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THE BORING CTENOSTOMATE BRYOZOA:
TAXONOMY AND PALEOBIOLOGY
BASED ON CAVITIES IN CALCAREOUS SUBSTRATA

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Rosert A. PoHowsky

1978

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BULLETINS

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PALEONTOLOGY

(Founded 1895)

Vol. 73

No. 301

THE BORING CTENOSTOMATE BRYOZOA:
TAXONOMY AND PALEOBIOLOGY
BASED ON CAVITIES IN CALCAREOUS SUBSTRATA

By

Rosert A. PoHowsky

March 30, 1978

Paleontological Research Institution
Ithaca, New York 14850 U.S.A.

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CONTENTS

Page
ANTS Sec C Geert ere oe ee wate neem cena ve ctasenc eee denacetencwoscscewars 5
HENCE SROKA Wea SNS peer ec re eae i ee enero rr eee reece Pe Eee eee)
UST ans Co CAA UO a eee ae ae ee ee ce ona cawerneeceteneeecrecie: cases 7
HZTOSDECTS ANG OD CLIVE) eeseetee ceases eee aa ee eae eae creme unateacnt csemcsecressaese 11
DETESEO retell ee SUTIN geese ste seasons cae ameae cen nee cc ca ce acaceccectnecstaset antes csnveseasateeidealen 15
IPT OCEGUTES AMC CECINIR ITC Soca eee eso oo ee aa gta ae aes serena eet Sasa 20
TRREF BLOND 0) ce Oe Sel RE eh te 22
Anatomys ange biology of DOGID EMG y.O ZO aD Siesta ater ee cetera eect cnesereaace 23
Interpretation and taxonomy of bryozoan borings
Generaleiconsid erations crecsseesrcce cr tere streetcar eeecege eecae ee rence cee ene 30
SSS a Bye cease re a re tee a OR eae Me ae td a ee ae chs 31
Morphologymotebry.oz 0 am DOT II gis) er reese eee cee eae ee cee oanes 35
Systematic PaleOmMtolo gry, coccececqc.scece eee sae ences ea cae a ae ccc cage reseed twa eeaes 42
Ropalonarirdaes Nickles! and Basslery 1900) pecse se erecce eee ee eee 46
@ebigmyiop onic a eens eb ela eee cee sc ee ee eee ee ecr os ses teescacee 57
Worptelllidiaes: cms) barn, ceee ee a es ee 68
Penetrantiidae silens, 1946) 2 ee ea seeecscts 77
Cookobryozoomidaey ns Lams = ere seer ee ee ec ace one cect asece eet coscessesece 92
Spathiporidae: ins. fain, 2e:..ee se ee a eee ee a ee eee 95
denebriporid dem: Orb my 1s Fees see one ae ee ene sees 109
mmergentitdae: Silém, 1946. - cesses cts ratere ct oe sce ccc ces ence neren eae eee es eancects 120
Med rally Wir @ Nt ANNA ceo ce cc see eal ee ae aS Be AE ew acceeaad 129
Stratieraphiceranges) OL seme ral tesserae ee tee eeteaaaeeresae anes senseeneae cee cscoececeamacs 135
taxONOMIG POSItIONS) (Of <SPCCLES! srsses eee cee een aac ee ee es careaet 137
IB volutionmand wap ly) Om eniy es acksreracece coer ae eae ae ee eee ate se Sece veces cecscsstassae 140
shopicseandefunthensin y.esthg atoms cere cece sree serene eee BAe eee sie ES 147
IRELETENCES) eee sien soho pecs sees Soba ote cca cee aeas ee eee bce MA en Se et 150
Va Sip sce cca cre ese cee acta A Sop reteset cesta ce neeseee coasters oe Beebe cca 159

LIST OF TEXT FIGURES

Text-figure Page

A.
B.

Ropalonaria venosa Ulrich
Terebripora ramosa d’Orbigny

C-E. Terebripora sp.
F. Spathiopora sp.

G. Terebripora sp.
OS ins ny A RR RS gE ate PERE Sos SER Seen en oe aan aka Me ss es ah te pee acsceenna 16
A. Spathipora sertum Fischer
B-E. Spathipora comma (Soule)
F. Orbignyopora? capillaris (Dollfus)
G. Orbignyopora archiaci (Fischer)
H. Haimeina michelini (Terquem)
SEPA NLOZOOIUS ald stolons) LONI 4p CMC Elysee ence oe eee eee 26
A. Penetrantia sp.
B. Spathipora sp.
C. Orbignyopora archiaci (Fischer)
D. Immergentia sp.
Ne es tia SC nd FW Bd ae cee Ses cuvades ue zacueensausoctstibenemmneerres Se ee ee ee ee te itenc 71
A. Voigtella regalis, n. gen., n. sp.
B. Marcusopora ripleyensis, n. gen., n. sp.
C. Foraripora pesavis Voigt and Soule
ba Stratigraphic anges ose gemen aly (1'3))) eescesccecq sect ceeeeeeree ance ea eee 136
Ga Barly astozenya tr DOT g ESTO ZO a) ecar cece anasto cena eee 142
Al. Immergentia sp.
A2. Terebripora ramosa d’Orbigny
B1. Marcusopora ripleyensis, n. gen., n. sp.
B2. Cookobryozoon lagaaiji, n. gen., n. sp.
B3. Orbignyopora? tridelta, n. gen., n. sp.
B4. Penetrantia sp.
B5. Spathipora elegans Fischer
B6. Spathipora occidentalis, n. sp.
C1. Ropalonaria venosa Ulrich
C2. Haimeina michelini (Terquem)
C3. Spathipora ambidextra, n. sp.
D. Penetrantia? sp.

THE BORING CTENOSTOMATE BRYOZOA:
TAXONOMY AND PALEOBIOLOGY
BASED ON CAVITIES IN CALCAREOUS SUBSTRATA

Rosert A. PoHowskKy

ABSTRACT

The boring Bryozoa (Upper Ordovician—Recent) live immersed in cal-
careous substrata that the organism penetrates by purely chemical means. All
known species are here assigned to the order Ctenostomata Busk, 1852, [? in-
cluding Penetrantia Silén, 1946]. Until now, the group has been known in ana-
tomical detail almost exclusively from studies on the internal soft parts of Holo-
cene species. Fossil remains of these bryozoans have been confused with various
borings and shallow pits of diverse origin.

The classification of previously recognized species is revised, and 13
genera including 48 species are recognized. There are six new genera: Castero-
pora, Cookobryozoon, Fischerella, Marcusopora, Orbignyopora, and Voigtella.
Casteropora and Fischerella are assigned to the Bryozoa with slight reserva-
tion. The following 20 new species are erected: Cookobryozoon lagaatji, Im-
mergentia atypica, I. boydekina, I. lanceolata, I. losangelina, I. patagoniana, I.
subangulata, Marcusopora ripleyensis, Orbignyopora? cornbrashica. O.? tridelta,
Penetrantia soulei, Ropalonaria? bugei, Spathipora ambidextra, S. brevicauda, S.
cheethami, S. magnivorticellopsis, S. occidentalis, Terebripora miniatura, Voig-
tella regalis, and V. secunda.

New and figured material includes the ancestrulae and early astogenetic
stages of several fossil species. In addition, various heterozooids, reversed
zooids and teratological abnormalities are recognized in fossils of several
genera. Some groups are characterized by the occurrence of enantiomorphic
autozooids. There is substantial evidence that at least the initial portions of
entire colonies occur in dextral and sinistral forms in some species.

The confinement of zooids beneath an inflexible calcareous shield has some-
times been accompanied by the development of features resembling those which
are generally associated with the cheilostomes. The occurrence of ovicells in
Spathipora cheethami, a boring species from the Middle Jurassic (Cornbrash)
of England, is an example.

In Penetrantia densa Silén (Recent), a probable ctenostome, the presence
of ovicells, an operculum, and a calcareous body wall suggest indirectly that
the Cheilostomata may be polyphyletic. Ovicells (and opercula?) may be more
likely to develop in lineages wherein the zooids are protected by a solid external
skeleton (of bryozoan or molluscan origin). The possibility of independent evo-
lution of these features in at least two groups of “shielded” ctenostomes (1.é.,
in Penetrantia Silén and in one or more independent lines of calcified, encrusting
ctenostomes) is worthy of thorough consideration.

ACKNOWLEDGMENTS

This study is by no means an individual effort; without the
generous assistance of numerous people, its completion would have
been impossible. Unfortunately, space precludes individual mention
of everyone to whom [| am in some way indebted, but the following
persons and institutions may be cited as having been particularly
helpful.

Many sincere thanks are due, first to the faculty of the Depart-
ment of Geology of the University of Cincinnati for instruction pre-
requisite for the undertaking of this study. In this regard, I am
especially indebted to my advisor, Dr. Kenneth E. Caster, for his
suggestions, enduring interest in my work, and critical reading of
the manuscript.

6 BULLETIN 301

Much of the research for this study was undertaken at the
British Museum (Natural History), and I am grateful to the
Keepers and staff of that institution for the many courtesies shown
to me during my visit. I am indebted, above all, to Miss P. L. Cook,
whose encouragement, assistance, and discussions greatly expedited
my efforts. The following other staff members were also particu-
larly helpful: P. J. Chimonides, R. Cleevely, R. Croucher, V. K.
Din, R. Harris, N. J. Morris, P. C. Nuttall, R. Symes, J. Taylor, and
R. Wise. The valuable aid of Museum photographers and the staff
of the Electron Microscopy Unit is also gratefully acknowledged.

Through the courtesy of R. V. Melville, I obtained some im-
portant specimens and photographs from the Institution of Geo-
logical Sciences (London). His helpfulness, and that of A. Horton
and Mrs. B. Coleman (1.G.S.) is much appreciated.

The specimens examined during the course of this investigation
are housed in the various repositories listed herein. To the many
museum curators who diligently prepared requested loans go my
sincere thanks. In a few cases, photographic negatives were sent in
lieu of actual specimens, and I am grateful to E. Buge (Muséum
national d’Histoire naturelle, Paris) and J. D. Soule (Allan Hancock
Foundation, Los Angeles) for this extremely helpful service. The
thoughtful donation of specimens by the following persons is also
greatly appreciated: W. C. Banta, B. W. Cameron, Miss P. L. Cook,
A. B. Hastings, D. P. Najdin, F. Strauch, and F. Westphal. I am
especially indebted to Mrs. E. Marcus for sending me the bored
shells and prepared slides studied by her late husband, Prof. Dr.
Ernst Marcus.

Much of the literature on boring Bryozoa is not in English,
and immensely helpful translations were prepared by J. Cosby, Mrs.
F. Vieira, Mrs. H. Sabo and Mrs. J. Sandborn. Mrs. Vieira’s lengthy
translation of Marcus, 1938, (Portuguese) was especially useful.

During the research phase of this work, some aspects of the
investigation were discussed with R. Cuffey, A. B. Hastings, G.
Hillmer, D. Jebram, W. J. Kennedy, C. T. Scrutton, L. Silén, J. D.
and Mrs. Soule, Prof. E. Voigt, and B. Walter, in addition to some
of the persons cited previously. I thankfully acknowledge the bene-
ficial information and advice offered by numerous people, but any
misconceptions or inaccuracies contained herein are strictly those
of the author.

Bortnc CTENOSTOMATE Bryozoa: -PoHOWsSKY 7

Research for this study was made possible and generously sup-
ported by an N.D.E.A. Graduate Fellowship at the University of
Cincinnati and a Fulbright-Hays Grant from the U.S.-U.K. Educa-

tional Commission in London.

INTRODUCTION

The boring Bryozoa, here assigned to the order Ctenostomata
Busk, 18521, are an ethologically defined group of ecologically aber-
rant species which live totally “immersed” within solid calcareous
substrata in the marine environment. Except for the operculum in
the genus, Penetrantia Silén, 1946, only the lophophore ever extends
above the surface of the inhabited object. (Of course, sexual repro-
duction involves the free-swimming larvae common to all bryo-
zoans.) Probably because of their sheer abundance, the shells of
gastropods and pelecypods are the substrata most commonly em-
ployed in post-Paleozoic seas, but other calcareous objects are also
invaded — especially in the Paleozoic, when brachiopods and crin-
oids were the most readily available “hosts.” (The term is placed
in quotation marks because none of the bryozoans considered herein
show any evidence of being parasitic; the boring habitus is solely a
means of ensuring protection and anchorage while engaging in the
heterotrophic, filter-feeding process characteristic of bryozoans.)

Boring bryozoans penetrate exclusively by chemical means and
must be clearly differentiated from the relatively few species of
Ctenostomata which reputedly employ mechanical processes to
penetrate less substantial media. These species and their typical
substrata are listed below:

Hypophorella expansa Ehlers, 1876; leathery tubes of poly-
chaete annelids (e.g., Chaetopterus and Terebella).

Watersiana paessleri Calvet, 1912; tunic of colonial ascidian,
Polyzoa gordiana.

Harmeriella terebrans Borg, 1940; calcareous walls of cheilo-
stome Bryozoa (e.g., Tubiporella levinsent).

Bulbella abscondita Braem, 1951; rotting wood.

Those Cheilostomata which are known to produce shallow pits on
encrusted shells [e.g., Hippothoa divaricata Lamoroux, 1821; Elec-
tra monostachys (Busk), 1854, pl. 10, fig. 5] are also excluded from
the group under consideration.

1One of these, Penetrantia Silén may be a cheilostome.

8 BULLETIN 301

Beyond question, the borings discussed in this work represent
the bulk of the known fossil Ctenostomata. Encrusting species pre-
served (“immurated”) beneath sessile benthonic organisms (é.g.,
Arachnidium brandesi Voigt, 1968) are eminently worthy of addi-
tional study but are known from comparatively few occurrences.
Putative fossil ctenostomes preserved as non-immurated encrusta-
tions (e.g., Ascodictyon Nicholson and Etheridge, Eliasopora Bassler,
and Marcusodictyon Bassler) lack well-documented Recent ana-
logues within the order and are, therefore, of questionable affinity.
One such genus, Vinelloidea Canu, was recently recognized as a
foraminifer (Voigt, 1973).

As if refusing to be outdone by the pelecypods-bivalves-lamelli-
branchs, and perhaps acquiring impetus from the recurrent flurries
of energetic perorations that have been published concerning the
proper name for the phylum Bryozoa, boring bryozoans have also
been termed “burrowing,” “penetrating,” “perforating,” and cor-
responding non-English equivalents thereof. The group is united,
fundamentally, by a common mode of life, and it may have arisen
through the convergence of several lineages of epibenthonic cteno-
stomes. But even if this ethological assemblage were unquestionably
monophyletic, its informal nomenclature would clearly be without
legal restraints, so an author is free to exercise his powers of per-
sonal choice in the matter. Moreover, it is sometimes expedient to
use several different names alternatively within a given discussion
in order to avert the monotony of repetition. If the reader can under-
stand what group of organisms is being considered, any term will suf-
fice. If nomenclatorial leeway exists, an author should briefly but
explicitly define the group he is discussing.

Within this study, “boring” bryozoans predominates, but vari-
ous informal synonyms are also used. Brevity and alliteration
generally vindicate the vapid and groundless pun.

For additional discussion of terminological matters consult
Pohowsky (1974), which also gives grounds for the preferred usage
of standard zoological nomenclature for bryozoan borings.

The present work is concerned primarily with a revision of the
classification of all boring Bryozoa; it consequently deals with the
evolution of the group throughout its entire known range (U. Ordo-
vician—Recent). Although the soft parts of these organisms are of

Borinc CTENOSTOMATE Bryozoa:- PoHowsKY 9

obvious importance in the interpretation of their biological rela-
tionships and living habits, only the preservable borings are of direct
utility to the paleobiologist. For this reason, and because the struc-
ture and taxonomic value of the borings have been largely over-
looked or discounted by most contemporary workers, the present in-
vestigation concentrates on these features. Study and direct compari-
son of the more evanescent structures of boring bryozoans is a major
undertaking in itself, and except for the taxonomic errors discussed
in the systematic section, a number of otherwise creditable publica-
tions on soft parts have already been prepared by Marcus, Silén,
the Soules, and Bobin and Prenant.

Because the internal features of most Recent taxa have been
described by these authors, these descriptions are not repeated here-
in. However, a diagnosis of the external features which are pre-
sumably reflected in the borings is presented for all such species,
but only one (Penetrantia densa Silén) 1s considered in significantly
greater detail. Whenever possible, anatomical relationships to some
soft parts of the bryozoans are inferred, but only features whose
presence is reflected externally can be detected. Thus, the number
of tentacles, features of the digestive tract, sexual organs and other
internal features remain problematic in species erected on the basis
of borings alone. However, existing “soft-part” species should be
recognizable on the basis of their borings, and conversely, there is
no reason why the soft parts of a few fossil taxa might not be studied
if living members are someday discovered. The type species of Tere-
bripora d’Orbigny, T. ramosa d’Orbigny (Recent), is known only
from its borings, and sectioning of specimens from the type locality
is urgently needed. The internal features of Terebripora are known
only from Soule’s investigation of “Jmmergentia” philippinensis
Soule.

In conjunction with a taxonomic revision based exclusively on
borings, it is necessary to annul the widely promulgated notion that
the fossil remains of shell-penetrating Bryozoa are but a nebulous
array of variably nondescript holes whose unalterably questionable
origin justifies their continued assignment to the backwaters of pale-
ontological research. The following quotations are largely responsi-
ble for engendering this attitude:

It will become clear without detailed description that almost every colony
of the same species could have a different aspect according to the amount

10 BuLLETIN 301

of attrition it has been subjected to . . . Therefore it is difficult to dis-

tinguish between the fossil species, perhaps irregularly polished . . .I do

not know of any other bryozoans in which with only one specimen dif-
ferent species can be distinguished so easily, particularly in fossil material.

(Marcus, 1938, p. 283)

Then there is the question if really all the species that have been
enclosed in Terebripora and Spathipora really belong to those genera as
they have now been characterized by Marcus’s investigations of their
genotypes. As has already been mentioned, the remaining species are only
known by their traces in the substrate.

I have found it extremely difficult, not to say impossible, to decide with
any certainty upon the systematic position of a boring bryozoan on those
characters only ... a direct comparison between Recent, anatomically re-
searched species and fossil ones will possibly never give satisfying results.
(Silén, 1947, pp. 37, 38).

In so far as superficial external appearances are concerned, deter-
mination of the genera and species is hopeless. (Soule, 1950b, p. 378)

The three families . . . [Terebriporidae, Immergentiidae, Penetrantii-
dae]... cannot be readily differentiated by the pattern of the tracings that
appear upon the surface of the shell in which the zoaria are immersed. The
only means of positive identification of the families and the genera is
examination of zoaria that have been removed from shells by decalcifica-
tion. (Soule, 1953, p. 751)

It is obvious that excessive abrasion and other destructive
processes can render practically any fossil unrecognizable, but with
all due respect for the contributions made by the foregoing authors,
the opinions enunciated above simply do not hold true in reference
to fresh or slightly altered specimens. Such borings retain a wealth
of taxonomically diagnostic information about their originators: they
cannot be dismissed as unrecognizable and should not be regarded
as trace fossils. Moreover, artificial casting techniques often permit
identification from borings whose surface aspect has been con-
siderably disrupted. As expressed in an earlier discussion on this sub-
ject (Pohowsky, 1974), bryozoan borings are bona fide “body fos-
sils,’ and are potentially comparable with Recent, “soft-part”
species. Although some preservable characters of living species have
been described (e.g. zooid length), comparison with fossils is present-
ly difficult because zoological studies have often avoided detailed
consideration of the borings. Flaccid colonies extracted via decalci-
fication retain only a portion of the information that is readily ob-
tained through casting. If tentacles were preserved in fossils, a pale-
ontologist would be remiss in not counting them. Well-preserved
borings are available to the zoologist and their important characters
should be studied as intensively as are those of the “internal”
anatomy.

Concerning our present knowledge of fossil bryozoan borings, it

Borinc CTENOSTOMATE Bryozoa: PoHowsky 11

is evident that no scientific discipline prospers through neglect. One
is inclined to suspect that these interesting and, at times, splendidly
preserved remains may seem enigmatic because of a self-fulfilling
prophecy rather than an intrinsic absence of features amenable to
biological interpretation.

PROSPECTS AND OBJECTIVES

Boring bryozoans are easily overlooked and economically un-
important. Their minor role in energy transfer within the ecosystem
is probably much like that of other gymnolaemates, and although
they obviously contribute to the breakdown of some types of cal-
careous marine sediment, their destructive activities appear to be
far exceeded by those of boring sponges, thallophytes, and numerous
other organisms. Their brief mention on a half dozen pages in the
prodigious bibliographic work on marine borers by Clapp and Kenk
(1963, 1136 pp.) is strikingly evincive of their ranking in this cate-
gory. The group has attracted the enduring attention of a small
number of zoologists, and the paleontological literature on their re-
mains is widely scattered, mostly limited in scope, and sometimes
less than enlightening.

In several respects however, boring bryozoans have an impor-
tance far out of proportion to their ecological and economic roles.
Because of their peculiar mode of life, they comprise one of the best
fossil records of the soft parts of any invertebrate organisms. More-
over, as members of the Ctenostomata, these unique fossils appear
as propitious devices for monitoring what are otherwise poorly known
episodes in bryozoan evolution. They are, in a sense, bryozoological
analogues of the Burgess Shale, Bundenbach, Mazon Creek, and
Solnhofen faunas.

It is evident that an understanding of these fossil borings may
prove valuable in establishing guidelines for the taxonomy of Recent
species, for it has been suggested that the frequency of convergence
in some bryozoan lineages makes analysis of fossil material a strong
prerequisite for phylogenetic classification.

Appreciable convergence in the evolutionary patterns of some Bryozoa
makes it unlikely that a phenetic approach, even one delimiting polythetic
groups based on characters inferred to reflect genetic differences, can be
used to approximate a phylogenetic classification without consideration of
occurrence in time and space as an indication of probable genetic continuity.
(Boardman, Cheetham and Cook, 1969, p. 319)

At present however, our knowledge of the anatomy of these fossils

12 BuLLeTIn 301

is far too inadequate to permit much more than a purely speculative
reconstruction of evolutionary patterns. Boardman and Cheetham
(1968, p. 1352) observed that, “The Ctenostomata and Cyclosto-
mata are so poorly known [from their fossil records] that any usable
synthesis requires extensive basic research.”

The stolonate nature of boring bryozoans (resulting in colonies
with widely separated zooids), and their growth in apparent inde-
pendence of shell microstructure — and in probable independence
of currents — makes them excellent subjects for the investigation of
genetically determined variation in budding patterns and orientation
within the colony. As noted by Medd (1966, p. 11), an understand-
ing of zoarial development is important in the study of this colonial
phylum, yet

Most works are restricted to a consideration of the variation of the
morphological features of the zooecium, without attempting to correlate
this variation with the zoarial development.

The unusual habitus of boring species may also render them useful
in elucidating developmental processes which in other bryozoans are
commonly masked by microenvironmental factors and the crowding
of zooids. Clearly, there is ample room here for the application of
what Seilacher has referred to as “experimental” paleontology, for
bryozoan borings are promising constituents of, “. . . a paleontologi-
cal record . . . full of fossil experiments which help to unveil ancient
processes, may they be in the fields of morphogenesis, phylogeny,
ecology or behavior.” (Seilacher, 1968, p. 285)

Boring bryozoans are important because they hold a peripheral
position in the realm of bryozoan adaptation. Like lunulitiform (free-
living) cheilostomes, pagurid crustaceans, helicoplacoid echinoderms,
cetaceans, bats, and many other diverse groups, the shell-penetrating
Bryozoa are useful indices of the adaptive limitations of a particular
living system.

Considering these matters and some important developments
in research techniques, a survey of the literature on bryozoan borings
leaves one with the impression that the field is in many respects
pristine. In an effort to prepare a more useful treatment of this
group in its first monographic revision, the following objectives were
established:

1. To describe and illustrate bryozoan borings in a manner that
will foster their recognition. Repeated confusion of these excavations

Borinc CTENOSTOMATE Bryozoa: PoHowsky 13

with those of cirripeds, sponges, polychaetes, thallophytes, and other
unrelated organisms is due largely to widespread unfamiliarity with
the diagnostic features of the bryozoans examined here.

2. To promote the synthesis of modern paleontological and
zoological research on boring bryozoans. Soft parts of living species
were described by Marcus in 1938, but few subsequent paleontolo-
gical papers have considered taxa known largely from their internal
features. Although this work concentrates mainly on classifying
inadequately known borings, an artificial boundary between fossil
and Recent specimens must not be upheld indefinitely.

3. To collect numerous well-preserved specimens to assist in the
attainment of the first two objectives. A primary obstacle limiting
our ability to interpret bryozoan borings has long been a scarcity
of suitable material for study. The discovery of well-preserved fos-
sils will perhaps do more than anything else to discredit the group’s
reputation for paleontological inscrutability.

4. To stimulate future study of boring bryozoans by directing
attention to some structures, morphogenetic processes and aspects
of phylogenesis which are deserving of further investigation.

Working toward these objectives, considerable time was devoted
to the collection and preparation of new material, and emphasis has
been placed on photographic documentation. Useful illustrations
are of signal importance in all taxonomic studies, and particularly
so in those dealing with groups which are unique or abstruse. With
accurate descriptions, they are essential in classification for this
group.

Although sketches are invaluable for emphasizing anatomical
features of special taxonomic significance, all drawings (particularly
those executed without the aid of a camera lucida) may reflect to
some degree the vagaries, prejudices, or misconceptions of an artist.
Thus, borings figured by Nineteenth Century workers often have an
unnaturally regular, stylized aspect (Text-figs. 1 (A, B); 2 (A, F-
H)), and some more recent papers contain sketches that deviate
significantly from the accompanying description (e.g., Soule, 1950a,
pl. 2, fig. 2).

Well-preserved bryozoan borings can be collected, and useful
photographs of these structures can be obtained through the micro-
scope, via macrophotography, and by means of SEM studies of

14 BuLLetin 301

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TEXT-FIGURE 1
A. Ropalonaria venosa Ulrich, 1879. Most detailed of two figures published

with original description. Note occasional suggestion of ‘cell mouths” men-

tioned by Ulrich. (Ulrich, 1879, pl. 7, fig. 24a). Magnification not indi-
cated.

