant, and many such remains
have been found in Europe. On the other hand, the so-called indusial limestone
of Auvergne, which is from two to three metres thick over a wide area, is largely
composed of the cases of Phryganoid larvae. Similar masses of tubes occur also in
the Green River Eocene of Wyoming.
Order 34. LEPIDOPTERA Linnaeus. (Butterflies and Moths).
Terrestrial Insects with suctorial mouth pjarts, in wltich tlie mandibles are almost
invariably reduced and the first maxillae are either small or, in higher forms, frolonged
in a spirally coiled proboscis; antennae multi-
articulate and of various shapes. Fore and hind
loings unequal in size, membranous and densely
covered with scales ; the hind pair shorter and
■usually ivithout enlarged anal area. Longitu-
dinal veins giving off but a limited number of
straight branches, and with very few cross-veins.
Fid. 1577.
rhratjtiuUoecites dumesi Oppeiih. Middle Jura ;
Siberia, ^/g (after Oppeiiheiin).
Fig. 15TS.
Eocimda lameeri Handl. Lltliograpliie
Stone (Ujiper Jura) ; Soleuhofen, Bavaiia.
An Upper Jurassic Lepidopterid, the antennae
and ocelli restored, -i/y (after Haudlirsch),
SUBPHYLUM III
INSECTA
815
Tliorax much abbreviated., legs simiilar, with sjntrs ; no cerci or terebra. Larvae with
mandibles, thoracic and abdominal legs.
The earliest undoubted traces of Lepidoptera are found in Jurassic strata of
England, Spain, Bavaria and Siberia, and comj)rise a nuiulier of genera belonging to
the family Palaeontinidae. Phragmatoe- »
-v^
cites (Fig. 1577), Eocicada (Fig. 1578), and
Prolystra Oppenheim are examj^les, these
forms being somewhat distantly allied to
the non-suctorial Limacodidae of our own
day. Several modern families make their
appearance in the Tertiary, but are repre-
sented by relatively few species. The
total number of Tertiary species is not
over 85, as against some 60,000 Recent
l)utterflies and moths. Among North
American examj^les may be mentioned the
following from the Miocene lake beds of
Florissant, Colorado, all described by
Scudder : Prodryas ]^)ersei)hone (Pig. 1579),
Barbarothea florissanti (Fig. 1580), Jwpiteria charon, Lithodryas styx, Nymphalitcs
obsctirics, Prolibythea vagabunda, Psecadia mortuella, and Stolopsyche libytheoides.
From the same locality Cockerell has described Chlorippe wilmattae and some other
species, including a wel^-preserved larval form knoMU as Phylledestes vorax.
Pig. 1579.
rrodryus persejihone Scudder. jrioceue lake beds
Florissant, Colorado, i/i (after Scudder).
Order 35. DIPTERA Linnaeus. (Flies).
Terrestrial or uiujjhibious Insects with highly specialised suctorial month parts.
Antennae either long and multiarticulate, or consisting of a limited number of similar
or dissimilar joints. Only the fore wings are prominent ; these are usually icell developed,
membranous, highly specialised, narrow, with
■' - few cross -veins, and longitudinal veins
.sparingly branched. Hind wings always
, . .;!w>_ni . „,;j^ reduced to clubbed filaments, the so-called
Fig. 1580.
TUirUanitbea florissanti Scudder.
Miocene lake beds ; Florissant, Colo-
rado. Vl (alter Sinidder).
CL CU
Fici. 1581.
Architijmla seebacMana Handl. Uiiper
Lias ; Dobbertiii in Mecklenburg. 6/2 (after
Ilandlirsch).
" haltercs." Thorax much abbreviated, legs generally homonomous, with five-jointed tarsi ;
abdomen ivithout terebra or visible cerci.
Upwards of 44,000 Recent and 1550 Tertiary species are known, 125 of the
latter being North American. The earliest Flies are found in the Upper Lias, and
comprise about 30 species, nearly all of which belong to the suborder Orthorrapha
of Brauer. They are grouped in the following named families : Protorhyphidae,
Mycetophylidae, Bilnonidae, Psychodidae, Eoptychopteridae, Architipulidae (typified
by the genus Architipula Handl.) (Fig. 1581), Tipulidae and Rhypliidae. In the
816
AETHROPODA
PHYLUM VII
Tertiary of North America tlie same suborder is abundantly represented, especially
in the Miocene lake beds of Colorado, where thousands of individuals and hundreds
of species have been found. The suboi'der Cyclorrapha is likewise well represented
Fig. 1684.
Penthetria falcahda Handl. Oligocene ;
British Culuinbia. 3/j.
Fig. 1582.
Nccromyza pedata Scudder. Miocene ; Oeningen,
Baden. I'-^/j (after Scudder).
Fig. 1585.
Chironomus meyeri Heer. Miocene ; Oeningen,
Baden. *>/j (after Heer).
Bihio sticheli lla,w\\. 9 Miocene; Gotschee, Carintliia.
•J/i (after Handlirsch).
Pio. 1586.
I'ltlonhohis Jlorigerus Scudder.
.Miocene lake beds ; Fl(iris.sant,
Colorado, ^/i (after Scudder).
in the Miocene of Colorado, where numerous species occur, also in British Columbia,
arid in the Green River Eocene of AVyoining. In the European Tertiary nearly all
of the modern families are represented, a few examples of which are shown in the
accompanying Figs. 1582-86. The most interesting genus from the Florissant locality
is Glossina, the tsetse fly, two species of which occur here but not elsewhere in the
western world.
SUBPHYLUM III
INSECTA
817
Order 36. SUCTORIA De Geer (Siphonaptera, Aphaniptera auct.). (Fleas).
Small, wingless, semiparasitic Insects with slender body, suctorial mouth parts, short,
clubbed antennae, and legs adapted for
springing ; tarsi jive-jointed.
The sole representative of this order in
the fossil state is a species of Palaeopsylla
Wagn. (Fig. 1587) preserved in Baltic
amber of Lower Oligocene age. It is
interesting to note that Kecent species of
this genns are restricted to central Europe,
and still inhabit the same region as in
mid-Tertiary times.
region as
t Order 37. PROTOHEMIPTERA
Handlirsch.
Fig. 1587.
Palaeopsylla klehsiana Dampf. Lower Oligocene ;
lialtic amber. aB/^ (after Dampf).
Head small with projecting suctorial
mouth parts differing from the beak of true Hemiptera only in that the palpi of the
second maxilla are not fused in the middle line. Body stout, tvith a broad pronotum.
JFings horizontally expanded, the venation primitive, resembling that of the Palaeo-
dictyoptera, and with 'numerous cross-veins ; the anal area not separated off by an anal
furrow so as to form a distinct region or " clavus." Front
\ ' legs long and probably raptorial.
^ tut
The sole representative of this group so far as
known is Eugereon Dohrn (Fig. 1588), the genotyjje
of which is the highly interesting E. boeckingi
Dohrn from the Lower Permian of Oldenburer.
It is a generalised form, and may he regarded as
a connecting link between the Palaeodictyop-
tera on the one hand, and the Homoptera and
Hemiptera on the other.
t Order 38.
PALAEOHEMIPTERA
Handlirsch.
A provisional group, estab-
lished for the reception of cer-
tain fragmentary remains,
mostly wings, which combine
in themselves the characters of
the Homoptera and Hemiptera.
The " clavus " or anal region
is separated by a straight ridge,
the corium and membrane are
not distinctly separated.
Fic. 15S8.
Euyereon boeckingi Ddlun. Perniian ; Birkenfeld in Oldenburg,
3/4 (after Dohrn).
Here are placed the families Prosbolidae (typified by the genus Prosbole Handl.)
VOL. I 3 G
818
AETHKOPODA
PHYLUM YIl
Fio. 1589.
Prosbole hirsuta Handl. Upper Permian ; Tichagori, Russia.
2/1 (after Handlir.sch).
(Fig. 1589), and Scytinoirteridae, botli restricted to the Permian, and the Dimorpho-
,-— ^ ptilidae from the Lias.
Order 39. HEMIPTERA
Linnaeus (Heteroptera
auct.). (Bugs).
Terrestrial or aquatic Insects
with suctorial mouth 'parts con-
sisting of a mobile prognathous
beak (the fused palpi of the
second maxillae) which contains
the setiform mandibles and first
maxillae. Antennae never multi-
articulate and exhibiting a variety of form, often concealed in aquatic forms. Fore
wings covering the abdomen, their apical areas mostly membranous and overlapping,
their basal moieties generally coriaceous, with a definitely limited anal area or '■'■ clavus."
Hind wings concealed and with a somewhat reduced venation. Body more or less stout
and, depressed ; prothorax
large ; legs similar, vnth fe%v
tarsal joints, and variously
adapted as for raptorial,
saltatorial, fossorial, or
natatory functions ; cerci
wanting.
Two main divisions are
recognised, Gymnocerata or
terrestrial Bugs, and Crypto-
cerata or aquatic Bugs.
Both groups are represented
in the Mesozoic, but many
of these ancient types cannot
be included within tlie limits
usually assigned to modern
families. During the Ter-
tiary, on the other hand, no forms existed whicli differ markedly from Recent tyjies,
and nearly all of the modern families are here represented. The following named
families are among the most important of those occurring in the Mesozoic :
t Archegocimicidae (tyj^ified by Archegocimex) (Fig. 1590), f Progonocimicidae,
t Eocimicidae, f Eonabidae, f Hadrocoridae, f Cuneocoi-idae, Proboscanionidae,
t Apopnidae, f Pachymeridiidae, f Protocoridae, f Sisyrocoridae, f Diatillidae,
Coreidae, Nepidae, Belostoiuidae (typified by the genus Mesobelostomum Haase) (Fig.
1591), Naucoridae, Notouectidae, and Corisidae.
Fic. 1500.
Archegocimex geinitzi
Handl. Upper Lias ; Dob-
bertiii in Mecklenburg.
fi/i (after Handlirsch).
Fig. 1591.
Mesohelostomimi deperdUum Gerniar.
Upjier Jura ; Solenhofen,
(after Deiclnniiller).
Bavaria. ^/-j
Order 40. HOMOPTERA Leach. (Plant-lice, Wax-bugs,
Harvest-fiies, etc.).
Exclusively terrestrial Insects ivith hypognathous suctorial mouth parts having the
same conformation as in the Hemiptera. Antennae usually ivith heteronomous segments,
often short and bristle-like. Wings as a rule not overlapping and disposed in a more
tectiform attitude, rarely coriaceous; '■'■clavus^' in most forms distinctly bounded. Hind
wings generally smaller than the forward pair, sometimes with an enlarged anal lobe.
SUBPHYLUM III
INSECTA
819
Prothorax relatively large; legs similar, or the third jmir adapted for springing;
abdomen without cerci ; females often with a terehra.
This grouj) is divided into five suborders, the most primitive of which is the
Auchenorhyucha, ranging from the Lias onward. It is represented in Mesozoic rocks
by 50 species, in the Tertiary by about 200, and in the modern fauna by upwards
of 10,000. Most of the Jurassic species belong to the families Fulgoridae (typified
by Fulgoridimn Handl.) (Fig. 1592) ; f Procercopidae (typified by Procercopis Handl.)
Fulgoridium, pallidum Handl. Upper
Lias ; Dobbertin in Mecklenburg. B/i
(after Handl irsch).
Fio. 1593.
Procercopis alutacea Handl. Upper Lias ; Dobbertin in
Mecklenburg, -^/i (after Handlirscli).
(Fig. 1593) ; and Jassidae. One species of Cicadidae is reported from the Cretaceous,
and a dozen from Tertiary strata. The Fulgoridae, Cercopidae and Jassidae are
represented by numerous species in the Tertiary, and are now flourishing families.
The suboT'ders Psylloidea and Aphidoidea have a continuous range from the Jura
onward, and the division of Aleurodoidea is Tertiary and Recent, but is represented
by relatively few species. Plant-lice (Aphididae) and Harvest-flies (Cercopidae and
Cicadidae) occur frequently in the Tertiaries of Utah, Wyoming, Colorado and British
Columbia.
Class 2. APTERYGOGENEA Brauer (Ajytem Linnaeus).^
Purely ivingless Insects. Abdomen \oith from six to twelve segments. No meta-
morphosis.
Order 1. THYSANURA Latreille.
Small Apterygote Insects with orthopteroid, free mouth parts and simple multiarticu-
late antennae. Compound eyes present ; head ivith broad basis joined to thorax, which
consists of three divisions; tergite usually well developed, pleurite and sternite small;
prothorax as large as, or larger than the mesothorax. Abdomen consisting of ten well-
developed segments and bearing distinct cerci, a ter-
minal filum, and reduced styliform abdominal legs on
most of the segments.
The families belonging to this grouj), Machilidae Fn'- 1594.
and Lepismidae, are ectotrophous — that is, the mouth Mackilis seticomis (Koch and
^ 1-1-T111 1- Berendt). Lower Ohgocene ; Baltic
parts are not buried in the head, but are arranged in amber. •■2/1 (after Koch and Berendt).
the fashion usual among mandibulate Insects. Both
families are represented in Baltic amber of Lower Oligocene age, the genus Machilis
Latr. (Fig. 1594) being specially abundant. Lepisma Linn, is represented by several
European and one North American species in the Oligocene.
^ Olfers, W. M., Die Ur-Insekten (Thysanura and Collembola im Bernstein),
physikal.-okon. Ges. Konigsberg, 1907, vol. xlviii. *
Schrifteu <ler
820 AETHEOPODA phylum vii
Order 2. CAMPODEOIDBA Handlirsch {Jrchinseda Haeckel).
Small Apterygote entotroplious Insects {month parts or tropin reduced and buried in
the head), with feebly-developed eyes and long, simple, muUiarticulate antennae. Body
segments very nearly equal ; ten well-developed abdorainal segments, most of them with
reduced styliform legs ; cerci elongate or chelate.
The so-called abdorainal legs in this grouj) and in the Tliysannia are appendages
which help to support the abdomen, and serve also as tactile organs. They are
called by Grassi false legs or " Pseudozampe." The Eecent genus Campodea Westwood
occurs also in Baltic amber of Lower Oligocene age.
Order 3. COLLEMBOLA Lubbock. (Spring-tails).
Trophi reduced and buried in the head, eyes feebly developed, antennae sometimes
uneq'ually segmented. Thorax with very -unecpial segments but ivith homonomous legs.
Abdomen consisting of not more than six segments, the first of rchich is furnished with a
ventral tube or papilla, and modified legs forming a springing apparatus being present
posteriorly.
About 450 Eecent s^Decies of Spring-tails are known, and 70 have been recorded
from Baltic amber of Lower Oligocene age. The crustacean characters which we
tind to-daj^ in the Collembola, the Thysannra, and the Ephemerida, are, as pointed
out by G. H. Carpenter, without doubt inherited survivals, indicating a true relation-
ship Ijctween the two subphyla of Branchiata and Insecta.
Order 4. PROTURA Silvestri (Myrientoma Berlese).
Minute subterraneous Insects without antennae and eyes.
This order is without known rejjresentatives in the fossil state.
Geological Range and Distribution of Insecta.
It is estimated that about 1000 Paleozoic, as many Mesozoic, and upwards of
8000 Cenozoic Insects have been described by different authors. The total is,
however, a mere fragment of the insect fauna of past periods, and very small in
comparison with the half million species now in existence.
The earliest fossil Insects which have been definitely recognised are members of
the Palaeodictyoptera. Their first appearance in Europe is at the base of the Upper
Productive Coal Measures (Ouralien or Stephanien superieure of Coinmentry, France,
and the corresponding '• unteres Obercarbon " of German geologists). From the
Upper Coal Measures of France, Germany, Belgium, Bohemia, and other localities in
EurojDe, and froiu the Lower Productive Coal Measures (Kanawha and Allegheny
formations) of Pennsylvania, Illinois and elsewhere in the United States and Canada
has been obtained a large number of higlily interesting types.^ Other representatives
^ The Little Kiver Group of St. Joliu, New Brunswick, whicli has yielded a number of insect
remains, was formerly regarded as of Devonian age, but is now assigned on the evidence of
Paleoliotany to the Lower Productive Coal Measures, corresponding to the Kanawha Group (upper
division of tlie Pottsville). A supposed insect wing, described by Moberg under the name of
Protocimex sibiricus, from the Graptolite beds of Sweden is probably not of Arthropod nature.
Another doubtful fragment, the so-called Palaeoblattina dourillei of Brongniavt, from the
Mesosilurian of Calvados, is interpreted by Agnus as part of the pleural lobe of a Trilobite.
Suggestive traces have been found in Devonian rocks of the south-east of Ireland, but no indubitalile
indications of Insects prior to the Carboniferous have been as yet forthcoming. The insect remains
found at Fairplay, Colorado, are now thought to be of Permian insteail of Triassic age. Those
from the Florissant lake beds are now referred to the Miocene, instead of to the Oligocene, as
formerly.
suBPHYLUM III INSECTA 821
of various primitive groups are known from the Permian of Russia, Germany, West
Virginia, Kansas and Colorado, so that on the whole we are fairly well acquainted
with these heterometabolic ancestors of modern orders. Unfortunately, however, very
little evidence is forthcoming from the Trias, during which era the transition from
the heterometabolic to the holometabolic stage probably took place. Nevertheless,
a few fossil remains are known from the Trias of Sweden, Germany, Austria,
Switzerland and China. Numerous tracks of supposed Insects, and also what are
believed to be the aquatic larvae of an alder-fly {Mormolucoides articulatus Hitchcock),
occur in the dark shales of the Connecticut Valley Trias.
A fairly rich insect fauna has been discovered in the Lias of Sehambelen in
Aargau, Switzerland, Dobbertin in Mecklenburg, Brunswick, "Weyer in Austria, and
several localities in Somerset, Gloucestershire and Yorkshire, England. A few
remains are preserved in the Stonesfield Slate near Oxford, England, and in strata
of the same age in Siberia ; and a considerable number of sjiecies occurs in ihe Purbeck
of the southwestern counties of England. Richest of all, however, is the Upper
Jurassic insect fauna, especially that which is found in the Lithographic Stone
(Kimmeridgian) of Bavaria. Contrariwise, the Cretaceous is markedly deficient in
information respecting this group of invertebrates.
Tertiary sediments have yielded an enormous quantity of well-preserved insect
remains. Among the more important localities that have furnished material of this
nature, mostly of mid-Tertiary age, may be mentioned the freshwater deposits of
Florissant, Colorado, Aix-en-Provence, Oeningen on Lake Constance in Baden, Radoboj
in Croatia, Rott (Upper Oligocene lignite) near Bonn on the Rhine, Brunnstatt in
Alsace, Sieblos in Bavaria, Bilin in Bohemia and Gabbro in Tuscany ; also the
Oligocene strata at Quesnel in British Columbia, and the Green River Eocene of
AVyoming, western Colorado and eastern Utah. But by far the largest and most
varied assemblage of Tertiary insect remains is obtained from Oligocene amber in
East Prussia.
Finally, in the Pleistocene, the interglacial clays of Switzerland, German}^ and
Ontario, the jDeats of northern France and England, the ozokerite of Galicia, and the
lignites of Husbach in Bavaria, deserve mention as localities which have furnished
fossil insect remains. In the accomj^anying table is indicated the geological range of
the different orders of Insects.
[The preceding chapter on Insecta has been prepared especially for the present work by
Professor Anton Handlirscli, of the Imperial Museum of Natural History at Vienna. A
few minor emendations have been suggested by Dr. W. J. Holland, Director of the Carnegie
Museum at Pittsburgh, and others by Professor T. D. A. Cockerel], of the University of
Colorado. — Editok. 1
822
AKTHROPODA
PHYLUM VII
Table showing the Vertical Range of Fossil Insects.
Orders.
Class I. Pterygogenea
1. Palaeodictyoptera
2. Mixotermitoidea
3. Reculoidea
4.
Protortlioptera
5.
Orthoptera
6.
Pliasmoidea
7.
Dermaptera
8.
Diploglossata .
9.
Thysanoptera .
10.
Protoblattoidea
11.