B. Terebripora ramosa d’Orbigny, 1847. Most detailed of two figures pub-
lished with original description. D’Orbigny, 1847, pl. 10, fig. 17; slightly
modified to facilitate reproduction. Magnification not indicated.

Borinc CTENOsTOMATE Bryozoa: Ponowsky 15

artificial casts — yet these illustrative techniques have rarely been
utilized to any real advantage in studies on_ shell-penetrating
Bryozoa. Those specimens illustrated by Soule and Soule (1969a,
figs. 12-17) are mostly worn, and most of the photographs of bryo-
zoan borings in recent papers by Boekschoten (1966, 1967) are of
marginal value for identification purposes. Some of the best avail-
able photographs of bryozoan borings are apparently to be found in
Voigt and Soule (1973), and in a liberally retouched collection pub-
lished by Canu and Bassler in 1923.

HISTORICAL RESUME

A lengthy and purely chronological account of the study of
boring bryozoans would add little to their understanding. However,
the frame of reference provided by the following brief history of
the group’s investigation seems important in a work of this nature.
Supplementary details are recorded throughout the section on syste-
matic paleontology — notably in discussions of Ropalonaria venosa
Ulrich and Terebripora d’Orbigny.

Scientific research on these peculiar bryozoans began with the
erection of two species of Terebripora by d’Orbigny in 1847. Over
the next two decades several additional taxa were recognized by
other authors. The first sizable study of the group was published by
Fischer in 1866. Although Fischer erected numerous species as-

C-E. Terebripora sp. [probably T. falunica (Fischer) or T. miniatura, n. sp.]

(Marcus, 1938.)

C. Description presented by Marcus: “Adult colony of Terebripora
ramosa d’Orb.; e- primary stolon; s- secondary stolon; u- supple-
mentary stolon; z- autozooid.” (Marcus, 1938, text-fig. 2A.); xX 23.

D. Description presented by Marcus: “Region of ancestrula of Tere-
bripora ramosa d’Orbigny.” Letters correspond to those in previous
figure. (Marcus, 1938, text-fig. 2B). Magnification not indicated.

E. Description presented by Marcus: “Portion of primary stolon (e) of
Terebripora ramosa d’Orb., with autozooid (z), zooid bud (bd),
secondary stolon (s), and tubular pores (c) for communication with
surface of shell.” (Marcus, 1938, text-fig. 2C.) Magnification not
indicated.

F. Spathipora sp. Description presented by Marcus: “Two autozooids of
Terebripora ramosa d’Orb. joined to stolon (¢); a- duplicature; d- muscles
of duplicature (parieto-diaphragmatic muscles); m- parietal muscles;
o- ovum; #- proventriculum; r- septum of insertion (with uniporous
rosette or septula) ; f- testicle.” (Marcus, 1938, text-fig. 2D.) Magnification
not indicated.

G. Terebripora sp. Description presented by Soule: “Immergentia philip-
pinensis n. sp., shell surface showing a zoarium with the placement of the
zooids, specimen mounted in clarite.” (Soule, 1950a, pl. 2, fig. 3.) Magni-
fication not indicated.

16 BuL.etin 301

TEXT-FIGURE 2

A. Spathipora sertum Fischer, 1866. Note attachment of zooids at proximal
end. (Fischer, 1866, pl. 11, fig. 4; slightly modified for reproduction.)
Magnification not indicated.

B-E. Spathipora comma (Soule), 1950.

B. Description presented by Bobin and Prenant: “Portion of colony seen
in situ in shell. Note the secondary stolons (double lines) and anasto-
mosing stolons (single lines), the openings of the zooecial chambers
(in black), the frontal processes (ff), and the kenozooids with
spherules (sf). (Bobin and Prenant, 1954, text-fig. 1-I.) x 36.

Borinc CTENOSTOMATE Bryozoa: PoHowsky 17

signed to Terebripora and a new genus, Spathipora, his poor descrip-
tions and failure to illustrate most of these renders many of them
unrecognizable in the absence of available type material. Subsequent
nineteenth century studies were much shorter and introduced few
additional species, but Ulrich’s report of the oldest known boring
bryozoan (Ropalonaria venosa Ulrich, 1879; U. Ord.) during this
interval is worthy of mention.

Two of the earlier contributions appearing in the present century
(Ulrich and Bassler, 1904; Canu and Bassler, 1923), appreciably
advanced knowledge of the group in the United States, but as in
all foregoing works, the bryozoan affinities of the borings discussed
in these studies was strictly inferential. Not until 1938 was the
origin of some presumed bryozoan borings established with certainty.
In that year, Marcus extracted and described the soft parts of two
species which he assigned to Terebripora ramosa d’Orbigny and
Spathipora sertum Fischer. Although at least the first of these iden-
tifications was incorrect, the importance of Marcus’s contribution
is obvious. Another major zoological study was published by Silén
in 1947. In that work, Silén discussed intensive research on two
genera (Penetrantia and Immergentia) which he erected in the pre-
vious year. Since 1947, results of zoological investigations have ap-
peared in a number of publications by Bobin and Prenant, Silén,
and the Soules.

Regrettably, the descriptive work of these zoologists has only
lately begun to influence paleontological studies. In the first of the

C. Description presented by Bobin and Prenant: “A kenozooid with
spherules, after decalcification, with thickened cuticular layer. sp,
kenozooid with spherules; sr, attachment stolon; st, stolon.” (Bobin
and Prenant, 1954, text-fig. 1-V.) x 200.

D. Description presented by Soule: “Terebripora comma, n. sp.,
showing anatomy of autozooid. A- anus; C- caecum; D- diaphragm:
E- esophagus; G- gizzard; I- intestine; M- mouth; O- orifice;
PM- parietal muscle; PS- pseudo stolon: PVM- parieto- eyaginales
muscle; R- rectum; RM- retractor muscle; S- stolon; T- tentacle;
TS- tentacle sheath; U- septum; V- vestibule.” (Soule, 1950b, text-
fig. 2; slightly modified for reproduction.) X 160.

E. Description presented by Soule: “Terebripora comma, n. sp., . .
showing anatomy of kenozooid. BB- brown body; N- pmbrve!
(Soule, 1950b, text-fig. 3; slightly modified for reproduction.) X 160.

F. Orbignyopora? capillaris (Dollfus), 1877. Most detailed of three figures
of “Terebripora capillaris n. sp.’ published with original description.
(Dollfus, 1877, pl. 1, fig. 4.) * 20.

G. Orbignyopora archiaci (Fischer), 1866. (Fischer, 1866, pl. 11, fig. 3;
slightly modified for reproduction.) Magnification not indicated.

H. Haimeina michelini (Terquem), 1855. (Terquem, 1855, pl. 26, fig. 6.) X 4.

18 ButtetTIn 301

two major papers on putative fossil ctenostomes to appear since
1938, Condra and Elias (1944) erected a host of Carboniferous and
Permian species which differ markedly from all other borings of
known bryozoan origin. Considerable progress was made when Voigt
and Soule (1973) collaborated in describing five new Cretaceous
species which are unquestionably bryozoans. However, even this
encouragingly bipartisan effort is weakened by some serious taxo-
nomic and morphologic misunderstandings.

Neglect of biological studies by paleontologists, the general
aversion to borings shown by zoologists, and the frequent collection
of poorly preserved borings by both groups of workers has greatly
impeded our interpretation of these fossil remains. The recent rele-
gation of the group to the trace fossils (Boekschoten, 1970; Bromley,
1970, 1972) is symptomatic of the existing uncertainty (Pohowsky,
1974).

In retrospect, severe confusion of one sort or another seems to
have afflicted the study of these organisms for more than a century.
Perhaps because they were accustomed to dealing with the more
“typical” members of the phylum, some earlier workers have shown
considerable puzzlement or skepticism when confronted with species
which truly bore. Although D’Orbigny (1847, p. 22) explicitly
described the boring habitus of Terebripora, Busk (1852, p. 29) and
Hincks (1880, p. 286) placed the genus in synonymy with Hip-
pothoa Lamoroux, an encrusting cheilostome which sometimes pro-
duces shallow pits in calcareous substrata. Waters (1879, p. 115)
noted the power of Aetea Lamoroux (Cheilostomata) to dissolve
the shells on which it grows and suggested that some of the borings
reported by Fischer (1866) might be of this kind. Later, Waters
(1904, p. 54) considered Terebripora ramosa d’Orbigny to be a
junior synonym of Hippothoa distans MacGillivray (Recent), and
even suggested that “Terebripora” capillaris Dollfus (Devonian)
and some of the Jurassic specimens described by Fischer (1866)
were probably Hippothoa!

Ulrich (1879, p. 26) mistakenly described his specimens of
Ropalonaria venosa as “impressions” of an encrusting bryozoan and
asserted that the species is related to Hippothoa — even though he
assigned it to the cyclostome family, “Crisidae” [Cristidae]. His mis-
interpretation of Ropalonaria’s mode of life induced Vine (1884) to

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 19

assign some nondescript calcareous encrustations to the genus. The
degree of Ulrich’s misunderstanding of Ropalonaria is indicated by
his erection of R. pertenuis (1886) for what is obviously an en-
crusting, uniserial cyclostome.

The substantial distinction between the true boring bryozoans
and those which merely produce shallow pits seems to have escaped
even Fischer (1866), who based two of his numerous species of
Terebripora on the oval excavations of cheilostomes. As recognized
by Voigt (1962, p. 61), Brydone (1936, p. 88) more recently erected
Terebripora robusta for a bryozoan of this type. His description con-
cludes with what must surely rank as one of the most outright con-
cessions to irrationality and prevailing consensus imaginable:

It must be very questionable whether species which, like the above,
are only partially immersed can be properly referred to a genus founded
for zooecia wholly immersed, but it is the recent practice.

In reality, the last person to publish such an assignment was ap-
parently Fischer (1866; Terebripora eocemca, T. contorta). The
mistake was subsequently repeated by Gorodiski and Balavoine
(1961, p. 2; Spathipora indistincta).

Taxonomic confusion in zoological studies was introduced when
Marcus (1938) described and figured the extracted zooids of a puta-
tive colony of Terebripora ramosa d’Orbigny. Although the borings
he assigned to this species are certainly those of Terebripora (prob-
ably 7. falunica Fischer), the zooids illustrated in his text-figure 2D
(Text-fig. 1F herein) clearly belong in another genus — probably
Spathipora Fischer. Marcus’s undetected error served only to rein-
force the assignment of Spathipora comma (Soule) to Terebripora by
Soule (1950b) and Bobin and Prenant (1954). Apparent unfa-
miliarity with the borings of 7. ramosa (the type species) permitted
Soule and Soule (1968) to place “7.” eltaninae in Terebripora. “T.”
varians Soule and Soule, 1969a may not belong in this genus, either.

The generic affinities of Jmmergentia phillipinensis [sic] Soule
remain in doubt because none of the specimens figured in the orig-
inal publication (Soule, 1950a) was indicated to be the holotype.
The zooid Soule illustrated in plate 1, figure 5 evidently belongs with
Immergentia Silén, but the colony shown in plate 2, figure 3 (Text-
fig. 1G herein) is clearly a Terebripora. It is difficult to reconcile the
borings in plate 2, figure 2 with either of the other two drawings.

20 BuLteTINn 301

PROCEDURES AND TECHNIQUES

The specimens examined in the course of this work were ob-
tained from a variety of sources. The study of preexisting types and
some other material was made possible by loans from numerous
repositories, but the collections of D’Orbigny and Fischer were
examined in the Muséum national d’Histoire naturelle in Paris.
Some specimens were received as gifts from private collections, and
colonies of Ropalonaria venosa Ulrich were collected by the author
from an exposure near Cincinnati, Ohio.

The majority of specimens reported herein were located during
an extensive search through the large collection of fossil gastropods
and pelecypods in the British Museum (Natural History). Using
a low-power jeweler’s loupe, numerous well-preserved borings were
discovered in more than 150 shells. It is estimated that the boxes
of mollusks examined would occupy some 8,000 sq. ft. of drawer
space if they were closely packed, and the time expended in actually
scanning the shells was nearly 200 hours. Obviously, bryozoan bor-
ings are not particularly common — but considering the fact that
many poorly preserved specimens were not removed for further
study, one might realistically expect to locate two or more colonies
per hour in a search of this nature.

Specimens obtained in this search were dominantly from the
Cenozoic, but many Mesozoic fossils were also found. No Paleozoic
colonies were located, but shells of this age constituted only about
5% of the material examined. Although the material considered in
this work consists largely of post-Paleozoic borings from Europe
and North America, specimens from most geological periods and from
widespread parts of the globe are included. Such an assemblage of
borings could not have been gathered without the availability of a
large collection of mollusks.

All specimens discussed herein were examined through a stereo-
binocular microscope. Although little can be done to improve the
visibility of some colonies preserved in opaque shells, many such
borings become more evident when a thin layer of water-soluble
ink is applied with a brush. Visibility is almost always improved
through this procedure if the substratum is translucent; Von Hage-
now (1840, p. 671) noted long ago that chalk-filled borings in belem-
nites could be observed more readily if the belemnite was moistened

Borinc CTENOsSTOMATE Bryozoa: PoHowsky 2A

or coated with oil. Oil, glycerine, or water are to be preferred over
ink whenever the substratum tends to absorb the ink generally,
rather than just within the borings. However, repeated applications
of water or ink often reduce the transparency of many shells by dis-
solving parts of the constituent crystals. To avoid such damage and
to facilitate observation and photography, a thin layer of clear,
commercial fingernail polish 1s useful. Entrapment of bubbles can be
avoided by careful application, and even hardened coatings are
easily removed with acetone. A layer of polish applied after a coating
of ink has been allowed to dry usually produces exceptionally satis-
fying results (Pl. 13, fig. 1; compare untreated colony in Pl. 13, fig.
De

Photography of many specimens — particularly those on flat
surfaces — was accomplished by means of a Zeiss Photomicroscope
IT, using a low-power objective lens. When considerable relief was
involved, or a different magnification was desired, specimens were
photographed by mounting a 28-mm Nikkor lens in a reversed posi-
tion on up to 24 inches of extension tubes. In a few cases, a 55-mm
Nikkor lens in the normal orientation gave the most suitable results.
At all magnifications, a stage micrometer was photographed to ac-
curately gauge the final enlargement of the plate figures. The length
of almost all the autozooids (Lz) was determined by direct measure-
ment from these illustrations.

Polyester-resin casts were usually prepared whenever sufficient
and adequate material was available. Casting of suitable specimens
is not difficult, and it permits the observation of minute structural
details that cannot be seen at the shell surface. Small fragments are
easily coated with gold and examined with a scanning electron
microscope. All casts illustrated in the present study were prepared
from the polyester, EM-301, manufactured by Trylon, Ltd. Details
of the casting process are discussed in another publication (Pohow-
sky, 1974). The techniques employed here are not new; Gatrall and
Golubic (1970) used similar methods to study endolithic fungi, and
Voigt and Soule (1973) recently utilized polyester resins in the in-
vestigation of some boring bryozoans from the Cretaceous.

A knowledge of both the surface configuration and internal
morphology of a boring is desirable, and in some cases both aspects
of the same colony are shown for comparison. In two cases (PI. 2,

bo
bo

BuLteTIN 301

figs. 3, 4; Pl. 17, figs. 5, 6), one of the negatives in such a pair has
been inverted to produce a mirror-image print in which the ana-
tomical components are more easily compared with those in the
associated photograph.

When numerous young colonies were available, various growth
stages were photographed to provide a record of the early astogeny
within a species (PI. 13, figs. 5-9; Pl. 17, figs. 1, 2; Pl. 18, figs. 1-5;
Pl. 23, figs. 1-3). Of course, the sequences shown are somewhat arti-
ficial, and there is evidence that corresponding parts of colonies
sometimes developed at different rates in any two individuals. Asto-
geny within single colonies is illustrated in a number of species, and
in Ropalonaria? arachne (Fischer) the developmental sequence pre-
ceding the formation of a teratological zooid can be inferred in two

cases (PI. 3, figs. 4, 5).

REPOSITORIES
The following abbreviations for repositories are employed in
this study:
aN Ul MRIS Soe Allan Hancock Foundation, University of Southern

California; Los Angeles

BMNH ... British Museum (Natural History); London

(Ci Rares Geologisches Institut der Universitat Koln

GLNW .. .Geologisches Landesamt von Nordrhein Westfalen;
Krefeld, Germany

GPIUB .. .Geologisch-Palaontologisches Institut der Univer-
sitat Bonn

GSM ..... Institute of Geological Sciences; London

MGU ..... Moscow State University; Moscow B 234

MNHN ... Muséum national d’Histoire naturelle; Paris

INTER 332 Naturhistoriska Riksmuseet; Stockholm

RAP Heiss Robert A. Pohowsky reference number

ROM. .... Royal Ontario Museum, University of Toronto

UCGM ... University of Cincinnati Geological Museum; Cin-
cinnati, Ohio

USGS .... United States Geological Survey

USNM ... United States National Museum (National Museum
of Natural History); Washington, D.C.

{SC} EE mee. Central Geological Museum; Leningrad (Atabekian
collection )

Borinc CTENOSTOMATE Bryozoa: PoHowsky 23

ANATOMY AND BIOLOGY OF BORING BRYOZOANS

Although Marcus (1938) was the first worker to describe the
soft parts of boring bryozoans, most of our knowledge of the biology
of this group has been gathered in subsequent studies by Silén
(1946, 1947, 1956), Soule (1950a, 1950b, 1954), Bobin and Prenant
(1954), and Soule and Soule (1968, 1969a). Silén (1947) discussed
the anatomy and biology of Penetrantia and Immergentia in con-
siderable depth, and Soule and Soule (1969b) prepared a useful
summary of zoological and paleontological information published up
to that time. It is beyond the scope of this study to recount the re-
sults of the above investigations in significant detail, but insofar
as the borings considered herein are the products of once-living
organisms, a general discussion of the biology and soft-part anatomy
of these bryozoans is essential.

The 48 species recognized herein constitute a small fraction of
known (extant and fossil) bryozoans. In his commendable introduc-
tion to the phylum, Ryland (1970, p. 9) indicated that the total
number of described species is approximately 20,000. About 4,000 of
these are living. Although relatively few bryozoologists have inves-
tigated the boring species, it is obvious that the shell-penetrating
mode of life is aberrant. Most bryozoans live attached to the surface
of a more-or-less stationary object.

Presumably, the boring habitus offers an appreciable selective
advantage to those ctenostomes which have evolved the chemical
mechanisms required to dissolve shell. Unlike the Stenolaemata, and
most other Gymnolaemata, the ctenostomes typically lack any form
of calcareous exoskeleton. Immersion within a solid substratum
would, therefore, appear to reduce greatly the danger of mechanical
disruption or predation. The accumulation of detrital, silt-sized par-
ticles on zooids of Cryptopolyzoon Dendy (Ctenostomata) is per-
haps another example of a “quest” for greater protection.

There is no evidence that boring bryozoans are in any way
parasitic on the tissues of infested mollusks. Parasitism is readily
excluded by the observation of living colonies in the shells of mol-
lusks whose soft parts were obviously removed before boring was
initiated. Furthermore, borings on the exterior of a shell never seem

24 BuLtetTIn 301

to penetrate the innermost layers, and it appears that infested gas-
tropods are able to deal effectively with zooids encountered by the
encroaching mantle (PI. 11, fig. 7). Evidently, bryozoans in the
shells of living gastropods can simultaneously be buried and acquire
new territory for colonial expansion for as long as the “host” survives.
Silén (1947, pp. 23, 24) observed abandoned borings in the first-
formed whorls of adult snails which apparently retained active por-
tions of the same colony in the larger, exterior volutions.

As reported by Soule and Soule (1969, p. 795), nothing is known
about the anatomy, life span, or pelagic habits of the larvae of
boring bryozoans. It is obvious that successful larvae eventually
settle on a suitable calcareous object, but the detailed factors in-
fluencing substratum selection are unknown. Studies on cheilostomes
suggest that many bryozoan larvae are unwilling to settle in places
which appear suitable to the observer (P. L. Cook, personal com-
munication). Boring groups may have definite preferences for cer-
tain types of shells, but no strong “host” specificity has been
conclusively demonstrated to date. Silén (1947, p. 23) reported that
he never observed a “dead, free-lying” shell of Pecten septemradiatus
which was devoid of Penetrantia concharum, but one cannot be cer-
tain that many of the older mollusks in the areas he studied were
not equally infested. Some species are known to settle on shells of
both living and dead mollusks, but this is perhaps to be expected,
because parasitism is not involved. Of greater interest is Silén’s in-
dication (1947, p. 23) that P. concharwm inhabits only “dead” shells.
Perhaps the larva of this species avoids shells which retain the
periostracum.

After a larva settles, shell penetration begins with the produc-
tion of the initial zooid, the ancestrula. The ancestrula of P. con-
charwm was figured by Silén (1947, text-fig. 3), but the earliest
stages of colony development have not been described previously
in other species. The ancestrula always appears to be entirely em-
bedded within the substratum, and astogeny invariably proceeds
with the production of one or more thin, tubular stolons (Text-fig.
6). In most of the living groups, these processes have been shown to
be little more than series of elongated kenozooids—zooids without
a polypide, muscles or orifice, and serving essentially to produce and
connect the various other zooids in a colony. Metabolic products

Borinc CTENOSTOMATE Bryozoa:. PoHOWsKY 25

are obviously transported within them during the budding process,
and presumably during succeeding, regenerative phases as well.
Small, cellular communication devices (septulae) separate keno-
zooids from one another, and from other zooids of greater internal
complexity. In one genus, Jmmergentia Silén, true kenozooidal
stolons appear to be lacking. In this case, the feeding zooids (auto-
zooids) are instead connected together by attenuated portions of
their distal ends.

In a pattern that varies appreciably among different families,
stolons progressively give rise to numerous autozooids. The latter
are tubular in general appearance, and relate to the stolon in a man-
ner that is of considerable taxonomic importance. Some autozooids
are attached to the stolon by means of a short “stem,” the peduncle,
and incline in the shell at an angle that is strongly influenced by the
organism’s genotype. Other groups lack a peduncle and have zooids
orientated horizontally, directly along or slightly below the associated
stolon. It is convenient to distinguish these groups artificially as
“pedunculate” and “non-pedunculate,” respectively (cf. Text-figs.
S.A Band 3°C, D).

Like all living marine bryozoans, the autozooids of boring
species possess a filter-feeding device consisting of a number of
ciliated tentacles (approximately 8-14) arranged in a circle around
the mouth. This organ, the lophophore, is extruded from the cham-
ber of the autozooid by means of hydrostatic pressure created by
the contraction of parietal muscles. Rapid withdrawal of the lopho-
phore is accomplished by a retractor muscle. Food collected by the
tentacles enters the mouth and passes through a U-shaped gut. The
digestive tract terminates at an externally directed anus located
at the base of the tentacles, near the insertion of the retractor
muscle. In some groups, a portion of the gut is thickened into a
muscular gizzard. Feeding and excretion of waste occur only when
the polypide is in the extended position. When the lophophore is re-
tracted, the opening to the exterior is closed by a setigerous collar
in most ctenostomes, but a trapdoor-like operculum (analogous to
that of cheilostome bryozoans) has supplanted this device in Pene-
trantia. As probably occurs in all marine bryozoans, polypides (con-
sisting largely of the gut, lophophore and muscles) periodically
degenerate. Their remains (“brown bodies”) are often within the
coelom, next to a newly regenerated polypide.

26 BULLETIN 301

TEXT-FIGURE 3

Autozooids and stolons from four genera of boring bryozoans: A. Pene-
trantia sp.; B, Spathipora sp.; C, Orbignyopora archiaci (Fischer); D, Im-
mergentia sp.

Morphological features: PS, principal stolon; AS, adventitious stolon; P,
peduncle; AP, aperture of zooid; V, vane; FP, frontal pore; T, tubulet.

Zooids are viewed obliquely from above the surface of the substratum,
here transparent. Solid black areas represent openings connecting parts of the
colonies with the external environment. Figures A, B, and D show features
seen in several cast specimens of each of the respective genera. Orbignyopora

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 27

With the possible exception of Spathipora (S. elegans Fischer),
Penetrantia is the only extant genus of shell-penetrating bryozoans
which possesses ovicells for the brooding of larvae prior to their
release. In all other Recent genera, brooding apparently occurs with-
in the coelom. Coelomic brooding in Spathipora comma (Soule) is
sometimes associated with a degenerated polypide [Soule, 1950b,
p. 381, text-fig. 3 (Text-fig. 2E herein) ]. In Penetrantia at least, the
brooding zooids seem to be sufficiently specialized to warrant their
consideration as heterozooids adapted for reproduction—+z.e., gono-
zooids. In this genus, ovicells consist of a globular space between the
peculiar, double cuticular layers of the body wall. The morphology
of gonozooids in Penetrantia has proven useful in distinguishing
the various species (Soule and Soule, 1969b, p. 799).

Kenozooids are generally acknowledged to be another kind of
heterozooid. The only other type reported in the ctenostomes is the
peculiar sac zooid found in Spathipora comma (Soule) [Bobin and
Prenant, 1954, p. 140, text-fig. 1-V (Text-fig. 2C herein)] and a
number of fossil species discussed in the present study. The term,
sac zooid, is here preferred over “cénozoécie a sphérules,” used by
Bobin and Prenant. These authors reported that sac zooids of S.
comma are filled with “granulations réfringentes” resembling those
which they observed in Hypophorella expansa Ehlers and Valkeria
uva L. Such granules are evidently stored in sac zooids, but their
function and mode of origin are unknown.

Some noteworthy features common among boring bryozoans,
but virtually unknown in other Ctenostomata, are the short pro-
cesses (tubulets) which extend to the surface of the substratum
from the frontal sides of either or both stolons and zooids in many
species (PI. 12, figs. 4, 6; Text-fig. 3). While tubulets obviously con-
nect the underlying portions of the colony with the surface, their
precise function is unknown. Marcus (1938, p. 294) speculated that
these processes might be responsible for providing oxygen required

archiaci has not been cast, and fig. C is based largely on the zooids illustrated
on Pl. 5, figs. 1-4, notably the last. The zooid of O. archiaci (1.0-1.6 mm long)
is presented at approximately one-half to one-third the magnification used for
the other three specimens.

Only in fig. C does the distal direction with regard to the zooid body coin-
cide with the distal direction along the principal stolon to which the zooid is
directly or indirectly attached. In all four examples, that stolon is growing
toward the upper right.

28 BULLETIN 301

in connection with the boring process. Silén (1947, p. 32) acknowl-
edged the plausibility of Marcus’s suggestion and added that the
tubulets might also assist in excavating dissolved matter from the
borings. Tubulets appear to be lacking on stolons located close
to the surface, but it seems possible that such stolons may still com-
municate with the exterior by means of homologous openings, for
which the term, frontal pore, is proposed (Text-fig. 3B).

No mechanical devices for excavation are known in any of the
species examined thus far, and it is evident from the intricate nature
of the borings that mechanical processes can be excluded without
question. McIntosh (1874, p. 345) was perhaps the first to comment
on the impracticality of a rasping process. Marcus (1938, p. 278)
suspected that phagocytosis might be involved, but he also theorized
that boring might be accomplished by the carbonic acid produced
during respiration. Beginning with the premise that an acid was
responsible, Silén (1947, pp. 25-32) conducted some revealing ex-
periments on bored shells and the tissues of Penetrantia. After pre-
liminary quantitative analysis indicated that shells penetrated by P.
densa contain abnormally high amounts of phosphate, staining tech-
niques were employed to determine the distribution of this ion
relative to the borings. Evidence of particularly high levels of
phosphate in the shell immediately surrounding the zooid hollows,
as well as in the growing tips of the actual stolons led Silén (p. 27)
to postulate that the boring process involved phosphoric acid.

Although phosphoric acid cannot be excluded as the boring agent
in P. densa, there is reason to believe that Silén’s approach to this
intractable problem was slightly amiss. Most significantly, he in-
correctly interpreted the raised, white areas surrounding the borings
to be chemically altered parts of the original shell (Silén, 1947, p.
26, text-fig. 56). Examination of the specimens in Plate 11 leaves
no doubt that some of the structures Silén referred to were secreted
by the bryozoan. A narrow “bleached” zone is present around many
parts of the holotype, but this is almost certainly not what Silén
illustrated in text-figure 56.

Using one of the staining tests employed by Silén (ammonium
molybdate ++ stannous chloride), I was unable to detect appreciable
concentrations of phosphate in shell fragments from which the soft
tissues of P. densa (paratype) had been removed by a solution of

Borinc CTENOSTOMATE Bryozoa: PoHowsky 29

sodium hypochlorite. These results were confirmed in an electron
probe study by Dr. R. Symes, [British Museum (Natural History) ],
using another similarly treated fragment of the same shell.

Silén (1947, p. 28) remarked that the phosphate in bryozoan
tissue remaining in the borings he stained may have been merely
dispersed through the adjacent parts of the shell by the reagents
used in its detection. My own experiments and observations suggest
that this might be so — although admittedly, treatment with sodium
hypochlorite might have removed any phosphate located amid the
erystals of the shells prior to their analysis. However, the solid,
white secretions of P. densa seem to consist of calcium carbonate,
with little associated calcium phosphate.

The presence of phosphate in the tissues of Penetrantia is more
certain, but as Silén observed (p. 28), this ion is also found in Electra
pilosa (Cheilostomata) and other marine invertebrates which have
no ability to penetrate. The abnormal abundance of this ion in P.
densa is perhaps a clue to the boring process, but the reported in-
fluence of phosphoric acid on shells infested by this species appears
to warrant further documentation.

In considering the means by which bryozoans bore, it must be
remembered that at least some species are able to penetrate the
overlying periostracum of a mollusk shell, in addition to the calcare-
ous layers (Silén, 1947, p. 31). Furthermore, the chemical(s) em-
ployed must be capable of destroying the thin (but abundant)
organic membranes present within various layers of a shell. Obvious-
ly, these bryozoans are able to dissolve the organic matter within
their own body walls; if this were not so, fusion of stolons with other
parts of the same colony would be impossible. Although the efforts
of Silén have brought us closer to an understanding of the methods
by which bryozoans bore, little is known about the biochemical
processes involved.

Without question, both fossil and extant species of shell-pene-
trating ctenostomes are widely distributed around the globe. Soule
and Soule (1969b) prepared a distribution map revealing that all
Recent species have been collected from latitudes less than about
64 degrees in both hemispheres. However, one is inclined to agree
with their observation that existing biogeographical data are heavily
weighted toward the collecting sites of a small number of workers.

30 BULLETIN 301

Except for depth, little precise ecological data have been
recorded for most species. The majority of Recent specimens have
been obtained from shallow water — sometimes from tidal pools—
though Penetrantia and Immergentia have been collected from

depths of over 400 m (Soule and Soule, 1969b, p. 795).

INTERPRETATION AND TAXONOMY OF
BRYOZOAN BORINGS

GENERAL CONSIDERATIONS

The growth of shell-penetrating Bryozoa is necessarily accom-
panied by a contemporaneous removal of specific portions of the
confining substratum. As correctly reported by Silén (1947, p. 8),
excavations produced during the astogeny of Penetrantia duplicate
the external form of the colony with striking fidelity.

The entire zoarium is immersed in the shell in a system of canals and
hollows with smooth walls exactly representing the shape of the stolos
[sic] and zooids.
Although this statement refers directly to a single genus, SEM study
of polyester-resin casts reveals that it is apparently applicable to all
other boring genera as well. The extent to which this assumption is
true is of the utmost importance, for upon this premise rests the
validity of all taxonomic efforts based purely on bryozoan borings.

Of course, all phylogenetically based classification derives from
the recognition of anatomical features presumed to be homologous
in the several organisms conjoined within a given taxon. In taxo-
nomic procedures, careful interpretation is critical, for evolutionary
convergence sometimes produces remarkably similar features in
genetically disparate groups. Recognition of such features depends
on both the failure of convergence to occur with the utmost pre-
cision, and on the dissimilarity of the majority of corresponding
characters in two or more organisms.

Except by means of high-resolution zone electrophoresis of tis-
sues, genetic continuity can be firmly established only by empirically
observing individual organisms from generation to generation. All
indirect and ex post facto judgements in this matter are necessarily
based on the study and interpretation of available phenotypic traits,
and are, therefore, to some degree subjective. Obviously, subjectivity

Borinc CTENOSTOMATE BryozoA: PoHowsky oa

is increased when some phenotypic characters are not preserved, as
unfortunately in bryozoan borings. Nevertheless, many of the fea-
tures evident in these remains are useful in constructing classifica-
tions, and in making concomitant inferences regarding evolutionary
lineages. Some of the structures seen in borings may even have
greater validity as taxobases than do a few aspects of the soft-part
anatomy.2 The taxonomist must consider all available data; much
helpful information is obtainable from the fossil record. In the present
study, paleontological evidence is cited in support of the alignment
of Penetrantia Silén with the Ctenostomata. Soule and Soule (1969b,
p. 801) recently placed this genus with the cheilostomes.

GLOSSARY

Strictly speaking, the extensive vocabulary applied to the ana-
tomy of “typical” bryozoan colonies cannot be employed in a discus-
sion of specimens which, except for one Recent species (Penetrantia
densa Silén), retain no material traces of the organism. Nevertheless,
bryozoan borings reveal a number of features which are readily
attributed to particular soft parts of the species involved. Because
the introduction of special, new terms for what are simply molds
or casts of these tissues seems needless and undesirable, some
established bryozoan terminology will be used. As long as it 1s recog-
nized that these terms here refer indirectly to once-living features
inferred to have been present at a particular position in an ap-
parent bryozoan boring, there seems to be no viable reason for
coining special terms or repeatedly speaking of the “cavity of a
zooid’”’’, Vertebrate paleontologists freely discuss features revealed in
the tracks of quadrupeds, and the use of established morphologic
terms in describing molds of numerous invertebrate fossils is ac-
cepted as a matter of course.

2Jebram (1970, pp. 12-17 (Inaugural Dissertation, Kiel, and in press)
experimentally raised colonies of ctenostomes [Bowerbankia gracilis Leidy and
Farella repens (Farre)]| and concluded that both the quality and quantity of
nutrition can be influential in determining the number of tentacles per polypide
and the ability of a colony to attain sexual maturity. Nutritional factors also
appeared to influence the size of zooids and the density of their distribution
along the stolons. Although it seems likely that natural conditions are more
variable and complex than those produced in the laboratory, such experimental
studies may prove important in the selection of reliable taxobases.

3Reference to “loges d’autozoécies” by Bobin and Prenant (1954) was ap-
propriate because these authors were mainly concerned with the tissues filling
the cavities.

32 BULLETIN 301

Apart from this conceptual difference in application, the only
substantial deviation from conventional terminology occurs in con-
nection with stolons. As already indicated, the true stolons of Recent
species of Ctenostomata consist of elongated kenozooids separated
from one another and “normal” zooids by septulae — internal fea-
tures whose presumed former presence I have only once detected in
a boring itself (Penetrantia densa Silén, Pl. 12, fig. 2). According to
Silén (1947, p. 43), those elongated processes connecting the distal
ends of zooids in Immergentia are not to be regarded as true (keno-
zooidal) stolons because they are not separated from their respective
zooids by septulae. We may infer that this was also the condition
in fossils of this genus, but direct evidence of the nature of these
tubular processes in the borings themselves will probably remain
undetected. Because of their outward resemblance and apparent
functional analogy to true stolons, all narrow, attenuated connecting
tubes in borings of /mmergentia are herein termed stolons also.

Several terms new to the Bryozoa must be introduced for cer-
tain features which lack well-established homologues in non-boring
members of the phylum. The following terminology is useful in a
discussion of bryozoan borings and is employed in describing the
organisms considered in this work. Some of the more important
features described are illustrated in Text-fig. 3.

A. TERMS RELATING TO STRUCTURES

A dventitious stolons— stolons which arise sporadically at various positions in
a colony and which serve merely to connect various parts thereof. Adventi-
tious stolons lack autozooids and heterozooids. (Cf. principal stolons.)
The term is applicable to many taxa, but lacks meaning in Casteropora, and
in those species of Penetrantia and Spathipora wherein regularity of the
budding pattern of stolons is usually not evident.

Ancestrula— the initial zooid in a colony, from which, ultimately, all other parts
of the colony are derived.

A perture— an opening at the surface of the substratum, representing the junc-
tion of a zooid with the surface in life, but not including openings of
tubulets, vanes, or associated stolons. In nearly all cases, the aperture is
restricted to the region of the orifice, through which the polypide extruded,
or through which larvae were released. An aperture always occurs at or
near the distal end of a zooid.

Ascus— hydrostatic organ in some cheilostomes.

A stogeny— life history (ontogeny) of a colony (asty).

Autozooid— a zooid which had a fully operational polypide, and whose chief
distinction is its former function as a module for feeding. Autozooids are
invariably the most numerous kind of zooid in a mature colony.

Budding pattern— the geometric and sequential relationship existing among the
stolons and zooids in a colony.

Cardelle— denticle for hingement of the operculum in cheilostomes.

Borinc CTENOSTOMATE Bryozoa: PoHOWSKY 33

Enantiomorphic— adjective applied to zooids and colonies occurring as mirror-
image twins (i.e., with dextral and sinistral forms).

Frontal pore— a small opening in the frontal surface of a stolon (s./.) or zooid,
through which communication with the surface of the substratum Was
achieved — presumably by means of a cellular communication device
(septula) during life. (Cf. tubulet.)

Gonozooid— a heterozooid specialized for reproduction and recognizable as
such by its possession of an ovicell (q.v.).

Heterozooid— a zooid adapted for some specialized function(s) other than
feeding, and in which the polypide was presumably vestigial or absent.
With regard to soft parts, this obviously includes the kenozooids known
to occur within stolons in Recent species. In this study however, kenozooids
are considered distinct from “zooids” (s.s.) (g.v.).

Lateral stolon— a principal stolon or adventitious stolon budded laterally from
a zooid or stolon.

Lyrula— median, commonly anvil-shaped tooth on proximal edge of orifice,
located below the mucro, commen in some cheilostomes.

Ovicell— a bulbous chamber on a gonozooid, used for brooding larvae prior
to their release through the aperture.

Peduncle— a short stem connecting an autozooid or heterozooid to a principal
stolon (q.v.).

Parent stolon— the stolon from which a zooid or stolon arose.

Poster— part of operculum in cheilostomes on proximal side of cardelles, serving
for closure of part of orifice opening into ascus.

Principal stolon— (Herein usually termed “stolon” for brevity): a thin, hori-
zontally trending process which generally remains close to the substratum’s
surface and shows, in most species, a pronounced tendency to arise at a
particular position in a colony, relative to the autozooids. In Casteropora,
Penetrantia and Spathipora, stolons arise from other stolons with little or
no discernible regularity, but the production of zooids distinguishes these
processes from adventitious stolons. Because they frequently fuse with other
parts of a colony, principal stolons may duplicate the function of adventi-
tious stolons in this respect.

Reversed zooid— a zooid which is morphologically normal, but whose distal
end is directed proximally along the associated stolon.

Rimule— fissure or small cleft at proximal edge of orifice in some cheilostomes,
serving as opening to the ascus.

Sac zooid— a heterozooid which resembles a sack hanging basally from a
principal stolon, or (as in Spathipora) from a peduncle arising from a
principal stolon.

Stolon— (s.s.): Herein, an abbreviated term for “principal stolon,” (q.v.).

(s.l.): A thin, tubular process extending from a zooid or another stolon,
and serving (actually or potentially) to give rise to either or both addi-
tional stolons and zooids, or else simply to connect various parts of the
colony.

Taxobase— a parameter useful in organic classification.

Tubulet— a swelling or tubular process extending frontally from any part of
a boring bryozoan and terminating at an opening in the surface of the
substratum. Most (or all) stolons and zooid vanes may have communicated
with the surface by means of small openings (frontal pores, g.v.) in the
body wall, but the term, tubulet, is applicable only when there is some
evidence of a frontal process or pronounced swelling. In life, tubulets
presumably contained cellular communication devices (septulae).

Vane— a thin, planar extension of a zooid, commonly joining the zooid with
a stolon or the surface of the substratum, and often giving rise to tubulets.

Zooid— broadly speaking, an individual in a bryozoan colony, partitioned in
life from adjoining zooids by minute communication organs (septulae in
Ctenostomata). In most Recent genera, elongated and highly atrophied
zooids (kenozooids) compose most of the stolonate portion of the colony.

34 BULLETIN 301

However, reference to “zooids’ in fossils considered herein is made in
contradistinction to “stolons” (qg.v.). and their kenozooidal components in-
ferred to have been present in most groups during life.

B. TERMS RELATING TO DIRECTION

Basal— opposite of frontal (g.v.).
Distal— (1) re zooids: toward the apertural end.
(2) re path of stolons and sides of pedunculate zooids: in the direction
of stolonal growth.
(3) re sides of stolons: the side of a stolon facing away from its parent
stolon.
Frontal— toward the surface of the substratum. (Not used in reference to zooids
which are essentially vertical in orientation.)
Horizontal— parallel to the surface of the substratum in the area under con-
sideration.
Lateral— approximately horizontal, and more or less perpendicular to the distal
direction of a stolon or zooid.
Proximal— opposite of distal (g.v.).
V ertical— perpendicular to the surface of the substratum.

It should be noted that the peduncle, tubulets, and various
types of stolons discussed in this study have received different
names in publications by Marcus (1938), Silén (1947), Soule
(1950a, b, 1953, 1954, 1963), Bobin and Prenant (1954), and Voigt
and Soule (1973). Partly because of their derivation at different
stages in my understanding of the bryozoans involved, precise com-
parison of some of these terms is difficult. The explanation of
terminology presented by Bobin and Prenant (1954, p. 132) is help-
ful, though it must be remembered that mention of Terebripora pre-
sumably includes reference to Spathipora comma (Soule) as well
as some of those specimens described by Marcus which are referable
to Terebripora. Also, the anastomosing stolons of Bobin and Prenant
— defined to be devoid of autozooids — probably bore sac zooids
in some of Marcus’s specimens of Terebripora. Anastomosing stolons
are, therefore, not fully equivalent to adventitious stolons as de-
fined herein.

The following explanation is offered to assist in the comparison
of terminology. Terms used in the present work are italicized.

Principal stolons are basically equivalent to:
primary and secondary stolons (Marcus)
primary stolons (Silén)

(some) primary stolons (Soule)
principal stolons (Bobin and Prenant)
main stolons, major stolons (Voigt and Soule)

Adventitious stolons are basically equivalent to:
connecting and supplementary stolons (Marcus)
secondary stolons (Silén)

(some) primary stolons (Soule)

anastomosing stolons (Bobin and Prenant)
some (main stolons = major stolons) (Voigt and Soule)

e

Borinc CTENOSTOMATE Bryozoa: PoHowsky 35

Peduncle is equivalent to:
tertiary stolon (Marcus)
secondary stolon (Soule; Voigt and Soule)
connecting stolon (Bobin and Prenant)
attachment stolon (Voigt and Soule)
Tubulets (on stolons) are equivalent to:
frontal processes (Silén; Bobin and Prenant)
accessory stolons, tubules (Voigt and Soule)
Tubulets (on autozooids) are equivalent to:
pseudostolons (Soule)

MORPHOLOGY OF BRYOZOAN BORINGS

Most of the features defined in the foregoing glossary are con-
sidered in the descriptions, discussions or plate explanations pre-
sented in connection with the various taxa within which they occur.
However, a general discussion of the principal characters revealed in
bryozoan borings is presented below by way of introduction, and in
an effort to summarize inferences made here regarding the soft-part
anatomy and biological processes in the organisms these traces
represent.

Several distinct families possess pedunculate autozooids (Text-
ficed eB Plo tig. 4; Pl Siig, 7Pl 12 tie. 2; Pl 1; tis. 7), but
present knowledge of the evolution of these taxa is insufficient to
suggest they constitute a monophyletic group. Species with non-ped-
unculate zooids (Text-fig. 3 C, D; Pl. 1, fig. 7; Pl. 3, fig. 1; Pl. 4, fig.
1; Pl. 7, fig. 6; Pl. 20, fig. 4; Pl. 23, fig. 5) may also be polyphyletic.
Although zooids in non-pedunculate groups are invariably directed
horizontally along the stolon, those in pedunculate taxa may lie at
different angles which are of taxonomic significance at both generic
(compare Pl. 8; Pl. 16) and specific levels (compare PI. 15, fig. 7;
Pl. 16, fig. 2).

The shape of the aperture, and its location relative to the princi-
pal stolon are sometimes of value in classification, but because the
aperture is necessarily located at the surface of the substratum, its
outline is easily obscured by abrasion and solution. This is particu-
larly true in some non-pedunculate groups (¢.g., Terebripora
d’Orbigny), wherein collapse of the thin shell layers overlying the
horizontal autozooids commonly produces a cleft of varying length.
The apertural notches reported by Fischer (1866, p. 297, Pl. 11,
figs. 1, la, 3, 3a), Rovereto (1901, p. 221, text-fig. 1), and Voigt
(1962, p. 61), are probably all of non-biological origin.

36 BuLLteETIN 301

Marcus correctly interpreted this cleft in Terebripora and also
noted the significant proximal-lateral sinus in the aperture of this
genus [Marcus, 1938, p. 283, text-fig. 2C (Text-fig. 1E herein)].
This feature is especially prominent in the fossil specimen of T.
ramosa d’Orbigny shown in Plate 19, figure 4. The soft parts asso-
ciated with this sinus have not been described, but Marcus (1938,
p- 283) briefly mentioned a small sac (“saquinho”) in his discussion
of the borings of Terebripora. It seems possible that this small open-
ing may serve a function analogous to that of the poster in the aper-
ture of some cheilostomes, 7.¢., the sinus may provide for the passage
of water into a space surrounding part of the body wall of the zooid,
to permit the extrusion of the lophophore. Other boring genera ap-
parently accomplish this vital process without the aid of a sinus.
Silén’s indication that zooids of Penetrantia are attached to the
boring only at the proximal and distal ends (1947, p. 8) suggests
that most of the periphery might serve as a chamber of hydrostatic
compensation in this genus. The possible functional analogy of this
space to the ascus of some cheilostomes is evident.

In many species of Penetrantia, the aperture appears to be
countersunk — i.¢c., as though its edges had been chamfered. Soule
and Soule (1969a, pp. 6, 7, text-fig. 4) reported this condition in
P. operculata (Recent), and it is present in some fossil species as
well (PI. 10, figs. 1, 2). This peculiar trait may be related to the oc-
currence of an operculum in all species of Penetrantia in which the
soft parts have been examined. As noted previously P. densa
(Recent) commonly secretes calcium carbonate around the aper-
ture. It may also be unique in its ability to reinforce the operculum
with calcium carbonate — presumably to affect the closure of zooids
during regeneration. The operculum of Penetrantia has never been
observed in fossil specimens, but some small “papillae” evident on
a developing zooid from the Upper Cretaceous (PI. 9, fig. 6) may
represent the sites of origin of some opercular (occlusor) muscles.

Except for kenozooids, strongly specialized zooids (hetero-
zooids) were long regarded to be lacking in the Ctenostomata
(Borg, 1926, p. 485). In 1946, Silén’s revelation of gonozooids in
Penetrantia appeared to contradict this opinion, but Soule and Soule
(1969b, pp. 800, 801) recently cited the ovicells of this genus as an
argument for aligning Penetrantia with the Cheilostomata. In the

Borinc CTENOSTOMATE Bryozoa: PoHOowskKy 37

present work however, the discovery of gonozooids in Spathipora
cheethami (PI. 15, figs. 1-3), from the Middle Jurassic (Cornbrash )
of England stands as a strong indication that ovicells occasionally
develop in the ctenostomes. The occurrence of S. cheethami ante-
cedes the appearance of the earliest reported cheilostome (Pyri-
poropsis portlandensis Pohowsky, 1973) by approximately 20 m.y.
Ovicells may also be present in S. elegans Fischer (PI. 15, fig. 4), a
Recent species eminently worthy of additional study.

Yet another kind of heterozooid was recognized in the cteno-
stomes by Bobin and Prenant (1954). These authors reported the
occurrence of sac zooids (“cénozoécies 4 sphérules”) in Spathipora
comma (Soule) and noted that these globular bodies were filled
with “granulations réfringentes” (Text-fig. 2C) resembling those
present in Hypophorella expansa Ehlers and Valkeria uva L. (Bobin
and Prenant, 1954, p. 140). Features here regarded to be sac zooids
are also discernible in Ropalonaria venosa Ulrich (Pl. 1), R.?
arachne (Fischer) (Pls. 2, 3), Orbignyopora? capillaris (Fischer)
(Pl. 4, fig. 3), Terebripora d’Orbigny (Pl. 19, fig. 1; Pl. 20, fig. 2;
Pl. 21, fig. 6), in at least some species of Spathipora [e.g., S. brevi-
cauda (PI. 16, fig. 2) and in S. longirima Canu and Bassler (Pl. 16,
fig. 5)]. The assertion by Bobin and Prenant that sac zooids are
homologous with autozooids is supported by observations made in
fossil material — notably by their occasional occurrence in place of
the autozooid which is usually produced at the proximal end of the
ancestrula in Ropalonaria venosa Ulrich (PI. 1, fig. 4). The presence
of sac zooids in fossil bryozoans is interesting, but the significance of
their occurrence is not clear. It is uncertain whether these zooids
developed once or repeatedly during ctenostome evolution, and the
function of the granules found in some of these bodies is unknown.

The stolons of boring bryozoans are generally used in asexual
proliferation of the colony — i.e., for the production of additional
autozooids or heterozooids. In most genera, such stolons (principal
stolons, Text-fig. 3 A-D) show a strong tendency to arise regularly
at specific locations relative to the autozooids. In these taxa, it is
often possible to distinguish another type of stolon (adventitious
stolons) which may arise at a variety of locations and apparently
never bear zooids (Text-fig. 3 C, D; Pl. 2, fig. 4; Pl. 21, fig. 3; PI.
23, fig. 9). It seems probable that these processes serve only to

38 BuLteTIN 301

transport metabolic products, but in some species they might also
give rise to zooids. In life, septulae lie at the ends of the kenozooids
forming the stolons of most genera, and evidence of these features
can be seen in the peduncles of Penetrantia densa (PI. 12, fig. 2).

The stolons of most boring bryozoans appear to be more or less
terete, but Silén (1946, pp. 2, 4) noted that those of Penetrantia
densa and P. brevis are flattened laterally. This is also evident in
some stolons of Haimeina michelini (Terquem). As a rule, stolons
are about 0.01-0.02 mm in diameter, but those in a few species
(e.g., Voigtella regalis, n. gen, n. sp.) seem to be exceptionally thin.

In some genera (e.g., Penetrantia, Text-fig. 3A), stolons often
bear numerous processes (tubulets) which extend to the surface of
the substratum. In species lacking these processes, the stolons are
invariably located close to the surface, and it may be seen or in-
ferred that communication with the exterior was achieved by means
of frontal pores (Text-fig. 3B).

The occurrence of tubulets is not restricted to stolons; they
are commonly associated with autozooids as well (PI. 4, fig. 2; Pl. 5,
figs 4; Pl. 7, fig. 3; Pl. 16, fig. 6; Pl. 17, fig: 8; Pl. 19, fig.4): In non-
pedunculate genera, autozooidal tubulets are laterally disposed. In
both pedunculate and non-pedunculate taxa, they often arise from
a narrow vane associated with the zooid (Pl. 20, fig. 4; Text-fig.
2D). Vanes and tubulets apparently assist the zooid in maintaining
communication with the environment. Inasmuch as these features
appear to form at an early stage in the development of autozooids
(Pl. 19, fig. 2), it seems possible that they initially play a role in
the disposal of calcium carbonate. Marcus (1938) and Silén (1947)
have ascribed this function to the tubulets present on stolons.

It is obvious that a host of taxonomically useful structures can
be discerned in the borings of bryozoans. However, in addition to
these “static” features, it is also possible to interpret a “dynamic”
aspect of these remains. Whereas the traits discussed above are per-
haps of concern only to the bryozoologist, some of the phenomena
mentioned below may be of broader interest.