Blattoidea
12.
Mantoidea
13.
Isoptera .
14.
CoiTodentia
15.
Mallophaga
16.
Sipliunculata .
17.
Coleoptera
18.
Hymenoptera .
19.
Hadentomoidea
20.
Embioidea
21. Sypliaropteroidea
22. Hapalopteroidca
23. Perlaria .
24. Protephemeroidea
25. Plectoptera
26. Protodonata
27. Odonata .
28. Megaloptera
29. Raphidioidea
30. Neuroptera
31.
Megasecoptera
32.
Panorpatae
33.
Trichoptera
34.
Lepidoptera
35.
Diptera .
36.
Suctoria .
37.
Protolieniiptera
38.
Palaeolieniiptera
39.
Hemiptera
40.
Homoptera
Class II. Apterygogenea {Aj)tcr~
1. Tlij^sanura
2. Canipodeoidea .
3. Collenibola
4. Protura .
a)
O cc
K
INDEX
[Names of genera and subgenera regarded as synonyms are printed in italics, all others in Roman.]
Abacocriniis, 194
AlmttiJi, 296
Aljlacomya, 449
Abra, 495
Abracrinus, 194
Abrotocrinus, 222
Acaeocrinus, 194
Acambona, 414
Acauthactinella, 62
Acantherpestes, 793
Acanthina, 558
Acanthinites, 648
Acantlioearis, 751
Acanthoceras, 669
Acanthocites, 513
Acanthocladia, 342
Acanthoclema, 344
Acanthoclymenia, 628
Acanthocrinus, 188
Acanthocyathus, 95
Acantliocystites, 150
Acanthodictya, 61
Acantholithus, 112
Acantlionautilu.s, 606
Acantliopleura, 513
Aciinthii,<j)ijngla, 62
Acanthotelson, 756
Acaiithoteuthis, 683
Acaiithothyris, 400
Acasta, 746
Avasie, 726
Acavus, 576
Acentrotremites, 172
Acervularia, 86
Aceste, 297
Acestra, 62
Acharax, 438
Achradocrinus, 219
Achiudocystites, 151
Achrochordocrinus, 232
Acila, 440
Acdeistoceras, 611
AcHsina, 538
Aeloeodictya, 61
Acmaea, 520
Acritis, 371 f
Acrochordiceras, 640
Acrocrinus, 201
Acrocului, 541
Acrogenia, 346
Acroidaris, 275
Acropora, 107
Acrosalenia, 279
Acrotliele, 376
Acrothyra, 376
Acrotreta, 376
Acrura, 256
Actaeonella, 566
Actaeonina, 566
Acteocine, 568
Acteoii, 565
Actinacis, 107
Actinocamax, 682
Actinocei'ainus, 447
Actinoceras, 609
Actinoconchu.s, 418
Actinocriiius, 197
Actinodesnia, 444
Actinodiclya, 61
Actinoiloiita, 455
Actinomya, 468
Actiuopora, 322
Actinopteria, 448
Actinosepia, 688
Actinostoma, 341
Actinostreon, 450
Actinostronia, 122
, Actinotaxia, 326
Adacna, 490
Adelactaeon, 566
Adelnstrea, 101
Adeloblatta, 803
Adeloptlialiims, 783
Adeonella, 339
Adolfia, 410
Adniuiirid, 440
Aecliinina, 738
Aegor, 761
Aegliipe 405
Aeglina, 721
Aegoceras, 656
Aeolopneustes, 282
Aeropsis, 297
Aesclinidium, 810
Aesiocrinus, 225
Aesiocystis, 159
Aetea, 348
Aetliocystis, 157
Aetostreon, 450
Aganides, 631
Agaricia, 103
Agaricocrinus, 196
Agassiceras, 657
Agassizia, 296
Agassizocrinus, 224
Agathelia, 95
Agatheinera, 800
Agathiceras, 641
Agelacrinus, 159, 156
Agiud, 499
Aglaspis, 77ii
Aglithodictya, 61
Agnesia, 524
Agnostus, 710
Agoniatites, 630
Agraulos, 717
Agria, 482
Agriocrinus, 199
Agrion, 811
Aguthasia, 404
Aipocoias, 606
Akera, 567
Alaria, 550
Albertella, 717
Ahcto, 319
Alectrioii, 550
Alectryonia, 450
Alexia, 574
Alipes, 551
AUageerinus, 209
Allionia, 237
Allocrinus, 191
Allocystites, 155
Allodesma, 470
Allomorphina, 29
Allonema, 318
Anonychia, 445
Allopagus, 469, 489
AUoprosallocrinus, 195
Allorhynchus, 398
Allorisma, 465
Alocolytoceras, 652
Aluta, 735
Alveolina, 39
Alveolites, 114
Alveopora, 107
Amaltheus, 659
Amaiiropsis, 543
Ambites, 633
Amblypneustes, 282
Amblypygus, 289
Amblysiphonella, 71
Ambocoelia, 412
Ambonycliia, 445
Amiella, 786
Amicula, 513
Amiskwia, 135
Amita, 444
Ammobaculites, 2(i
Ammodiscus, 25
Aminolagena, 25
Amnicola, 545
Amnigenia, 451
A)iwrphocystis, 152
Ainperleya, 530
Ampheristocrinus, 218
Amphiasti'aea, 98
Amphibola, 573
Aniphiceras, 657
Amphicliaena, 495
Amphiclina, 419
Amphiclinodonta, 419
Amphicoelia, 445
Amphicrinus, 205
Amphidesma, 495
Amphidonta, 450
Amphidromus, 576
Aiiiphigenia, 400
Amphilichas, 721
Amphion, 725
Amphipeltis, 758
Ampliipora, 124
Ampliispongia, 62
AmphistPgina, 34
Anipli i.^ili'ijilila, 385
AmphitUeliori, 59
Amphitomella, 418
Amphiura, 256
Ataplwra, 197
Aniplioracrinus, 197
Aniplexopora, 336
Am plexus, 83
Ami)ulla, 561
Ampiillina, 543
Ainjiyx, 712
Amusium, 458
Amygdalocystites, 151
Aniynilispes, 793
Anabacia, 103
Anabaia, 417
Anadara, 443
Anagyiniiites, 645
Anancliytes, 292
Anapella, 498
Aiiaphragma, 339
Anarcestes, 629 .
Anasirenites, 648
Anaspides, 755
Anastoniopora, 342
Anastrophia, 394
Anathyris, 417
Aiiatimya, •^^'16
Aiiatina, 466
Anatinella, 498
Awitomites, 639
Aniizyga, 408
Ancluira, 551
Ancilla, 562
Ancillaria, 5<"i2
Aiicistroceras, 601
Aiicistrocrania, 379
Ancryopyge, 723
Anculosa, 548
Ancyloceras, 670
Aiicylus, 575
Androgynoceras, 656
Angaria, 529
Angelinoceras, 601
Anisactinella, 418
Anisocardia, 471
Anisocriniis, 203
Anisophyllum, 84
Anisothyris, 499
Anisotrypa, 335
Anodonta, 455
Anodontites, 455
AncKlontopsis, 470
Anolcites, 648
Anolotichia, 328
Anomactiiiella, 418
Anomalantlms, 286
Anomalina, 33
Anomalocaris, 733
Anonialoceras, 605
Anomalocriniis, 213
Anomalocystites, 150
Anonialodonta, 445
Anutiudoides, 72
Anonialospongia, 72
Anomia, 461
Anoinoclonella, 56
Anomphalus, 532
824
TEXT -BOOK OF PALEONTOLOGY
Anopaea, 447
Anoplia, 389
Anoploceras, 606
Anoplophora, 452
Anoplotheca, 41G
Anoptychia, 537
Antalis, 509
Antedon, 236
Antheiuocrinus, 189
A7tt!iocrinus, 216
Antlioeystis, 153
Anthonyia, 474
Anthracochiton, 512
Antluacomartus, 791
Anthracomya, 452
AnUiraconectes, 783
Anthracopeltis, 774
Anthracopliaiisia, 759
Anthramjite.ra, 451
Anthracosia, 451
Antlirapalaeiiion, 757
Antinomia, 403
Antipleura 439
Antiptychia, 407
Antirhynchondla, 394
Antocyrtis, 44
Anuscula, 440
Aorocrinus, lOtl
Aparchites, 737
Apasmophyllnm, 84
Aphanaia, 440
Aplieleceras, 604 .
Aplietoceras, 600
Aphragmites, 59(3
Aphrostroma, 124
Aphj/llHe.s, 630
Apioceras, 611
Apiocrinus, 230
Apiocystites, 154
Apion, 805
Aplocems, 608
Aiiorrhais, 551
Apricaidia, 477
Apsendesia, 321
Aptychopsis, 754
Aptyxiella, 549
Aptyxis, 549
Apiis, 733
Arachnocrimis, 219
Arachnocystites, 152
Arachiioides, 288
Araeacis, 96
Arbacia, 281
Arbnscvlites, 390
Area, 443
Ai-ainopora, 346
Arcestes, 642
Arcliaediscus, 34
Archaeocidaris, 300
Arcliaeocrimis, 188
Archaeocyathua, 105
Archaeolepas, 744
Arcliaeoniscus, 758
Archaeoplax, 767
Archaeoscyphia, 53
Arcliaeospliaerina, 37
Areharenicola, 139
Aixhasterias, 248
Arcliegetes, 813
Archegocimex, 818
Archegocystis, 155
Archidesmus, 793
Archimedes, 341
Archinacella, 520
Archiorhyncliii.f, 805
Architarbus, 791
Arcliitectoiiica, 538
Architipiila, 815
Arcliiiilus, 793
Arcomya, 4(;6
Arcomyopsis, 438
Arcopagia, 494
Arctitii'ta, 387
Arenicola, 141
Arethusina, 715
Argas, 753
Argnstar, 248
Argia, 811
Argina, 443
Argoiiauta, 688
Argopatagus, 297
Argyrotliea, 365
Argyrotheca, 405
Aricardium, 490
Arieticeras, 658
Arietites, 655
Aristerella, 462
Aristocystites, 150
Aristozoe, 752
Arnioceras, 655
Arpadites, 648
Arrhoges, 551
Artemis, 492
Arthaberites, 635
Arthracantha, 200
Arthraster, 251
Arthroclema, 343
Arthrolycosa, 790
Artluoiiliycus, 141
Artliropleura, 758
Arthropora, 345
Arthrorachis, 710
Arthrostyhis, 342
Arystidicta, 61
Asaphellus, 719
Asaphis, 495
Asajjhus, 719
Ascidaspis, 722
Ascoceras, 596
Ascocystites, 160
Ascodictyon, 31S
Asemoblatta, 803
Aspenites, 634
Aspergillvm, 468
Aspidiscus, 99
Aspidites, 645
Aspidocaris, 754
Aspidoceras, 665
Aspidodiadema, 276
Aspidophylluiii, 86
AsiJidoiJOia, 333
Aspidosoma, 249
Aspidotliyris, 401
Aspidura, 256
Assilina, 36
Assiiiiinea, 545
Astacus, 764
Astarte, 472
AfitartopHs, 457
Asteractinella, 62, 63
Asterias, 247, 252
Asteriatites, 237
Asteiina, 251
Asteroblastus, 167
Asteroceras, 655
Asteroorinus, 201
AstPi'oderrna, 57
Asteropyge, 726
Ast}ienodonta, 452
Astlienosoma, 278
Asthenothaerus, 467
Astieria, 664
Astraemorpha, 104
Astraeospongia, 62
Astraliuiii, 528
Astrangia, 98
Astreopora, 108
Astrlielia, 95
Astrocladia, 55
Astrocnida, 255
Astrocoenia, 101
Astrocoma, 237
Astroconia, 62
A!<tromnn^, 172, 190
Astrocystitps, 160
Astroides, 76, 106
Astropecten, 247, 249
Astrophytov, 255
Astropyga, 278
Astrorhiza, 24
Astylucrinus, 224
Astylomanun, 56
Astylospongia, 55
Asyiiiptoceras, 616
Atactodea, 498
Atactopora, 333
Atactoporeila, 331
Atd.nister, 248
Ataxioceras, 664
Ataxocrinus, 213
Ateleocystites, 150
Atelestocrimis, 218
Atergatis, 767
Athleta, 561
Athyris, 417
Atikakania, 105
Atlanta, 536
Atocus, 806
Atoma, 564
Atomodesma, 449
Atops, 713
Atractites, 681
Atretia, 400
Atrina, 446
Atrypa, 409
Atrypina, 408
Attoides, 790
Aturia, 603
Atys, 568
Aucella, 449
Aulacoceras, 680
Aulacophyllum, 83
Aulacopleura, 715
Aiilacorhynchus, 389
AulacostPphanus, 665
Aulacotbyris, 406
Anlocopium, 53
Aulocrinus, 224
Aitlonotreta, 371
Aulo]ihyllum, 86
Aulopora, 116
Aulosteges, 391
Auricula, 574
Aurigeru.s, 665
Aurina, 561
Austinella, 381
Austinocrinus, 233
Austriella, 399
Autodetus, 543
Avellaiia, 567
Ariciihi, 447
Aviculopecten, 457
Aviculopinna, 446
Axinopsis, 487
Axinus, 487
Axosmilia, 100
Aysheaia, 136
Azara, 499
Azor, 495
Babinka, 444
Bactrites, 629
Bactrocrinus, 218
Bactropora, 343
Buctnqms, ib2
Bactrotheca, 571
Bdctrynium, 3S9
Baculina, 654
Baculites, 654
Baculocystites, 150
Badiotella, 460
Badiotites, 644
Baerocrinus, 211
Baetis, 809
Bairdia, 740
Bakewellia, 447
Balanocrinus, 233
Balanocystites, 151
Balauophyllia, 105
Balantionella, 64
Jldlantivm, 570
Balanus, 746
Balatonites, 647
Baltoceras, 598
Baiubaganites, 635
Banftia, 141
Barbarotliea, 815
Barbatia, 443
Baroda, 494
Barrandeite.s, 638
liarrandella, 395
Barrandeoceras, 600
Barraiideocrinus, 195
Barrettia, 484
Barroisella, 374
Barroisia, 71
Barroisiceras, 669, 672
Bartlettia, 455
Barycrinus, 218
Baryphyllia, 99
Baryphyllum, 82
Barysniilia, 101
Basilicus, 719
Basiliola, 400
Basterotia, 469
Bathnioceras, 597
Bathybius, 17
Bathymelia, 382
Batliycrinus, 230
Bathycyathus, 95
Bathynotus, 715
Bathysiphon, 24
Bathvtoiua, 563
Bathyurellus, 718
Bathyuriscus, 718
Bathvurus, 718
Batillus, 529
Batissa, 474
Batocrinus, 195
Batolites, 482
Batostoina, 338
Batostoiiiella, 335
Battersbyia, 87
Bayania, 537
Bayanoteutliis, 683
Bayha, 524
Bayleia, 478
Bdellacoiiia, 251
Beachia, 401
Becksia, 67
Beecheria, 403
Bela, 563
Beleinnitella, 683
Beleuinites, 681, 683
Beleninocrinus, 215
Beleinnocystis, 151
Belemnopsis, 682
Belemnosis, 683
Bdeninoteutbis, 684
Belgrandia, 545
Belinurus, 773
Bellardia, 550
Bellardiella, 564
BpUerophoii, 522
Beloceras, 631
Beloptera, 683
Belopteriua, 683
Belosepia, 686
Belosepiella, 68()
Beloteutliis, 688
Beltina, 783
Bembexia, 525
Beneckeia, 646
Berenicea, 319
Berthelinia, 464
Beyrichia, 738
Beyrichiella, 738
Beyrichiopsis, 738
Beyrichites, 647
BejTichocrinus, 195
Benichona, 735
Bicavea, 323
Bicia, 373
Bicrisina, 320
Bideiitia, 732
Bidiastopora, 320
Bifuhi; 416
Bi'flabellaiia, 326
Bifrontia, 538
Biiiencrina, 29
Biiliugsella, 380
Billingsia, 372
Billiiigsites, 597
Bilobites, 383
INDEX
825
Biloculiiia, 3S
Binuliolites, 481
Birostritex, 482
Bisiiimonea, 320
Bithinia, 544
Bittium, 550
Bittnerula, 413
Bitubigera, 320
Blairocrinus, 197
Blanchardia, 808
Blastoidocrinus, 167
Blauneria, 574
Bohemura, 254
Boletia, 282
Bolivina, 28
Bollia, 738
Bolma, 528
Bontaea, 467
Borelis, 39
Borsonia, 564
Boskovicia, 544
Bosnites, 635
Bosqiietia, 740
Bothnoci(lari.s, 270
Bothrocorbula, 499
Bothromicromus, 813
Bothiyocampe, 44
Botriopygus, 290
Botryllopora, 330
Botryocrimis, 221
Botryodift}-a, 60
Botsfoidia, 375
Bouchard ia, 407
Bourgetia, 537
Bourgueticrinns, 229
Bruchiocrinus, 212
Brachiospoiigia, 62
Biachylepas, 745
Brachymcrus, 394
Brachyprion, 385
Bracliypyge, 791
Biachythyris, 410
Bracliytreina, 539
Braduria, 735
Bradyl)latta, 803
Bialiniaciiims, 200
Braiichi])odite.s, 732
Braneonia, 395
Brasilia, 658
Brecliites, 468
Breynia, 297
Briarocrinus, 191
Brilonella, 524
Biissomorpha, 297
Brissopatagiis, 297
Brissopsis, 297
Brissus, 297
Brocchia, 541
Brodieia, 658
Broeckia, 439
Broeggeria, 371
Brongniartiella, S13
Brontfiopsis, 720
Brontes, 720
Bronteus, 720
Bryopa, 468
Bueanclla, 521
Bucaiiia, 521
Bucaiiopsis, 523
Bucanospira, 530
Buccinopsis, 557
Buccinulus, 565
Biiccinum, 556
Buchiceras, 671
Buchiola, 439
Biichites, 648
Buddliaites, 645
]5idiniina, 29
Bnlimulus, 576
Bulla, 567
Bullaea, 568
Bullaria, 567
Bullina, 566
BulUndla, 568
Bullinula, 566
Buniastus, 720
Bundonbacliia, 254
BuuodcUa, 777
Buiiode.s, 777
Burgessia, 733
Buriu, 769
Bursa, 555
Bursacrinus, 225
Bushia, 467
Buskopora, 330
Busycou, 557
Buthus, 770
Byssocardiuin, 490
Byssomya, 499
Byssonycliia, 445
Byssopteria, 445
Bytlunella, 545
Bythoerinus, 229
Bythocypris, 740
Bythopora, 335
Bythvtrypa, 328
Caeabocrinus, 191
Cactocrinus, 197
Cadoceras, 663
Cadomella, 389
Cadomia, 440
Cadomites, 663
Cadomoceras, 658
Cadulus, 510
Caecella, 498
Caecum, 547
Cainocrinus, 233
Calais, 688
Calamocrinus, 238
Calaiuophyllia, 'M
Ca/amopiini., 113
Calapoecui, 114
Calappa, 765
Calathocrirms, 225
Calathospongia, 61
Calcarina, 33
CalceocrintiK, 213
Calceola, 88
Caleidocriuus, 206
Callavia, 714
Callianassa, 764
Callicriiuis, 192
Callidernui, 250
Calliostoina, 532
Callistochiton, 513
Callistoplax, 513
Callizoe, 752
Callocanlia, 491, 493
Callocliiton, 513
Callocystites, 153
Callogonia, 491
Callonenia, 538
Callopegma, 53
Calloponia, 529
Callopora, 337
Calloporella, 337
CaUoporina, 337
Callotrypa, 335
Calostylis, 105
Calpiocriuus, 203
Calvetiua, 353
Calycanthocrinus, 20S
Calymeue, 724
Calynnie, 294
Calyptogena, 476
Calyptraea, 542
Cauiarella, 394
Camnrium, 416
Cainarocrinus, 160, 190
Cauiarophorella, 396
Camarophoria, 395
Camarospira, 416
Cameroceras, 595
Canierospongia, 68
Cauierotheca, 571
Camerothyris, 407
Camitia, 532
Campodfa, 820
Campophylhini, 84
Cauijjtocrinus, 201
Cainptouectes, 458
Camjryloce^^haluJ^; 782
Canipyloceras, 608
Campylosepia, 686
Canadia, 136
Canadocystis, 151
Canavarites, 660
Cancellaria, 562
Cancer, 767
Cancrinus, 763
Cariinia, 83
Canistrocrinus, 189
Cantantostoma, 525
Cantliaridus, 532
Cantliarus, 556
Capellinia, 395
Caphyra, 717
Caprina, 479
Caprinella, 480
Caprinula, 480
Capulus, 541
Carabocriuus, 217
Caratomus, 289
Carbouarcfl, 442
Carbonia, 739
Carbonieola, 451
Carcinocarcinus, 767
Cdirinosoma, 783
Cardiaster, 294
Cardilia, 498
Cardinia, 452
Cardinocrania, 379
Cardiocaris, 754
Cardioceras, 663
Caniiocystis, 160
Cardiola, 439
Cardiolites, 751
Cardiomorplia, 439
Cardiomya, 469
Cardita, 475
Carditamera, 476
Carditella, 476
Cardiutn, 4S9
L'arduocrinus, 221
Caricella, 561
Carinaria, 536
Cariuaropsis, 523
I'arinifer, 326
Carinopora, 341
Carnarvonia, 750
Carnites, 635
Carolia, 461
Carolwrinus, 194
Carosyphaera, 42
Carpenteria, 33, 451
Carpenteroblastus, 172
Carpenterocrinus, 232
Carpocrinus, 194
Carpocystis, 156
Carpomanon, 56
Carpospongia, 56
Carterella, 57
Carterina, 124
Carychium, 574
Caryocaris, 751
Caryocrinus, 153
Caryocystites, 152
Caryomanon, 56
Caryophyllia, 95
CaryophyUites, 239
Caryospongia, 56
Casearia, 65
Cassianella, 448
Cassianocrin us, 225
Cassidaria, 554
Cassidula, 574
Cassidulina, 29
Cassidulus, 290
C'assiope, 540
Cassis, 556
Castmiocrimis, 190
Castocrinus, 213
Catazyga, 408
Oatenipora, 117
Catillocrinus, 214
CatiUus, 447
Catopygus, 290
Catosira, 537
Catulloceras, 658
Caunopora, 123
Cavaria, 324
Cavea, 324
Cavolina, 570
Cea, 323
CelkirUi, 348
Cellepora, 350, 353
Celleporki, 353
Cellularia, 348
Cellulipora, 320
Celtites, 640
Cenoceras, 607
Cenocrinus, 233
Cenomariites, 668
Ceuosphaera, 42
Centrechinus, 277
Centrioerinus, 191
Centroeeras, 606
I'entvocrinus, 199
Centronella, 400
Centrotheca, 571
Ceplialogi'aptus, 130
Cephaloraphidites, 51
Ceramella, 346
Ceramocnnus, 219
Ceraiiiophylla, 328
Ceramopora, 327
Ceramoporella, 327
Ceratarges, 722
Ceratiocaris, 750
Cwatisolen, 496
Ceratites, 647
Ceratocephala, 722
Ceratocystis, 151
Ceratodictya, 60
Ceratoliclias, 722
Ceratopsis, 738
Ceratopyge, 717
Ceratosiphon, 551
Ceratostreon, 450
Ceratotheca, 571
Ceratotrochus, 94
Ceratozona, 513
Ceraurus, 724
Cercomya, 466
Cerioaivu, 326
Ceriocrinus, 225, 231
Cerionites, 72
Ceriopora, 326
Ceritella, 549
Ceritliidea, 550
Cerithiiiella, 549
Cerithinpsis, 550
Cerithiuni, 550
Cermatia, 793
Cernina, 543
Ceromya, 465
Cerylimopsis, 805
Cetciciiiicha, 469
Cetomya, 469
Chaena, 500
Chaeudcaris, 753
Chaeuomya, 439
Chaenojiea, 500
Chaetetes, 117
Chaetopleura, 513
Chaiiiodictyon, 340
Chalmasia, 449
Chama, 477
CiMperia, 480
Charioiiella, 416
Chartrouia, 660
Chascothyris, 401
Chasmatopora, 340
Chasmops, 727
Chauliodes, 812
Chauliodites, 811
Cheiloceras, 631
Cheirocrinus, 154, 213
Cheiropteraster, 251
Cheirurus, 724
Cbelifer, 789
Vlidocrinus, 225
Chemnitsia, 537
826
TEXT -BOOK OF PALEONTOLOGY
Cheiiendopora, 59
Clienopus, 551
Chicagncriiuis, 193
Chicoreus, 558
Chilina, 574
Cliilocyclus, 53S
Cliilopora, 326
Chiloporella, 328
Cliilostomella, 29
Chilotrypa, 330
Chiridota, 313
Chiton, 513
Chitonellus, 513
Chkuiocrinns, 232
Clilamydoconcha, 448
Chlamys, 457'
Clilidonophora, 404
C'hoaiioeeras, 596
Chojfatui, 603
Cholocriims, 203
Chonaxis, 85
Chondrostronia, 124
Ohiinechiton, 512
Choneplax, 513
Chonetella, 389
Chiinetes, 389
Chonetina, 389
Chonopectus, 391
Chonophyllum, 85
Choiiostegitcs, 116
Chonostropliia, 389
Choriplax, 512
Churistites, 410
Clioristoceras, 649
Choristodon, 494
Chresmoda, 799
Christaiiia, 385
Chrysodonius, 557
Chrysomelon, 278
Chrysostoma, 532
Chthamalus, 747
Cibolocriiius, 225
Cicatrea, 472
Cidaris, 272
Cidaroblastus, 171
Cigara, 151
Cimitaria, 465
Cincta, 407
Cinulia, 567
Circe, 493
Circopora, 124
Cirrus, 531
Cirsotrema, 538
Cistella, 405
Citrocystis, 152
Cladangia, 98
Cladiscites, 643
Cladochonus, 116
Cladocora, 97
Cladocrinus, 206
Cladnpora, 114
Claiiculus, 531
Clarkella, 392
Clathrodictyon, 123
Clathropora, 345
Clathrospira, 525
Clathrospongia, 60
Clathurella, 564
Clausa, 324
Clausilia, 576
Clava, 550
Clavaehldstus, 170
Clavagella, 468
ClavaUila, 563
Clavella, 559
Claviclausa, 324
Ckwisparsa, 320
Clavulina, 29
Cleidophoius, 440
Cleidoiheca, 571
CIt'iocriims, ISO
Cleinilivridiiia, 4IS
Chiotkyris, 417, 418
Cleistecliiuus, 297
Cleinatncriiius, 199
Ck'ineutia, 492
Cleodictya, 61
Ckodora, 570
Cleonoceras, 667
Clesydrospongia, 61
Clidiophora, 467
Clidochirus, 204
Cliftoiiia, 387
Climacaniniina, 29
Climacograptus, 130
Climactichnites, 142
Clinoceras, 611
Clinopistha, 438
Clinopora, 321
Clintonella, 409
Cliinira, 563
Clio, 570
C]ionites,'648
Clionychia, 445
Clisiophyllnm, 85
Clisocolus, 491
Clisospira, 543
Clitauibouites, 392
Clonocriuus, 190, 190
Clonopora, 321
Clorinda, 395
Closterocrinus, 218
Clydonautilus, 602
Clydoiiites, 648
Clynienia, 628
Clymenonantilus, 602
Clypeaster, 285
Clypeina, 321
Clypeoceras, 645
Clypeus, 290
Clypites, 634
Cnemidiastrum, 57
Cnemidium, 57
Cnisma, 442
Coccocrinus, 199
Coccophyllum, 101
Coccoseris, 112
Coccoteuthis, 687
Cochlearia, 538
Cochloceras, 650
Cochlodesma, 467
Cochlolejms, 542
Codakin, 486
Codaster, 168
Codechiiius, 278
Codiacrinus, 221
Codiacystis, 155
Codiopsis, 277
Codoceras, 612
Codoiiasttr, 168
Codonites, 169
Coelastarte, 472
Coeliocrinus, 223
Coeloeentrus, 527
Coeloceras, 662
Coeloclema, 328
Coeloconus, 343
Coelocorypha, 59
Coelocriiius, 187, 196
Coelocystis, 154
Coelodon, 467
Coeloeanlus, 525
Coelogasteroceras, 605
Coeloina, 766
Coelomactra, 497
Coelonautiliis, 604
CoelopUnirus, 281
Coeloptycliium, 67
Coelosmilia, 100
Coelospira, 417
Coelostyliiia, 537
Coenagiion, 811
Coenites, 114
Coeniioyathus, 95
Coenocystis, 157
Coeno(ji-uptu.s, 130
Coenotliyris, 407
Coleoloidos, 572
Coleolus, 572
Collina, 662
Collonia, 529
Collyrites, 292
Coloboceiitrotus, 283
Coloceras, 604
Colospongia, 71
Colpocaris, 751
Colpoceras, 595
Columbplla, 556
Columbellaria, 553
Collumbellina, 553
Columbites, 640
Columnaria, 87
Columnastraea, 101
Columnopora, 114
Coins, 559
Colynimatina, 55
Comarocystites, 151
Coinastrocrinus, 284
Coiiiatulina, 237
Comatulithes, 237
Coniaturella, 237
Combopliyllum, 82
Comelicania, 418
Cominella, 556
Coinoseris, 104
Composita, 418
Composocrinus, 194
Compressidens, 509
Conipsoiiietra, 237
Coinptonia, 250
Conactaeon, 566
Concliicolites, 139
Conchidium, 394
Couchocele, 487
Conchodon, 453
Concholepas, 558
Oonchopeltis, 520
Condylociiiius, 189
Condylopyge, 710
CoiifusaMrea, 101
Congeria, 463
Conocardium, 446
Conoceras, 597
Conoclypeus, 2S4
Conocoryphe, 713
Conocrinus, 229
Conolampas, 291
Conorbis, 564
Conoteuthis, 684
Conotreta, 376
Coiiotuligera, 321
Conradella, 522
Conradia, 373
Constellaria, 334
Conularia, 572
Conulus, 284
Convexastrea, 101
Cophinoceras, 603
Coptostyllus, 548
Coralliochama, 480
Coralliopliaga, 472
Corallium, 76, 110
Coraster, 296
Corbicella, 487
Corbicula, 474
Corbis, 486, 486
Corbula, 499
Corbulamella, 499
Corbuloitiya, 499
Corburella, 470
Cordillerites, 633
Cordylocriinis, 199
Corimya, 467
Corneocyclas, 475
Cormicaprina, 479
Coriiulites, 139
Corniispira, 37
Coroniceras, 655
Coronida, 768
Cnivniirrinux, 191
Coronnla, 747
Corydocephahis, 721
Corylocriuus, 153
Coryiii.hiifrinii'!, 190
Coryiiibopora, 321
Corynella, 70
Coryiiotrypa, 319
CoscintiUa, 345
Coscinium, 346
Coscinopora, 64
Coscinotrypa, 346
Cosmiolithes, 112
Cosmoceras, 668
Cosmocrinus, 221
Cosmogyria, 658
Costidiscus, 653
Cottaldia, 277
Cotylecrinus, 241
Cotylederma, 241
Cotyledonocrinii s, 201
Cranaena, 403
Crangopsis, 757
Crania, 378
Cranielhi, 378
Craniops, 379
Craniscus, 379
CraspeditPS, 664
Craspedoelilton, 513
Craspedophylluui, 85
Craspedopoma, 540
Craspedosoma, 792
Craspedostoma, 529
Crassatelltt, 474
Crassatellina, 474
Crassatellites, 474
Cmssina, 472
Crassineila, 472, 474
Craterella, 54
Craterinn, 150
Craticularia, 63
Cremacrinus, 213
Crenatula, 447
Crenella, 463
Creniceras, 658
Crenipecten, 457
Crepidophylluni, 85
Crepidula, 542
Crepipora, 328
Crescentilla, 754
Crescis, 326
Creseis, 570
Creusin, 747
Cribrilina, 350
Cribrobhistus, 171
Cribrostomnm, 29
Crieopora, 320
Crinocystis, 160
Criocpras, 670
Crisia, 318, 570
Crisidia, 318
Crisina, 320
Cristellaria, 30
Cromus, 723
Cromyocrinus, 224
Cronicus, 809
Crossopodia, 141
Crossostoma, 529
Crotaloceplialus, 724
Crotalocrinus, 216
Crucibulum, 542
Cruratula, 407
Cryphcieus, 726
Cryptabacia, 102
Cryptacantliia, 402
Cryptaenia, 524
Cryptangia, 98
Cryptaulax, 549
Cryptaxis, 108
Cryptoblastus, 172
Cryptocaris, 754
Cryptoeeras, 605
Cryptochiton, 513
Cryptocliorda, 562
Cryptoclymenia, 628
Cryptocoelia, 71
Cryptocopnia, 101
Cryptoconus, 563
Cryptocrinus, 157
Cryptodictya, 61
Cryptodon, 487
Cryptoglpna, 325
Cryptolithus, 711
Cryptomya, 499
CryptonoUa, 402
INDEX
827
Cryptoplax, 512, 513
Crypto'plocus, 549
Cryptopora, 400
Cryptoporus, 400
Ci-yptoschisma, 109
Cryptozoe, 751
Crystallocystis, 152
Crytopora, 341
Ctenol)olbina, 738
Cteiiocephahi.s, 713
Cteiioceras, 599
Ctenocrinus, 190
Cteiiodonta, 440
Ctenoptorus, 784
Ctenostreon, 460
Cuccoceras, 648
Cucullaea, 442
Cucullaria, 442
CucuUella, 440
Culicoorinus, 199
Cultellus, 496
Cuniingia, 495
Cuiiiulipora, 351
Vupelliiecrinus, 199
Cuphoselenus, 551
Cupressocrimis, 210
Cupularia, 351
Cupuloprinus, 215
Curculioides, 789
OurcuUopsis, 805
Curticia, 371
Curtonotus, 472
Cuspidaria, 469
Cuvierina, 571
Cyatliaxonia, 81
Cyathidium, 241
Cyatliocriiius, 220, 221
Cyathocystis, 159
Cyatliodonta, 467
Cyatliophora, 101
Cyatliophyciis, 61
Cyathopliyllimi, 84
Cyatlioseris, 102
Cybele, 724
Oyclas, 472, 475
Cyclaster, 297
Cyclidia, 583
Gydina, 492
Cycloceras, 599, 660
Cycloclyiuenia, 628
Cyclocoelia, 381
Cycloconcha, 470
Cyclocriiuis, 72, 160, 232
Cyclocystoides, 159
Cyclolites, 103
Cyelolituites, 601
Cyclolobus, 642
Cyclomops, 552
Cyclonema, 530
Cyolonssa, 557
CycloxjUorus, 540
Cyclophtlialainu.s, 788
Cyolopliyllnm, 86
Cyclopora, 347
Cycloporella, 347
Cycloporidiuin, 121
Cydoporina, 341
Cyclorhina, 397
Cyclosiihaeroma, 758
Cyclospira, 410
CyflostOMia, 540
Cyclostoiuiceras, 611
Cyclostrema, 532
Cyclothyris, 398
Cyclotrypa, 329
Cyclotus, 540
Cydus, 372, 773
Cylichna, 568
Cylirncrinus, 195
Cylindm, 560
Cyliiidrites, 566
Cyliiidrolndlina, 566
Cylindroinitra, 560
Cyliiidroi)hyma, 56
Cylleiie, 557
Cymaceras, 658
Cymaclyinonia, 628
Cymatoceras, 607
Cymatocliitdii, 512
Cymatoplilebia, 810
Cyinhitifs, 657
Cyiiibiuni, 561
Cymbopliora, 498
Cyvu'Ila, 469
Cymia, 558
Cynodunta, 560
Cypellia, 64
Cypellocrinus, 199
Cyphaspis, 721
Cypliocrinus, 187
Cyphon, 805
Cyphosoiiia, 280
Cyphotrypa, 334
Cypraea, 553
Cyprella, 741
Cypresis, 741
Cyprimnlia, 472
Cypiicardinia, 471
Cyprimrilites, 442
Cypridea, 740
Oypridclla, 741
Oyiiridelliiia, 741
Cypridiiia, 741
Cypridiiiella, 741
Cyjiriineria, 492
CyprUia, 472
Cypris, 740
Cyprosiiia, 741
Cyrena, 474
Cyrenella, 4S7
Cyreiioida, 487
Cyricaidella, 471
Cyrtactinocera.s, 609
Cyrtendoceras, 596
Cyrtia, 412
Cyrtidocrinus, 203
Cyrtina, 412
Cyrtocalpis, 44
Cyrtoceras, 611
Cyrtocerina, 597
Cyrtochilus, 054
Cyrtoclynieiiia, 028
Cyrtocrinu.t, 240
Cyrtodonta, 442
Cyrtodo ntopMs, 445
C'yrtolites, 521
Cyrtolitiiia, 521
Cyrtopiniia, 446
Cyrtopleurites, 648
Cyrtopora, 322
Cyrtorizoceras, 610
Cyrtotheca, 413
Cyrtulus, 559
Cystaster, 159
Cystechiims, 294
Cystii)liylluni, 87
Cystispongia, 68
Cystocidaris, 299
Cystodictya, 346
Cythere, 739
Cytherea, 493
Cytliereis, 739
Cytherella, 740
Cytherellina, 740
Cytheridea, 739
Cytherideis, 739
Cytherodon, 440
Cytheropteron, 739
Cytinopsis, 413
Cytis, 323
Cytocrinus, 190
Cytodaria, 500
Cytograptus, 132
Dactylioceras, 662
Dactylocrinus, 205
Padylocystis, 156
Uadyloteuthis, 682
Diictylus, 565
Dadocriiius, 232
Daedalus, 141
Dalila, 439
Dallina, 406
Dalmanella, 382
Dalmaiiites, 726
Dalmanitina, 726
Dalmatites, 64()
Danilia, 532
Danubites, 647
Daondla, 448
Daphnella, 564
Daphnites, 648
Daraelites, 633
Darellia, 658
Dasyceras, 652
Davidsonella, 372, 389
Davidsonia, 385
Daviesiella, 389
Davila, 498
Davousti, 452
Dawsonoceras, 599
Dayia, 409
Dazieduszyclia, 410
Deacanemos, 237
Dearbornia, 376
Decadocrinus, 223
Decadopecteii, 457
Def'ranciopora, 326
Deiplioii, 725
Deiroceras, 609
Dejanira, 534
Dekayella, 333
Dekayia, 333
Delgadella, 372
Delphinula, 529
Delphinulopsis, 534
Deltacrinus, 213
Dvlthyridca, 406
■Ddtlmris, 408
Delthyris, 411
Deltoceras, 600
Deltocyathus, 95
Democrinus, 229
Deiickiiiaiinia, 600
Dendracis, 108
Dendrastm; 288
Derulricopora, 342
Dendrocriuus, 215
Dendrocystites, 151
Dendrograptus, 128
Dendrophyllia, 106
Dendropupa, 576
Dendrostrea, 450
Denkmannia, 401
Dentalina, 30
Dentalium, 509
Deocrinus, 188
Derbya, 386
Dermatoiuya, 469
Dermatopora, 349
Deroceras, 662
Deshayesia, 543
Desmidocrinus, 194
Desmoceras, 667
Desmograptus, 128
Desoria, 296
Detocriuus, 225
Deutocystites, 150
Dlabolocrinus, 188
Dkidema, 277
Diadiploceras, 605
Diam(3nocrinus, 189
Diamesopora, 347
Dianulltes, 335
Diaphana, 568
Diaphorites, 662
Diaphorostoma, 541
Diaphragnius, 390
Diapora, 123
Diastoiiia, 537
Diastopora, 319, 319, 320
Diastoporiiia, 320
Dicaiiiara, 416
Dicellogi-aptus, 130
Dioeras, 477
Dieeroeardium, 454
Dichocrinus, 201
Dichograptus 129
Dichotrypa, 346
Dlcoelosia, 383
Dicranella, 738
Dicr<miscus, 387
DicranoKraptus, 130
Dicrauopora, 345
Dicranuius, 722
Dicroloina, 551
Dictyocenis, 599
Dictyoconites, 680
Dictyocrinites, 72
Dictyoarinvs, 72, 160
Didyograptus, 128
Dictyomitra, 44
DictyoiU'lla, 396
Dictyonema, 128
Dictyopleurus, 282
Dictyospongia, 60
Dictyothyris, 404
Didacna, 490
Didymites, 642
Didymograptus, 129
Didymopora, 329
Dielasma, 402
Dielasiiiina, 403
Dielasmnides, 403
Diemptfius, 561
Digitaii, 472
Diguoiuia, 374
Digonioceras, 607
Dikelocephalina, 720
Dikelocephalus, 720
Dilobella, 738
Dimerella, 399
Diinerocrinus, 187, 205
Diiiiorwn, 612
Diinorphaiaea, 103
Diiiiorpliastrta, 104
Uimorphina, 31
Dimorphites, 639
Diiiiorphoceras, 637
Dimorjihccrinus, 169
Dimorpliograptus, 132
Dimorphosoma, 551
Diniya, 459
Dimyodon, 459
Diiiarella, 401
Diiiarites, 648
Diiieura, 806
DiiKibilus, 373
Dinocystis, 159
Diiiopilio, 791
Diiioplax, 513
Diiiorthis, 382
Diodoceras, 607
Dionide, 711
Dionites, 648
Dioristella, 416
Diorugoceras, 604
Diphragmoceras, 595
DiphyUes, 403
Diphyphyllnni, 84
DipiUdia, 478, 482
Diplacomocera.s, 671
Diplagnostus, 710
Di pleura, 724
Diploceras, 595
Diplocidaris, 274
Diploclema, 321
Diploconus, 683
Diplocraterion, 141
Diplocrinus, 233
Diplocteiiium, 100
Diplodonia, 487
Diplot'pora, 112
Diplograptus, 130
Dlplonioceras, 654
Diplopodia, 277
hiplopora, 342
Diploporaria, 342
Diploria, 99
Diplosireiiites, 648
Diplospirella, 418
Diplostoma, 71
Diplotheca, 571
I Diplotrypa, 338
828
TEXT -BOOK OF PALEONTOLOGY
Dipsaccus, bUd
Dipterocaris, 754
Diptychoceias, 653
Dischides, 510
Discina, 378
Discinisca, 378
Discinocaris, 75-t
Discinolejiis, 370
Discinopsis, 377
Discites, 604
Discitoceras, 604
Discocavea, 325
Discoceras, 600, 655, 668
Discoclymenia, 628
Discocyatlius, 95
Discocystis, 159
Discocytis, 323
Discodermia, 55
Discofacigera, 321
Discohelix, 527
Discoidea, 283
Discophyllites, 651
Discorbina, 32
Discors, 490
Discoseaphites, 670
Discosorus, 609
Discosparsa, 319
Discotarbus, 791
Discotroehus, 94
Discotropites, 638
Discotypa, 337
Disculina, 404
Disjectopora, 124
Distichites, 648
Distichoceras, 659
Distortrix, 555
Ditaxia, 325
Dithyrocaris, 753
Ditreniaria, 525
Ditvetus, 549
Dittmarites, 648
Dittopora, 339
Divaricella, 486
Dizygocrinns, 196
Dochraostoma, 290
Dolatocrinus, 191
Diilichocriims, 229
Doliclwpteron, 444
Dolichopterus, 783
Dolium, 555
Domatoceras, 60i;
Donacicardium, 484, 496
Donax, 496
Dorateuthis, 688
Dorsetensia, 660
Dorycrinus, 196
Dorydernia, 57
Dosinia, 492
Douvilleia, 566
Douvilleiceras, 669
Douvillina, 385
Dreissenia, 463
Dreissensiomva, 463
Drepauella, 738
Drepanites, 648
Drepanopterus, 784
Drillia, 563
Bromia, 765
Dryinadusa, 799
Drymotrypii, 340
Dualina, 439
Diimortieria, (i57
Duncanella, 82
Durga, 454
Dux, 438
Dyhowalddla, 320
Dyeria, 530
Dysagririii, 811
Dysaster, 292
Dyscolia, 404
Dystactella, 438
Eastonia, 498
Eatonia, 397
Eburna, 556
Eccylioinplialus, 527
Eceylioptems, 527
Ecliinarachnius, 288
Bchinaster, 252
Echinasterella, 251
Echinohrissns, 289
Echinocardium, 297
Echinocaris, 751
Echinochama, 478
Echinocorys, 292
Bchinocrepis, 298
Echinocyamus, 286
Echinocyphus, 282
Echinocygtites, 157, 299
Echinodiscus, 288
Echinoencrinus, 154
Ecliinognathus, 783
Ecliinolampas, 291
Ecliinometra, 283
Bchinoneus, 289
Echinopsis, 276
Eckinospatagus, 294
Echinosphaerites, 152
Echinostrephus, 282
Bohinotliuria, 278
Echinus, 281
Ectenocrinus, 212
Ectenodesina, 444
Bctolcites, 648
Ectomaria, 525
Edaphoceras, 607
Edentula, 447
Edmondia, 439
Edrioaster, 159
Edriocrinus, 206
Edtvardsocrin us, l'.i9
Egeria, 496.