By comparing colonies in various stages of development, it is
possible to obtain a general (though somewhat artificial) view of
astogeny within a particular species. This kind of reconstruction of
early astogeny is illustrated in Plates 13, 17, 18, 23. In numerous

Borinc CTENOSTOMATE Bryozoa: PoHowsky 39

other cases, the progressive stages in the growth of a colony may be
interpreted from the study of a single specimen (e.g., Text-fig. 4A;
Piel ties 2s le. tie, 2° PO: fie. 3. Pl. 8, fie. 1))..'Colontes of
Voigtella regalis, n. sp. (Pl. 6, fig. 3) and Haimeina michelin (Ter-
quem) (PI. 8, fig. 1) undergo a marked change in the budding pat-
tern at different stages of astogeny. Although these visible changes
occur more abruptly than do variations in the architecture of zooids
within the zones of astogenetic change recognized in other bryozoans
(Boardman, Cheetham, and Cook, 1969), it seems likely that all such
processes are directed by fundamentally similar systems of axial,
physiological gradients. In Voigtella regalis (Text-fig. 4A; Pl. 6,
fie. 3), two different patterns of budding appear to alternate re-
peatedly, just as zones of astogenetic change alternate with zones
of astogenetic repetition in the cheilostomes.

Just as one observes the astogeny of a species one can study
zooid ontogeny (PI. 8, fig. 6; Pl. 20, fig. 3; Pl. 9, fig. 1; PI. 12, fig. 2).
The striking similarity of the developmental sequences shown in
Plate 9, figure 1 and Plate 12, figure 2, is important evidence of the
probable relationship of Haimeina michelim (Terquem) and Pene-
trantia densa Silén.

Abnormalities of growth and development are of special inter-
est in all phyla, for they often contribute to a greater understanding
of the fundamental processes underlying morphogenesis. The pe-
culiar, looped path of a stolon in Plate 21, figures 1, 2, is of con-
siderable importance in interpreting the nature of the basic en-
vironmental factors which obviously influenced its growth. While it
might be asserted that the stolon’s growth was determined simply
by tactile factors in the initial part of the loop, other reasons must
be invoked to account for its direct return to the surface in a “free”
arch. Directives conceivably responsible for this behavior may be
phototropic, geotropic, or both.

In considering how boring bryozoans retain their position at the
shell surface, it must be recognized that borings can occur in all
orientations in the shells of living gastropods. We must consider the
reports of specimens from water depths well below the photic zone
—e.g., Penetrantia concharuwm from 300 m (Silén, 1946, p. 5).

The occurrence of enantiomorphic zooids and colonies in some
boring bryozoans is of great interest, for dextral and sinistral in-

40 BULLETIN 301

dividuals are more widely known among non-colonial organisms —
notably the gastropods. Cheetham (1968, 1973) already focused
attention on enantiomorphism in cheilostomes by using “zooecial
asymmetry” to interpret evolution in poricellariids. Even humans are
subject to “mirror imagery,” though the medical condition of situs
imversus viscera is extremely rare (Gardner, 1964, p. 83). An under-
standing of this phenomenon in bryozoans may prove valuable in
the interpretation of paleo-environments. The temperature depend-
ence of the dextral/sinistral coiling ratio in Globigerina pachyderma
(Ehrenberg) is widely known from the publications of Bandy (e.g.,
1960).

In his analysis of the cause of inverse symmetry, Conklin
(1903, p. 584) noted that “. . . one gets a mirrored image of the
structures at the animal pole if he views them from the vegetative
pole through the transparent egg.” He then concluded that overall
reversals in the symmetry of animals is caused by a reversal in the
polarity of the egg. While dextral and sinistral zooids in Cooko-
bryozoon (Pl. 13), Terebripora (Pls. 19-21), and Immergentia (PI.
22, fig. 6; Pl. 24, figs. 1, 5) obviously do not form directly from
an egg, it appears that these features originate at the simplest levels
of cellular differentiation and organization. They do not merely
arise in later stages of development by a fortuitous occurrence of
the zooid on one of the two sides of a stolon. Zooids in Immergentta,
for example, develop as a basal-medial expansion of an ostensibly
symmetrical stolon, and in many species there is no appreciable
shift of the enantiomorphic zooid aperture toward either side of the
stolon during any stage of ontogeny. In a few genera, entire colonies
seem to be enantiomorphic (Pls. 13, 18). A few workers have noted
the propensity of some gymnolaemates to produce initial lateral
buds on only the right or left side of the ancestrula (Cummings,
1904, p. 58; Waters, 1924, pp. 594, 595), and additional study on
this phenomenon may be revealing.

For reasons not apparent, Ropalonaria arachne (Fischer) oc-
casionally formed zooids with an extra aperture (PI. 3, figs. 2, 3).
Such zooids presumably contained two polypides which functioned
normally, and it is possible that such peculiarities may have arisen
by events similar to those which produce Siamese twins in verte-
brates. Other types of zooids with double polypides have been re-

Borinc CrENOSTOMATE Bryozoa: PoHowsky 41

ported by Waters (1913, p. 488; 1924, p. 598), and Oda and Naka-
mura (1973). The occurrence of reversed zooids in Terebripora
falunica Fischer (PI. 21, figs. 1,6) may be due to the early degenera-
tion of a normally orientated Siamese twin (compare PI. 3, figs. 2,
3), but it was more likely to have been caused by a local reversal of
the physiological gradients during a critical stage of zooid develop-
ment. The importance of physiological polarity in morphogenesis
has been revealed by the classic work of Child and others (Child,
1923). Curiously, zooid reversal (along with patterned zooidal
enantiomorphism) occurs regularly in Cookobryozoon lagaaiji (PI.
13; Pl. 14, figs. 1-3). Zooid reversals are occasionally seen in Tere-
bripora d’Orbigny as well (PI. 21, fig. 1).

On the basis of a cursory study of a small number of tera-
tological zooids, it appears that some developmental abnormalities
may occur more commonly in the older, more complexly intergrown
portions of a colony. Their frequency bears a positive relationship
to the number of stolonal fusions, and it seems reasonable to postu-
late that these fusions occasionally produce teratologies by dis-
rupting the normal complex of morphogenetic gradients or by pro-
viding these gradients alternative pathways to act upon (e.g., PI. 3,
fig. 4; also note the chaotic budding produced by the fusion of two
colonies shown in PI. 20, fig. 5). It is apparent that fusion alone is
insufficient to guarantee a developmental abnormality. The locus
and timing of fusion are undoubtedly critical factors; if this were
not so, teratological zooids would occur in greater numbers than
were observed.

In interpreting the structural components and life processes
represented in a presumed bryozoan boring, one must initially
establish that the specimen was produced by a bryozoan. Although
there are some misidentifications in the literature there is little likeli-
hood that an investigator who has carefully examined true bryozoan
borings would subsequently confuse these fossils with borings of
another origin. Even when preservation is imperfect, the cavities
produced by sponges, algae, fungi, cirripeds, polychaetes, and mol-
lusks differ significantly in size, shape or overall configuration from
those made by Bryozoa. Readers interested in comparing descrip-
tions and illustrations of these and other boring organisms should
consult Carriker, Smith, and Wilce (1969, pp. 629-1020).

42 BULLETIN 301

The only organisms which might be confused with the shell-
penetrating Bryozoa by virtue of their colonial anatomy, similar size,
and roughly comparable external form, are the hydroids — but at
present there is no evidence that any hydroids truly bore. How-
ever, it is interesting to note that an apparent hydroid, Protulophila
Rovereto, 1901, does become embedded in its calcareous substratum.
As discussed by Scrutton (1973), Protulophila grew on the tubes of
serpulid polychaetes in a manner such that the youngest polyps sur-
rounded the opening of the tube and benefited from the currents
created by the feeding annelid. In turn, the polychaete may have
been protected from predators by the stinging nematocysts of the
hydroid. The symbiotic relationship was apparently analogous to
that involving sabellid polychaetes and the Recent hydroid, Pro-
boscidactyla. In contrast to Proboscidactyla, in which only the
hydrorhiza is buried in the detritus of agglutinated tubes, Protu-
lophila became fully “immersed” with calcareous tubes, retaining
only small openings at the surface through which the polyps ex-
tended to feed. Scrutton (1973) demonstrated that Protulophila
was truly embedded and did not bore into the tube subsequent to its
formation. Rather, the hydroid was progressively enveloped within
the external layers of the wall as they were being deposited by the
polychaete.

Such symbiotic, embedded hydroids are known from the Juras-
sic through the Neogene. One of the oldest reported occurrences of
these remarkable fossils is “Immergentia?” lissajoust Walter, 1965,
from the Upper Jurassic (Oxfordian) of France. Walter’s expressed
doubt in assigning his species to Immergentia Silén was certainly
justified.

SYSTEMATIC PALEONTOLOGY

The following, descriptive section has been abbreviated con-
siderably by omitting repeated mention of features shared by all,
or nearly all species. In all groups having the zooids arranged hori-
zontally or vertically along the path of the stolon (7.e., in all non-
pedunculate genera), it is convenient to speak of the zooids as
“alternating” with the stolons, even though studies on Recent speci-
mens of Jmmergentia indicate that the zooids in at least some fossil
borings may merely be expanded portions of the processes termed
“stolons.” In any case, the zooids in such genera “alternate” with

Borinc CTENOSTOMATE Bryozoa: PoHowsky 43

stolons in that they are always separated by these processes, rather
than being budded directly from one another. Repeated mention
of this attribute common to all non-pedunculate species will, there-
fore, be omitted from the systematic descriptions. Pedunculate genera
(e.g., Penetrantia Silén, Spathipora Fischer) do not present this
same appearance of zooid-stolon alternation, though zooids in these
forms are obviously separated by a principal stolon even when they
bud directly opposite one another. Examination of the soft parts
of Penetrantia and Spathipora comma (Soule) by zoologists (Silén,
1947, p. 7; Soule, 1950b, p. 380) indicates that zooids in fossils of
pedunculate genera were probably separated by one or more dis-
crete kenozooids.

In both pedunculate and non-pedunculate groups, laterally-
budded stolons show tendency to form an angle of 30 to 70 degrees
with the distal extension of the parent stolon (PI. 1, fig. 2; Pl. 3, fig.
1; Pl. 11, fig. 6; Pl. 13, fig. 1). These lateral stolons commonly curve
distally (with regard to the parent stolon) in a gentle arc. In some
colonies, however, lateral stolons may lie at right angles to the
stolon, or even in a reflexed orientation. Some gentle, erratic curva-
ture commonly occurs, but the general direction of growth appears
to be independent of variations in the microstructure of the substra-
tum (PI. 18, figs. 1-6).

Minute fluctuations in delicate physiological processes within
the tip of the stolon are probably responsible for minor irregularities
in the direction of growth. Despite such imperfections, many species
tend to form colonies with a typical pattern, just as many trees tend
to produce branches in a manner that is related to taxonomic divi-
sions based on other characters. Differences in the general aspect
of large colonies are imposed chiefly by the various budding pat-
terns, and are of such complexity that an illustration is invariably
substituted for an involved description. It must be remembered,
however, that the density of zooids and stolons (particularly in
pedunculate groups) is probably a function of the environment and
age of the colony in most cases.

Mention of the ability of stolons to fuse with various parts of
zooids and other stolons is also deleted. The phenomenon of fusion
is ubiquitous among boring Bryozoa and occurs with increasing
frequency in larger colonies.

44 BULLETIN 301

One additional concept warrants explanation. In descriptions of
a number of non-pedunculate species it is repeatedly stated that the
“zooids produce stolons” when, in fact, an analysis of astogeny
reveals that the stolons are apparently well developed before the
zooid has even begun to form. This is certainly true in the sense that
the zooid has not yet expanded, but it seems likely that the long,
barren stolons extending outward to the distal limits of a colony are
subdivided by septulae as they form. Those laterally budded stolons
would then arise from immature, incipient autozooids.

The selection of taxobases to be employed in this study was
accomplished by studying those preservable features considered
taxonomically useful by zoologists, and then thoroughly surveying
the variety of characters evident in numerous fossil specimens. The
following structures are useful for the classification of bryozoan
borings:

1. Ancestrulae and autozooids: size, shape, and orientation
relative to the associated principal stolon(s).

2. Heterozooids: presence or absence, relation to principal stolon,
location in budding pattern.

3. Budding pattern of stolons from ancestrula and in subsequent
astogeny.

4. Tubulets and adventitious stolons: presence or absence, loca-
tion, abundance.

Except that the variability of features in the fourth group is
usually high within a given colony, the order of listing is otherwise
not intended to indicate the relative reliability or weighting of
characters. Other taxonomically useful structures occur in a few
groups and are noted in the descriptions of those species involved.
For the most part, slight variations in the spacing of autozooids —
considered genetically significant in some earlier paleontological
works — are here generally regarded to be dependent on age and
environmental influences. Neviani (1902, p. 42) correctly observed
that the spacing of autozooids tends to be variable within a colony.

The classification proposed here is not final. It contains a num-
ber of taxonomic assignments which are possibly incorrect, but which
are nevertheless proposed to emphasize some important morphologi-
cal similarities; alternative possibilities for classification may be sug-
gested.

Bor1nc CTENOsSTOMATE Bryozoa: PoHowskKy 45

To illustrate the incompleteness of this study, particular atten-
tion may be called to three genera that largely or entirely comprise
species exhibiting similar zooidal anatomy and budding pattern. It
is possible that most of the species assigned to Orbignyopora, n. gen.
and Spathipora Fischer will be placed in new genera when their
ancestrulae and early astogeny are compared with those of the re-
spective type species. Similarly, a new genus may have to be de-
fined for the Mesozoic species here assigned to Ropalonaria Ulrich.

The nature of the ancestrula and early astogeny is undoubtedly
a critical generic taxobasis for all shell-penetrating Bryozoa, so it is
pertinent to ask how one may assign a specimen to a genus when
this character has not been observed. In this study, such assignments
are necessarily based upon similarities in other important features,
and it is readily acknowledged that some tentative groupings are
probably polyphyletic assemblages of two or more lineages with
somewhat homeomorphic autozooids and stolonal branching. The
degree of certainty in taxonomic assignment is influenced by the
relative age of the specimens involved, and the likelihood that there
has been evolutionary convergence among them. These considera-
tions are familiar to anyone who attempts to compare fossils: none
are complete records of the once-living organism.

This study has many taxonomic shortcomings, but the classi-
fication proposed here is intended as an improvement upon class-
ifications by foregoing authors — particularly in the removal of
numerous unrelated species from Ropalonaria Ulrich and Terebripora
d@Orbigny. A major objective of this study is the recognition that
bryozoan borings have greater taxonomic and paleobiological value
than has generally been perceived.

The parameter Lz, measured for many species, is defined as the
length of the zooid. The number in parentheses following Lz indicates
the number of specimens measured.

46 ButteTin 301

Phylum BRYOZOA Ehrenberg, 1831
Class GYMNOLAEMATA Allman, 1856

Order CTENOSTOMATA Busk, 1852

Family ROPALONARIIDAE Nickles and Bassler, 1900

Diagnosis. — Non-pedunculate boring Bryozoa with bilaterally
symmetrical autozooids lying horizontally along stolon throughout
their entire length. Aperture disposed medially along stolon. Lateral
stolons arise opposite one another at or slightly distal to aperture.
Ancestrula produce stolons proximally, distally, and bilaterally op-
posite one another at or slightly distal to aperture.

Range. — U. Ord., ?U. Jur., ?L. Cret.

Genus ROPALONARIA Ulrich, 1879

1866. ?Partim Terebripora d’Orbigny, Fischer, Mus. nat. Hist. nat. (Paris),
Nouv. Arch., T. 2, p. 303. (Non Terebripora d’Orbigny, 1847, Voyage
dans l’Amérique méridionale, T. 5, pt. 4, pp. 22, 23, pl. 10, figs. 16, 17.)

1879. Ropalonaria Ulrich, Cincinnati Soc. Nat. Hist., Jour., vol. 2, pp. 26, 27,
pl. 7, figs. 24, 24a.

1884. Non Rhopalonaria’ Ulrich, Vine, Ann. Mag. Nat. Hist., ser. 5, vol. 14,
pp. 84-86, text-fig. IV 3-5.

1886. Non Ropalonaria Ulrich, Ulrich, Geol. Nat. Hist. Sur. Minnesota, 14th
ANN Rpt pao:

1904. Non Rhopalonaria Ulrich, Ulrich and Bassler, Smithsonian Mise. Coll.
(Quart. Issue), vol. 45, pp. 266, 268, 269-272, pl. 66, figs. 4-11; text-figs.
32, 53%

1914. Non Rhopalonaria Ulrich, Dienst, Kénig. Preuss. Geol. Land., Berlin,
Jahrb., Bd. 34, pp. 599, 600, pl. 18, figs. 16, 17.

1915. Non Rhopalonaria? Ulrich, Girty, U.S. Geol. Sur., Bull., No. 593, p. 38,
ally IBIh, sayea, op

1929. Non Rhopalonaria Ulrich, Bassler, Palaont. von Timor, (Stuttgart), Lief.
16, Rt. 23) p. 40; pl. 235, figs. 1-3:

1944. Non Rhopalonaria Ulrich, Condra and Elias, Geol. Soc. America, Bull.,
Vole 55, pps 5464547 plell tes. ie 2 spl ai2ietiesoe2 58 7s ple sectio nso

1954. Non Rhopalonaria Ulrich. Fritz, Jour. Paleont., vol. 28, pp. 118, 119, text-
Higeele

1965. Non Ropalonaria Ulrich, Kiepura, Acta Pal. Polonica, vol. 10, pp. 21-23,
pl. 1, fig. 3, text-fig. 2.

1970. ?Partim Chaetophorites Pratje, Pugaczewska, Acta Pal. Polonica, vol.
15, pp. 427, 429, 430, pl. 2, fig. 4. (Non Chactophorites Pratje, 1922, Cen-
tralbl. f. Min., pp. 299-301.)

1973. ?Partim Terebripora (?) d’Orbigny, Voigt and Soule, J. D., Jour.
Paleont., vol. 47, pp. 24-26, pl. 2, fig. 1.

Type species. — Ropalonaria venosa Ulrich, 1879; O.D.
Diagnosis. — Bryozoa with the characters of the family, Ropalo-
nariidae Nickles and Bassler.

4Rhopalonaria is a nomen vanum introduced by Vine (1884, p. 84) for
Ropalonaria Ulrich, 1879. Vine’s misspelling occurs in most of the subsequent
publications mentioning the genus.

Borinc CTENOSTOMATE Bryozoa: PoHowsky 47

Range. — U. Ord., ?U. Jur., ?L. Cret. (Aptian).

Discussion. — Ropalonaria is the oldest known genus of boring
bryozoans. It has long served as a repository for practically all bryo-
zoan-like borings occurring in the Paleozoic. In the Paleozoic how-
ever, the genus is at present known only from the occurrences of R.
venosa in a narrow sequence of the bryozoan-rich Upper Ordovician
beds in the vicinity of Cincinnati, Ohio.

Although the Jurassic and Cretaceous bryozoans herein tenta-
tively assigned to Ropalonaria are widely separated from R. venosa
in time, their budding pattern and autozooidal anatomy is funda-
mentally similar to that of the type species. The most obvious dif-
ferences among the species consist of slight shifts in the locus of
lateral branching, the tendency of sac zooids in R. venosa and R.?
arachne to arise at different characteristic positions relative to the
autozooids, and the apparent absence of sac zooids in R.? bugei.
The discovery of related, temporally intervening species will certain-
ly assist in clarifying the relationship of the Mesozoic species to R.
venosa. Discovery of the ancestrula and initial budding pattern in
R.? arachne and R.? buger will also be of help.

“Terebripora (?)” bassleri Voigt and Soule (Aptian) is here
referred to Ropalonaria with reservation. It apparently represents
the youngest existing record of the genus, but it should not be
recognized as a distinctive species until it has been distinguished
morphologically from R.? arachne (Fischer).

Ropalonaria venosa Ulrich, 1879 Pl. 1, figs. 1-7; Text figs. 1A, 6C1

1879. Ropalonaria venosa Ulrich, Cincinnati Soc. Nat. Hist., Jour., vol. 2, pp.
26, 27, pl. 7, figs. 24, 24a.
1946. sarees venosum Ulrich, Fritz, Jour. Paleont., vol. 20, p. 87, (nom.

Material and occurrence. —

Figured: BMNH D.52264 (cast) (SEM STUB 11), U. Ord.
(Richmond Gp., Waynesville Fm., Blanchester Mbr.), base of dam,
Acton Lake, Hueston Woods State Park, near Oxford, Ohio; UCGM
40061, 40062, 40066, 40077, U. Ord. (Richmond Gp., Waynesville
Fm., Blanchester Mbr.), base of dam, Acton Lake, Hueston Woods
State Park, near Oxford, Ohio; USNM 43115 (3 syntypes), U. Ord.
(Richmond Gp., Waynesville Fm.), Clarksville, Ohio.

Not figured: UCGM 40078-40086, U. Ord. (Richmond Gp.,
Waynesville Fm., Blanchester Mbr.), base of dam, Acton Lake,

48 BULLETIN 301

Hueston Woods State Park, near Oxford, Ohio; USNM 43111, U.
Ord. (Richmond Gp., Waynesville Fm.), Oregonia, Ohio; USNM
43112, U. Ord. (Richmond Gp., Waynesville Fm.), Versailles, In-
diana; USNM 43113, U. Ord. (Richmond Gp., Waynesville Fm.),
Waynesville, Ohio; USNM 43114, U. Ord. (Richmond Gp., Waynes-
ville Fm.), Hanover, Indiana.

Type locality and horizon. — Clarksville, Ohio; U. Ord. (Rich-
mond Gp., Waynesville Fm.). Ulrich (1879, p. 27) indicated only
that the type specimens were found in the upper part of the Hudson
River Group (= Cincinnatian Series) at Clarksville, but the label
with USNM 43115 states that the syntypes are from the Waynes-
ville Fm. Ulrich (1893, p. 114) indicated that the holotype had been
mislaid or lost; but no holotype is designated in the literature.

Range. — U. Ord. (Richmondian).

Diagnosis. — Ropalonaria with lateral stolons arising directly at
sides of aperture. Sac zooids occur proximal to any (but not every)
autozooid.

Description. — Autozooids horizontal, bilaterally symmetrical;
disposed medially along stolon throughout their entire length and
consisting of basally and laterally directed expansion thereof. Cross
section oval with major axis vertical; proximal half expanded
basally slightly more than distal half. Proximal end tapers abruptly.
Shape of aperture unknown, but not strongly elongated.

Heterozooids (sac zooids) common, occur proximal to some
autozooids at any position in colony, extend deeper into substra-
tum than autozooids, and never give rise to lateral stolons.

Ancestrula resemble autozooids (in frontal view), but with
stolon produced from proximal end and giving rise to autozooid or
sac zooid; other stolons emanating distally and bilaterally opposite
one another at site of aperture.

Subsequent budding from autozooids occurs as at distal end of
ancestrula.

Tubulets and adventitious stolons unknown.

Measurements. —Lz (10) = 0.20-0.35 mm. (Based on PI. 1,
fies.2 35.5).

Discussion. — Although the bryozoan nature of Ropalonaria
venosa was recognized by Ulrich in 1879, the correct ordinal affinity
of the species was not determined for some time thereafter. Ulrich

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 49

(1879, p. 26) originally placed it within the Cristidae (Cyclosto-
mata), but he also indicated a relationship to Hippothoa (a cheilo-
stome). In 1882 (p. 149) he moved the species to another cyclostome
family, the Tubuliporidae.

In his original publication of R. venosa, Ulrich described the
type specimens as “adnate” and “incrusting,’ and remarked that
“the fronds themselves are rarely found, but instead we find a series
of impressions” (1879, p. 87). The actual “fronds” which he did see
were in reality natural casts standing in slight relief on the weathered
substrata. This misinterpretation prompted Vine (1884) to erect
R. botellus for a problematic calcareous encrustation from the
Silurian (Wenlockian) of England. The misunderstanding was in
full swing, and Ulrich (1886, p. 59) soon erected R. pertenuis for
what is obviously an encrusting, uniserial cyclostome (Stomatopora
proutana Miller). Vine (1887a, p. 183) conveniently removed
Ropalonaria to the Stomatoporidae.

The first definite assignment of Ropalonaria to the Ctenosto-
mata (by Ulrich, 1890, p. 367) came with little explanation, but
Vine (1892, p. 83) quickly acknowledged the justification of the
transfer. He had already suggested the idea (Vine, 1884, p. 87),
though in an ambiguous manner. Nickles and Bassler (1900) gave
further support to Ulrich’s decision and established the family
Ropalonariidae for Ropalonaria alone. Ulrich and Bassler (1904)
and Condra and Elias (1944) also recognized the ctenostomatous
nature of R. venosa, but their assignment of a diverse assortment
of borings to Ropalonaria bespeaks a deficient understanding of the
organisms involved.

Although Ulrich and subsequent workers correctly placed R.
venosa with the ctenostomes, little progress was made toward a cor-
rect interpretation of its anatomy and habitus. Ulrich’s difficulty
stemmed in part from his professed initial unfamiliarity with the
ctenostomes (Ulrich and Bassler, 1904, p. 259). All authors who
have grappled with the problem have evidently overlooked, mis-
understood, or rejected D’Orbigny’s correct interpretation of the
fundamental anatomy and mode of life of Terebripora ramosa
d’Orbigny, 1847 (Pl. 19, figs. 1, 2). The poor preservation of Ul-
rich’s specimens was, in part, a confounding influence. It may well
have been a major factor in his decision to place R. venosa with

50 BuLLETIN 301

the ctenostomes, but it also led him to infer (Ulrich, 1893, p. 114)
that R. venosa was related to the Recent encrusting ctenostome,
Arachnidiwm. This genus lacks hard parts and has little chance of
being fossilized, except by means of the “Einmauerung” or “Immura-
tion” process described in several publications (e.g. Vialov, 1961;
Voigt, 1966).

The question of the location of the aperture in R. venosa has
played an important role in the interpretation of this species. Ulrich
(1879, p. 27) noted that the “cell mouths” seemed to be near the
middle of the “cell,” and he included a suggestion of these features
in one of his original illustrations (Text-fig. 1A). Ulrich and Bassler
(1904, p. 263) also mentioned a “subcentral . . . orifice-like spot”
and concluded that the known remains of Ropalonaria were “the
creeping base of some otherwise unknown bryozoan.” They im-
mediately suggested a relationship to Aetea, a Recent cheilostome
which they regarded to be a ctenostome. Thus, while acknowledging
the general similarity of the “method of growth” in R. venosa and
Terebripora ramosa, they denied that the “cells” of Ropalonarna
were actually zooids that were fully embedded in the substratum.
Most recently, Bassler (1953, p. 35) contended that Ropalonaria
was only partly embedded in the substratum, and that the zooecia
are “unknown, probably deciduous and developed by budding from
a subcentrally located pore in the internodes.”