Bgeta, 474
Ehrenbergina, 29
Eichwaldia, 396, 396
Eileticus, 793
Elaencrinus, 171
Elasmostoma, 71
Eleana, 798
Elder, 761
Eldonia, 313
Elea, 324
Eleutherocaris, 752
Eleutherocrania, 379
Bleutherocrinus, 170
EHgmus, 451
Elkaiiia, 372
Ellipsactinia, 120
Ellipsoearis, 754
Ellipsocephalus, 717
ElHpsoidina, 29
Elliptocephala, 714
Elpe, 741
Blymella, 439
Elymocaris, 762
Emaiginula, 526
EinWa, 469
Embolus, 570
Eirieraldella, 776
Emileia, 663
Emmelezoe, 752
Emmonsia, 114
Emperoceras, 654
Euallhelia, 95
Enallociinus, 216
Endiitloxphen, 400
EnilUiuitiireras, 603
Eucuiloceras, 606
Encope, 288
Encrinurus, 723
Enn-inus, 225, 233
Endoceras, 595
Knd,,!ohus, 605
Endothyra, 33
Eiidoxocrinus, 233
Engoiioceras, 671
Enicliaster, 294
Ennalaster, 294
Ennei-wystis, 153
Eiiopleura, 150
Enoploceras, 606
Enoplochiton, 513
Enoploclytifi, 763
Ensis, 496
Entalina, 510
Entaliopsis, 509
Entalis, 509
Entalium, 508
Entalopliora, 230
Enteletes, 383
Euteletoides, 383
Entodesnia, 468
Entoliuin, 458
Entoniidella, 741
Entomis, 741
Entoinocaris, 750
Entnmnconchus, 742
Bobuthus, 788
Eoeicada, 815
Eoeidaris, 300
Eocyclina, 492
Eocystites, 151
Eodiadenia, 276
Bodiscus, 711
Eoharpes, 711
Eoluidia, 255
Eooholus, 372
Eoortliis, 381
Eophrynus, 791
Eophyton, 134
Eopteria, 439, 733
Eoscoipius, 78S
Eosphaeroiiia, 758
Bospirifer, 411
Bo.stiuphomena, 384
Eotrochus, 543
Eotrophonia, 137
Eozoon, 37
Epactocrinus, 219
Ephemera, 809
Epliippioceras, 604
Epliip]>inni, 461
Ephippodoiita, 4SS
Epiaster, 294
Epicyrta, 407
Episageceras, 633
Episiphon, 509
Epismilia, 97
Epithyrls, 402, 403
Epitonium, 538
Erato, 554
Eremites, 618
Brenioceras, 611
Eretmocrinus, 195
Brettopterus, 7S5
Eriohthus, 769
Eridophyllum, 84
EridorthU, 381
Bridotrypa, 329, 335
Erinocystis, 155
Briphyla, 472
Briptyclia, 567
Brisocrinus, 225
Brodona, 499
Ervilia, 498
Brycina, 488
Erycinella, 488
Eryma, 763
El-yon, 7t)2
Eryx, 498
Bscasona, 735
Eitchara, 350
EscliarUes, 824
Bscharoijora, 345
Estheria, 734
Estheriella, 734
Estlioniopora, 336
Estonioceras, 607
Etallonia, 566, 763
Btheria, 455
Btlieridgaster, 251
Btheridgia, 68
Etlieridgina, 391
EilniiiipliyUnia, 105
Ktisus, 767
Etyus, 767
Eublejitus, 79ii
Eucaenus, 301
Jluealathis, 404
Eucalytoerinus, 192
Euchxris, 469
Euchasma, 439, 733
Eiichilotheca, 571
Buchirocriniis, 213
Buchrysalis, 538
Euciroa, 469
Bucladia, 255
Eucladoorinus, 200
Buconactaeon, 566
Buconia, 525
Bucorystes, 765
Eucratea, 348
Eucrinus, 187
Eucucloderaa, 381
Eucyclus, 530
Eucymba, 561
Eucyrditium, 44
Eucysti.s, 155
Eueythara, 564
Budea, 69
Eudesella, 388
Eudesia, 406
Eudesicrinus, 241
Budoxochiton, 513
Eugeniacrinus, 239
Eugereon, 817
Eugyrina, 55
Euhelia, 95
Eulimella, 537
Euloma, 715
Bulophoceras, 672
Euiiiegalodoii, 454
Bumetria, 414
Eumicrutis, 448
Eunella, 402
Bunema, 530
Eunicites, 139
Bunoa, 377
En,obolus, 371
Euomphalopterus, 527
Buomphalus, 527
Eupachycrinus, 224
Eupatagus, 297
Eupera, 475
Euphemus, 523
Euphoberia, 793
Euphyllites, 652
Euproiips, 774
Eupsammia, 105
Euractinella, 418
Euraphia, 747
Burhodia, 290
Euryale, 255
Bury care, 715
Eurychilina, 738
Eurydictya, 345
Eurymya, 462
Eurynoticeras, 667
Buryocrinus, 205
Eurypneustes, 282
Eurypterella, 783
Eurypterus, 782
Eurysoma, 783
Eurystomites, 600
Eusarcus, 783
Eusiphonella, 70
Buspilopora, 345
Buspira, 543
Euspirocriiuis, 218
Bustoma, 650
Bustylus, 537
Eutaxocrinus, 205
Eutermes, 804
Enthemon, 255
Euthria, 567
Buthydesma, 439
Euthyris, 417
Eutomoceras, 646
Eutrephoceras, <)07
Eutrochocrinns, 196
Euzonus, 792
Bvactinopora, 346
Exapii.nurus, 777
Bxelissa, 549
INDEX
829
Exogyra, 4o0
Extnwrinus, 232
Fabella, 48S
Fabnlaria, 3'.i
Falcilituites, 600
FalcuUi, 508
Faorina, 29(5
Fasciculipora, 321
FasciiiPlla, 5-18
Fasciolaria, 550
Fascipoi-a, 321
Faseiporina, 321
Faunus, 548
Favia, US
Favicella, 330
Favistella, 87
Favositella, 328
Pavosites, 113
Felania, 487
Fenestella, 341
Fenestralia, 341
Fenestiaimra, 341
Fenestrella, 341
FergensUi, 320
Fibula, 549
Fibularia, 287
Ficula, b^}b
Field ia, 750
Filicea, 323
Filicrisin, 318
Filicrisina, 320
Filifascigera, 322
Filisparsa, 319
Fimbria, 4Sti
Fimbriella, 487
Fimbriotliyris, 407
Finkelnburgia, 381
Fischeria, 474
Fissidentaliimi, 509
Fissirostra, 400
Fissurella, 52i), 526
Fi.ssun^llidea, 52ti
Fissuridea, 520
Fissnriroatra, 406
Fistiilana, 500
Fistulipora, 329
Flabellocrin ws, 225
Fiabt'llothvri.s, 4015
Flabelliini; 94, 570
Flemiiigia, 531
Flemingites, 045
Foordiceras, (505
Ploridiiia, 351
Flustrdluria, 350, 351
Forbesia, 545
Forbesiceras, 671
Forbesiocrinus, 204, 204,
205
Fordilla, 439
Fordinia, 371
Forticida, 800
Foricula, 324
Fortisia, 5(57
Fossariopsis, 534
Fossarulus, 545
Fossanis, 540
Fragilia, 494
Fragum, 490
Frenula, 406
Frenulina, 40(5
Frieleia, 4(J0
FroiidiiMilaria, 30
Fulgoraria, 501
FuJgoritlitiiii, 819
Fulgur, 557
Fungia, 102
Fungocystites, 156
Fuselia, 410
Fusiiius, 559
Fusispira, 538
Fustiaria, 509
Fusulina, 34
Fusus, 559
Gadila, 510
Gadinia, 573
(ladus, 510
Gufraiiuin, 493
Clithitcn, 474
Galatliea, 764
Galaxea, 100
Galenopsis, 760
(jalt'oila, 554
Galeoniiiia, 488
Galerites, 284
Galeropygiis, 285
Gdlerus, 542
Gammarocriiuis, 240
Gainniarus, 759
Gamopleura, 570
Gampsonyx, 756
Ganymeda, 237
Garantiana, 664
Gargantua, 351
Gaiiiieria, 672
Gasocaris, 756
Gasjjesi, 385
Gasterocoma, 219
Gast-rana, 494
Gastrioceras, 636
Gastrochaeiia, 500
Gastrocrinus, 221
Gaudryceras, 652
Gaudryina, 29
Gazaeiiinis, 187
Gecarciuus, 767
Geinitzdla, 335
Geinitzia, 803
Geisouoceras, 598
Geiiiellaria, 348
Gemma, 494
Gemmcllaria, 479
Gemmellaroia, 392
Gemmipora, 108
Genabaoia, 103
Genea, 557
Geiiicopatagus, 297
Geniiafacriniis, 195
Genota, 563
Geocoiiia, 237, 256
Geocrinus, 194
Geophilds, 793, 139
Geoteuthis, 687
Gepliyroceras, 631
Gephyrocrimis, 238
Geialiiiura, 788
Geraphrynus, 791
Gpi-atarbdS, 791
Geroneui-a, 797
Gervillia, 447
Geyerella, 387
Geyeroceras, 652
Oii)bula, 532
Gigantoceras, 608
Gilb(^rtsociinu.s, 188
Giityella, 403
Gisortia, 554
Gissocriiius, 220
Ghiharif:, 455
Gladiograptiis, 132
Glanduliiia, 30
Glaplidius, 723
Glaphyrocvstis, 155
Glassia, 409
Glassina, 415
Glaucomya, 494
Glaucomyacidap, 494
Glanconia, 546
Glauconome, 342, 343
Gleiiotremites, 237
Globigerina, 31
Globoblastus, 171
Gloria, 439
Glossina, 374
Glossites, 439
Glossoceras, 597
Glossograptus, 130
Glossotbyris, 404
Glossotrypa, 330
Glottidia, 374
Glycimeris, 443, 499, 500
Glyphaea, 7(;2
Glyphidites, 648
Glypbioceras, 636
Glt/phis, 526
Glypbocyphus, 282
Glypliostoma, 564
Gliiiititster, 187
Glyptecbimis, 282
Glypticus, 276
Glyptobasis, 531
Glyptocarrlia, 439
Gl'yptocidaris, 280
Glyptocrimis, 189
Glyptocystites, 154
Giyptodcsma, 444
Glyptograptus, 130
Glyptopora, 346
Glyj^tosceptivn, 110
Glyptoscorpius, 785
Glyptosphaerites, 156
Giiathia, 758
GnafhodoH, 498
Gnorimocrinus, 205
Goldius, 720
Gomphoceras, 613
Goiiiphocystites, 156
Gomphoides, 810
Gonambonites, 392
Gongylospoiigia, 60
Gouiacriniis, 218
GoniasteroidocrinKS, 188
Goniastrea, 99
Goniobasis, 548
Goiiioceras, 6(J9
Gonioci<laris, 273
Gonioeladia, 346
Gonioclyiiieuia, 628
Goniocoelia, 416
Goniocora, 97
GoJiiodiscus, 711
Goiuoloboceias, 631
Goniomya, 466
Goiiiophora, 462
Goino])lioriis, 279
G()iuo])liyllum, 87
Goniopygus, 276
Gonioximut, 472
Gnnioteiitliis, 682
Goniotrypa, 345
Gonocriniti's, 154
Gonodactylus, 768
GoKodon, 486
Goodallia, 472
Gorgoiiella, 110
Gorgon ia, 110
Gorgonocephalus, 255
Gosavia, 561
Gosseletia, 445
Gosseletina, 524
Gothocrinus, 215
Gothogiaptus, 132
GotUtndia, 373
Gould ia, 474, 493
Graeopbonus, 788
Grammatodon, 441
Grainmoceras, 658
Gramiuysia, 439
Granatocriiius, 171
Graphiocdnus, 222, 225
Graplio('eras, 658
Grajihularia, 110
Grapta(;ine, 509
Graptodictya, 345
Grasia, 292
Grateloupia, 492
Greenfieldia, 415
Gresslya, 464
Griesbai'hites, 639
Gripbodictya, (il
Grossouiyria, 663
Grotriania, 472
Gruenewaldtia, 409
Grylbi.s, 799
Grypbaea, 450
Gr!ip!iaeostrm, 450
Giypliochiton, 512
Grypoceras, C02
Gualtieria, 297
Guembelites, (548
Gueraiigeria, 452
Guettardia, 64
Guiittardicriiius, 232
Guilfordia, 528
Guiidlacliia, 575
Gwynia, 405
Gymnites, 645
Gymnocriims, 240
Gymnotoceras, 647
Gypidia, 394
Gypidida, 395
Gyronema, 530
Gyropleura, 478
Habelia, 776
Habrocrinus, 194
Hadeiitomum, 806
Hadioerinus, 191
Hadropliylliim, 82
Haenleiiiia, 447
Hageiiowiiiella, 349
Halia, 561
Halicardia, 468
Halilucites, 646
Haliotis, 523
Haliris, 4(i9
Hallicystis, 154
Halliella, 738
Hallina, 408
Hallirhoa, 54
Halloceras, 603
Hallodictya, 61
Hallopoi-a, 337
Halloporina, 337
Halobia, 448
Haloniitra, 102
Halonympha, 470
Halorella, 399
Halorites, 639
Haly.siocriiius, 214
Halysites, 117
Haminea, 567
Hainites, 653
Hammatoeeras, (i60
Hamulina, 654
Hamulus, 508
Hatnusina, 531
Hanleya, 512
Hapalocrinus,'199
Hapaloptera, 807
Haplaiaea, 105
Haploceras, 6(51
Haplocoiius, 721
Haplocrinus, 208
Haplocystis, 159
Haplohelia, 95
Haplooecia, 321, 324
Haplophragmium, 26
Haplopleuroceras, 660
Haploscapha, 447
Haplosmilia, 101
Haplostiche, 26
Harmocrinus, 189
Harpa, 562
Harpactocarcinus, 767
Harpagodes, 552
Harpax, 459
Harpes, 711
Harpina, 711
Harpopsis, 562
Harpoceras, 658
Harttina, 402
Hastimima, 785
Hastula, 562
Hauericeras, 667
Hauerina, 38
Hauerites, 635
Haugia, 660
Haustellum, 558
Hautkenia, 547
Hebertella, 381
Hedenstroemia, 634
Hederella, 320
830
TEXT -BOOK OF PALEONTOLOGY
Helcion, 520
Helcioniscus, 520
Helcionopsis, 620
Helianthaster, 251
Heliaster, 251
Helicaulax, 551
Helicoceras, G54
Helicodictya, (50
Helicodonta, 5V0
Helicophanta, 576
Helicopora, 341
Helicoryptus, 532
Helicotoma, 527
Helictites, 648
Heliocrinus, 152
Heliolites, 112
Heliophylluni, S4
Heliopora, 111
Heliotrypa, 345
Helix, 576
Helmersenia, 372
Helininthochiton, 512
Heloceras, 599
Helonyx, 510
Helopora, 342
Heraiarthrum, 512
Heiniaspis, 777
Hfiniaster, 295
Hemicardiwin, 444
Hemicellaria, 324
Hemicidaris, 275
Hemicosmites, 152
Hemicrinus, 240
Hemicystites, 159
Heinidiadema, 275
Hemidonax, 484, 496
Hemifusus, 657
Heinigyraspis, 719
Hemimactra, 498
Heminajas, 452
Hemipatagus, 294
Hemipedina, 277
Hemiphragma, 338
Hemiphragnioceras, 612
Hemiplethorhynchus, 398
Hemiplicatiila, 461
Hemipneustes, 293
HPinipronites, 393
Hemiptyehina, 403
Heniisiiius, 548
Hemithyris, 399
Heinitrypa, 341
HeptMkictylus, 552
Heptastyiis, 106
Heraclites, 648
Hercoceras, 605
Hercocrinus, 188
Hercoglossa, 603
Hercynella, 573
Hermatostroina, 123
Hernodia, 320
Herpetocrinus, 212
Herpetolitha, 102
Hertha, 237
Hesperagrion, 811
He.speriella, 524
Hesperites, 648
Heteraster, 294
Heterasti'idiiim, 2, 121
Heterelasma, 403
Heteroblastus, 172
Heterocardia, 498
Heterocentrotus, 283
Heteroceras, 654
Heterocrinus, 212, 212
Heterocystites, 153
Heterodiadeiiia, 277
HeUrodicei'ds, 477
Heterodictya, 344
Heterodonax, 495
Heteronema, 318
Heterophyllia, 87
Heteropora, 326
Heterosalena, 279
Heteroschisma, 168, 509
Heterosteglna, 35
Heterotypa, 333
Hettaiigia, 484
Hexaeriiius, 200
Hexagonella, 330
Hexahwystis, 152
Hexanieroceras, 612
HviteUu, 499
Hihernula, 237
HiboKfhes, 682
Hildoceras, 65S
Himanto2)terus, 783
Hindella, 415
Hiiidia, 56
Hindsiella, 488
Hinnites, 458,
Hippugus, 469
Hipparioiiyx, 386
Hippochrenes, 552
Hipponicharion, 735
Hippouix, 642
Hippoptidium, 462
Hippoporina, 352
Hippopiis, 490
Hippurites, 482
Histioderma, 141
tUstriiTinus, 200
Hochstetteria, 449
H(;dotermes, .804
Hoernesia, 447
Holaster, 293
Holasterella, 62
Holcodiscus, 667
Holcospongia, 71
Holcostephanus, 664
Holectypus, 2S4
Hollandites, 647
Hollina, 738
Holmia, 714
Holmiceras, 601
Holocrinus, 232
Holocystis, 101, 150
Hologyra, 533
Holopea, 530, 539
Holopella, 538
Holopueustes, 282
Holopus, 241
Holorhynclius, 395
Holothuria, 313
Homaloceras, 601
Homalocrimis, 203
Homalonotus, 724
Homarus, 764 .
Homelys, 761 '•
Hoiiterites, 639
Homocrimis, 217
Homocystites, 164
Homoeosolen, 323
Homoeospira, 414
Homolamisas, 297
Hoinomya, 466
Honiotrypa, 332
Homcitrypella, 332
Hoplites, 668
Hoplitoides, 671
Hoplocriims, 211
Hoplolichas, 722
Hoplomytilus, 449
Hiiploparia, 764
Hurioceias, 659
Horio.stoina, 641
Hormotoma, 525
Hornera, 324
Huddlestonia, 658
Hueiiella, 392
Hughmilleria, 785
Hungarites, 646
Hurdia, 750
Huronia, 609
Hustedia, 414
Hyalaca, 570
Hyalostelia, 62
Hyalotragos, 58
Hyattechinus, 301
Hyattelhi, 416
Hyattidina, 415
Hyboclypeus, 292
Hybocrinus, 211
Hybocystis, 211
Hybocystites, 154
Hyboechinus, 306
Hydatina, 667
Hydnoceras, 60
Hydractinia, 120
Hydreioiiocriiius, 223
Hydriocriniis, 222
Hydriodictya, 60
Hydrobia, 545
Hymenocaris, 750
Hyvienocyduft, 36
Hyiuenopliyllia, 99
Hynniplioria, 407
Hvoci'inus, 238
Hyolithellus, 572
Hyolithes, 571
Hypagnostus, 710
Hypalocrinus, 234
Hypanthocri.nus, 192
Hypechinus, 282
Hyperammina, 25
Hypei-lioceras, 668
Hyperocriniis, 196
Hypbantaenia, 61
Hyphasmopora, 344
Hypocladiscifts, 643
Hypocriims, 157, 219
Hypodiadeiiia, 275
Hyponome, 160
Hypothyridina, 398
Hypothyris, 39S
Hypotrema, 4(>1
Hypsipleura, 537
Hyptiocrinus, 187
Hysocrinus, 208
Hystatoeeras, 672
Hystricurus, 716
Ichthyocrinns, 204
Ichthyosarcolites, 480
Idaliiia, 39
Idiocrinus, 187
Idiostroma, 124
Idiotrypa, 335
Idmonea, 320
Idonearca, 442
Jgoceros, 541
Uariona, 290
Illaenus, 719
IHycrinus, 230
Ilyodes, 793
Imbricaria, 560
Indoceras, 671
Infraclypens, 292
Infulaster, 294
Inocellia, 812
Inoceraiiius, 447
Tntrapora, 345
Inversaria, 324
Inyoites, 646
locrinus, 212
Iphidea, 370
Iphidella, 370
Iphigenia, 4'.i6
Iridina, Abb
Iridometra, 237
Isanda, 532
IsasttT, 294
Isastrea, 98
Isoanotia, 494
Ischadites, 72
Ischnochiton, 513
Iscliyriiia, 733
Ischyrodonta, 442
Isidora, 575
Isis, 233
Ismeiiia, 405, 408
Isoarca, 443
Isobuthus, 788
Isocardia, 491
Isochilina, 737
Isoerania, 379
Isocrinus, 206, 233
Isoculia, 439
Isodonta, 496
Isogonomon, 447
Isogramma, 389
Isonema, 538
Isopleiira, 653
Isorliapliinia, 57
Isorhynchus, 393
Isoteius, 719
Isotrypa, 341
Isoxys, 735
Itieria, 549
Ivania, 524
Jaeulella, 25
Jaekelocystis, 154
Jahnites, 670
Janeia, 438
Janiceps, 418
Janira, 467
.Taponites, C37, 645
Jerea, 54
Jereica, 58
Joannisella, 487
Joannites, 642
Jodamia, 482, 482
Jonesella, 738
Jonesina, 738
Jouaimetia, 501
Jovellania, 610'
Jovites, 639
Juglandociimis, 153
Julopsis, 793
Julia, 464
Julus, 792
Jupiteria, 815
Juvavella, 401
Juvavellina, 401
Juvavites, 639
Kampecaris, 793
Kan in a, 565
Kanopliyllum, 82
Karpinskya, 409
Katharina, 513
Kayserella, 386
Kayseria, 418
Keilostoma, 537
Kelaeno, 688
Kellia, 488
Kelliella, 489
Kerainospliaera, 40
Keyserlingia, 376
Keyserlingina, 387
Keyserlingites, 647
Kingena, 406
Kingki, 406
Kionoceras, 600
Kirkbya, 738
Klipsteinia, 648
Kloedenella, 738
Kloedenia, 738
Knemiceras, 671
Kochia, 444
Koenenites, 631
Kokenella, 524
Kokenia, 522
Koninckella, 419
Koninckia, 107
Koninckina, 419
Koninckites, 645
Koninckoceras, 606
Koninckocidaris, 301
Koninckodonta, 419
Koninckophylluin, 86
Kraussia, 408
Kraussina, 408
Kreiscberia, 791
Kustarachne, 789
Kutorgiiia, 371
Kymatites, 644
Labechia, 124
Labiduromnui, 800
Labiosa, 498
Lacazdhi, 366
INDEX
831
Lacazella, 388
Lnmzina, 38
Lachesis, 563
Lacuna, 540
Laciiiu'lla, 540
Ijacuniiia, 539
Laevicardium, 490
Laevidentaliuin, 509
Lagaiuim, 286
Lagena, 29
1,1 uje n iuc r i n lis, 209
Laguncula, 544
Lahuseiiioerinus, 189
Lukhmina, 372
Lamanskya, 384
Lambrus, 766
Lampania, 550
Lampterocrinus, 187
Lanceolites, 635
Lanieria, 284
Ijapeirousia, 482
Lapillocystites, 150
Lapparentia, 545
Ijaijwortliura, 255
Laqueus, 406
Lartetia, 545
Lasaea, 488
Ijasiograptus, 131
Jjaternula, 466
Luterocaoa, 320
Laterocea, 323 .
Latirus, 559
Latonieandra, 98
Latusastrea, 97
Latzi'lia, 793
l^aubella, 524
Leaia, 734
Leanchoilia, 732
Lebedictya, 60
Lecanites, 644
Lecanocriiius, 203
Leca7wcrinus, 205
Lecythiocrinus, 221
Lecytliocriniis, 221
Leda, 441
Leila, 455
Leioclionia, 59
Leiocidaris, 273
Leioderma, 561
Leiomya, 469
Leioniyaliiia, 449
Leiopedina, 278
Leiopteria, 448
Leiorhyiichus, 398
Leiostoma, 559
Leiostracosia, 67
Lejopyge, 710
Leiiita, 288
Lenticeras, 672
LeiUiculites, 35
Lepadocrinus, 154
Lepadocystis, 154
Lepas, 745
Lepeditta, 734
Leperditella, 737
Leperditia, 737
Lepeta, 520
Lepetella, 520
Lepetopsis, 520
Lepidaster, 251
Lepidecliiiius, 306
Lepidesthes, 306
Lepidocentrus, 301
Lepidocidaris, 300
Lepidocoleus, 743
Lepidoderma, 782
Lepidodistis, 159
Lepidopleurus, 512
Lepidolites, 72
Lepidosp<ingia, 67
Lepidurus, 733
Lepisma, 819
Lepocrinuf:, 154
Lepralia, 352
Leplaster, 250
Leptaena, 384
Leptaenalosia, 391
Leptaeiiisia, 385
Lejitdtioiiia, 384
Lepta.straea. 98
Leptella, 384
Ivi'ptembolon, 372
Leptesthes, 474
Leptobolus, 372
Leptoceras, 653
Leptochiton, 512
Leptocoelia, 417
Leptocrinus, 194
Leptodesma, 444
Ijeptodomus, 439
Leptodus, 387
Leptograptus, 130
Leptomaria, 524
Lepton, 488
Leptophragma, 64
Leptophyllia, 103
Leptopoina, 540
Leptoria, 99
Leptosolen, 496
Leptospisula, 498
Leptostrophia, 385
Leptoteuthis, 687
Leptotrypa, 334
Leptoxis, 548
Leskia, 297
Leuconia, 574
Leucozonia, 560
Leuctra, 808
Leuroceras, 604
Leveilleia, 524
Lfiwisiella, 532
Libitina, 472
Lichas, 721
Lichenalia, 347
Lichenocriiius, 160
Lichenocystis, 157
Lichenoides, 157
Lichenopora, 325
Lichenotrvpa, 330
Liebea, 449
Liiiuln, 467
Li'llia, 660
Lima, 460
Limacino, 570
Limaea, 460
Liniauomia, 461
Limatula, 460
Limnaeus, 574
Limnocardium, 490
Limopsis, 442
Linioptera, 448
Limuloides, 777
Limulus, 774
Linearia, 494
Lindstroemaster, 248
Lindstroemella, 378
Lingula, 374
Lingular ins, 374
Lingulasma, 374
Lingulelasma, 374
Lingulella, 372
Lingulina, 30
Lingulipora, 374
Lingulobolus, 371
Lingulocaris, 751
Lingulodiseina, 377
Lingulops, 374
Linnarssonella, 377
lAnnars^onia, 376
Linthia, 296
Linuparus, 763
Lioceras, 658
Lioolema, 336
Lioclemella, 336
Liolopliura, 513
Liopeplum, 561
Liopistlia, 409
Lioplax, 544
Liospira, 525
Liothyrina, 365, 404
Liothyris, 404
Liotia, 529
Liparoceras, 656, 657
Lisgocaris, 754
Lispoceras, 604
Lispodesthes, 551
Lissoceras, 661
Lissochilus, 534
Lissopleura, 401
Lithactinia, 102
Lithagxion, 811
Litharaea, 106
Lithobius, 793
Litliocampe, 42
Litliocardium, 490
Lithocrinns, 204
Lithodendron, 99
LithudoMus, 463
Lithodryas, 815
Lithogaster, 762
Lithoglyphus, 545
Lithophagus, 463
Litliophylax, 766
Lithopdma, 528
Lithe istrotion, 86
Litiopa, 540
Litoceras, 600
Litoricola, 766
Littorina, 539
LittorineUa, 546
Lituites, 601
Lobantale, 509
Lobites, 641
Loboearcinus, 767
Lobocrinus, 196
Lobolithus, 160, 190
Lobopora, 353
Lobopsamniia, 106
Locularia, 322
Loculipora, 341
Loczyella, 388
Lodanella, 150
Loftusia, 120
Lonchodomas, 712
Longobardites, 634
Lonsdaleia, 86
Lophoblastus, 172
Lophoceras, 607, 658
Lophocrinus, 221
Lopholepis, 322
Lophonotus, 793
Lophophyllum, 84
Lophoseris, 103
Lophosmilia, 100
Lophospira, 525
Lorica, 513
Lorieella, 513
Loricites, 512
Loricula, 744
Loriolaster, 251
Loripes, 486
Lotorium, 555
Lovenechinus, 303
Lovenia, 297
Loxoceras, 608
Loxonema, 536
Loxopteria, 444
Lucapina, 526
Lueapinella, 526
Lucina, 485, 486
Ludwigia, 658
Lumbricaria, 139
Luinbricit.es, 139
Lunatia, 543
Lnnulicardiiim, 444
Lunulites, 350
Lutetia, 489
Lutraria, 498
Luzonia, 470
Lychnoeaniuni, 44
Lycodes, 453
Lycophoria, 394
Lycophryti, 36
Lymnaea, 574
Lynceites, 735
Lyonsia, 468
Lyonsiella, 468
Lyra, 406, 560
Lyriocrinus, 189
Lyriopecten, 457
Lyrodesma, 455
Lyropora, 341
Lysactinella, 60
Lysiosquilla, 768
Lysis, 558
Lysocystites, 157
Lytoceras, 652
Lyttonia, 387
Macandrevia, 406
Macarocriniis, 194
Maccoya, 303
Macha, 495
Machilis, 819
Machomya, 466
Mackenzia, 118
Maclurea, 527
Maclurina, 527
Maconia, 494
Macraster, 294
Macrocallista, 493
Maerocaris, 751
MacroceplialitPS, 603
Macrocheilus, 536
Macrochilinn, 536
Macrocrinns, 195
Maerocypris, 740
Macroeystella, 157
Macwdon, 441
Macronotella, 738
Macropneustes, 297
Macroscaphites, 653
Macroschisma, 526
Macrostylocrinus, 191
Mactra, 497
Mactrella, 497
Mactroderma, 497
Mactromya, 466
Maetropsis, 498
Mactrotoma, 497
Madi-epora, 107
Maeneceras, 630
Magalompliala, 522
Magas, 407
Magasella, 407
Magellania, 408
Magila, 763
Magnosia, 277
Maia, 766
Maiocercus, 791
Malacostroma, 124
Malaptera, 551
Malletia, 441
Malleus, 449
Malocystis, 151
Mammites, 669
Mandaloceras, 612
Mangilia, 564
Mannia, 408
Manticoceras, 631
Maragnicrinus, 222
Maretia, 297
Margarites, 532, 638, 640
Margarya, 544
Marginaria, 349
Marginella, 560
Marginifera, 390
Marginuhna, 30
Mariaciinus, 190
Marmolatella, 5iS,3
Marsipella, 24
Marsipocrinus, 199
Marsupiocrinui;, 189, 199
Marsupites, 235
Martesia, 501
Maitinia, 412
Martiniopsis, 412
Mastigocrinus, 220
Matercula, 444
Matheria, 442
Matheronia, 477
Mathikla, 537
Matthewia, 571
Matuta, 765
832
TEXT-BOOK OF PALEONTOLOGY
Mazza, 560
Mazzalina, 560
Mecochiius, 763
Mecynocloii, 471
Medlicottia, 633
Medusaster, 251
Meekechinus, 307
Meekella, 387
Meekoceras, 645
Meekocytis, 154
Meekopora, 330
Medusites, 134
Megacystites, 150
Megalaiiteris, 402
Megalaspis, 718
Megalitliista, 57
Megalodou, 453
Megalograptus, 783
Megalomastonia, 540
Megalonms, 454
Meganeura, 809
Mmjanteris, 402
Megapliyllitps, 641
Megapodagrioii, SU
Megaptem, 445
Megaraphidia, 812
Megarhiza, 59
Megarhyndms, 392
Megatebennus, 526
Megateutlus, 682
Megathyris, 405
Megerha, 405
Megerliiia, 408
Megistocriniis, 195
Meiocardia, 491
Melanipus, 574
Melanagrion, 811
Melania, 547
Melanopsis, 548
Meleagriiia, 448
Melia, 600
Meliceritites, 324
Mellita, 288
Melo, 561
Meloceias, 611
Melocriiius, 190
Melonecliinus, 304
Melonella, 56
Melongena, 557
Me!onitcs, 304
Melonoceni!!, 611
Membianipora, 349, 350
Meinbraniporella, 350
Meneghiuiceras, 652
Menipea, 348
Meiiiscopora, 353
Menophyllum, 84
Mentzelia, 412
Meoma, 297
Meretrix, 493
Merista, 616
Meristella, 415'
Meristina, 415
MOTstoeriims, 204
Meristospira, 415
Meiocrinus, 215
Meroii, 492
Mesalia, 546
Mesenteripora, 319
Mesidotea, 758
Mesites, 156
Mesoblajtus, 172
Mesoceras, 597
Mesocrinus, 229
Mesocystis, 156
Mesodesma, 498
Mesogiuptus, 130
Mesoleuctra, 808
Mesonacis, 714
Mesonennira, 80S
Mesothyra, 753
Mfisotreta, 377
Mesotrypa, 333
Mespiloerinus, 203, 232
Mesuropi^talu, 810
Metablastus, 170
Metacoceras, 605
Metacrinus, 234
Metalia, 297
Metaplasia, 412
Metaporhinus, 292
Metasibirites, 639
Metatirolites, 648
Metengonoceras, 671
Meticlithyocrinus, 205
Metoiceras, 671
Metopaster, 250
Metoptoma, 520
Metriopliyllum, 84
Metuki, 557
Miehelinia, 115
Mickwitzella, 371
Mickwitzia, 370
Micrabaoia, 103
Micraster, 296
Microblastidium, 67
Microceras, 521
Microconchus, 138
Microcriinis, 237
Mierocylus, 82
Microcyphus, 282
Microderoceras, 656
Microdisciis, 711
Microdoma, 531
Microdon, 471
Microinaia, 766
Micromelania, 545
Microniitra, 370
Micropedina, 278'
Micropocrinus, 241
Micropora, 351
Microporella, 351
Micropsis, 280
Microsehiza, 537
Microseris, 102
Microsolena, 104
Microthorax, 766
Microthyris, 406
Microtropites, 638
Mila, 444
Miliola, 38
Miliolina, 38
Millepora, 119
Millericrimis, 231
Milneria, 476
Miltha, 486
Miltites, 639
Miiiiocuras, 629
Miinocystites, 157
Miiiiulus, 387
Miocidaris, 272
Mischoptera, 813
Miskoia, 136
Missouricriniis, 215
Mithracites, 765
Mitoclema, 321
Mitra, 560
Mitraefusus, 557
Mitraster, 250
MitrocystfiUa, 160
Mitrocystites, 160
Mixosiphouoceras, 610
MixotPiiiies, 797
Mizalia, 790
Miihergia, 375
Model'ia, 529
Modiella, 449
Modiola, 463
Modiolaria, 463
Modiolodon, 462
Modioloides, 439
Modiolopsis, 462
Modioiiiorpha, 462
Mogiilia, 523
Mohrensternia, 645
Moira, 296
Mojsvarites, 651
Molaria, 776
Moltkia, 110
Moiiac-hocTinus, 230
Monia, 461
Moiinu'iella, 373
Monobolina, 377
Monoceros, 558
Moiiocondylaea, 455
Monodacna, 490
Monodonta, 531
Moiiograptus, 132
MoiiopliyllitRS, 650, 651
Monopleura, 478
Monoprion, 132
Mohopteria, 448
Monorakos, 727
Monotis, 448
Monotrypa, 339
Monotrypella, 336
Monticulipora, 331
Montlivaltia, 96
Moorea, 738
Mooretleldella, 898
Mopalia, 513
Murio, 554
Mormolucoides, 811
Morphoceras, t)64
Morrisia, 405
Mortoniceras, 672
Mourlonia, 624
Mucronella, 352
Muehlfeldtia, 405
Muelleria, 455
Muensterites, 648
Muensteroceras, 636
Mulinia, 498
MuUetia, 447
Multicavea, 326
Multitvibigera, 322
Mi^tizonopora, 326
Muniericeras, 669
Murchisoiiia, 525
Murex, 558
Musculus, 403
Mutela, 455
Mutiella, 487
Mya, 499
Mya cites, 464
Myalina, 449
Myalinodontn, 448
Myalinoptera, 449
Mycetopoda, 455
Mycocrinus, 214
Mydodattylus, 212
Myocaris, 754
Myochania, 467
Myoconclia, 462
Myodora, 467
Myoiieia, 470
Myoma, fif^io
Myophoria, 456
Myophoriopsis, 457
Myoplusia, 440
Myopsis, 466
Myrianites, 141
Myriopora, 353
Myriozonin, 853
Myristira, 557
Myrtea, 486
Myrtillocrinus, 219
Mysidia, 449
M ystrophora, 393