Although I have examined all of the syntypes of R. venosa,
and numerous chorotypic specimens showing much better preserva-
tion, I have been unable to find any reliable evidence that the
aperture of the zooids is located anywhere but at the distal end, be-
tween the laterally-directed pair of stolons. The only aperture-like
feature occurring near the midpoint of the zooid with any degree
of regularity is readily attributed to fracturing of the thin layer of
substratum sometimes remaining over the cavity occupied by the
zooid. Occasionally, the minerals filling the cavities may also pro-
duce a spot of some sort at this position. In well-preserved material,
an opening at the distal end can be observed, but even in these
specimens the outline of the aperture has probably been altered
somewhat.

It should be noted that the zooids of many specimens have been
significantly enlarged by the accretionary growth of crystals filling

Borinc CTENOSTOMATE Bryozoa: PoHowsky 51

the interior. The specimen in Plate 1, figure 4 shows appreciable
expansion of the zooids, due to progressive replacement of the brachi-
opod shell by what are probably calcite crystals. Care must be taken
to obtain measurements only from zooids that do not appear to have
been affected in this manner.

The occurrence of authigenic minerals within the zooidal cavi-
ties of R. venosa offers evidence that the aperture is located at the
distal end. Many specimens (e.g., Pl. 1, fig. 2) tend to have pyrite in
the proximal end, and a lighter-colored mineral (probably calcite)
in the distal end. This seems to be a good indication that the proxi-
mal end constituted a more reducing environment after the burial
of the shell. Obviously, Eh values in the cavity would be less nega-
tive (or perhaps positive) near the aperture, since this region would
be better exposed to oxygen within the water-saturated sediment.
Therefore, the restriction of pyrite to the proximal end of many
zooids seems to reveal that the aperture is located distally.

The presence of heterozooids (sac zooids) in R. venosa (PI. 1,
figs. 2, 4-7) is of considerable interest, but it is presently uncertain
whether the sac zooids in younger boring ctenostomes are truly
homologous or independently evolved. Similar features are found
in Spathipora comma (Soule) (Recent), and it is possible that the
sac zooids of R. venosa served an equivalent function involving the
storage of “granulations réfringentes.” There is no question that
these structures in R. venosa are truly heterozooids; they are readily
distinguished from autozooids by both their shape and their failure
to produce lateral stolons.

The sac zooids of R. venosa may have been noted by previous
workers. Vine (1884, p. 89) mentioned “abortive or ‘blind cells’ of
Ropalonaria,” but failed to describe or illustrate such zooids. Sac
zooids are almost certainly among those in an illustration by Ulrich
(1893, text-fig. 8e), but with the possible exception of the “blind
cells” mentioned by Vine, no author has reported heterozooids in
Ropalonaria.

I have examined the ancestrulae of nine colonies of R. venosa
from the Hueston Woods locality near Cincinnati, Ohio (PI. 1, figs.
3, 4). All of the ancestrulae resemble the autozooids in most respects,
but they differ by producing a stolon from the proximal end. In
most cases this stolon gives rise to an autozooid which is indistin-

52 BuLLeETIN 301

guishable from the ancestrula (Text-fig. 6C1; Pl. 1, fig. 3). In two
specimens (UCGM 40077, 40078), the stolon produces a sac zooid
before giving rise to an autozooid (PI. 1, fig. 4).

Both sac zooids and autozooids in R. venosa form by the ex-
pansion of a preexisting stolon. The ontogeny of stolons, autozooids,
and sac zooids is illustrated in Plate 1, figure 2.

Ropalonaria? arachne (Fischer), 1866 Pl. 2, figs. 1-6; Pl. 3, figs. 1-6
1866. Terebripora arachne Fischer, Mus. nat. Hist. nat., Nouv. Arch., T. 2,

1970. An eee tenuis Magdefrau, Pugaczewska, Acta Pal. Polonica,
vol. 15, pp. 427, 429, 430, pl. 2, fig. 4. (Non Chaetophorites tenuis
Magdefrau, 1937, Beitr. naturk. Forsch. §. W. Deutschland, Bd. 2, p. 60,
pl. 6, fig. 8.)

Material and occurrence. —

Figured: BMNH D.52265 (on BMNH 1.12957), M. or U. Jur.
(Callovian or Oxfordian), Popilani, Lithuania, MNHN R-50375
(lectotype), M. or U. Jur. (possibly Callovian, probably Oxfordian),
Villers-sur-Mer, Calvados, France; BMNH D.52266 (fragments +
cast) (SEM STUB 7) (on BMNH 65752), U. Jur. (Oxfordian;
argiles oxfordiennes de Dives), Dives-sur-Mer, Calvados, France;
GSM 113444 (cast) (SEM STUB 13) and GSM 113439 (cast)
(SEM STUB 9), U. Jur. (U. Oxfordian; Ampthill Clay), Ampthill
sewage works, % mi. S. of Ampthill, Bedfordshire, England; BMNH
D.52267 (on BMNH 43357), U. Jur. (Kimmeridgian; Kimmeridge
Clay), probably England.

Not figured: MNHN 79510-1 (paralectotype), U. Jur. (Ox-
fordian), Trouville-sur-Mer, Calvados, France; BMNH D.52268
(RAP 232), U. Jur. (U. Oxfordian; Ampthill Clay), Toll farm,
Mepal, Suffolk, England (Gift of A. B. Hastings); GSM 113440-
113443, U. Jur. (U. Oxfordian; Ampthill Clay), Ampthill sewage
works, % mi. S. of Ampthill, Bedfordshire, England; BMNH
D.52269 (on BMNH L.L.17000), U. Jur. (Oxfordian), on shore,
“Kosminsk,” U.S.S.R.; BMNH D.52270 (on BMNH L.9723), U.
Jur. (Kimmeridgian; Kimmeridge Clay), probably England.

Type locality and horizon. — Villers-sur-Mer, Calvados, France;
M. or U. Jur. (“Callovian” (Fischer, 1866, p. 303); “probably Ox-
fordian” (E. Buge, personal communication) ).

Range. —?M. Jur. (Callovian), U. Jur. (Oxfordian, Kim-
meridgian).

Borinc CTENOSTOMATE Bryozoa: PoHowsky 53

Diagnosis. — Ropalonaria? with lateral stolons arising slightly
distal to aperture. Sac zooids occur as initial zooid on some new
lateral stolons, but never in irregularly repeated alternation with
autozooids in linear sequence.

Description. — Autozooids horizontal, bilaterally symmetrical;
disposed medially along stolon throughout their entire length and
consisting of a basally and laterally directed expansion thereof. Cross
section essentially circular; proximal and distal ends taper about
equally rapidly. Aperture slightly proximal to distal end of zooid;
round to moderately oval with major axis parallel to length of
zooid. Distal end of zooid consists of stolon-width ridge basal to
aperture and tapers distally into stolon.

Heterozooids (sac zooids) common, extend basally about as
far as autozooids and never give rise to lateral stolons; occurring as
initial zooid on new lateral stolon, never in irregularly repeated
alternation with autozooids in linear sequence. Reversed zooids and
teratological zooids — especially zooids greatly reduced in size, or
with supernumerary aperture at proximal end — sometimes present
in advanced colonies.

Ancestrula not seen. Autozooids produce distal stolon and pair
of bilaterally opposite stolons arising just distal to aperture.

Measurements. —Lz (12) = 0.38-0.56 mm. (Based on PI. 2,
fips) 55cb13 3,dic.. 1).

Discussion. — Fischer did not figure this species, but the mollus-
can substrata which he listed (1866, p. 303) are in the collections of
the Muséum national d’Histoire naturelle in Paris. Although the
types are poorly preserved, they retain sufficient structure to indi-
cate that they are undoubtedly the same species of boring broyozoan
as that which appears to be common and widespread in the Upper
Jurassic of Europe. I have studied many well-preserved bryozoan
borings from Oxfordian and Kimmeridgian sediments; all are at-
tributable to “Terebripora” arachne Fischer.

Although Ropalonaria? arachne is much closer to Terebripora
than to R. venosa in time, it is anatomically more similar to the
latter species. The most important features shared with R. venosa
are the bilateral symmetry of the zooids and the divergence of the
lateral stolons near the aperture. In Terebripora, zooids are marked-
ly asymmetrical (occurring as enantiomorphs having the aperture on

54 BULLETIN 301

the right or left side of the stolon), and the lateral stolons diverge
at approximately the mid-length of the zooid. While poor preserva-
tion may account for the apparent absence of tubulets in R. venosa
and in the type specimens of R.? arachne, much well-preserved
material assignable to the latter species suggests that these features
are present in R.? arachne only on those adventitious stolons arising
from the basal surface of autozooids (PI. 2, figs. 3, 4). Adventitious
stolons originating from other sites in the colony seem to lack tubu-
lets. In contrast, most (and perhaps all) species of Terebripora have
tubulets on the autozooids. These processes are particularly well de-
veloped in the type species, TJ. ramosa.

The sac zooids of R.? arachne (PI. 2, figs. 3-6; Pl. 3, figs. 3-5)
are similar in form to those in R. venosa, but as noted in the diag-
nosis, they occur at different positions in the budding pattern. As
apparently in Terebripora, sac zooids of R.? arachne occur only as
the initial zooid on a newly budded lateral stolon. In contrast with
R. venosa, they appear sporadically between the autozooids in a
linear, distally budded series. From the examination of sac zooids
in crowded portions of colonies, I suspect that they developed only
on stolons whose fusion with another part of the colony occurred
too abruptly to provide sufficient space for the development of an
autozooid. Although insufficient space may have influenced the
“decision” to form a sac zooid, other determinative factors were
definitely involved. On the periphery of a colony from the Kim-
meridge Clay (BMNH D.52270), two sac zooids occur on lateral
stolons which were growing without obstruction.

An attribute of R.? arachne having far-reaching significance for
the Bryozoa is the occasional occurrence of reversed zooids, and
zooids showing pronounced developmental abnormalities (Pl. 2, fig.
2; Pl. 3, figs. 2-5). These teratologies are important in the inter-
pretation of morphogenetic processes within bryozoans (and numer-
ous other phyla), and are considered briefly in the section on the
morphology of bryozoan borings. It may be noted here, however,
that the zooids possessing two apertures probably had two func-
tional polypides lying end-to-end or alongside one another.

Zooids with two polypides lying parallel to one another have
been reported in the Ctenostomata (Alcyonidium duplex, Prenant
and Bobin, 1956, p. 219) and in several species of Phylactolaemata

Bortnc CTENOSTOMATE Bryozoa: PoHowsky 55

(most recently by Oda and Nakamura, 1973). In these cases both
polypides had the lophophore directed distally and would have
utilized the same aperture. Zooids possessing more than one aperture
for polypide extension have not been reported previously in the
Bryozoa.

The colonies shown in Plate 2, figure 2 suggest significant bio-
chemical differences between two conspecific organisms. Within
both colonies, stolons nearly always fuse and terminate growth upon
encountering another portion of the same colony. In marked con-
trast, contact between portions of different colonies apparently never
results in fusion in this species. Stolons simply appear to grow be-
neath the obstructing element and continue on their previous courses.

The unusually pronounced development of barren stolons (t.e.,
great lengths of stolon devoid of zooids) in these same colonies is
also worth considering. Expansion of stolons into new areas of the
substratum exceeded the rate at which zooids could develop, and
one might postulate that this condition was prompted by optimum
environmental conditions. It is evident, however, that the apparent
“success” of the colony might be attributable to circumstances re-
_ tarding the formation of new autozooids. Expressed somewhat meta-
phorically, the colonies might have been biologically programmed to
continue the relatively economical production of stolons under such
conditions in the expectation that more favorable conditions would
eventually return. Jebram (1970, p. 12, text-figs. 1, 2, and in press)
noted similar development of relatively barren stolons in the en-
crusting ctenostome, Bowerbankia gracilis Leidy, when he fed the
colony with the marine alga Monochrysis luther. A colony raised
on the dinoflagellate Cryptomonas sp., attained a much more
luxuriant complement of zooids.

I have not examined the specimen which Pugaczewska (1970)
assigned to Chaetophorites tenuis Miagdefrau, but its appearance in
the illustration and occurrence in the Lower Kimmeridgian strongly
suggest that it belongs with R.? arachne.

Ropalonaria? bugei, n. sp. Pl. 3; fig. -7

Etymology. — Named in honor of E. Buge.
Material and occurrence. —

Figured: BMNH D.52271 (holotype) (on BMNH 65990), M.

56 BULLETIN 301

Jur. (U. Callovian; argile de Dives (“vaches noires”)), Dives-sur-
Mer, Calvados, France.

Not figured: BMNH D.52272 (3 paratypes) (on BMNH
65990), M. Jur. (U. Callovian; argile de Dives (“vaches noires”) ),
Dives-sur-Mer, Calvados, France.

Type locality and horizon. — Dives-sur-Mer, Calvados, France;
M. Jur. (U. Callovian; argile de Dives).

Range. — M. Jur. (U. Callovian).

Diagnosis. — Ropalonaria? with lateral stolons arising slightly
distal to aperture. Sac zooids and adventitious stolons absent. Auto-
zooids shorter than those of R.? arachne.

Description. — Autozooids resembling those of R.? arachne in
frontal view but significantly smaller. Heterozooids absent. Ances-
trula not seen.

Lateral stolons arising distally from autozooids and bilaterally
opposite one another from point slightly distal to aperture, producing
colony resembling R.? arachne. Zooids commonly separated from one
another by approximately twice their length.

Tubulets and adventitious stolons absent.

Measurements. —Lz (7) = 0.19-0.22 mm. (Based on PI. 3,
fig. 7).

Discussion. — The great similarity of autozooids and budding
patterns in R.? buger and R.? arachne seems to outweigh their dif-
ference in size and the apparent lack of heterozooids in the former
species. The two bryozoans were probably closely related, and their
contiguous (or possibly overlapping) stratigraphic ranges suggest
that an ancestral-descendant relationship may have existed. Unfor-
tunately, the ancestrula has not been located in either species, so
their apparent similarity and possible relationship to R. venosa can-
not be confirmed.

Ropalonaria? buget may be distinguishable from R.? arachne
by other means. In the former species, stolons originating opposite
one another are sometimes of different lengths; some pairs show
strongly retarded growth even though younger, more distal pairs
along the same parent stolon are “normally” developed. The pro-
duction of lateral stolons in R.? arachne seems to proceed in a more
orderly manner.

Borinc CTENOSTOMATE Bryozoa: PoHowsky 57

Ropalonaria? sp.

1973. Terebripora (?) bassleri Voigt and Soule, Jour. Paleont., vol. 47, pp.

24-26, pl. 2, fig. 1.

“Terebripora” (?) bassleri is known only from the holotype
(USNM 170580), from the Lower Cretaceous (Aptian) at Farring-
don (Hampshire), England. The type is moderately well preserved
and might be a specimen of Ropalonaria? arachne (Fischer), as the
autozooids are about 0.53 mm long and have the aperture located
symmetrically along the path of the stolon — not tangent to it. The
position of the aperture, and the paired principal stolons that arise
slightly distal to the zooids clearly rule out assignment of this speci-
men to Terebripora, Orbignyopora, or Marcusopora. Unfortunately,
the presence of sac zooids in “7.” (?) bassleri cannot be established
without casting the specimen, so the range of R.? arachne cannot
be reliably extended to the Aptian. Speculation by Voigt and Soule
(1973, p. 25) that “7.” (?) basslert might be a species of Immer-
gentia Silén is discounted because zooids in the Aptian type are
demonstrably horizontal, whereas those of Immergentia are more
or less vertical (Silén, 1946, text-fig. 10).

It should be noted that the museum catalogue number pub-

lished by Voigt and Soule (USNM 170508) is incorrect.

Family ORBIGNYOPORIDAE, n. fam.

Diagnosis. — Non-pedunculate boring Bryozoa with bilaterally
symmetrical autozooids lying horizontally along stolon throughout
their entire length. Aperture disposed symmetrically along solon.
Lateral stolons arise opposite one another at or near midlength of
zooid. Ancestrula produces stolons proximally, and bilaterally op-
posite one another at or near midlength of zooid.

Range. — ?M. Sil., ?L. Dev., ?M. Dev., ?M. Jur., ?U. Cret.,

Paleocene-Pliocene.

Genus ORBIGNYOPORA, n. gen.

1866. Partim Terebripora d’Orbigny, Fischer, Mus. nat. Hist. nat., Nouv.
Arch., T. 2, p. 302, pl. 11, figs. 3, 3a. (Nox Terebripora d’Orbigny,
1847, Vovage dans |’Amérique méridionale, T. 5, pt. 4, pp. 22, 23, pl.
10, figs. 16, 17.)

1875. Terebripora d’Orbigny, Manzoni, I Briozoj del Pliocene antico di Cas-
trocaro, (Bologna), p. 7, pl. 6, fig. 68.

1877. ?Terebripora d’Orbigny, Dollfus, Soc. Linn. Normandie, Bull., sér. 3,
T. 1, pp. 97-99, 102, 103, pl. 1, figs. 2-4.

58 BULLETIN 301

1901. Terebripora d’Orbigny, Rovereto, Palaeont. Italica, vol. 7, p. 221, text-
fig. 1.

1904. ?Partim Rhopalonaria Ulrich and Bassler, Smithsonian Misc. Coll.
(Quart. Issue), vol. 45, pp. 268-271, pl. 66, figs. 4-10. (Non Ropalonaria
Ulrich, 1879, Cincinnati Soc. Nat. Hist., Jour., vol. 2, pp. 26, 27, pl. 7,

figs. 24, 24a.)

1914. ?Rhopalonaria Ulrich, Dienst, Konig. Preuss. Geol. Land., Berlin, Jahrb.,
Bd. 34, pp. 599, 600, pl. 18, figs. 16, 17.

1923. Partim Terebripora d’Orbigny, Canu and Bassler, U.S. Nat. Mus. Bull.,
INO.) 125; py 15; ply 3, digs. 6,907,

1954. ?Rhopalonaria Ulrich, Fritz, Jour. Paleont., vol. 28, pp. 118, 119, text-
fre. 1

1968. ?Partim Cyclopuncta Elias, Miller, Bohr-Réhren von unbekannten An-
neliden und anderen Organismen in unterdevonischen Brachiopodenklap-
pen aus der Eifel und dem Siegerland (Rheinisches Schiefergebirge),
Univ. Koln, p. 106, pl. 4, fig. 6. (Non Cyclopuncta Elias, 1958.)

1968. ?Partim Spathipora Fischer, Miiller, ibid., pp. 82, 106, pl. 4, figs. 1-2a, 6.
(Non Spathipora Fischer, 1866, Mus. nat. Hist. nat., Nouv. Arch., T. 2,
pp. 309, 310, pl. 11, figs. 4, 4a.)

1973. ?Partim Terebripora (?) d’Orbigny, Voigt and Soule, J. D., Jour.
Paleont., vol. 47, pp. 27, 28, pl. 2, figs. 4-6.

Etymology. — Named in honor of A. D. d’Orbigny.

Type species. — Orbignyopora archiact (Fischer), 1866.

Diagnosis. — Bryozoa with the characters of the family, Or-
bignyoporidae.

Range. —?M. Sil., ?L. Dev., ?M. Dev., ?M. Jur., ?U. Cret.,
Paleocene-Pliocene.

Discussion. — Orbignyopora consists of four species sharing
similar zooidal anatomy and position of stolonal branching. In view
of the poor preservation of most known pre-Cenozoic specimens
the wisdom of including them within the genus appears dubious.
However, a well-preserved specimen of O.? capillaris[?] from the
Middle Devonian of New York (PI. 4, fig. 2) is so similar to O.
archiact from the Cenozoic (PI. 5, figs. 1-5) that the extension of
the range of this genus to include O.? capillaris seems plausible.
Other invertebrate genera have even longer ranges, and like these
taxa, Orbignyopora is an example of possible polyphylogeny masked
by repeated occurrences of deceptive homeomorphy.

The question of unity among the species here assigned to the
genus on the basis of budding pattern and generalities of external
zooidal anatomy will approach resolution when well-preserved topo-
typic specimens displaying the ancestrula are collected and com-
pared. The ancestrula has been located only in O.? tridelta, and its
unique pattern of stolon production in this species seems to aug-

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 59

ment the evidence of other characters distinguishing Orbignyopora
from the several other non-pedunculate, boring genera with hori-
zontally disposed zooids.

Orbignyopora archiaci (Fischer), 1866 Pl. 5, figs. 1-5; Text-figs. 2G, 3C

1866. TLerebripora archiaci Fischer, Mus. nat. Hist. nat., Nouv. Arch., T. 2, p.
S02 ple Uitisss3. Sa.

1875. ?Yerebripora archiaci Fischer, Manzoni, I Briozoi de] Pliocene antico
di Castrocaro, (Bologna), p. 7, pl. 6, fig. 68.

1901. ?Terebripora manzonii Rovereto, Palaeont. Italica, vol. 7, p. 221, text-
fig. 1.

1923. Terebripora elongata Ulrich and Bassler, U.S. Nat. Mus. Bull., No. 125,
joo MSs yolk Sy sare, Ws aly

1969. Terebripora arachiaci Fischer, Soule, J. D. and Soule, D. F., Amer. Zool.,
vol. 9, No. 3, ed. 2, p. 793 (nom. null.).

1973. ?Terebripora (?) echinicola Voigt and Soule, Jour. Paleont., vol. 47, pp.
27, 28, pl. 2, figs. 4-6.

Material and occurrence. —

Figured: MNHN 79512-1, (holotype), L. Tertiary (“Zone of
Serpula spirulaea”), Brassempory, Landes, France; USNM 68391,
Miocene (Bowden Marl), Bowden, Jamaica; BMNH D.52273 (RAP
307), U. Miocene or Pliocene, hills near Bythmia[?], Candia, Crete;
BMNH D.52274 (on BMNH G.598), probably Pliocene (Astian) of
Italy.

Not figured: BMNH D.52275 (on BMNH G.49268, colony A),
L. Eocene (Ypresian, probably Cuisian), Gan, Basses-Pyrenees,
France; BMNH D.52276 (on BMNH G.4489), Pliocene (marl),
Latakia, Syria.

Type locality and horizon. — Brassempory, Landes, France; L.
Tertiary (Paleocene: “Zone of Serpula spirulaea”).

Range. — ?U. Cret., Paleocene-Pliocene.

Diagnosis. — Orbignyopora with unusually large zooids bearing
a row of numerous tubulets along both lateral extremities of the
entire frontal surface.

Description. — Autozooids long, horizontal, bilaterally sym-
metrical; disposed symmetrically along stolon throughout their en-
tire length and consisting of basally and laterally directed expansion
thereof. Zooids clavate, with proximal end slightly broader than dis-
tal end and tapering rapidly to form a blunt tip in frontal view.
Aperture circular.

Heterozooids not detected; ancestrula not seen.

Zooids produce stolons distally, and bilaterally opposite one

60 BuLLeTIN 301

another from sub-surface points at or somewhat distal to midlength
— but never at site of aperture, and rarely in its vicinity. Lateral
stolons grow to substratum surface and give rise to autozooids with
proximal end near parent zooid. Subsequent zooids in linear series
usually more widely spaced, commonly at a distance approximating
half their length.

Numerous (15-30) tubulets extending to substratum surface
from both frontal-lateral sides of zooids. Autozooids sometimes
giving rise to adventitious stolons.

Measurements. — Lz (13) = 1.0-1.6 mm. (Based on PI. 5, figs.
1-5).

Discussion.— The zooids of Orbignyopora archtaci are signi-
ficantly larger than those of all other boring bryozoans except
Foraripora pesavis Voigt and Soule. Because all well-preserved
specimens resembling the holotype in budding pattern and zooid
size also have the more subtle characters of the holotype (e.g., auto-
zooidal tubulets, medially disposed aperture), the assignment of the
poorly preserved holotype of Terebripora elongata Canu and Bassler
to the species is justified. Similar reasoning suggests that T'erebripora
manzonu Rovereto is also synonymous.

According to Rovereto (1901, p. 221), the holotype of his
species is the specimen which Manzoni (1875, p. 7) assigned to T.
archiaci Fischer. Manzoni illustrated the zooidal anatomy and bud-
ding pattern of his specimen, but he failed to indicate the size of the
zooids. Rovereto illustrated a single zooid, the apparent length of
which falls at the lower end of the range observed in the specimens
figured herein (PI. 5). On the basis of its illustrated zooidal anatomy
and poorly documented size, T. manzonu might be assignable to
Orbignyopora? tridelta (PI. 5, fig. 6). However, Manzoni’s illustra-
tion of frequent lateral budding enhances the probability that this
specimen belongs with O. archiact (Fischer).

The shape of the aperture in O. archiaci cannot be determined
with accuracy in the holotype or in most other specimens I have
examined. Because the zooids lie tangent to the surface of the sub-
stratum, the true outline of the aperture is usually destroyed by the
slightest amount of weathering, intrastratal solution, or pre-deposi-
tional abrasion. I was fortunate to find the colony shown in Plate
5, figure 4, in which the perimeters of some apertures appear to be

Borinc CTENOSTOMATE Bryozoa: PoHowsky 61

preserved intact. In view of the apparent fragility of this structure,
Rovereto’s report of a lanceolate, notched aperture in 7. manzonii
is suspect. Similarly, Fischer’s illustration of a notch in the aper-
tures of the holotype of O. archiacit (Text-fig. 2G) reflects deficient
preservation.

“Terebripora” (?) echinicola Voigt and Soule, 1973, might be a
junior synonym of O. archiaci, but the poor preservation of the
Upper Cretaceous (Campanian or Maastrichtian) type material
from glacial drift in northern Germany precludes a firm assignment.
The large zooids (1.3-1.7 mm long) appear to lie along the stolon
and give rise to laterally budded stolons near their midlength, but
details such as tubulets and aperture position have evidently been
obliterated.