Mytilarca, 445
Mytilops, 449
Mytilopsis, 463
Mytilus, 463
Nacella, 520
Naiadites, 451
Naites, 141
Naiinites, 637
Naniio, 596
Nannogomphus, 810
Nanocrinus, 219
Nanthacia, 799
Naranaio, 494
Naraoia, 733
Narthecoceras, 596
Nassa, 556
Natica, 542
Naticella, 533
Naticopsis, 533
Natiria, 533
Nauiiiachocriiius, 230
Nautilus, 607
Neiu-ra, 469
Neat vet ia, 400
Nebalia, 749
Necrocarcinus, 765
Necrogammarus, 759_
Necroscilla, 768
NecTotaulius, 814
Nectotelson, 756
Neitliea, 457
Nemagraptus, 130
Neuiapodia, 141
Nemastoiuoides, 791
Nemataxis, 344
Nemutocriniif<, 214
Nematopora, 343
Nematotrypa, 344
Neniatura, 545
Nemertites, 141
Nemodou, 442
Neobolus, 372
NeocatiUus, 447
Neocatopygus, 290
Neocoiuites, 668
Neocrinus, 233
Neocystites, 160
Neoliindia, 56
Neolampas, 291
Neolenus, 716
Neolimulus, 776
Neoinegalodon, 454
Neortiioplilebia, 813
Neoschizodus, 456
Neothyris, 408
Nephriticeras, 604
Nephrvps, 764
Neptocarcinus, 767
Neptnnea, 557
Neptunus, 767
Nereites, 141
Nerinea, 549
Neriiiella, 549
Nerita, 534
Neritaria, 534
Neritina, 534
Neritcidomus, 534
Neritouia, 534
Neritomopsis, 533
Neritopsis, 534
Neumayria, 663
Neusina, 26
Neverita, 543
Newberria, 401
Nicholsonella, 334
Nicholsonia, 112, 345
Nicomedites, 645
Nieszkowskia, 725
Nileus, 719
Niuella, 529
Nipterella, 57
Nipterocriuus, 204
Nisusia, 380
Nodelea, 324
Nodicrescis, 320
Nodosaria, 30
Noetia, 443
Noetliiigia, 394
Nomisnioceras, 631
Norella, 399
Norites, 633
Normaunites, 663
Nothoceras, 613
Nothozoe, 751
Nototliyris, 403
Novaculina, 495
Nubecularia, 87
Nucleatula, 401
Nucleociiuus, 171
Nucleolites, 2S9
Nucleospira, 416
Nuenla, 440
Nunditnii, 440
Nuculiua, 441
INDEX
833
Nuinmnlina, 36
Numiimlites, 35
Niittaliiia, 513
Nyassa, 452
Xyctiloclms, 555
Nyctopoiii, 114
Nympliaeoblastus, 172
Xyinphaeops, 763
Xyinphalites, 815
Nymphastm', 250
Nystia, 545
Oliliitothiii, 452
Obo'lella, 375
Oliolelliiic, 373
Obolus, 371
Ochetoceras, 65S
(ii'liu'lini, 558
< )ctonaria, 730
Oetotremacis, 111
Ueuliua, 95
Uculospongia, 71
Orlaiaia, 750
Odoiifoceras, 0(39
Odoutopenia, 447
odoiitopleura, 722
Odoatittijipa, 330
Odostoiiiia, 537
Ofeoptyeliius, 665
Oecotraiistes, 65S
Oediscliia, 79S
OchkvteVu, 377
Oesia, 141
Otta, 742
Ottastei-, 293
Otniuiii. 718, 719
Ogygiocaiis. 71S
Ogygites, 719
Ogyg(jpsis, 71S
ohiocriiiHS, 212
Oleostephanus, 664
Oldliaiiiia, 388
Olpiielloides, 714
Oleiielhis, 714
Olenikitt'S, ii47
OlPiioides, 71ii
Ulfuiis, 715
Oliijiicriniir', 206
01ig(jpi>i-us, 304
Oligotoma, 563
t)liva, 562
Oni-(iiiih'.<, 171
Olivella, 562
Olhirrhius, ISS
Oiiuda.ds, 53S
Omlxiiiia, 3Si'.
0 IK iih 111 ill, 546
( )inplialo(.-irvns, 527
< iiiipluilc.iphyllia, 10:1
(linpUaliipteruii, 543
(Jniphulotrochus, 528
Oiiipliyiiia, 85
Oncliiiuietopu.s, 719
Onchotvochns, 94
Oncoceras, 611
Onrocliilus, 534
Oui'iicriniis, 203
Oncodnceras, 606
Oiiciijiiii, 552
Oiicopaiia, 763
Oiicophnra, 494
Oiicosiiira, 531
Oiiithix-liitou, 513
Oiiyeliaster, 255
(liiiirliiii, 444
Oiiycliocella, 350
Oiiychocrinus, 206
Oiiychopterus, 782
( )oi'Hras, liio
Oonia, 537
Oonoceras, 610
Opabinia, 732
< )i)ercnlina, 35
( )pliieeras, 645
opliidioceras, 601
( ipliileta, 527
VOL. I
Opliioceras, 655
Ophiocoiiia, 256
Ophiocrinus, 189
Ophiocnnus, 212, 221
Ophiocten, 256
Opliiuderiiia, 256
Opliiolepis, 25ii
Opliioimisiiuu, 25ii
Opbiiaphidites, 51
Ophinrella, 256
Ophiuiites, 237
Ophlura, 256
Opthaliuidiuiii, 38
Opiliotarljus, 791
Opis, 473
Opisoiiia, 473
OpisthoptPi'a, 445
Oplopliorus, 761
Oppelia, 658
Oppelismilia, 97
Orbicella, 98
Orliiri'lln, 377
Orbiculiua, 39
Orbicidoidea, 377
Orbignyella, 331
Orbignyia, 482
Orbipecteii, 457
Orbipoia, 33(i
' Orbitoides, 36
Orbitolina, 27
Orbitolites, 39
Orbitremitt's, 171
Orbuliiia, 31
Oreaster, 251
OHostoma, 528
Oriskania, 401
Ormoceras, 609
Oriiitliaster, 296
OriiitliHlla, 406
Orocystites, 152
Oropliocrinus, li!9
Orozoe, 752
Orthambonltes, 381
Orthaulax, 553
Orthidiuiii, 385
Ortbis, 381
Orthisina, 392
Ortlioceras, 598
Ortbocidaris, 274
Ortbocriims, 187
Ortliode.siiia, 46.2
Ortbodiiiiti.scus, 470
Ortbograptus. 130
Ortlioidea, 407
Orthoiiotiiaed, 408
Ortbonota, 462
Ortboiiycliia, 541
Orthopblebia, 813
Ortbopora, 344
Ortbopsis, 27(1
Ortltoptiirlni.^, 479
! Ortlinriiyiicbnla, 396
OrthoMuiiiii, 566
Orthostropbia, 382
Ortliotetes, 386
Ortbotbeca, 571
Orthotlwtes, 386
Orthothetina, 387
Orthnthrii; 391
Ortlioticbia, 383
Ortbotoiiia, 406
Orthotropia, 395
Ortonia, 139
Orusia, 381
Oryctocepbalus. 716i
Osculipora, 322
Osiliuus, 531
Osiiiylus, 813
Ofttmrnteiithis, 683
Ostrea, 45li
Otoceras, 646
Otopoina, 540
Otostoiiia, 534
Ottawacriims. 215
Ottoia, 141
Otusia, 380
Ovula, 554
Ovnlactaeon, 566
OweneHa, 521
Owenites, 637
Oxyclymenia, 628
Uxydiscus, 522
Oxygyrus, 536
Oxynoticeras, 660
Oxystele, 531
(_)xytoina, 448
Oxyuropoda, 757
Pachastrella, 51
Pacbinion. 59
Pacbyeardia, 452
Pacliyclypeus, 285
Pachydictya, 316
Pacbydiscus, 667
Pachydomella, 740
rachydon, 499
Pacbygyra, 101
Pacbylasiua, 747
Pacbylocrinus, 222
Pacbyniagas, 407
rachynwgalodon, 454
Pachyinytilus, 463
Paobyphylluni, 86
Pacbypoiiia, 528
Pacbypora, 114
Pacbypteria, 459
Pachiirhfincliiis, 407
Pacbyrisina, 454
Pwhystrmna, 123
Pacbyteicbisiiia, 65
Pacbyteutliis, 6S2
Pacbytyloilia, 71
Pafdeuniiits, 714
Pagurus, 7ii4
Palaeacis, 106
Palapacinapa, 520
Palaeaniutela, 452
Palaeaiioilouta, 452
Palaeastacus, 764
Palaeaster, 248
Palaeechinus, 303
Palaega, 758
I'ldneiiKu-hu!', 765
Palaemysis, 757
Palaeoblattina, 820
Palaeobolus, 371
Palaeobrissus, 297
Palaeocainpa, 793
Palaeocardita, 475
Palaeocaris, 755
Palaeocarpilius, 7ii7
Palaeocbrysa, 813
Palai'iii-hiiariiia, 600
Palaeoconia, 251
Pnku'ocorhis, 487
Palaeocorystes, 765
I'ulaeocrania, 379
Palaeocreusia, 747
Palaeocrimis, 217
PalaeocycliiH, 82
Palaeocypris, 740
Palaeocystites, 152
Palaeodiscus, 299
Palaeogamiiiarus, 759
Palaeogoniatites, 630
Palaeograpsus, 766
Palaeolaiiipas, 291
Palaeomanon, 56
I'olaeomya, 484
Palaeonarica, 533
Palaeonantilm, 600
Palaeonectria, 249
Palaeoneilo, 440
Palaeonisa, 537
Palaeopbiura, 254
Palaeopbonus, 787
Palaeopinna, 446
Palaeopneustes, 295
PaUieoporites, 112
Palaeopsylla, 817
Palaeorcbestia, 756
Palaeosaccus, 61
j P(daci)sreptron, 110
Palaeosolen, 496
' Palaeostella, 249
Palaeostoma, 297
Palaeotbrips, 800
I Palaeotropiis, 297
Palasterina, 251
Palasteriscus, 251
Paleanatina, 438
Pakorcii, 442
Palenarthrus, 793
Paleoeardia, 445
PaUiigenia, 809
Palimirina, 763
Pidliiim, 457
Pahnocvstis, 155
Paltodiis, 140
Paltopleuroceras, 659
Paltorbynchus, 805
Pn.luditm, 544
Panda, 576
Pandora, 467
Panoniya, 500
Panope, 500
Panopea, 500
Panopeus, 767
Papbia. 493, 498
Papyridea, 490
Paracardiuni, 439
Paraceltites, 640
Paracocbloceras, 650
Paractinoceras, 609
Paracyatbns, 95
Paracyclas, 485
Paradoxecbinns, 282
Paiadoxides, 714
Paragynmites, 645
Parajurvavites, 629
Parakymatites, 644
Paialanipas, 290
Paralecanites, 644
Paralegoceras, 636
Parallelodon, 441
Parambonites, 393
Paramelania, 548
Paianiya, 499
Parannites, 637
Paranoniia, 461
Parapacliydiscns, 667
Paiapareliites, 737
Paiapborbyncbus, 39S
Parapbylli'tes, 630
Paiapopanoceras, 641
Parapronoi'ites, 633
Pararca, 439
Pararcpstes, 642
Parastarte, 494
Parastropbia, 394
Paratbisbites, 648
Pai-atropites, 638
Parazyga, 414
Paricfitbyocrinus, 206
Parisocrinus, 218
Parkeria, 120
Parklnsonia, 665
Parmophonis, 526
Parodoceras, 631
Paroniceras, 657
Pnropsis, 448
Paroteruies, 804
ParyphostoiiKi, 537
Pasceolus, 72, 160
Passyia, 488
Patella, 520
Patellina, 33
Patflliocrinu.s, 191
Patellostium, 522
Patenaria, 322
Paterina, 370
Paternia, 372
Patrocardiuu), 444
Patterson ia, 62
Fa'vonana, 110
Pavotuhir/erii, 322
PaxUhisf, 682
Peacbella, 714
3 H
CO 1
TEXT -BOOK OF PALEONTOLOGY
Pecchiolia, 4(39
Pecteii, 457
Pedalwn, 447
Pedicularia, 554
Pedina, 278
Pedinopsis, 277
Pedum, 458
Peuinoceras, 001
Fehtiiiii, 323
Pflagoiliseus, 37.'^
Pehijiothuria, 313
Pelanechiiius, 278
Peltairon, 533
Peltastes, 279
Peltocaris, 754
Peltoceras, i3C5
Peltnra, 715
Penipliix, 762
Peiieroplis, 39
PunwituUtes, 110
Pcrmiretejiora, 343
Pentwrmx, 251
Pentacrinus, 232, 233
Pentactinella, 418
PenfaiUii, 224
Peiitagonaster, 240
Peiitagonia, 410
Pentanierella, 395
PentainenHvrds, 612
Pentamerns, 395
Pentaphyllum, 84
Pentastere, 395
Pentata, 439
Pentepliyllum, 172
Pentremites, 1()9
Pentreinitidea, 1C9
Pephricaris, 752
Peregrinella, 399
Peieiraea, 552
Pergamidea, 449
PergensHlla, 320
Pericosmus, 290
Pericyclus, 030
Periechopfiniis, 194
Periglyptocnnus, 190
Perimecturus, 70S
Periiietoceras, 000
Peripleurites, 049
Periploiua, 407
Periplouiya, 406
I'erifiii'nsti'S, 297
Peripora, 321
PerischoL-iclaris, 300
Perisehodoinus, 300
Perisphiiictes, 003
Peristernia, 5(i0
Perla, 808
Perna, 447
Pernopecten, 457
Pernostrea, 447
Peronelhi, 09
Perouiceras, 072
Peronidella, 09
PeroHoceras, 002
Peronopora, 332
Peronopsis, 710
Perpliearia, 560
Persona, 555
Pctahixis, 86
Petaloconcluis, 547
Petalocrinns, 217
Petalogiaptus, 130
Petalopora, 324
Petalo.spyris, 44
Petalotryjia, 337
Petersia, 553
Petigopora, 333
Petigunis, 718
Petraia, 72
Petmster, 248
Petricola, 494
Petricolaria, 494
Petrocrauia, 378
Pexidella, 418
Plmcites, 35
Phaeoceras, 004
Phaciiides, 480
Pliacopidella, 720
Phacops, 720
Phaenopora, 345
Pliaenoscliisma, 108
Phalacrouia, 710
Phalaugella, 320
Phalaugiotarbus, 791
Phanerotiinis, 527
Pliarella, 490
Plion'tra, 374
Pharetrella, 571
Pharetriuni, 508
Pliarostoma, 724
Pliasgauocaris, 751
Phasianella, 529
Phagicnius, 529
Phenacoceras, 032
Pheuacolepas, 520
Phenacolestes, 811
Pliialocrimtx, 225
Phiilolophora, 353
Philhedra, 378
Pliiline, 508
Philipjiiella, 459
Philis, 487
Phillippites, 647
Phillipsastrea, 87
Phillipsia, 721
Pli i I lipsocr in lit:, 197
Philobrya, 449
PliUocrinus, 223
Pliiiiiocrinus, 209
Phloioceras, 004
I'hoen icocrinus, 194
Plioladella, 405
Pholadocaris, 754
Plioladoinya, 460
Pholas, 501
Pholidechiuus, 302
Pholidocidaris, 300
Pholidopliylhuu, 84
Pholidops,' 379
Pliolidostropia, 385
Plioniiedites, 648
Plioniiopora, 324
Plioriiiosella, 00
Plionnosouia, 278
Phoriis, 543
Plios, 550
Phractopora, 346
Phragmatoecites, 815
Pliraginoceras, 613
Phragmodictya, 61
PJi r'tgiiioiites, 522
/•/( riKjiiiostoiita, 523
Pliragmoteutliis, 684
Phragmotlieca, 571
Phi-eatura, 739
Pliryuocrinus, 230
Pliryuus, 788
Phryssouotus, 793
Phthonia, 438
Plivcticeras, 658
Pbyllacantlius, 273
Phyllaugia, 98
Pliyllobrissus, 290
Phylloceras, 052
Phyllocoenia, 101
Phyllocrinus, 240
PliVllodictya, 340
Plivllodocites, 141
Phyllofmiicia, 322
PhVllograptus, 129
Pliyllonotus, 558
Phyllopora, 341
J'hyHoiinrind, 340
Phyllosuiilia, ino
Phvlloteuthis, i;88
Ph'yloblatta, 803
Phyuiatella, 54
1'liyiiKi.tifei; 527
Phyniechinus, 277
Physa, 574
Pliysetocrinus, 197
Pliysocaris, 751
Pliysodoceras, 000
Pliysospongia, (il
Phytoi:nntfs, 237
Phytogyra, 102
Plct-etocrUins, 233
Pictonia, 064
Pikaia, 137, 141
Pileolus, 535
I'ih'iipsls, 541
Pilriitnjpa, 329
Pileus, 285
Piloceras, 596
Pilocystites, 150
Piiuelites, 662
Pinaeites, 030
Pinacoceras, 030
Pinacophyllum, 101
Pinacotrypa, 330
Pinna, 440
Pinnatopora, 342
Pinnigena, 440
Pinnouaris, 754
Pionocriniin, 194
Pionodema, 382
Pironaea, 482
Pisauella, 556, 500
Pisania, 556
Piaidiuin, 475
Pisocrinus, 208
Pithodca, 537
Placenta, 4tU
Placenticeras, 671
Placiphorella, 613
Placites, 636
Placocoenia, 101
Placoeystites, 151
Placoparia, 725
Placiiphoropsis, 513
Placophyllia, 100
Placopsilina, 20
Placosmilia, 100
Plarii n.a, 401
Placunanoniia, 401
Pliiciinemd, 401
Placunopsis, 401
Plaesioniys, 382
piagioglypta, 509
Plagioptychus, 479
Plagiostonia, 460
Plauaxis, 540
Planctoceras, 600
Planetoceras, 604
Plannlites, 141
Planorbella, 570
Planorbis, 574
Planurbulina, 32
Planulina, 33
Plasniopora, 112
Plasmoporella, 112
Platidia, 405
Platyacra, 531
Platybrissus, 295
Platyceras, 541
Platychilina, 534
Platyehonia, 58
Platyelynienia, 628
Platycrinus, 199
Pliitycyslis, 150
Ptatyinetopus, 721
Platymya, 466
Platyodon, 499
Platyostonia, 541]
Platyperla, 808
Platyschisiua, 527
Platystropliia, 381
Plaxiphora, 513
Plecotrenia, 574
Plectaiiibonites, 384
Pleetella, 384
Plectoceras, 601
Plectoderina, 01
Plectodermatiuni, 07
PlectoddU, 470
Plectomya, 400
Plectortiiis, 381
Pleiodon, 455
Plesiastraea, 98
Plesiocypriua, 472
Plesiodicera^, 477
Plesiolampas, 291
Plesiosira, 791
Plesioteuthis, 688
Plesidthyris, 407
Pletliomytilus, 445
Plethopora, 326
Plethorhyucha, 397
Plethospira, 525
Pleurocaris, 756
Pleurocera, 548
Pleuroceras, 548, 659
Pleuroeora, 97
PJeunu-rinus, 199
Pleurocteniuui, 710
Pleuiijcystites, 154
Pleurodiadema, 277
Pleurodictyum, 114
Pleurodonta, 439, 576
Pleurolytoceras, 652
Pleui'onieris, 476
Pleuroniya, 464
Pleuronautilus, 600
Phuronotns, 527
Pleurophorus, 471
Pkurorhynrhus, 446
Pleuiostonia, 04
Plcunitoiiin, 563
Pleurotomaria, 524
Plicatocrinus, 238
Plic-atula, 459
Plicigera, 418
Pliwmya, 466
Plintlio.sella, 55
Pliomera, 725
Plionierop^, 725
Pliorhvtis, 495
Ploeophyllia, 101
Plocoseyphia, 07
Phiniatella, 354
Phimatellitus, 354
PhiiimUtea, 744
Plycliophylluni, 85
Plycliospira, 414
Pocillopora, 90
PocuUiia, 570
Podagrion, 811
Podocidaris, 281
Podocrates, 763
Podocyrtis, 44
Poecilasma, 745
Poeeiloniorphus, 658
Polinices, 543
Pollui, 556
PoUicipes. 745
Pollingeria, 137, 142
Polorthus, 501
Polvl)lastidiuni, 60
Pofyi-nitx, 232
Polyclieles, 761
Polycidaris, 274
Polycoeliit, 09, 82
Polycyclus, 649
Polvcyphus, 278
Polyd'onta, 531
Polygnatlms, 140
Polygonosphaerites. 72
Polygyra, 57(i
Polyjerea, 55
Polyh'jiKs, 745
PolyMiara]ihiuina, 54
Polynioipliiua, 31
Polyniorpliites, 657
Polyochera, 789
Poiyodotitd, 574
Polyosepia, 64
Polypeltes, 190
Polvpbeninpsis, 537
Polypl>y"ia, 102
Polypliynia, 735
Polyplectus, 660
Polyjiora, 341
Polvptchites, 004
Polyschides, 510
INDEX
835
Polysolenia, 111
Polystomella, 34
Polytaxia, 325
Polytoechia, 393
Polytrema, 326
Polytremacis, 111
Polytremaria, 525
Polytropis, -528
Polyxeiius, 792
Pomatias, 540
Pomatocrinus, 231
Pomatograptus, 132
Pomatospirella, 418
Pomocystis, 155
Pontocypris, 740
Popaiioceras, 641
Poi'cellia, 524
Porella, 352
Poricella, 353
Porina, 352
Poristoma, 353
Porites, 107
Porocidaris, 273
Porocrinus, 160, 217, 225
Poromya, 469
Porospliaera, 121
Porospongia, 65
Portlockia, 539
Portunites, 767
Posidoniella, 449
Posidonomypa, 449
Potamides, 550
Potamobius, 764
Potamoviya, 499
Potamon, 767
Poterioceras, 611
Poteriocrinns, 222
Potoceras, 606
Pourtalesia, 298
Praeanaspides, 755
Praearctunis, 758
Praecardium, 439
Praeglyphioceras, 636
Praelima, 439
Praelucina, 439
Praesphaeroceras, 662
Pmsina, 464
Prasopora, 332
Preatya, 763
Preconia, 472
Prenaster, 296
Prestwichia, 774
Priumun, 561
Primitia, 738
Primitiella, 737
Piiiniioa, 110
Prionastrea, 98
Prioniodus, 140
Prionomyrmex, 806
Pi'ioiiotropis, 672
Priscochitoii, 512
Prismodictya, 60
Prismopora, 346
Pristiograptus, 132
Proarcetes, 642
Proavites, 644
Probeloceras, 631
Probolaeum, 512
Probolium, 726
Proboscidella, 391
Proboscina, 319
Procardia, 466
Procarnites, 635
Procercopis, 819
Procerites, 663
Prodivocrinus, 213
Prodromites, 634
Prodryas, 815
Prodiicta, 390
Productella, 389
Productus, 390
Proetus, 721
Proflscheria, 474
Prographnlaria, 1 10
Prohemerobius, 813
Proidotea, 758
VOL. I
Proisocrinus, 232
Projovellania, 610
Proleanites, 632
Prolibyhea, 815
Prolimulus, 774
Prolobella, 462
Prolobites, 629
Piolucina, 486
Prolystra, 815
Promacrus, 438
Proiuathihla, 537
Promedlicottia, 033
Promelocrinus, 190
Pronannites, 636
Pwnites, 392
Pronoe, 492
Pronoella, 492
Pronorites, 633
Propeaniusium, 458
Propinacoceras, 633
Proplanulites, 664
Proptychites, 645
Propygope, 404
Proricaris, 754
Prorokia, 472
Proscorpius, 788
Prosocoelus, 472
Prosodacna, 490
Prosopon, 765
Prososthenia, 545
Prospondylus, 459
Pros.serella, 412
Protalochiton, 512
Protaraea, 112
Protaster, 254
Protasteracanthion, 249
Protaxocriiius, 205
Proteocystites, 156
I Proteroblastus, 156
Proterocidaris, 306
Protetraclis, 53
Proteusites, 640
Protholoturia, 313
Prothyris, 438
Protichnites, 142
Proto, 546
Protobactrites, 599
Protobalanus, 746
Protoeardia, 490
Protocaris, 732
Protoeidaris, 306
Protocimex, 820
Protocrinites, 156
Protocrisiiia, 320
Protocycloceras, 599
Protocystis, 151
Protodiceras, 454
Protolimulu.s, 774
Protolindenia, 810
Protolycosa, 790
Protoma, 546
Protomya, 439
Protonerita, 534
Protoma. 390
Protopalaeaster, 248
Protopharetra, 105
Protophasma, 801
Protophragmoceras, 612
Protopilio, 791
Protoretepora, 341
Protorhynclia, 396
Protorthis, 3S0
Protoschizodus, 472
Protoscolex, 137
Protosiphon, 376
Protosolpuga, 789
Protospongia, 60
Protosycon, 71
Protowarthia, 521
Protozyga, 408
Pi'otrachyeeras, 648
Proutella, 347
Prunocystis, 155
Psammhelia, 95
Psamniobia, 495
Psammocarcinus, 767
Psammosoleii, 495
Psecadia, 815
Pselioceras, 606
Psephidia, 494
Pseudalaria, 549
Pseudamusium, 458
Pseudedniondia, 484
Pseuderiphyla, 474
Pseudoastacus, 763
Pseudobelus, 682
Pseudocerithium, 549
Pseudochaetets, 118
Psendocidaris, 275
Pseudocrania, 379
Pseudocrintes, 153
Pseudocythere, 739
Pseudodiadema, 277
Pseudodiceras, 477
Pseudofossarus, 533
Pseudogalathea, 757
Pseudoglossothyris, 404
Pseudoglyphaea, 762
Pseudohornera, 340
Pseudokingena, 406
Pseudolingula, 374
Pseudoliva, 556'
Pseiulomelaiiia, 537
Pseudometoptoma, 378
Pseudomoiiotis, 448
Pseudoiiautilus, 603
Pseudoneri7iea, 549
Pseudoniscus, 777
Pseudopedina, 278
Pseudoplacuna, 461
Pseudoploeoscyphia, 54
Pseudosageceras, 634
Pseudoscalites, 539
Pseudosirex, 806
Pseudosphaerexochus, 725
Pseudosquilla, 768
Pseudostichopus, 313
Pseudotoma, 563
Pseudotropites, 660
Pseudozainpe, 820
Psiloceras, 655
Psilodon, 490
Psilomya, 469
Ptenoceras, 605
Pteria, 447
Pterincopecten, 467
Pterinea, 444
Pterocaris, 754
Pterocera, 552
Pterocerella, 551
Pterochiton, 512
Pterocodon, 44
Pterocoma, 237
Pterocrimts, 230
Pterodoiita, 552
Pteronautilus, 606
Pteroiiites, 448
Pteronotus, 558
Pteroperna, 448
Pterophloios, 389
Pteropora, 346
Pteropsis, 498
Pterotheca, 571
Pterotocrinus, 201
Pterygonietopus, 727
Ptervgotus, 784
Ptilocella, 346
Ptilocrinus, 238
Ptilodictya, 344
Ptilograptus, 128
Ptilopora, 342
Ptiloporella, 342
Ptiloporina, 342
Ptilotrypa, 345
Ptychagnostus, 710
Ptvcharcestes, 642
Ptychites, 637
Ptycliocaris, 752
Ptychoceras, 653
Ptychocladia, 318
Ptychocriiius, 187
Ptychodesnia, 449
Ptychomphalus, 524
Ptychomya, 474, 493
Ptychonemit, 339
Ptychoparia, 715
Ptychopygp, 719
Ptychostoma, 536
Ptychostylus, 548
Ptygmatis, 549
Ptyssoceras, 605
Puella, 439
Pugiunculus, 571
Pugnax, 398
Pugnellus, 552
Pugnoides, 398
Pugnus, 567
Pulchellia, 671
Pwllastra, 493
Pulsellvm, 510
Pulvinulina, 33
Puncturella, 526
Pupa, 576
Pupillaea, 526
Purpura, 558, 558
Purpurina, 539
Purpuroidea, 539
Pustularia, 537
Pustulopora, 320
Puzosia, 667
Pycinaster, 250
Pycnocrinus, 189
Pycnodonta, 450
Pycnolithus, 112
Pycnoniphalus, 532
Pyenopegma, 56
Pyciiophyllum, 84
Pycnosaccus, 203
Pygaster, 285
Pygaulus, 289
Pygites, 403
Pygocardia, 472
Pvgocephalus, 756
Pygope, 403
Pygorhynchus, 290
Pygurus, 291
Pyramidella, 537
Pyrazus, 550
PjTenella, 550
Pyrgifx, 116
Pyrgidium, 545
Pyrgoma, 747
Pyrgiila, 545
Pyrgulifer, 547
Pyrgulifera, 547
Pyrieavea, 326
Pyrina, 289
Pyritonema, 62
Pyrocystites, 156
Pyrogojiolon, 508
Pyrula, 555, 557
Pythina, 488
Pythiopsis, 574
Pyifidocririus, 194
Pyxis, 390
Quebecia, 375
QnenstedHa, 116, 494
Quenstedtoceras, 663
Quinqueloculina, 38
Quoyia, 540
Radioaivea, 326
Radiofaseigera, 323
Radiolites, 481, 482
Radiopora, 326
Radula, 460
Rafinesquina, 384
Ramulina, 31
BnneUa, 555
Rangia, 498
Raniella, 765
Raniiia, 765
Rauiuoides, 765
Rapaua, 558
Raphidia, 812
Raphiopliorus, 712
Raphistoma, 527
3 H 2
836
TEXT-BOOK OF PALEONTOLOGY
Bapliistomella, 524
Raphistomina, 528
Kapliitoma, .'i64
Rastrite.s, 132
Receptaculites, 72
Eeckur, 769
Recula, 797
Redlicliella, 376
Redonia. 440
Regina, 439
Reiflingites, 647
Reineckia, 665
Remeleoceras, 607
Remondia, 474
Remopleurides, 717
Rensselaeria, 400
jLe7isselandia, 401
Reophax, 25
Reptaria, 320
Reptelea, 324
Reptocavea, 324
Reptocea, 323, 326
Beptoceritites, 324
Reptofascigera, 320
Beptomulticava, 326
Reptomulticlaiisa, 325
Reptonmltisparsa, 320
Requienia, 477
Retecava, 320
SeteJea, 325
Reteuoa, 322
Reteocrimis, 186
Retepoia, 353
Reteporina, 342
Reticularia, 412
Reticulipora, 325
Retiograptus, 131
Retiolites, 132
Retusa, 568
Retzia, 414
Rliabdammina, 24
Rliabdoceras, 649
Rliabdoeidaris, 273
RhabdoniPson, 343
BhthiluplniJIui, 99
Rhabdopleura, 539
Rhabdosispoiigia, 60
Rhabdns, 509
Rliacodiscula, 55
Rliacophyllites, 652
Khadinoceras, 604
Rhadinoerinus, 221
Rhaetina, 403
Rhagadinia, 55
Rhagasostoma, 351
Rhaphanocrinus, 187
Rliaphidonema, 71
Rhectocyma, 472
Rhinacantha, 558
Rliineceras, 604
Rhinidictya, 345
Rhinobolus, 373
Rhinobrissus, 297
Rliinocaris, 753
Rhinoelama, 470
Rhinopora, 347
Rliipidocardium, 446
Rliipidocrinus, 189
Rhipidocystis, 150
Rhiindogoryia, 110
RhipidogjTa, 102
Rhipidomella, 382
Rhipiodomys, 382
Rliipidopora, 321
Rhizammina, 24
Bhizangia, 97
Rliizocrinus, 229
Rhizophyllum, 88
Rliizoporidium, 121
Rliizopoterion, 66
Rhizostomites, 134
Rliodaraea, 106
Rhodocriiius, 188
Rliodophylhim, 86
Rhoechinus, 306
Rhorabi/era, 207
Rhombina, 741
Rhombopora, 343
Rliombopteria, 444
Rhombotrypa, 337
Rhopalocoma, 251
Rhopaloerinus, 206
Rliopalonaria, 317
Rhynchidia, 533
Rliviichomya, 466
Rhyiiclionella, 398
Rhynchoiiellina, 399
Rhyiicliopora, 398
Rhyndioporina, 398
Rhyncliora, 408
Rhynchorina, 408
Rhynchorthoceras, 601
Rliynchospira, 414
Rhynchostreon, 450
Rhyncliotetra, 398
Rhynchotrema, 396
Rhynehoti-eta, 397
Bhyneopygus, 290
Rhytimya, 465
Ribeirella, 732
Ribeiria, 732
Richthofenia, 391
Ricinula, 558
Rimella, 553
Rimula, 526
Ringicula, 567
Ringiuella, 567
Rissoa, 546
Rissoina, 545
Rizoceras, 610
Rocellaria, 500
Roemeraster, 251
Roemerella, 378
Roemerispongia, 61
Roemeroceras, 671
Romiiigeria, 116
Romingerina, 401
Rostellaria, 652
Rostellites, 561
Rostranteris, 403
Rotalia. 33
Rotella, 532
Rotellina, 532
Rothpletzia, 541
Rotula, 288
Rouaultia, 563
Roudairia, 471
Rowleyelli, 403
Runa, 287
Bupertia, 33
Rustella, 370
Rutoceras, 603
Rutotia, 448
Ryderia, 469
Ryticeras, 603
Saccammina, 25
Saccohlastns, 170
Saecocaris, 751
Saccocoma, 239
Saccocrinus, 194
Saccorhiza, 25
Saccospongia, 57
Sactoceras, 60S
Sagda, 576
Sageceras, 634
Sageiiites, 639
Sageiiina, 25
Sagenocrinus, 204
Sagitta, 135
Saiutia, 461
Salenia, 279
Salicornaria, 348
Salmacis, 282
Salpingostoma, 521
Salteraster, 249
Salterella, 572
Sa III I isi 1 11 lie ri nna, 197
S:iiiill)t'ig('ria, 550
Saiidliiigites, 648
Sanguinolaria, 495
Sanguiuolites, 438
Sannionites, 595
Sao, 715
Sarmaticus, 529
Saxicava, 499
Saxidomus, 493
Scacchiiiella, 387
Scaevola, 531
Scalaria, 538
Scalaripora, 346
Scaldia, 484
Scalites, 527
Scalpellum, 745
Scambula, 474
Scapha, 561
Scaphander, 568
Scaphanidia, 533
Scapliarca, 443
Scapliella, 561
Scaplieus, 763
Scaphiocoelia, 401
ScapMocrinva, 222. 225
Scaphites, 670
Scaphula, 443
Scarabus, 574
Scenella, 520
Scenellopora, 328
Scenidium, 393
Sceptropora, 343
Selielhvienella, 386
Scluosia, 479
Schistoceras, 636
Schistophylloeeras, 652
Schizanibon, 376
Schizambonia, 376
Schizaster, 296
Sehizoblastus, 171
Sohizobohis, 377
Schizochiton, 513
Sehizocrania, 377
Schizocrinus, 189
Schizocystis, 155
Schizodentalium, 509
Schizodesma, 498
Sehizodiscus, 524, 735
Seliizodus, 456
Schizogoniuiii, 525
Scliizoloplia, 525
Schizonema, 382
Schizopholis, 375
Schizophoria, 383
Schizoplax, 513
Schizoporella, 352
Scliizoiarama, 382
Scliizorhabdus, 66
Schizostoma, 353, 527
Schizothaerus, 498
Scluzotreta, 378
Schloenbachia, 672
Schlotheimia, 657
Scldueteria, 667
Schmidtella, 737
Schmidtia, 371
Schroedeioceras, 600
Schucliertella, 386
Schuchertina, 370
Schultzicrinus, 219
Sclnvagerina, 33
Scintilla, 488
Scipionoceras, 654
Sclerocrinus, 240
Scolecoderma, 141
Scoliocystis, 155
Scoliostoma, 538
Scolithus, 141
Scolocystis, 157
Scolopendra, 793
Scousia, 555
Sciobicularia, 495
Scrupocellaria, 348
Sculda, 769
Sciirria, 520
Scutella, 287
Scutellina, 287, 526
Sciitus, 526
Scyllaridia, 763
Seyphocrinus, 160, 190, 215
Scytalia, 59
Seytalocrinus, 224
Sebargasia, 71
Sedgwickia, 439
Seebachia, 473
Seeleya, 525
Selenaria, 350
Selenella, 401
Selenopeltis, 723
Selenopora, 330
Seliscothon, 59
Selkirkia, 136
Sellaclvmenia, 628
Semele, 495
Semicava, 326
Semicea, 323
Semiclausa, 320
Semicoscinium, 341
Semielea, 324
Seniifascipora, 321
Semimulticavea, 326
Seminula, 395, 418 '
Semiopora, 346
Semiplicatula, 461
Senectus, 529
Sepia, 686
Septameroceras, 612
Septifer, 463
Septopora, 342
Seraplis, 552
Seriatopora, 96
Serietubigera, 321
Serpula, 137
Serpulites, 139
Serripes, 490
Sestromostella, 71
Setosella, 351
Shumardella, 398
Shumardia, 711
Sliumardites, 642
Sibirites, 640
Sicanites, 633
Sicyocrinus, 221
Siderastrea, 103
Sidneyia, 786
Sieberella, 395
Siemiradzkia, 666
Sigaretus, 542
Sigmaey.stis, 151
Silbyllites, 638
Silenki, 469
Silesites, 667
Siliu, 562
Siliqua, 496
Siliquaria, 547
Siluraster, 249
Silurina, 439
Sinibirskites, 664
Simoceras, 666
Sinuites, 521
Siuum, 542
Sipliodictyuni, 324
Siphonalia, 567
Siplionaria, 578
Siphonentalis, 510
Siphonia, 54
SiphonocoeHa, 69
Siplionocrinus, 187
Siphonodentalium, 510
Siplionotreta. 375
Siphoniotyphlus, 321
Sirenites, 648
Sismondia, 287
Sistrum, 558
Slimonia, 783
Smaragdinella, 568
Smilotroclms, 94
Smittia, 352
Smittina, 352
Smittipora, 351
Smittistoma, 353
Solanocrinus, 237
Solariella, 532
Solarium, 538
Solecardia, 488
Solemya, 438
INDEX
837
Solen, 496
Solenastrea, 98
Soleniscus, 538
Solenocaris, 751
Solenocheilus, (JOtJ
Solenopleura, 710
Solenopsis, 438
Solenospira, 525