Orbignypora? capillaris (Dollfus), 1877 Pl. 4, figs. 1-7; Text-figs. 2F

1877. Terebripora capillacea Dollfus, Soc. Linn. Normandie, Bull., sér. 3, T. 1,
p. 96. (Nom. null.)®

1877. Terebripora capillaris Doilfus, Soc. Linn. Normandie, Bull., sér. 3, T. 1,
pp. 97-99, 102, 103, pl. 1, figs. 2-4.

1904. ?Rhopalonaria attenuata Ulrich and Bassler, Smithsonian Misc. Coll.
(Quart. Issue), vol. 45, pp. 266, 268, 269, pl. 66, figs. 4, 5.

1904. ?Rhopalonaria robusta Ulrich and Bass!er, ibid., pp. 266, 269, 270, pl. 66,

fig. 6.

1904. ?Rhopalonaria tenuis Ulrich and Bassler, ibid., pp. 266, 270, pl. 66, figs.
7-9.

1904. ?Rhopalonaria medialis Ulrich and Bassler, ibid., pp. 266, 270, 271, pl.
66, fig. 10.

1914. ?Rhopalonaria tenuis Ulrich and Bassler, Dienst, Konig. Preuss. Geol.
Land., Berlin, Jahrb., Bd. 34, pp. 599, 600, pl. 18, figs. 16, 17.

1954. ?Rhopalonaria lambtonensis Fritz, Jour. Paleont., vol. 28, pp. 118, 119,
text fig. 1.

1968. ?Partim Cyclopuncta Elias, Miller, Bohr-Réhren yon unbekannten An-
neliden und anderen Organismen in unterdevonischen Brachiopodenklap-
pen aus der Eifel dem Siegerland (Rheinisches Schiefergebirge), Univ.
Koln, p. 106, pl. 4, fig. 6; non pl. 4, figs. 3-4a. (Non Cyclopuncta Elias,
1958, Jour. Paleont., vol. 32, pp. 50, 51, pl. 3, figs. 14, 16).

1968. ?Partim Spathipora Fischer, Miller, ibid., pp. 82, 106, pl. 4, figs. 1-2a, 6;
non pl. 4, fig. 7. (Non Spathipora Fischer, 1866, Mus. nat. Hist. nat.,
Nouy. Arch., T. 2, pp. 309, 310, pl. 11, figs. 4, 4a.).

Material and occurrence. —

Figured: USNM 43116 (in one of 24 whole specimens and frag-
ments), M. Sil. (Rochester Ls.), Lockport, New York; GLNW Sg
II-322, L. Dev. (Siegenian, Wildflaser zone, Seifen II, Fossil-Bank

5The apparent inadvertence of this misspelling in the title of Dollfus’s
publication is further substantiated by the anonymous author of a review ap-
pearing in Soc. géol. France, Bull., sér. 3, T. 6, pp. 103, 104.

62 BuLtetIn 301

“a”), Seifen bei Dierdorf, Germany; USNM 35089 [On one of three
fragments accompanying (but not part of) the holotype of Rho-
palonaria robusta Ulrich and Bassler. Ulrich and Bassler (1904, p.
269) indicated knowledge of only one colony.], L. or M. Dev.
(Camden Fm.), Camden, Tennessee; ROM 27119, M. Dev. (Hamil-
ton Gp.), Thedford, Ontario; UCGM 40068 (RAP 221), M. Dev.
(Marcellus Sh., Cardiff Sh. Mbr.), hillside quarry on E. side of
Swamp Rd., 2.2 mi. N. of Morrisville, New York (Gift of B. W.
Cameron); BMNH D.52277 (cast) (SEM STUB 17), M. Dev.
(Marcellus Sh., Cardiff Sh. Mbr.), hillside quarry on E. side of
Swamp Rd., 2.2 mi. N. of Morrisville, New York; USNM 43119,
M. Dev. (Hamilton Gp., lower shales (“Arkona beds’) ), Thedford,
Ontario.

Not figured: USNM 43116 (23 of 24 whole specimens and frag-
ments), M. Sil. (Rochester Ls.), Lockport, New York; GLNW
Sg II-322, 330, 610, L. Dev. (Siegenian, Wildflaser zone, Seifen II,
Fossil Bank “a”), Seifen bei Dierdorf, Germany; USNM 35089
(Holotype of Rhopalonaria robusta, and two of three accompanying
specimens not mentioned by Ulrich and Bassler), L. or M. Dev.
(Camden Fm.), Camden, Tennessee; UCGM 40087-40089, M. Dev.
(Marcellus Sh., Cardiff Sh. Mbr.), hillside quarry on E. side of
Swamp Rd., 2.2 mi. N. of Morrisville, New York, (gift of B. W.
Cameron); UCGM 40090 (RAP 219), M. Dev. (Hamilton Gp.,
Skaneateles Sh.), 3.1 mi. N. of bench mark in Hubbardsville, New
York, (gift of B. W. Cameron).

Type locality and horizon. — Near Barneville-sur-Mer (“near
an abandoned mill on the road to Portbail”), Manche, France; L.
Dev. (“upper Graywacke of Manche, graywacke with Spirifer”)
( Dollfus, 1877, p. 98).

Range. — ?M. Sil., L. Dev., ?M. Dev.

Diagnosis. — Orbignyopora? with zone of astogenetic change in
which lateral stolons are rare or absent, succeeded by zone of asto-
genetic repetition in which lateral stolons arise regularly. Zooids
resemble those of O. archiaci, but less than half their length; with
numerous laterally directed tubulets arising along midline of frontal
surface.

Description. — Autozooids greatly resemble those of O. archiaci
in form and relation to stolon, but only one-half to one-fifth as long.

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 63

Aperture ovoid, with broad end directed distally.

Heterozooids (sac zooids) present and extending basally well
beyond autozooids. Ancestrula not seen.

Zooids produce stolons distally, and laterally opposite one
another, at or slightly distal to zooid’s midlength. Initial zooids de-
velop on these stolons separated from parent zooid by distance
greater than half their length, but rarely exceeding their length. Sub-
sequent zooids in linear series commonly separated by distance equal
to their length. Production of lateral stolons generally restricted
from initial two to four zooids in new series.

Autozooids bear numerous laterally directed tubulets which
arise near medial line on frontal surface. Adventitious stolons often
present in older portions of colony.

Measurements. —Lz (10) = 0.34-0.47 mm. (Based on PI. 4,
fizs 3, L,,2)t

Discussion. — Pending the location and restudy of the holotype
or suitable topotypic material of Orbignyopora? capillaris, the under-
standing of this species will remain inadequate. Consequently, all
specimens herein assigned to O.? capillaris are placed there with
some reservation. The generic affinities of these Silurian and De-
vonian specimens will remain in doubt pending a comparison of their
early astogeny with that of the type species, O. archiaci. At this
point, the main objective is to underline the distinctiveness of O.?
capillaris from Ropalonaria Ulrich.

The above description is based largely on the specimens shown
in Plate 4, figures 1 and 2, but there is no assurance that the holo-
type possesses all of the diagnostic features evident in this well-
preserved material from Ontario and New York. Moreover, it is
possible that many, potentially distinguishable species in the Lower
Paleozoic had elongated zooids which budded near their midpoint.
If all parts of the holotype of O.? capillaris show the poor preserva-
tion reported by Dollfus (1877, p. 98), and if more than one species
of similar basic anatomy is demonstrably present in the type area,
then O.? capillaris will have to be considered unrecognizable. For
the time it may be tentatively assumed that the well-preserved
borings from the Hamilton Group are representative of the species
described by Dollfus. Taking into account the apparent worn state
of the holotype, the North American material certainly conforms to

64 BuLLETIN 301

the original description and illustration (Text-fig. 2F); the zooids
reportedly attain a length of 0.5 mm, are separated by a distance
approximating their length, and give rise to lateral stolons “three-
quarters of the way toward their extremity” (Dollfus, 1877, p. 98).

The preservation of the specimens illustrated in Plate 4, figures
4-7 is poor, but all show distinct evidence of lateral branching near
the midpoint of the zooids. This feature alone is sufficient to dis-
tinguish these specimens (and that in fig. 1) from Ropalonaria, the
genus to which they were heretofore assigned.

The natural casts of zooids shown in Plate 4, figures 4-6 are
almost certainly not representative of the original shape of the
borings. In figures 4 and 5 at least, the replacement of the calcareous
matrix by authigenic minerals within the cavities appears to have
masked significantly the true dimensions of the zooids.

Despite its poor condition, the specimen in figure 4 shows some
evidence of being fundamentally different from the specimens in
figures 1 and 2. Its zooids are more densely spaced, and appear to
have a swollen proximal end. Also, the initial zooids in new, laterally
budded series often bud laterally — so the presumed evidence of
a zone of astogenetic change in O. capillaris appears to be lacking
in this specimen. Despite these apparent differences it seems unwise
to consider “Ropalonaria” robusta Ulrich and Bassler to be distinct
from O.? capillaris until the boring bryozoans of the Silurian and
Devonian have been studied in greater detail.

Because future research could conceivably demonstrate that
“Ropalonaria” tens Ulrich and Bassler is distinct from Orbignyo-
pora? capillaris, “R.” attenuata and “R.” robusta, “R.” medialis
must retain its status as a junior objective synonym of “R.” tenuis.
The indicated holotype of “R.” medialis (USNM 43120) occurs on
the exterior of one valve of a Middle Devonian brachiopod from
New York. The exterior of the opposite valve of the same brachiopod
bears the circuitously designated holotype of “R.” tenws. Both
“colonies” lie in contact with the posterior margin of the valves,
and removal of the sediment encrusting the interarea reveals that
“R.” tenuis has grown across the hinge and onto the opposite valve.
There is little question that the “holotype” of “R.” medialis is
merely a distal portion of the holotype of “R.” tenuis. “R.” tenuts

has priority by a few lines (Ulrich and Bassler, 1904, p. 270).

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 65

Orbignyopora? tridelta, n. sp. Pl. 5, fig. 6; Text-fig. 6B3

Etymology. — The specific name refers to the appearance of
three convergent triangles between the three series of zooids ema-
nating from the ancestrula.

Material and occurrence. —

Figured: BMNH D.52278 (holotype) (on BMNH L.65483), L.
Pliocene, near Ayias, Simeous, Cyprus.

Not figured: BMNH D.52279 (one or more paratypes on same
shell as holotype).

Type locality and horizon. — Near Ayias, Simeous, Cyprus; L.
Pliocene.

Range. — L. Pliocene.

Diagnosis. — Orbignyopora? with zooids resembling those of
O. archiaci and O.? capillaris but intermediate in size. Tubulets few
or absent on autozooids.

Description. — Autozooids similar to those of O. archiact in
symmetry and relation to stolon, but somewhat smaller and taper
from maximum width at or near distal end to sharply pointed proxi-
mal end. Aperture circular to oval.

Heterozooids not present in portions of small colonies examined.

Ancestrula resembles autozooids, but only slightly more than
half as long as those in zones of astogenetic repetition; producing
stolons at proximal end and bilaterally opposite one another, slightly
distal to midlength. The three stolons give rise to linear series of
autozooids diverging from ancestrula at approximately 120 degrees
to one another.

All autozooids producing stolons distally; some bearing paired
or unpaired lateral stolons arising on or near basal surface. Produc-
tion of lateral stolons restricted from proximal part of zones of asto-
genetic change, and delayed until zooids are mature or nearly so.

Autozooids lacking tubulets in some cases, but sometimes bear-
ing as many as eight or ten on frontal surface. Adventitious stolons
not detected in available specimens.

Measurements. — Length of ancestrula = 0.48 mm; Lz (of con-
secutive zooids in linear series growing from proximal end of ances-
trula): 0.56, 0.66, 0.70, 0.70, 0.72, 0.80 mm (Based on direct
measurement of holotype).

Discussion. — Although the material available for study con-

66 BuLtetIn 301

sists of a few small colonies on a shell heavily bored by thallophytes,
these specimens show good evidence of being distinct from their con-
generic contemporary, Orbignyopora archiaci, and the two species
known from older strata. Of special interest are the readily visible
ancestrula and the early budding pattern of the holotype; these
features have not been detected in other species of this genus. As the
ancestrulae in other genera with non-pedunculate autozooids give
rise to the initial autozooids in fundamentally different ways, the
discovery of the ancestrula in a colony with Orbignyopora-like auto-
zooids is of considerable taxonomic importance. At present, the oc-
currence of a distinctive ancestrular budding pattern in an apparent
Orbignyopora merely emphasizes the dissimilarity of O.? tridelta and
Ropalonaria, Marcusopora, and Terebripora. Future studies of an-
cestrulae in other species of Orbignyopora will play a major role in
evaluating the generic affinities of these particular bryozoans.

As shown by the measurements of autozooids proceeding in a
series from the ancestrula, O.? tridelta has a broad primary zone of
astogenetic change. Within this zone, zooids attain greater size with
increasing distance from the ancestrula, and show evidence of a
restricted production of lateral stolons. Only four of the 15 auto-
zooids in the holotype have budded laterally, and the “earliest”
lateral stolon occurs on the third zooid from the ancestrula, in the
series emanating from its proximal end. This species also appears to
have a large zone of ontogenetic change in which the production of
lateral stolons is strongly delayed. Thus, many zooids which appear
to be mature are without lateral buds. By comparison, Terebripora
falunica Fischer produces paired lateral stolons even before the
zooids have begun to expand.

The presence of unpaired lateral stolons in O.? tridelta is of
uncertain significance. Perhaps stolons were about to develop on the
opposite side when the colony died.

One of the four lateral stolons in the holotype has given rise
to an autozooid at a distance of one to two zooid lengths from the
parent zooid. Mature zooids within zones of astogenetic repetition
in the paratype(s) have paired lateral stolens which produce zooids
at a much shorter distance.

Orbignyopora? cornbrashica, Nn. sp. Ply 5 ight

Borinc CTENOSTOMATE Bryozoa: PoHowsky 67

Etymology.— The specific name refers to the strata from
which all known specimens were collected.

Material and occurrence. —

Figured: BMNH D.52280 (holotype) (on BMNH L.69968),
M. Jur. (Bathonian or Callovian; Cornbrash), Fengate, near Peter-
borough, Northamptonshire, England.

Not figured: BMNH D.52281 (on BMNH 82429), M. Jur.
(Bathonian or Callovian; Cornbrash), Bournemouth, England;
BMNH D.52282 (on BMNH 20034a), M. Jur. (Bathonian or Callo-
vian; Cornbrash), Helpstone, England.

Type locahty and horizon.— Fengate, near Peterborough,
Northamptonshire, England; M. Jur. (Bathonian or Callovian;
Cornbrash).

Range. — M. Jur. (Bathonian or Callovian).

Diagnosis. — Orbignyopora? with short zooids having dispro-
portionately large aperture and width. Lateral stolons commonly
directed nearly at right angles to parent zooid.

Description. — Autozooids like those of O. archiaci in symmetry
and relation to stolon, but much shorter, and with disproportionately
large aperture and girth for their length. Proximal end sharply
pointed. Aperture circular to oval.

Heterozooids absent. Ancestrula not seen.

Autozooids produce stolons distally and bilaterally opposite
one another at or somewhat distal to midlength, and occasionally
close to aperture. Lateral stolons tend to arise perpendicular to
parent zooid and to continue growth in this direction.

Tubulets and adventitious stolons absent.

Measurements. — Lz (5) = 0.43-0.50 mm. (Based on PI. 5,
fig. 7).

Discussion. — Orbignyopora? cornbrashica differs most notice-
ably from other species in this genus in the proportions of its zooids,
and in the direction in which lateral stolons commonly trend. The
apparent absence of autozooidal tubulets is also a unique feature
within the genus.

It is possible that O.? cornbrashica may actually be a junior
synonym of “Terebripora” antiqua d’Orbigny, 1850, from the
Bathonian of Luc, France. The syntypes of the latter species
(MNHN 79508-1) are poorly preserved. It seems pointless to con-

68 BULLETIN 301

sider “J.” antiqua recognizable, because only a few of the most
fundamental characteristics can be observed. Furthermore, D’Orbig-
ny did not illustrate the species, and his brief description is of little
diagnostic value. Although the syntypes of “T.” antiqua seem to bud
laterally near the midlength of the zooid and the apertures are dis-
posed medially along the stolons, it will be necessary to study a con-
siderable amount of topotypic material from Luc before 0.? corn-
brashica can be placed in synonymy with the species named by

D’Orbigny.
Family VOIGTELLIDAE, n. fam.

Diagnosis. — Pedunculate boring Bryozoa with exceptionally
thin stolons producing zooids or zooid-stolon pairs in zones of asto-
genetic change. Only lateral stolons arise directly opposite one
another in zones of astogenetic repetition. Peduncle inserted at or
distal to midlength of zooid. Zooids typically tubular, elongated, and
inclined at widely varying angles between 20 and 70 degrees to the
horizontal. Distal end of zooids usually directed distally along (paral-
lel to) parent stolon.

Range. — ?Perm., U. Cret.

Genus VOIGTELLA, n. gen.

1848. Partim Talpina von Hagenow, Quenstedt, Petrefactenkunde Deutschlands,
Abt. 1, Bd. 1 (Cephalopoden), Tiibingen), p. 470, pl. 30, fig. 37 (partim).
(Non Talpina von Hagenow, 1840, Neues Jahrb. Min., pp. 670, 671.)

1929. ?Rhopalonaria Ulrich, Bassler, Palaéontologie von Timor, (Stuttgart),
Lief. 16, Pt. 28, p. 40, pl. 235, figs. 1, 3. (Non Ropalonaria Ulrich, 1879,
Cincinnati Soc. Nat. Hist., Jour., vol. 2, pp. 26, 27, pl. 7, figs. 24, 24a.)

1962. Spathipora Fischer, Voigt, Upper Cretaceous Bryozoa of the European
part of the U.S.S.R. and some adjoining areas, [in Russian], Moscow
Univ., p. 60, pl. 11, figs. 5-7. (Non Spathipora Fischer, 1866, Mus. nat.
Hist. nat. (Paris), Nouv. Arch., T. 2, pp. 309, 310, pl. 11, figs. 4, 4a.)

1965. Nygmites Magdefrau, Pugaczewska, Acta Pal. Polonica, vol. 10, p. 77,
pl. 2, fig. 1. (Non Nygmites Magdefrau, 1937, Beitr. Naturk. Forsch. S. W.
Deutschland, Bd. 2, H. 1, pp. 56, 57, pl. 5, figs. 3, 4.)

Etymology. — Named in honor of E. Voigt.

Type species. — Voigtella regalis, n.sp.

Diagnosis. — Bryozoa with the characters of the family, Voigtel-
lidae.

Range. — ?Perm., U. Cret.

Discussion. — Although the general aspect of the borings pro-
duced by this genus is in some respects like that of Spathipora

Borinc CTENOSTOMATE Bryozoa: PoHowsky 69

Fischer, this resemblance is superficial. The extraordinarily thin
stolons, the abrupt boundary between zones of astogenetic change
and zones of repetition, and the wide variation in the angle of in-
clination of zooids relative to the substratum are features unique
within the boring Bryozoa.

The two Cretaceous species, V. regalis and V. secunda, are
known from well-preserved borings of similar age and with readily
discernible budding patterns. The third species, V.? timorensis
(Bassler ), is known only from a poorly preserved Permian specimen.
It is possible that V.? timorensis might belong in another genus,
but only Vozgtella appears to share the combination of features
shown by this species. V.? timorensts is not referable to Ropalonaria

Ulrich.

Voigtella regalis, n. sp. Pl. 6, figs. 2-5; Text-fig. 4A

1962. Partim Spathipora prima Voigt, Upper Cretaceous Bryozoa of the Euro-
pean part of the U.S.S.R. and some adjoining areas, [in Russian], Mos-
cow Univ., pp. 60, 61, pl. 11, fig. 7 (pl. 11, figs. 5, 6 are Voigtella sp.)

Etymology. — L., regalis, royal.

Material and occurrence. —

Figured: UCGM 40069 (Holotype is colony associated with ar-
rows in PI. 6, fig. 3. Associated colonies are paratypes.) (RAP 227),
U. Cret. (L. Maastrichtian), Sengiley, Uljanovsk Province, U.S.S.R.;
MGU 672-b, U. Cret. (U. Maastrichtian), Trans-Caspian Province,
U:S.S_R.

Not figured: BMNH D.52283 (on BMNH L.8135), U. Cret.
(U. Campanian; Zone of B. mucronata), Thorpe, St. Andrew, Nor-
wich, Norfolk, England; UCGM 40091 (RAP 228), U. Cret. (L.
Maastrichtian), Chvalyusk, Saratov Province, U.S.S.R.

Type locality and horizon.—Sengiley, Uljanovsk Province,
U.S.S.R.; U. Cret. (L. Maastrichtian ).

Range. — U. Cret. (U. Campanian-U. Maastrichtian).

Diagnosis. — Voigtella with zooids restricted to proximal side
of parent stolon, directly opposite lateral stolon on distal side.

Description. — Autozooids joined to stolon by peduncle at-
tached slightly distal to midpoint; show pronounced tendency to in-
cline at 30-60 degrees to surface of substratum with distal end tilted
distally along (parallel to) stolon. Zooids long, straight, cylindrical,
and bluntly rounded at proximal end. Aperture variably oval, with

70 BULLETIN 301

major axis parallel to associated principal stolon (parent stolon).

Heterozooids absent; ancestrula not seen.

Budding pattern characterized by occurrence of zooids on proxi-
mal side of stolons, and by repetition of following sequence (Text-
fig. 4A): 1. Stolon (a) in zone of astogenetic repetition produces
bilaterally opposite pair of stolons (b) at somewhat regular inter-
vals. 2. Constituting a subsequent zone of astogenetic change, lateral-
ly budded stolons (b) produce autozooids at regular intervals on
proximal side (rarely on distal side), and lateral stolons (c) on
distal side, precisely opposite peduncles of autozooids. [Stolons (c),
constituting additional zone of astogenetic change, also give rise
to zooids on proximal side and opposing stolons on distal side.] 3.
Stolons (b), after having produced approximately three to five
stolon-zooid pairs, cease to produce zooids and thereafter form only
bilaterally opposite pairs of stolons, thus completing cycle by form-
ing subsequent zone of astogenetic repetition.

Tubulets absent. Principal stolons extremely thin. Presence of
adventitious stolons indeterminate; irregular network sometimes
observed perhaps produced by thallophytes.

Measurements. —Lz (5) = approx. 0.6-0.8 mm. (Estimated
from zooids in PI. 6, figs. 1-4).

Discussion. — Voigtella regalis is conclusively recognized only
by the presence of the characteristic budding pattern in conjunction
with the other features described above. While the shape of the
aperture and autozooid usually differ somewhat from that in JV.

TEXT-FIGURE 4

A. Foigtella regalis, n. gen., n. sp. Drawn schematically to illustrate astogeny
— see discussion of V. regalis in systematic part for explanation. The pro-
fuse fusion of stolons that often masks budding pattern in colonies is not
shown here. To preserve clarity, an advanced state of development is
shown on part of the right side only. Zooid length is about 0.7 mm.

B. Marcusopora ripleyensis, n. gen., n. sp. Interpretation of budding pattern
in region of ancestrula, based upon Plate 7, figure 7 (here rotated 90
degrees counter-clockwise). Arrow indicates proximal end of ancestrula.
Damage to this part of the ancestrula, seen in the plate figure, is not shown
here. Zooid length is about 0.3 mm.

C. Foraripora pesavis Voigt and Soule. Portion of holotype shows paired, op-
posite budding of zooids from enantiomorphic zooids which flex toward the
right or left side of the stolon. The five groups of zooids between the
dotted lines are those shown by Voigt and Soule (1973) on the left side
of plate 3, figure 1. The proportions between different parts of the present
illustration (freehand sketch) are slightly inaccurate. Zooid length is about
1.2 mm.

Borinc CTENOSTOMATE Bryozoa: PoHOWwsKY 71

secunda, identification from these features alone is open to question
even when based on the study of a large number of zooids. The ap-
parent shape of the aperture is subject to alteration by abrasion, and
there is no assurance that another species with indistinguishable
zooids, but with a different budding pattern resembling that of

Fi BULLETIN 301

V.? timorensis did not also exist in the Upper Cretaceous. In the ab-
sence of stolons, the diagnostically important budding pattern of an
apparent Voigtella cannot reliably be interpreted in detail.

The delicate stolons of Voigtella lie near the surface of the sub-
stratum, so evidence of their presence is readily obliterated by re-
moval of the sedimentary matrix that commonly fills the shallow
grooves. Only a slightly greater amount of abrasion or solution is
needed to destroy the subtle grooves. Thus, through one process or
another, the stolons in the holotypes of “Talpina” pungens Quenstedt
and “Spathipora” prima Voigt have been removed. The placement of
zooids along the stolons in these species is, therefore, in doubt, and
although both of these type specimens are probably senior synonyms
of V. regalis, their present condition precludes firm judgement on the
matter. Moreover, the original descriptions of these species do not
reveal the details of their budding patterns. Examination of addi-
tional material from the type areas of “T.” pungens and “S.” prima
may help to answer questions about their probable budding pat-
tern, but it nevertheless seems that taxonomy would best be served
by admission that the affinities of these species within Voigtella is
problematic.

Although the holotype of “S.” prima Voigt, 1962 is of question-
able relationship to V. regalis, the specimen illustrated in Voigt’s
plate 11, figure 7 (PI. 6, fig. 2) suggests that the zooids typically
occurred on the proximal side of the stolon. Voigt (1962, p. 60) con-
cluded that the stolons of the specimens he described were usually
undetectable because of their deep burial within the substratum.
This interpretation appears to be incorrect, as the stolons of well-
preserved specimens of Voigtella invariably occur close to the surface
(PI. 6, figs. 3-5; Pl. 7, figs. 1-4).

The occurrence of two “alternating” types of budding within
V. regalis and related species is of considerable interest. The presence
of various types of budding-pattern zonation within the more
“typical,” encrusting species of Bryozoa has long been recognized,
but only recently has this pervasive phenomenon been interpreted
perspicuously in theory (Boardman, 1968; Boardman, et al., 1969).
As conceived by these authors, zones of astogenetic change are com-
prised of zooids showing “. . . morphologic differences in more or
less uniform progression distally from generation to generation. . .”