Solidula, 5(35
Sollasella, 54
Sollasia, 71
Sonneratia, 668
Sonninia, 660
Sowerbiceras, 652
Sowerbya, 496
Spanila, 444
Spaniodera, 798
Spaniodon, 488
Sparsicavea, 324
Sparsicytis, 326
Spatagocystis, 298
Spatangopsis, 134
Spatangus, 297
Spatha, 455
Spathiocaris, 754
Spatiopora, 329
Speo, 565
Sphaenia, 499
Sphaera, 487
Sphaeractinia, 120
Sphaerechinus, 282
Sphaerella, 487
Sphaerexochus, 725
Sphaeriola, 487
Sphaerium, 475
Sphaerobolus, 371
Sphaerocaprina, 479
Sphaeroceras, 663
SphcLerocoelia, 71
Sphaerocoryphe, 725
Sphaerocriuu.s, 196, 218
Sphaerocystites, 154
Sphaeroidina, 31
Sphaeronites, 155
Sphaeropsociis, 804
Sphaerulites, 482
Sphenaulax, 64
Spheniopsis, 470
Spheuodiscus, 671
Spherwmya, 439
Sphenopoteriuvi, 106
SpheBotrochus, 94
Sphingites, 642
Sph>Tadocera.s, 601
Spiloblattina, 803
Spiiiigera, 551
Spiractinella, 62
Spirialis, 570
Spirifer, 410
Spiriferella, 410
Spiriferina, 413
Spirigera, 417
Splrigerella, 41S
Spirigerina, 409
Spirillina, 32
Spiroceras, 670
Spirodausa, 325
Spirocolex, 141
Spirocyathus, 105
Spirodeiitalium, 508
Spiroloculina, 38
SpiTophyton, 141
Spiroplecta, 27
Spiropora, 320
Spirorbis, 138
Spirostylus, 537
Spirilla, 685
Spirulirostra, 685
Spirnlirostrina, 685
Spisula, 497
Spondylobolus, 872
Spondylus, 459
Spongilla, 51
Spongiochiton, 513
Spongiomorpha, 106
Spongiostroma, 124
Spongites, 353
Spongophylhim, 86
Sporadoceras, 631
Sporadopyle, 64
Sporadoscinia, 66
Sportella, 488
Spyridiocrinus, 191
SpjToceras, 600
Squama, 745
Squamularia, 412
Squilla, 768
Staehella, 523
Stacheoceras, 641
Stacliyodes, 124
Stachyspongia, 59
Staliola, 545
Stauranderaster, 251
Stauria, 87
Stauiocephalus, 725
Staurocystis. 154
Stauroderma, 65
Staurolonche, 42
Stuurosoma, 158
Stavelia, 463
Stearnsia, 474
Stearoeeras, 604
Steganoblastus, 160
Steganocrinus, 197
Steganoporella, 351
Stegerhynchus, 397
Steininanuites, 648
Stelidiocrinus, 189
Stellipora, 334
Stelliporella, 112
Stellispongia, 70
Stellocavea, 326
Stelloria, 99
Stemmatocrinus, 225
' Stenarcestes, 642
Stenarthron, 788
Stenaster, 249
Stenocliirus, 763
Stenochisma, 396
Stenocrinus, 212
Stenodictya, 796
Stenogomphus, 810
Stenoraphalus, 558
Stenonia, 294
Stenopoceras, 606
Stenopora, 335
Stenosmilia, 101
Stenotheca, 541
Stenothyni, bib
Stephanites, 640
Stephanoceras, 663
Stephanocidaris, 273
Stephaiiocoenia, 101
Stephanocrinus, 207
Stephanophyllia, 105
Stereocrinus, 191
Stereopsammia, 106
Steueroceras, 669
Stiboria, 99
Stichocystis, 152
Stieliopora, 350
Stictocella, 346
Stictopora, 345, 345
Stictoporella, 345
Stictoporidra, 346
Stictoporina, 345
Stictotrypa, 347
Stigmatopygus, 290
Stireehinus, 282
Stirpulina, 468
Stoliczkaria, 121
Stolleya, 51
Stolopsyche, 815
Stolzenburgiella, 418
Stomatella, 528
Stomatia, 528
Stomatopora, 319, 319
Stomatopsis, 547
Stomechinus, 278
Stomonopneustes, 281
Stortiugocrinus, 209
Strabops, 781
Stramentum, 745
Straparollina, 527
Straparollus, 527
Streblites, 659
Streblotrypa, 344
Streuoceras, 665
Strenuella, 717
Strephodes, 87
Strepsidura, 657
Streptaster, 159
Streptelasma, 82
Streptis, 387
Streptooeras, 611
Streptocrinus, 221
Streptorhynchus, 387
Strepula, 738
Striatopora, 114
Stribalocystis, 153
Stricklandinia, 395
Strigatella, 560
Strigilla, 494
Strigocaris, 751
Strigoceras, 658
Stringocephalus, 401
Strohaeus, 536
Strobilepsis, 744
Strobilocy^^tites, 154
Stroll i ?os/;o ugiii, 62
Stroboceras, 604
Stromatoeystis, 159
Stromatoinorp}ia, 106
Stromatopora, 123
Stromatoporella, 124
Stromatotrypa, 339
Strombodes, 86
Strombus, 552
Strongylocentrotus, 282
Strophalosia, 391
Stropheodonta, 385
Strophieeras, 603
Stroi)hocheilus, 576
Strophocriims, 217
Strophomena, 386
Strophonella, 385
Strophostoma, 540
Strophostylus, 530
Strotocrinus, 198
Strotopora, 330
Strutliiolaria, 552
Studeria, 290
Stuorella, 524
Sturia, 637
Stylaraea, 112
Stylaster, 120
Stylastraea, 98
Stylaxis, 86
Stylina, 100
Styliola, 570
Stylocoeuia, 101
Stylocora, 97
Stylocrinus, 209
Stylodictyon, 124
Stylohelia, 96
Stylonurus, 783
Stylophora, 96
Stylophyllop.sis, 97
Style )phylluni, 97
Stylotrochus, 94
Styracoteutliis, 683
Subclymenia, 604
Subemarginula, 526
Subulites, 537
Suecoceras, 595
Suessia, 413
Suleocava, 320
Sulcuna, 741
Sunetta, 492
Supercytis, 323
Surcula, 563
Sutueria, 663
Swantonia, 392
Sycoceras, 611
Sycoeystites, 154
Sycum, 559
Symbatlioorinus, 209
Symphyllia, 99
Symphysurus, 719
Syinphytoci'inus, 239
Sympterura, 255
Synaplie, 738
Synapta, 313
Syncyclonenia, 458
Syndosmya, 495
Syneroerinus, 205
Syuhelia, 95
Synocladia, 342
Synodontites, 482
Synopella, 71
Syntrielasma, 383
Syntrophia, 392
Sypharoptera, 807
Syringoceras, 602
Syringocrinus, 151
Syringolites, 114
Syringopleura, 411
Syringopora, 116
Syringosphasria, 121
Syringospira, 411
Syringostroma, 124
Syriiigothyris 411
Syniola, 537
Systrophoceras, 601
Taeniaster, 249
Taeniodictya, 345
Taeniopora, 346
Tagelus, 495
Tainoceras, 605
Talarocrinus, 201
Tanaocrinus, 193
Tancredia, 484
Tanysiphon, 494
Taoiiurus, 141
Tapes, 493
Tarphyceras, 600
Tarsophlebia, 810
Tarsopterus, 7S4
Tauredon, 804
Taurinia, 556
Tauroeeras, 453
Taxocrinus, 205, 206, 221
Taxonus, 806
Tealliocaris, 757
Technocrinus, 191
Technophorus, 733
Tecticavea, 325
Tectura, 520
Teetus, 531
Tegula, 532
Tegulifera, 391
Teinostoma, 532
Telescopium, 550
Teliocrinus, 197
Tellidora, 494
Tellina, 494
Tetlinomya, 440
Tellinopsis, 439
Temnechinus, 282
Temnocheilus, 605
Temnocidaris, 274
Temnocrinus, 204
Tenmopleurus, 282
Temnotropsis, 525
Tenea, 487
Tenka, 444
Tentaculites, 572
Tenthredo, 806
Terataspsis, 722
Terebella, 138
Terebellaria, 325
Terebellum, 552
Terebra, 562
Terebratalia, 406
Terebratella, 408
Terebratula, 403
Terebratulina, 404
Terebratuloidea, 398
Terebripora, 317
Terebrirostra, 406
Teredina, 501
Teredo, 501
Teredolites, 501
838
TEXT -BOOK OF PALEONTOLOGY
Terquemia, 451
Tessarolax, 551
Tethyopsis, 51
Tetinka, 444
Tetracamera, 39S
Tetrachela, 762
Tetracidaris, 274
Tetracrinus, 540
Tetractinella, 41S
Tetracystis, 154
Tetradella, 738
Tetragonites, 652
Tetragonoceras, 606
Tetragraptus, 129
Tetrameres, 612
Tetrameroceras, 612
Tetramorion, 612
Tetranota, 522
Tetrapygus, 281
Tetrast'er, 248
Tetrataxis, 29
Teuthopsis, 688
Textularia, 27
Thais, 558
Thalamopora, 33, 71
Thalassina, 764
Thalassites, 452
Thalassoceras, 637
Thalassocrinus, 238
Thaleops, 720
Thallocrinus, 199
Thamnasteria, 103
Thamnastred, 103
Thamniscns, 341
Tlianinodictya, 61
Tliamnophyilum, 84
Thamnotrypa, 346
Thaumastoeoelia, 71
Theca, 571
Thecidea, 365, 388
Thecidella, 388
Thecidiopsis, 388
Thecidium, 388
Theeocyatiiiis, 95
Thecocyrtella, 413
Thecocystis, 159
Thecosiphonia, 55
Thecosmilia, 99
Thecospira, 419
Thecostegites, 117
The.lphusa, 767
Thenarocrinus, 215
Theonoa, 322
Thetsitea, 562
Thiara, 547
Thiemella, 382
Thiollierierinus, 234
Thlipsura, 739
Tholiasterella, 62, 63
Tholopora, 326
Thomasina, 374
Thomisus, 790
Tlioiacoeeras, 600
Thracia, 467
Thrinoceras 604
Thrips, 800
Thurammina, 25
Tliumiaimia, 669
Thyasira, 487
Thylacocrinus, 189
Thylacodes, 547
Thysanoceras, 652
Thysanocrinus, 187
Thysanodictya, 61
Thysanopeltis, 720
Thysanotus, 371
Tiaiacrinus, 158
Tiarechinus, 298
Tibetites, 635
TibieUa, 571
Tichogonia, 463
Tilesia, 322
Timanites, 631
Tindaiia, 441
TinoporuiS, 33
Tirolites, 648
Tissotia, 671
Titanocarcinus, 767
Tityus, 788
Tivela, 493
Tmaegoceras, 655
Tolypammiiia, 25
Tomocheihis, 539
Tonicella, 513
Tonicia, 513
Tonna, 555
Torellella, 572
Torinia, 538
Tormocrinus, 241
Tornatella, 565
Tornatellea, 565
Tomatina, 568
Tornoceras, 630
Torynifer, 398
TorynocriiiHS, 240
Toucasia, 477
Tournoueria, 545
Toxaster, 294
Toxometra, 237
Toxopneustes, 282
Trachyceras, 648
Trachydermon, 513
Trachydomia, 539
Tmchynerita, 539
Tiachyodon, 513
Trachypora, 114
Trachysagenites, 639
Tmchyteiithis, 687
Tragophylloceras, 652
Trapezium, 472
Traumatocrinus, 225
Tremabolites, 68
Tremadictyon, 63
Trematella, 335
Trematis, 377
Trematobolus, 376
Trematoceras, 604
Trematocystis, 155
Trematodiscus, 604
Trematonotus, 521
Trematopora, 339
Treinatopygus, 290
Trematospira, 414
Tremopora, 349
Treposella, 738
Trepospira, 525
Tresus, 498
Tretaspis, 711
Tretoceras, 609
Tretospira, 539
Triacrinus, 208
Triadosialis, 811
Triainoceras, 633
Triarthrus, 715
Tribaehiocriiius, 224
Tribliocrinus, 191
Triboloceras, 604
Trichasteropsis, 249
TrichUes, 446
Trichiulus, 793
Trichopteridium, 814
Tricoelocrinus, 170
Tridacna, 490
Triforis, 550
Trigeria, 401, 414
Trigondictya, 346
Trigonella, 406
Trigonelliiia, 405
Trigonia, 457
Trigonoceras. 604
Trigonocoe! ia, 442
Trigonocrinus, 241
Trigonocystis, 150
Trigonodus, 452
Trigonosennis, 406
Trigonotarbus, 791
Trigoiiotreta, 410
Trigonuliiia, 469
Triloculina, 38
Trimerella, 373
Trimeres, 612
Trimerocephalus, 726
Trimeroceras, 612
Trimerocystis, 154
Trimerus, 724
Trimorion, 612
Trinacria, 442
Trinemaeystis, 152
Trinucleus, 711, 711
Triodonta, 474
I Triplecia, 387
I Tripleuroceras, 610
Triplosoba, 808
Tripneustes, 282
Triptera, 571
Tripylus, 296
Triton, 555
Tritonalia, 558
Tritonidea, 556
Tritonium, 555
Trivia, 554
Trochalia, 548
Trocliammina, 26
Trochamminoides, 26
Trochiliopora, 326
Trochiscolitlius, 112
Troclioceras, 605
Trochocrinus, 194
Trochocyathus, 94
Trochocystites, 150
Trochoderma, 313
Trocholites, 600
Trocholitoceras, 600
Trochonema, 530
Trochoseris, 102
Trochosmilia, 99
Trochotoma, 525
Trochus, 531
Troostocrinus, 170
Tropaeum, 653
Trophon, 558
Tropiceltites, 640
Tropidocaris, 752
Tropidoleptus, 385
Tropidomya, 470
Tropidopora, 344
Tropites, 638
Truncaria, 557
Truncatula, 323
Truncatulina, 33
Tryblidium, 521
Tscliernvscliewia, 390
Tubina, 541
Tugonia, 499
Tnlotoma, 544
Turbina, 531
Turbinaria, 108
Turbinella, 560
Turbinilopsis, 539
Turhinocrinus, 190
Turbinolia, 94
Turbo, 528
Turbonellina, 531
Turbonilla, 537
Turbouitella, 539
Turniis, 501
Turonia, 55
Turricula, 560
Turrilepas, 744
Turrilites, 654
Turris, 563
Tiinitella, 546
Turritoma, 525
Turtoiiia, 488
Tuzoia, 750
Tyleria, 467
Tylocrinus, 195
Tylopoma, 544
Tylopterus, 783
Tympanotoma, 550
Typhis, 558
Tyrbula, 799
Udora, 761
Udorella, 761
Uintacrinus, 236
Ulocrinus, 224
Ulrichia, 738
Umbonium, 532
Umbraculuni, 568
UmbreUa, 568
Umbrelliua, 321
Uncinella, 413
Un-cinnUna, 398
Uncinulus, 397
Uncites, 413
Undularia, 536
Ungula, 371
Ungnlina, 487
UnguUtes, 371
Unicardium, 484
Unicrisia, 318
Unicytis, 323
Unio, 454
Uuiocardium, 490
Unionia, 452
Unitrypa, 341
Uperocrinus, 196
Uphantaeiiia, 61
Uranoceras, 608
Urda, 758
Urechinus, 294
Uronectes, 756
Ussuria, 637
Uvanilla, 528
Uvigerina, 31
Vaginella, 571
Vaginoceras, 595
Vaginopora, 353
Vaginulina, 30
Valenciennesia, 573
Valletia, 478
Valvata, 544
Valvatina, 570
Valvulina, 29
Vanuxemia, 442
Vasocrinus, 218
Vasseuria, 683
Vasum, 560
Velates, 534
Velofita, 474
Veloritina, 474
Venericardia, 475
Venerupis, 494
Veiiiella, 472
Venilicardia, 472
Ventriculites, 65. 71
Venus. 492
Vermetus, 546, 546
Vermiceras, 655
Vermicularia, 540
Verneuilia, 412
Verruca, 746
Verrucocoelia, 64
Verruculina, i59
Vertebralina, 39
Verticordia, 469
Vertigo, 576
Verturania, 448
Vesicomya, 491
Vestinautilus, 604
Vevoda, 438
VexilluM, 141
Vibracella, 351
Vicarya, 550
Villorita, 474
Vincularia, 350
Vinella, 317
Virgatites, 664
Virgularia, 110
Vitrinella, 532
Vitulina, 417
Viviparus, 544
Vlasta, 438
Vola, 457
Volborthella, 597
Volbortliia, 370
Voluta, 561
Volutella, 561
Volutifusixs, 561
INDEX
839
Volutilithe.s, 061
Volutodei'ma, 501
Volutomitra, 5li0
Volutomorpha, 561
Volvaiia, 5ii<>
Volviceramus, 447
Volvula, 568
Voh-uleUa, 568
Vulsella, 449
Vul.sellina, 44ii
IVrmgenia, 660, 665
WaaKftiiOLM'ras, 642
Wii'tgtii'ijiiu-'i-, 387
Waciisiiiutliicriims,
Wai'lnieioc-eras, 657
Wakulliua, 461
IViOdheiinia, 408
ir.(7/o»iii, 408
Waiiiieria, 714
205
Waptia, 733
Warthia, 523
Welschia, ii5S
Westoiiia, 371
Wliiteavesia, 462
Whitella, 442
WliitfieUiia, 415, 415
Willemoesia, 761
Williainia, 573
Wilsouia, 39S
AVimaiiella, 381
Witchi'Uia, i;60
Wiwaxia, 137
Woodocrinus, 223
Woitheiiplla, 137
WortliPiiia, 524
Wortlii'iiopora, 847
Xaiitlu), 7i')7
Xaiitliopsis, 7ii7
Xeiia-spis, 645
Xenufiter, 248
Xeuoeidaris, 274
Xenocdiins, lii3
Xenodi.sciis, 645
Xeiiopliora, 543
Xestulebeiis, 730
Xiijhidiocari.s, 751
Xiphotentliis, 681
Xylobiu.s, 793
Xylotrya, 501
Tolioia, 732
Yoldia, 441
Yorkia, 376
Zaeaiithoides, 710
Zaplnentis, S3
Zeaeiiiius, 223
Zeilleiia, 40ii
Zfllania, 405
Zemira, 557
Zenatia, 498
Zenl-erii'rinU):, 190
ZeuKlopleiii-us, 282
Zidoua, 561
Zittella, 553
Zittelispoiigia, (iS
Zitteloceras, 603
ZiziphiHus, 532
Zoiiatula, 326
Zonopora, 325
Zoopilus, 102
Zophocrinus, 15S
ZiiKinevfiia, 403
Ziirelievia, 660
Zygites, 524
Zygocriiius, 172
Zygopleura, 537
Zygospiia, 408
END or VOL. I
Printed by R. & R. Clark, Limited, Edinburgh.
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