Borinc CTENOSTOMATE Bryozoa: PoHowsky 73

(Boardman, et al., 1969, p. 302). Zones of change are customarily
followed by zones of astogenetic repetition, in which morphologies
and pattern of budding are “endlessly repeatable.” Although auto-
zooids in V. regalis undergo no discernible changes in form, the
short zones in which they occur (PI. 6, fig. 4) are invariably fol-
lowed by a much longer (and presumably “unlimited”) zone in
which only stolons are produced (PI. 6, fig. 5). It, therefore, seems
probable that the sequential zonation evident in V. regalis is attri-
butable to the same fundamental processes underlying “astogenetic
zonation” in other Bryozoa. In V. regalis the only apparent morpho-
logical variation occurring within zones of change is a slight increase,
distally, in the spacing between autozooids — and even this minor
alteration is not always observed (PI. 6, fig. 3). Moreover, it seems
unrelated to the eventual cessation of zooid production along the
stolon involved.

Clearly, the abrupt change in the budding pattern of V. regalis
does not occur as the culmination of a readily observed sequence of
anatomical transformations. Whatever variation occurs in the distal
direction within the zone of change is not of the sort that is reflec-
ted among the autozooids.

It seems that the sudden shift to the production of bilaterally
opposite stolons may come about in response to the sudden attain-
ment of the “threshold” intensity of a regionally active morpho-
genetic gradient whose strength does not influence the morphology
of the autozooids, but which nonetheless is responsible for deciding
whether autozooids or stolons are produced. Slightly different bio-
chemical gradients in other bryozoans may account for the more
pronounced morphological variation often noted in zones of asto-
genetic change.

Voigtella? timorensis (Bassler), 1929 Pl. 6, fig. 6

1929. Partim Rhopalonaria timorensis Bassler, Palaontologie von Timor, (Stutt-
Gant), waetie16) Ps 28, p. 40. ipl) 235) ties 3) “(ply 255) te) 2) Vorgtella
sp.).

Material and occurrence. —

Figured: GPIUB Bassler Nr. 2b (lectotype), Permian, Noil
Boewan, Timor.

Type locality and horizon. — Noil Boewan, Timor; Permian.

Range. — Permian.

74 BULLETIN 301

Diagnosis. — Voigtella with zooids developing on either or both
proximal and distal side of parent stolon, but not in association with
lateral stolon on opposite side. Development of lateral stolons re-
stricted to zone of astogenetic repetition.

Description. — Autozooids with aperture and peduncle like those
in V. regalis; typically inclined to surface at estimated angle of 20-40
degrees, with distal end tilted distally along (parallel to) stolon.
Zooids probably tubular and elongated.

Heterozooids and ancestrula unknown.

Five or more zooids occur on either or both proximal and distal
side of stolon in zone of astogenetic change, followed by zone of
astogenetic repetition without autozooids, but with stolons arising
opposite one another.

Presence of tubulets and adventitious stolons uncertain.

Measurements. — Because the only known specimen of V.?
timorensis is preserved in an opaque and weathered crinoid columnal,
the length of the zooids cannot be determined accurately without
casting. Considering that the diameter of the zooids and stolons has
evidently been enlarged somewhat by solution of the substratum,
it is probable that the components of the unweathered colony com-
pared favorably in size with those of V. regalis (cf. Pl. 6, figs. 3, 6).

Discusston.— The poorly preserved lectotype of this species
(Pl. 6, fig. 6), is one of two specimens from the Permian of Timor,
upon which Bassler (1929, p. 40) based “Ropalonaria” timorensis.
The other specimen (GPIUB Bassler Nr. 2a) is possibly a bryozoan
boring, but its poor preservation prohibits definite assignment to
any recognized family.

V.? timorensis is readily distinguished from the two other
species of the genus by the occurrence of most (and perhaps all)
zooids in the absence of lateral stolons or other zooids on the op-
posite side of the parent stolon. In contrast, zooids of both V.
regalis and V. secunda typically occur as members of a zooid-stolon
or zooid-zooid pair. V.? timorensis is further distinguished from
V. regalis by often having many of the zooids on the distal side of
the stolon.

Zooids in the lectotype of V.? timorensis were probably en-
larged by weathering. It is, therefore, possible that this species is
a junior synonym of “Ropalonaria” permiana Bassler (PI. 6, fig. 7).

Borinc CTENOSTOMATE Bryozoa: PoHowsky 75

Even if the zooids of both type specimens were comparable in size,
the absence of visible stolons in association with the zooids of “R.”
permiana prohibits examination of the taxonomically critical bud-
ding pattern.

Voigtella secunda, n. sp. Pl. 7, figs. 1-4

Etymology. — L., secunda, following.

Material and occurrence. —

Figured: UCGM 40070 (holotype) (RAP 216), U. Cret.
(Maastrichtian; Ripley Fm.), exposures in Bogue Chitto Creek at
Rt. 22, Dallas Co., Alabama; UCGM 40065 (paratype) (RAP 106,
on UCGM 32771), U. Cret. (Maastrichtian, Ripley Fm., Coon
Creek Mbr.), Dave Weeks place, Coon Creek locality, McNairy Co.,
Tennessee.

Not figured: UCGM 40092 (RAP 116, on UCGM 32817),
40093 (RAP 114, on UCGM 32771), 40094 (RAP 110, on UCGM
16113), U. Cret. (Maastrichtian; Ripley Fm., Coon Creek Mbr.),
Dave Weeks place, Coon Creek locality, McNairy Co., Tennessee.

Type locality and horizon.— Bogue Chitto Creek at Rt. 22,
Dallas Co., Alabama; U. Cret. (Maastrichtian; Ripley Fm.).

Range. — U. Cret. (Maastrichtian).

Diagnosis. — Voigtella, in zones of astogenetic repetition, pro-
duce only stolons arising bilaterally opposite one another, but form
either or both paired stolons and zooids in zones of astogenetic
change. Zooids occur on either side (or both sides) of stolon.

Description. — Autozooids attached to stolon by short ped-
uncle entering zooid in distal half, at proximal end of low vane
extending to aperture. Zooids nearly cylindrical, expanding slightly
toward rounded proximal end, and often gently curved. Angle of
inclination varies widely but usually less than 45 degrees to surface
of substratum. Direction of inclination more variable than in V.
regalis but usually distal. Aperture circular to highly elongated;
sometimes slightly curved, and typically continuous with narrow
opening produced by vane and associated tubulets.

Heterozooids absent; ancestrula not seen. Budding pattern
shows considerable variability in zone of astogenetic change, with
either or both zooids and stolons appearing opposite one another.
Zooids occur on either side (or both sides) of stolon. Zone of asto-

76 BULLETIN 301

genetic repetition characterized by repeated production of paired
lateral stolons.

Row of several frontal pores or short tubulets often present on
frontal edge of vane. Adventitious stolons, if present, would be dif-
ficult to detect amid typically confused array of thin principal
stolons.

Measurements. — Lz (7) = approx. 0.4-0.6 mm. (Based on PI.
7, figs. 2-4).

Discussion. — Comparison of Plate 7, figures 3, 4, with Plate 6,
figures 2-4 reveals that the illustrated, well-preserved specimens of
V. secunda and V. regalis are distinct. In the absence of stolons the
distinctiveness would be less obvious, although the holotypes do show
a tendency toward differential length and inclination of the zooids.

Although the well-preserved holotypes show obvious differences,
less perfect specimens could be confused. However, as long as stolons
are present to clearly reveal their interrelationship with the auto-
zooids, there can be little doubt about the affinities of a boring to
one of these two species. Stolons must be present to distinguish
either of the Cretaceous representatives from V.? timorensis; the
budding pattern is of critical diagnostic value within the genus,
Voigtella.

Partly because of the varied angles and directions of zooidal
inclination in V. secunda, the budding pattern of this species may
seem obscure even when stolons are present. When several portions
of a colony are intergrown, interpretation becomes even more diffi-
cult. In Plate 7, figures 1, 3, a zone of repetition producing only
stolons can be detected. Newly budded stolons constitute a new zone
of astogenetic change, and unlike stolons in the corresponding zone
of V. regalis, they produce either or both paired and unpaired zooids
and stolons in various combinations. Zooids show no obvious prefer-
ence for the proximal or distal side of a stolon.

Slight weathering has probably produced minor alterations in
the apertures shown in Plate 7, figures 1-4, but the two elongated
apertures in figure 4 were probably abnormally large to begin with.
The orifice through which the polypide extruded could not have
occupied the entire area of the aperture. Rather, a large portion
of the body wall of these zooids must have been exposed above the
surface of the shell.

Borinc CTENOSTOMATE Bryozoa: PoHowsky 77

The surface aspect of V. secunda resembles that produced by
Spathipora comma (Soule) (PI. 18, fig. 8). The effect is produced
largely by the vanes in both species, but no close relationship can
be inferred on this basis. The budding pattern, thin stolons, and
absence of sac zooids in V. secwnda suggest that the vanes of Spathi-
pora and V. secunda are examples of convergence.

Voigtella spp. indet. Plt.6, figs.1,,7

1848. Talpina pungens Quenstedt, Petrefactenkunde Deutschlands, Abt. 1, Bd.
1 (Cephalopoden), (Tiibingen), p. 470, pl. 30, fig. 37 (partim).

1929. ?Rhopalonaria permiana Bassier, Palaontologie von Timor, (Stuttgart),
Lief. 16, Pt. 28, p. 40, pl. 235, fig. 1.

1962. Partim Spathipora prima Voigt, Upper Cretaceous Bryozoa of the Euro-
pean part of the U.S.S.R. and some adjoining areas, [in Russian], Mos-
cow Univ., pp. 60, 61, pl. 11, figs. 5, 6. (pl. 11, fig. 7 = Voigtella
regalis.)

1965. Nygmites pungens (Quenstedt), Pugaczewska, Acta Pal. Polonica, vol.
O15 Wap ills 2, saves, Ae

The boring Bryozoa listed above are assigned to Vozgtella, but
their affinities within this genus are somewhat uncertain. Unfor-
tunately, the stolons of the indicated specimens have been destroyed,
sO important aspects of the budding pattern can only be inferred.
On the basis of their occurrence and preserved features, all except
“Ropalonaria” permiana are probably Vorgtella regalis.

Family PENETRANTIIDAE Silén, 1946

Diagnosis. — Pedunculate boring Bryozoa with vaneless zooids
essentially vertical in substratum. Peduncle inserted in distal half
of zooid. Ovicelled gonozooids typically present. Zooids typically
with operculum.

Range. —L. Jur.-Recent.

Genus PENETRANTIA Silén, 1946

1880. Spatipora Fischer, Seguenza, R. Accad. Lincei (Rome), Atti, ser. 3, vol.
6, p. 128, pl. 12, fig. 17, (mom null.). (Non Spathipora Fischer, 1866, Mus.
nat. Hist. nat (Paris), Nouv. Arch., T. 2, pp. 309, 310, pl. 11, figs. 4, 4a.)

1907. Terebripora d’Orbigny, Norman, Ann. Mag. Nat. Hist., ser. 7, vol. 20, pp.
208, 209, pl. 9, figs. 5-7. (Non Terebripora d’Orbigny, 1847, Voyage dans
Amérique méridionale, T. 5, pt. 4, pp. 22, 23, pl. 10, figs. 16, 17.)

1946. Penetrantia Silén, Ark. f. Zool., Bd. 38B, pp. 2-7, text-figs. 1-8.

1947. Penetrantia Silén, Silén, Ark. f. Zool., Bd. 40A, pp. 4-40, text-figs. 1-57.

1950. Penetrantia Silén, Soule, J. D., Amer. Microsc. Soc., Trans., vol. 69, pp.
360-362, pl. 1, figs. 1, 3, 4; pl. 2, fig. 1.

1956. Penetrantia Silén, Silén, Roy. Soc. New Zealand, Trans., vol. 84, pp. 93,
94, text-figs. 1-4.

78 BULLETIN 301

1963. Penetrantia Silén, Soule, Amer. Mus. Novit., No. 2144, pp. 22, 23, 27.

1966. ‘“‘Penetrantia” Silén, Boekschoten, Palaeogeog., Palaeoclim., Palaeoecol.,
vol. 2, pp. 364-366, text-fig. 9.

1969. Penetrantia Silén, Soule, J. D. and Soule, D. F., California Acad. Sci.,
Occas. Pap,, No. 78, pp. 3; 5, 7, text-figs. 1, 2-5, 12, 13.

1970. Iramena Boekschoten, Trace Fossils, (Liverpool), pp. 45, 46, text-fig. 1.

1973. Penetrantia Silén, Voigt and Scule, Jour. Paleont., vol. 47, pp. 30, 31, pl.
4, figs. 1-3, 5, 4.

Type species.—Penetrantia densa Silén, 1946; Silén (1946,
pz):

Diagnosis. — Penetrantidae with gonozooids.

Range.— tL. Cret. (Aptian), U. Cret. (U. Coniacian or L.
Santonian )-Recent.

Discussion. — The name, Penetrantia, has usually been applied
only to Recent bryozoans, but a few fossils have also been reported
— initially by Boekschoten (1966, p. 366) from the Pleistocene.
Later, he found specimens in the Pliocene as well (1967, p. 319).
However, in both of these publications, Boekschoten placed the
generic name within quotation marks — explaining that this was
done because his work was concerned with borings, whereas the
species under consideration (P. concharum Silén) “. . . was described
on the soft-part anatomy primarily” (Boekschoten, 1966, p. 365).
More recently (1970, p. 45), Boekschoten erected the “ichnogenus”
and “ichnospecies,” Jramena danica, for some middle Danian borings
with “round to reniform (zooid cavity) apertures situated in alter-
nating positions laterally to and close by the tunnels.” Although I
have not examined the type material from Fakse, Denmark, in-
vestigation of the anatomy and stratigraphic range of various
bryozoan borings suggests that Jramena damica Boekschoten is cer-
tainly a Penetrantia. Grounds for rejecting the application of trace-
fossil nomenclature to bryozoan borings were discussed in an earlier
publication (Pohowsky, 1974).

Borings attributable to Penetrantia have been described from
the Coniacian or Santonian of Austria (P. gosaviensis Voigt and
Soule, 1973). Additional representatives are reported from the
Maastrichtian of the United States and the Santonian of the
U.S.S.R. (See discussion of Spathipora sibirica). A probable Pene-
trantia derives from the Aptian of England. The English and Russian
specimens were observed on the shelis bearing the type specimens of
“Terebripora” (?) bassleri Voigt and Soule and “T.” (?) stbirica
Voigt and Soule, respectively.

Borinc CTENOSTOMATE BryYozoa: PoHOwskKY 79

Borings of Penetrantia are characterized by ovicells on ped-
unculate zooids orientated vertically in the substratum. In many
species, the apertures are noticeably reniform (Text-fig. 3A; Pl. 10,
figs. 1, 3, 5), and may appear to be chamfered. As these features of
the aperture are not present in the type species (P. densa Silén —
which seems to be unique in its ability to secrete calcium carbonate)
it may be necessary to remove some species to a new genus.

This description of bryozoan-secreted calcareous structures in
Penetrantia (P. densa) is the first documentation of such features
in any genus of boring bryozoans. The opinion of Voigt and Soule
(1973, p. 30) that Penetrantia’s double body wall, “. . . probably
an epithelium and an organic matrix, . . . suggests calcification of the
colony” was expressed without substantiation. The subsequent men-
tion of a “calcified apertural rim” would seem to suggest secretion
by the bryozoan itself, but no species are mentioned and illustrations
are wanting. Moreover, it has never been reported that Penetrantia
actively secretes the “central denticle” or the “lateral pointed pro-
jections” that Soule and Soule (1969b, p. 799) observed in some
species of the genus. These projections within the zooid cavity are
commonly presumed to be remnants of the molluscan shell that have
been carefully sculpted by the zooid. Except in P. densa, this may
be so.

Silén (1947, p. 4) indicated that in Penetrantia concharum and
P. brevis the apertures are often kidney-shaped, having been formed
so that “. . . a broad, convex projection of the shell remains there on
the side towards which the free margin of the operculum and thus
the anal side of the zooid . . . is directed . . .” (Text-fig. 3A). His
reported mention of a “calcareous tooth” (Soule and Soule, 1969b,
p- 799) is inaccurate; the “broad, convex projection of the shell” of
Silén (1947, p. 4) is not equivalent to the “median denticle” of
Soule and Soule (1969a, p. 7) and Voigt and Soule (1973, p. 30) or
the “central denticle” of Soule and Soule (1969b, p. 799). The
Soules clearly regarded the central denticle to be analogous to the
lyrula of cheilostomes — a feature located on the proximal side of
the aperture, the side to which the operculum is hinged.

The ancestrula and early budding pattern of Penetrantia have
been described in only one Recent species, P. concharuwm Silén
(Silén, 1947, p. 4, text-fig. 3), though Silén’s illustration might not

80 BuLtetin 301

depict the exact manner in which the three initial stolons of that
species arise. The configuration may be more like that in the Cre-
taceous specimens illustrated in Plate 9, figures 4, 7, where three
stolons arise from a short “peduncle” produced by the ancestrula.
The colonies with an ancestrula and five or six stolons in Plate 9,
figures 8-10 have not produced autozocids, so they are here assigned
to Penetrantia with some doubt.

Although some species might produce stolons in a diagnostic
manner either or both near the ancestrula and in subsequent asto-
geny, this possibility has yet to be investigated. Recent species of
Penetrantia have been recognized primarily on the basis of the char-
acters of the zooids (eé.g., number of tentacles, size and shape of the
autozooids and gonozooids). Fortunately, a number of these taxo-
bases are expressed in the borings.

One of the most noteworthy structures in Penetrantia is the
trapdoor-like operculum that closes the zooecium when the polypide
is retracted. The setigerous collar typically found in ctenostomes is
absent (Silén, 1947, p. 11). Opercula are pervasive in the Cheilo-
stomata, and the presence of this feature in all Recent species of
Penetrantia was cited by Soule and Soule (1969b, pp. 800, 801) as a
principal reason for ranking this genus with the cheilostomes. Silén
(1947, p. 33) defended his belief that the operculum of Penetrantia
is analogous to that of the cheilostomes, and the Soules (1969b, p.
799) have held the operculum-related accessory features (“median
denticle,” “central denticle,’ and paired “lateral pointed projec-
tions”) found in some species of Penetrantia (Soule and Soule,
1969a, p. 7; 1969b, p. 799; Voigt and Soule, 1973, p. 30) to be “ana-
logous” to the lyrula and lateral cardelles of cheilostomes such as
Parasmittina. Substantial proof that opercula can develop in non-
cheilostomate bryozoans is manifestly evident in the Middle Jurassic
to Upper Cretaceous cyclostomate superfamily, Salpingoidea von
Hagenow (Ryland, 1970, p. 137). Furthermore, the aperture of
Flustrelidra Bassler (Ctenostomata) is closed by a pair of lips, one
of which is controlled by muscles (Ryland, 1970, p. 32). The oper-
culum of Penetrantia may be an example of convergent evolution. If
so it is not surprising that analogous devices to assist in the articula-
tion of the operculum (Soule and Soule, 1969a; 1969b, p. 799) de-
veloped concurrently. Voigt (in Voigt and Soule, 1973, p. 30) has

Borinc CTENOSTOMATE Bryrozoa: PoHowsky 81

already conjectured that some cheilostomatous features (e.g., oper-
cula) may exist within the Ctenostomata (Soule elected to abstain
from this speculation). The discovery of calcified opercula in P.
densa Silén (Pl. 11, figs. 1-3) during this study suggests that the
structure of the operculum and associated features in Penetrantia
warrant more detailed investigation.

In removing Penetrantia to the cheilostomes, Soule and Soule
(1969b) also emphasized its possession of ovicells. Unless one is
willing to impugn the apparent affinities of Spathipora cheethami
(Middle Jurassic) with the ctenostomes, there is little question that
ovicells can occur in this order as well as in the Cheilostomata. Ovi-
cells may also be present in S. elegans Fischer (Recent, Chile).

Another line of evidence which may someday help to affirm the
ctenostomate nature of Penetrantia is its possible descendant rela-
tionship to Haimeina michelini (Terquem) (U. Trias., L. Jur.).
Haimeina lacks ovicells and shows an early astogenetic sequence un-
like that known in some Penetrantia, but the form and ontogeny of
its autozooids are remarkably like those in P. densa (cf. Pl. 9, fig.
te Pl. 12, tig: 2).

Other factors which may prove useful in evaluating the ordinal
affinities of Penetrantia include the peculiar body wall with two
layers of cuticle (Silén, 1946, p. 2; 1947, p. 8) and the appearance
(in specimens Soule believed to be P. densa) of the zooid muscula-
ture in the following order during ontogeny: 1. retractors, 2. aper-
turals, 3. parietals (Soule, 1954, p. 27; Soule and Soule, 1969b, p.
801). With two possible exceptions, this sequence differs from that
reported in some ctenostomes [including Spathipora comma (Soule)
and Immergentia californica Silén] examined by Soule in 1954 —
but if Penetrantia is aligned with the Cheilostomata, it differs from
all other members of that order by living totally immersed in shells.
Unfortunately, the unusual body wall of Penetrantia is presently of
little assistance in taxonomy; its double cuticle is evidently unique
in the Bryozoa.

In conclusion, the taxonomic position of Penetrantia Silén re-
mains uncertain — but there exists evidence that Silén’s (1947) as-
signment of the genus to the Ctenostomata was correct.

Penetrantia densa Silén, 1946 Pl. 11, figs. 1-7; Pl. 12, figs. 1-3

82 BuLLeETIN 301

1946. Penetrantia densa Silén, Ark. f. Zool., Bd. 38B, pp. 2-4, text-figs. 1-4.

1947. Penetrantia densa Silén, Silén, Ark. f. Zool., Bd. 40A, pp. 4-40 (partim),
text-figs. 2, 9, 10, 22, 32-41, 48-56.

1950. Penetrantia densa Silén, Soule, J. D., Amer. Microsc. Soc., Trans., vol.
69, p. 360, pl. 1, text-fig. 1.

1963. Penetrantia densa Silén, Soule, J. D., Amer. Mus. Novit., No. 2144, pp.
22, 23.

Material and occurrence. —

Figured: NHR 2351b (paratype: fragments + SEM STUB
10), NHR 2351c (paratype: RAP 244, specimen 1), Recent, near
shore, “at the lighthouses,’ Cape of Good Hope, South Africa.

Not figured: NHR 2350 (holotype), NHR 2351a (paratypes on
34 small gastropods), Recent, near shore, “at the lighthouses,” Cape
of Good Hope, South Africa; NHR 2352 (paratype), Recent, near
shore, Port Nolloth, South Africa.

Type locality and range.—near shore, “at the lighthouses,”
Cape of Good Hope, South Africa; Recent.

Diagnosis. — Penetrantia with zooids and stolons typically sur-
rounded by calcium carbonate secreted by the bryozoan. Autozooids
taper proximally, beyond midlength. Gonozooids as long as auto-
zooids. Stolons flattened laterally.

Additional description.— Zooids often closely spaced; some-
times separated by less than diameter of autozooids. Autozooid aper-
tures circular or subcircular; often raised by one or more layers of
white calcium carbonate deposits lining zooid chamber. Zooids oc-
casionally closed by calcareous shield initially developed as horseshoe-
shaped reinforcement of operculum. Small calcareous processes for
articulation of operculum occasionally present near distal end of
zooids. Autozooids typically with low, longitudinal ridge, beginning
near proximal end. Zooids taper gently toward proximal end and are
abruptly contracted at distal end.

Gonozooids with markedly oval apertures arranged with major
axis parallel to stolon. Distal edge of aperture (distal relative to
growth of stolon) typically with higher rim of bryozoan carbonate
deposits than proximal rim. Ovicell connected with aperture and
expanded gradually toward proximal end of zooid but not reaching
to proximal tip.

Stolons usually arise opposite one another and bear many short
tubulets that tend to be oval in cross section. Peduncles with slight
constriction near point of departure from stolon.

Measurements. —Lz (10) = 0.48-0.62 mm. (Based on PI. 12,

Borinc CTENOSTOMATE Bryozoa: PoHowsky 83

fig. 3, and 5 zooids of holotype). Autozooid diameter (5) = 0.10-
0.18 mm. (Based on direct measurement of holotype).

Discussion. — Penetrantia densa appears to be unique among
the boring Bryozoa in its ability to secrete calcium carbonate. White
calcareous deposits are often seen around both zooids and stolons.
The thickness of the deposits produced in a given area is possibly
controlled by microenvironmental influences — notably the local
rate of attrition or chemical dissolution of the shell (cf. Pl. 11, figs.
2,3). In Plate 11, figure 5, there is little evidence of wear, and any
deposits produced by the broyozoan are apparently masked by the
external layers of the gastropod shell. Some deposits may also be
hidden by the soft parts of the bryozoan.

Silén (1947, pp. 26, 27, text-fig. 56) recognized the presence
of “raised . . . tubes” around the zooids of P. densa, but he con-
sidered them to be portions of the mollusk shell that had been
chemically altered by the acid he suspected was employed in the
boring process.

The assumption that Penetrantia bores by means of phosphoric
acid coincides well with the observation that the surroundings of the
zooid hollows are more resistant against dissolution by sea water than
are the parts of the shell uninfluenced by the acid: phosphate of lime
is more difficult to dissolve than carbonate of lime, as is well known.
(Silén, 1947, p. 30)

Although the shell surrounding many parts of the holotype is dis-
colored (“bleached’’), tests conducted on a paratype (see section on
anatomy and biology of boring bryozoans) suggest that the raised,
white material surrounding the stolons and zooid cavities is domi-
nantly or entirely calcium carbonate, scanning electron microscopy
reveals that deposits secreted by the bryozoan are present in many
parts of some colonies (PI. 11, figs. 2, 3).

Silén (1947, p. 14) reported that an apparent brown body
(degenerated polypide) was almost always present in the zooids
of P. densa which he examined. Further evidence that zooids under-
go periodic regeneration in this species is provided by zooid cavities
lined with two or more concentric layers of calcium carbonate (PI.
11, fig. 2, bottom right). Some zooids appear to be tightly sealed
by a calcareous lid (e.g., Pl. 11, fig. 3, bottom right), and I suggest
that these zooids may be undergoing regeneration. The partial
covering seen in the zooid cavity at the top of Plate 11, figure 3 may
have been in the process of dissolving after regeneration was com-

84 Bu.tetTIn 301

pleted. It seems likely that closure came about by a gradual calcifi-
cation of the operculum. Several stages in this process may be seen
in Plate 11, figures 2-4 (arrows).

The distinct constrictions seen in the peduncles of P. densa (PI.
12, fig. 2) appear to coincide precisely with the internal “dia-
phragms” observed by Silén (1947, p. 15, text-figs. 32, 36). I have
been unable to discern similar evidence of septulae in the borings
of other bryozoans.

One of the paratypes, NHR 2352, occurs only on two or three
shell fragments derived from the columella of a small gastropod. The
exterior of this shell bears numerous specimens of another boring
organism, many individuals of which are of the same diameter as
zooids of P. densa. Unfortunately, many of the borings of the holo-
type have been destroyed — probably during treatment of the
gastropod shell to remove the soft parts of the colony. The best-
preserved borings are located just within the shell’s aperture, and
several autozooids in that region show evidence of bryozoan-de-
posited calcium carbonate.

Penetrantia brevis Silén, 1946

1946. Penetrantia brevis Silén, Ark. f. Zool., Bd. 38B, p. 4, text-figs. 5, 6.
1947. Penetrantia brevis Silén, Silén, Ark. f. Zool., Bd. 40A, pp. 4-40 (partim),
text-figs. 24-26, 42, 44-47.

Type locality and range. — San Antonio, Ibiza, Baleares, Medi-
terranean; Recent.

Diagnosis. — Penetrantia with gonozooids about half as long
as autozooids, and with ovicell extending (proximally) beyond por-
tion of zooid bearing peduncle. Autozooids 0.7 mm long, with proxi-
mal end blunt and curved in direction of peduncle. Stolons flattened

laterally. (Based on Silén, 1946.)

Penetrantia parva Silén, 1946

1946. Penetrantia parva Silén, Ark. f. Zool., Bd. 38B, pp. 4, 5, text-fig. 7.

1947. Penetrantia parva Silén, Silén, Ark. f. Zool., Bd. 40A, pp. 4-40 (partim),
text-figs. 7, 23.

1969. Penetrantia parva Silén, Soule, J. D. and Soule, D. F., California Acad.
Sci., Occas. Pap., No. 78, pp. 3, 5, text-fig. 1.

Type locality and range.— Moko Hinau Isl., Hauraki Gulf,
New Zealand; Recent.
Diagnosis — Penetrantia with autozooids about 0.4 mm long

Borinc CTENOSTOMATE Bryozoa: PoHowsky 85

and with pointed proximal end. Gonozooids shaped like those of P.
densa. Stolons terete. (Based on Silén, 1946.)

Penetrantia concharum Silén, 1946 Pl. 10, fig. 8

1946. Penetrantia concharum Silén, Ark. f. Zool., Bd. 38B, pp. 5, 6, text-fig. 8.
1947. Penetrantia concharum Silén, Silén. Ark. f. Zool., Bd. 40A, pp. 4-40 (par-
tim), text-figs. 1, 3-6, 8, 11-16, 19-21, 27-31, 43, 57.
1950. Penetrantia concharum Silén, Soule, J. D., Amer. Microsc. Soc., Trans.,
vol. 69, pp. 360, 361.
Type locality and range. —N. of Flatholmen, Gullmars Fjord,
west coast of Sweden; Recent.
Diagnosis. — Penetrantia with ovicells beginning and ending
distinctly short of proximal and distal ends of gonozooid. Autozooids

about 0.5 mm long, with pointed proximal end. Stolons terete.

(Based on Silén, 1946.)

Penetrantia sileni Soule, 1950

1950. Penetrantia sileni Soule, J. D., Amer. Microsc. Soc., Trans., vol. 69, pp.
361, 362, pl. 1, figs. 3, 4; pl. 2, fig. 1.

Type locality and range.— San Benito Islands, west coast of
Baja California, Mexico; Recent.

Diagnosis. — Penetrantia with gonozooids about half as long as
autozooids, and with ovicell not extending (proximally) beyond por-
tion of gonozooid bearing peduncle. Autozooids about 0.36 mm long.
Stolons usually terete. (Based on Soule, 1950a.)

Penetrantia irregularis Silén, 1956

1956. Penetrantia irregularis Silén, Roy. Soc. New Zealand, Trans., vol. 84,
pp. 93, text-figs. 1-4.

Type locahty and range.— Otago Peninsula, Little Papanui,
New Zealand; Recent.

Diagnosis. — Penetrantia with numerous adventitious stolons
arising from zooids, proximal to peduncle. Gonozooids about half as
long as autozooids, with ovicell not extending (proximally) beyond
portion of gonozooid bearing peduncle. Autozooids about 0.65 mm
long. Stolons terete. Tubulets absent. (Based on Silén, 1956).

Discussion. — Silén (1956, p. 93) reported that the “holes”
produced by the zooids of this species are circular. Presumably, this
refers to the apertures as well as the other portions of the zooid cavi-
ties. If so, P. irregularis differs in this regard from P. sowlet, which
possesses reniform apertures.

86 BULLETIN 301

Penetrantia operculata Soule and Soule, 1969

1969. Penetrantia operculata Soule, J. D. and Soule, D. F., California Acad.
Sci., Occas. Pap., No. 78, pp. 5, 7, text-figs. 2-5, 12, 13.

Type locality and range. — Haena Bay, Kauai, Hawaiian Is-
lands; Recent.

Diagnosis. — Penetrantia with gonozooids about half as long as
autozooids, and attached to principal stolon by peduncle arising from
side of ovicell directly opposite body of gonozooid. Proximal end of
gonozooid bluntly rounded and flattened in plane of ovicell and
peduncle. Autozooids 0.45-0.50 mm long. (Based on Soule and
Soule, 1969a.)

Discussion. — Soule and Soule (1969a, pp. 5, 6, text-fig. 4) in-
dicated that the aperture of P. operculata has “a blunt projection
extending into the opening from the lower rim.” They also remarked
that “the aperture of the zooid proper lies below the shell surface
and bears a prominent median denticle (lyrula), as well as lateral
hinge denticles (cardelles) for articulation of the operculum.”

An apparently unique feature of P. operculata which was
illustrated, but not otherwise mentioned, by Soule and Soule is the
attachment of the peduncle to the ovicell of the gonozooid. In all ac-
counts and illustrations of other species of this genus, gonozooids
are attached to the principal stolon by a peduncle arising from the

zooid body itself.

Penetrantia soulei, n. sp. Pl. 10, figs. 5, 6

Etymology. — Named in honor of J. D. Soule.

Material and occurrence. —

Figured: BMNH D.52292 (holotype) (on SEM STUB 28) (on
BMNH G.70412), Plio-Pleistocene, Kaloot, S. Walcheren, Nether-
lands; BMNH D.52293 (paratypes) (fragments + casts of borings
on shell bearing holotype) (on BMNH G.70412).

Type locality and range. — Kaloot, S. Walcheren, Netherlands;
Plio-Pleistocene.

Diagnosis. — Penetrantia with numerous adventitious stolons
arising from autozooids and gonozooids, proximal to peduncle, and
immediately giving rise to two additional stolons.

Additional description. — All zooids with rounded proximal end
which sometimes appears to be swollen. Gonozooids slightly more

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 87

than half as long as autozooids, with subspherical ovicell placed be-
tween proximal and distal ends. Zooid apertures reniform.

Measurements.—Lz (5) = 0.40-0.48 mm; length of gono-
zooids (2) = 0.32-0.34 mm. [Based on direct measurement of holo-
type (cast) ].

Discussion. — The peculiar, branching adventitious stolons seen
in P. soulet are unknown in other species of this genus. One or more
of these features typically arise from all zooids in a colony. Ad-
ventitious stolons usually produce bilaterally opposite branches near
the zooids, so that three processes appear to diverge from a point
and grow toward the surface of the substratum (PI. 10, fig. 6).

Silén (1956, p. 93) reported the presence of numerous adventi-
tious (“secondary”) stolons in P. irregularis Silén (Recent, New
Zealand). However, the adventitious stolons in that species appar-
ently do not regularly undergo the bilaterally opposite branching
seen in P. soulet. P. irregularis also differs in having longer auto-
zooids (Lz = about 0.65 mm) and apertures which are circular, ac-
cording to Silén.

Penetrantia spp. indet. Pl. 9, figs. 2-10; Pl. 10, figs. 1-4, 7;
Pl. 12, figs. 46; Text-figs. 3A, 6B4, 6D

1880. Spatipora laxa Seguenza, R. Accad. Lincei (Rome), Atti, ser. 3, vol. 6,
p. 128, pl. 12, fig. 17, (nom. null.).

1907. Terebripora ditrupae Norman, Ann. Mag. Nat. Hist., ser. 7, vol. 20, pp.
208, 209, pl. 9, figs. 5-7.

1909. Terebripora ditrupiae Norman, Borley, Roy. Comm. Coast Erosion, Rpt.
2, vol. 2, pt. 2, appendix 29, p. 1, (nom. null.).

1966. Penetrantia concharum Silén, Boekschoten, Palaeogeog., Palaeoclim.,
Palaeoecol., vol. 2, pp. 364-366.

1970. Iramena danica Boekschoten, Trace Fossils, (Liverpool), pp. 45, 46, text-
figeele

1973. Penetrantia gosaviensis Voigt and Soule, Jour. Paleont., vol. 47, pp. 30,
31, pl. 4, figs. 1-3, 5, 24.

Except for P. densa, identification of Penetrantia species on the
basis of their surface aspect is impossible — but specificially diag-
nostic patterns of stolonal branching may exist, particularly at the
ancestrula. Until such patterns or other taxonomically useful “super-
ficial” characters are investigated, casting will be mandatory to
classify borings attributed to this genus. The above species could
not be cast, so their anatomy remains too poorly known to permit
meaningful comparison with the Penetrantia already discussed.

Penetrantia is known from several widespread occurrences in
the Cretaceous. Penetrantia gosaviensits Voigt and Soule (Upper

88 BULLETIN 301

Coniacian or Lower Santonian) is here assigned to Penetrantia
Silén (rather than to Haimeima Terquem and Piette) because the
holotype possesses several zooids with slightly larger, oval apertures
reminiscent of those of the gonozooids in P. densa, a species it re-
sembles in other respects, despite its poor preservation.

The zooids illustrated by Voigt and Soule (1973, pl. 4, fig. 4)
are not demonstrably part of the holotype shown in the other figures
of the same plate. This is unfortunate, for one of the zooids in figure
4 is certainly an ancestrula. The colony in figure 4 may be a species
of Spathipora Fischer with the zooids orientated nearly vertically.

The supposed “induration” of the calcareous substratum im-
mediately adjacent to the borings of P. gosaviensis (Voigt and
Soule, 1973, p. 31) is perhaps better interpreted otherwise. It seems
more likely that the ferruginous filling of the boring has acted as a
resistant core that has protected the nearby shell layers from
abrasion.

An unquestionable Penetrantia from the Upper Santonian of
the U.S.S.R. occurs in association with the holotype of Spathipora
sibirica (Voigt and Soule). The Penetrantia involved were mis-
takenly believed to be part of the new species (see discussion of
S. sibirica).

Another, probable example of Penetrantia is present on the shell
bearing the holotype of “Terebripora (?)” basslert Voigt and Soule.
If this Aptian specimen from Faringdon, England, is a Penetrantia,
it is certainly the earliest record of the genus to date. Although no
stolons or gonozooids can be detected in the opaque substratum, the
zooids are orientated vertically, and many have the reniform aper-
ture known only in Penetrantia.

The Upper Cretaceous specimens illustrated in Plate 9, figures
2-10 are the earliest known representatives of the genus in North
America. The borings shown in Plate 9, figures 8-10 are assigned to
Penetrantia with reservation.

Based on its original description and illustration, “Spatipora”
laxa Seguenza (upper Miocene, Italy) undoubtedly belongs with
Penetrantia, as does “Terebripora” ditrupae Norman (PI. 10, fig. 7).
The holotype of this Recent species even retains evidence of the
“chitinous” operculum within some of the zooid cavities.

The specimens enumerated below are also assigned to Pene-

Borinc CTENOSTOMATE Bryozoa: PoHowsky 89

trantia Silén, though the young colonies in UCGM 40073 (PI. 9,
figs. 8-10) are placed there with doubt.

Material and occurrence. —

Figured: UCGM 40067 (RAP 102), 40072 (RAP 107, colony
A), 40073 (RAP 105), U. Cret. (Maastrichtian; Ripley Fm., Coon
Creek Mbr.), Dave Weeks place, Coon Creek locality, McNairy
Co., Tennessee; BMNH D.52294 (fragments + SEM STUB 12)
(on BMNH 20793a), Miocene, Touraine, France; BMNH D.52295
(fragments + SEM STUB 22), Pliocene, Wanganui, New Zealand;
BMNH 11.10.1 88B (holotype of “Terebripora” ditrupae Norman),
Recent, Shetland; BMNH D.52296 (fragments + SEM STUB 5)
(RAP 241, shell B), Recent, Bay of Santos, Brazil.

Not figured: Colonies associated with holotype of Spathtpora
sibirica (Voigt and Soule) (ZGM 22/9757), U. Cret. (U. San-
tonian), Mount Chodsa Kasian, S. W. Schaartus, Tadschikistan,
U.S.S.R.; UCGM 40102-40108, U. Cret. (Maastrichtian; Ripley Fm.,
Coon Creek Mbr.), Dave Weeks place, Coon Creek locality, Mc-
Nairy Co., Tennessee; UCGM 40109 (RAP 216), U. Cret. (Maas-
trichtian; Ripley Fm.), exposures in Bogue Chitto Creek at Rt. 22,
Dallas Co., Alabama; UCGM 40110 (RAP 215), U. Cret. (Maas-
trichtian; Ripley Fm.), large exposure along Rt. 27, 24 mi. N. of
Lumkin, Stewart Co., Georgia; BMNH D.52297 (on BMNH L.L.-
14860.9), Miocene, Touraine, France; BMNH D.52298 (on BMNH
45929), Miocene, Touraine, France; BMNH D.52299 (RAP 324),
probably Miocene, “Lapugy,” Transylvania, Rumania; BMNH
D.52300 (on BMNH 52418), Miocene (probably Tortonian (Grun-
der Schichten?)), Grund, Austria; BMNH D.52301 (on BMNH
82602), Pliocene (Astian), Buccheri, Sicily; BMNH D.52302 (on
BMNH G.624), Pliocene (Plaisancian), Bordighera, Italy; BMNH
D.52303 (on BMNH 68307), Pliocene (Astian), Valdandona, Italy?;
BMNH_ D.52304 (fragments + SEM STUB 25) (on BMNH
82698), Pliocene (Astian), Altavilla, near Palermo, Sicily; BMNH
D.52305 (on BMNH G.13967, Pliocene (Astian), Asti, Piedmont,
Italy; BMNH D.52306 (on BMNH G.G.12944), Pliocene (Caloosa-
hatchee Fm.), approx. 2.7 mi. N.W. of bridge, Harney Pond Canal,
Glades Co., Florida; BMNH D.52307 (on BMNH G.59323), Plio-
cene, Piacenza, Italy; BMNH D.52308 (on BMNH G.13829), al-
most certainly Pliocene, Castel Arquato, Italy; BMNH D.52309

90 BULLETIN 301

(RAP 314), Pliocene, Perpignan, Pyrénées Orientales, France;
BMNH D.52310 (on BMNH G.9510), Pliocene, Wanganui, New
Zealand; BMNH D.52311 (RAP 317), Pliocene, Wanganui, New
Zealand; BMNH_ D.52312 (RAP 304), Pliocene, “Fossil Creek,”
Maraekakaho, Hawkes Bay, New Zealand; BMNH D.52313 (RAP
241-1, shell B), Recent, Bay of Santos, Brazil.

Genus HAIMEINA Terquem and Piette, 1865

1855. Vioa? Nardo, Terquem, Soc. géol. France, Mém., sér. 2, T. 5, pp. 334,
335, pl. 26, fig. 6.

1856. ‘“Wurmlécher” Quenstedt, Der Jura, (Ttibingen), p. 46, pl. 4, figs. 1, 2.

1865. Haimeina Terquem and Piette, Soc. géol. France, Mém., sér. 2 ,T. 8, p.
133.

1866. Terebripora (?) d’Orbigny, Fischer, Mus. nat. Hist. nat. (Paris), Nouv.
Arch., T. 2, p. 306. (Non Terebripora d’Orbigny, 1847, Voyage dans
Amérique méridionale, T 5, pt. 4, pp. 22, 23, pl. 10, figs. 16, 17.)

Type species. — Haimeina michelim (Terquem), 1855; mono-
type.
Diagnosis. — Penetrantiidae without gonozooids.

Range. — U. Triassic (Rhaetian)- L. Jurassic (M. Lias).

Discussion. — Haimeina is known only from the type species.

Haimeina michelini (Terquem), 1855 Pl. 6, figs. 1-8; Pl) So fieaie
Text-figs. 2H, 6C2

1855. Vioa? michelini Terquem, Soc. géol. France, Mém., sér. 2, T. 5, pp. 334,
335, pl. 26, fig. 6.

1856. “Wurmlécher” Quenstedt, Der Jura, (Tubingen), p. 46, pl. 4, figs. 1, 2.

1865. Haimeina michelini (Terquem), Terquem and Piette, Soc. géol. France,
Meém., sér. 2, IT. 8, p. 133.

1866. Terebripora (?) quenstedti Fischer, Mus. nat. Hist. nat. (Paris), Nouy.
Arch., T. 2, p. 306.

Material and occurrence. —

Figured: BMNH D.52284 (on BMNH L.6537), L. Jur. (L.
Lias), Mickleton, Gloucestershire, England; BMNH_ D.52285
(fragments + SEM STUB 14) (on BMNH L.17606), L. Jur. (M.
Lias, Marlstone), Stroud, Gloucestershire, England.

Not figured: BMNH D.52286 (on BMNH L.23031), Trias.
(Rhaetian, Késsener Sch.), Marmorgraben bei Mittenwald, Ger-
many; BMNH D.52287 (on BMNH L.54603), L. Jur. (L. Lias), pit
between S. Cave and N. Cave, Yorkshire, England; BMNH D.52288
(on BMNH L.3932), L. Jur. (L. Lias), Lyme Regis, Dorset, Eng-
land; BMNH D.52289 (fragments + cast) (on BMNH L.13618),

L. Jur. (L. Lias), Nelson quarry, Stockton, Warwickshire, England;

Borinc CTENOSTOMATE Bryozoa: PoHowsky 9]

UCGM 40101 (RAP 217), L. Jur. (Lias alpha, Psilonotenkalk),
Stuttgart-Degerloch, Germany; BMNH D.52290 (on BMNH
67362), L. Jur. (M. Lias), Chideock, Bridport, England; BMNH
D.52291 (on BMNH 65983), L. Jur. (M. Lias), “Curcey,” France.

Type locahty and horizon. — Hettange, Moselle, France; L.
Jur. (L. Lias, Hettangian, sandstone).

Range. — U. Triassic (Rhaetian) — L. Jurassic (M. Lias).

Diagnosis. — Same as for the genus, because it is monotypic.

Description. — Autozooids more or less vertical in substratum
but with pronounced tendency to have distal end slightly tilted away
from associated principal stolon, and in direction of stolon’s growth.
Peduncle enters zooid at midlength, or slightly distal thereto. Zooids
nearly circular in cross section, except through region just distal
to proximal end, where broad, low ridges arise on side opposite ped-
uncle. Zooids expanding distally from pointed proximal tip; ridge
becoming undetectable near level of peduncle. Aperture circular or
nearly so, with diameter slightly less than that at midpoint of zooid.
Heterozooids unkrown.

Ancestrula circular in cross section, tilted slightly from vertical,
budding proximally to produce an autozooid and two stolons directed
laterally, in opposite directions and at right angles to vertical plane
between ancestrula and first autozooid. Both stolons then bifurcate,
with autozooid forming between new stolons at points of departure.

Subsequent budding produces zooids tending to occur opposite
one another but often appearing singly. Zooids widely separated on
newly formed stolons, but become more densely spaced as additional
budding produces zooids among initial ones. Single or paired prin-
cipal stolons arise laterally from other stolons at widely spaced inter-
vals. Occasionally, thin, flattened stolons arise from frontal surface
of other stolons and grow nearly parallel to them. These stolons
never produce zooids.

Short, laterally flattened tubulets sometimes formed on frontal
surface of principal stolons. Stolons usually terete but sometimes
flattened laterally.

Measurements. —Lz (10) = 0.39-0.50 mm. (Based on PI. 8,
figs. 7, 8).

Discussion. — Haimeina michelim, known primarily from the

92 BULLETIN 301

Lower and Middle Lias of Europe, may be ancestral to Penetrantia
Silén. A comparison of the anatomy and ontogeny of the specimens
illustrated in Plate 9, figure 1 and Plate 12, figure 2 reveals some
striking similarities.

Unfortunately, some important evidence that would be useful in
evaluating this relationship is unavailable. Except for a possible
Aptian Penetrantia (Penetrantia sp.), nothing is known about the
structure of any Penetrantiidae that may occur between the Lower
Jurassic and Upper Cretaceous, and little is known about the typical
pattern of budding near the ancestrula of most described Penetrantia
including the type species, P. densa Silén. The peculiar early asto-
geny of H. michelin appears to be unique. If this species is ancestral
to Penetrantia, its occurrence well before the earliest definite cheilo-
stome (Pyriporopsis portlandensis Pohowsky, 1973; Portlandian of
England ), argues strongly against the alignment of Penetrantia Silén
with the Cheilostomata (cf. Soule and Soule, 1969b, pp. 800, 801).

In surface aspect all observed specimens of Haimeina appear to
be referable to a single species. Although the location of the holotype
of H. michelin is unknown, the illustration presented by Terquem
(1855, pl. 26, fig. 6 — Text-fig. 2H herein) undoubtedly depicts the
same organism whose distinctive borings are seen in many specimens
of Plagiostoma throughout much of the Lower Jurassic of Europe.

Family COOKOBRYOZOONIDAE, n. fam.

Diagnosis. — Boring Bryozoa with enantiomorphic autozooids
disposed nearly horizontally and occurring in reversed orientation
within large portions of colony. Colonies show dextral and sinistral
forms recognizable by budding pattern. Ancestrula produces one
proximally directed stolon; lateral stolons subsequently arise opposite
one another, near autozooids, throughout colony.

Range. — M. Miocene-Pliocene.

Genus COOKOBRYOZOON, n. gen.

Etymology. — Named in honor of P. L. Cook.

Type species. —Cookobryozoon lagaaiji, n. sp.

Diagnosis. — Bryozoa with the characters of the family, Cooko-
bryozoonidae.

Range. — M. Miocene-Pliocene.

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 93

Discussion. — Cookobryozoon is known from only two occur-
rences of the type species, at the ends of the indicatd range. The
relationship of this genus to other genera of boring bryozoans is ob-
scure.

The name Cookobryozoon was derived in recognition that the
names of two other, exceptionally distinctive ctenostomes — Mono-

bryozoon Remane and Cryptopolyzoon Dendy — have a similar
suffix.
Cookobryozoon lagaaiji, n. sp. Pl. 13, figs. 1-9; Pl. 14, figs. 1-3;

Text-fig. 6B2

Etymology. — Named in honor of R. Lagaaij.

Material and occurrence. —

Figured: BMNH D.52314 (fragments + SEM STUB 18) (on
BMNH G.90134), Miocene (Temblor Fm., Olcese Sand Mbr.), near
Barkers Ranch, 1% mi. N.E. of “Kern River Park,” Kern Co.
[?], California, BMNH D.52315 (holotype = largest colony; para-
types = other colonies figured in whole or part) (on BMNH
G.39704-9, shell C), D.52316 (paratype) (fragments + SEM STUB
21) (on BMNH G.39704-9, shell A), D.52317 (paratypes) (on
BMNH G.39704-9, shell D), Pliocene (Kalimnan), McDonald’s
Bank, Muddy Creek, near Victoria, Australia.

Type locality and horizon. — McDonald’s Bank, Muddy Creek,
near Victoria, Australia; 1. Pliocene (Kalimnan).

Range. — M. Miocene-Pliocene.

Diagnosis. — Same as for the genus, since it is monotypic.

Description. — Autozooids enantiomorphic, with subcircular
aperture appearing to be flattened against right or left side of
stolon. Zooids lie across stolon at low angle, with slightly attenuated
proximal tip and flared distal end. Zooids regularly in reversed
orientation throughout large portions of colony, but in normal
orientation in other areas.

Ancestrula resembles autozooids and produces one proximally
directed stolon from near midpoint of frontal side. Stolons subse-
quently arise bilaterally opposite one another (or slightly offset)
and just proximal to autozooids. Initial lateral stolons arise close
to ancestrula.

Colonies strongly enantiomorphic, with stolon (emanating
proximally from ancestrula) having only reversed zooids with aper-

94 BuL_etin 301

tures all on left side (sinistral colony) or all on right side (dextral
colony), as seen distally along stolon. Apertures typically occur on
proximal side of other stolons. In some regions of colony, stolons on
side opposite zooid apertures develop more rapidly; in other areas
reverse is true (Pl. 13, fig. 1).

Heterozooids and tubulets absent. Adventitious stolons rare.

Measurements.— Lz (6) = 0.36-0.40 mm. [Based on direct
measurement of cast of paratype (D.52316)].

Discussion. — In view of its enantiomorphic colonies and zooids,
and its intriguing pattern of growth, Cookobryozoon lagaaiji is cer-
tainly one of the most interesting species of boring bryozoans. The
dextral or sinistral nature of a colony becomes apparent with the
production of the initial autozooid and continues along the entire
stolon from which this zooid arose (PI. 13, figs. 1, 5-9). In other
species with enantiomorphic colonies, dextral and sinistral members
that are easily distinguished in their early stages cannot be dif-
ferentiated at any appreciable distance from the ancestrula.

The autozooids of C. lagaaiji are in many respects identical, but
their occurrence as dextral or sinistral enantiomorphs in reversed
or normal orientation adds significantly to the variables which must
be considered in interpreting and describing a colony. Dextral auto-
zooids in this species are here defined as those that, in normal orien-
tation, have the aperture located on the right side of the stolon
(looking distally along the stolon). Although the pattern during the
course of astogeny undoubtedly reflects the repeated application of
a few simple principles, the nature of these rules for development is
better shown by Plate 13, figures 1, 5-9 and Plate 14, figures 1, 2
than in an involved description. Cookobryozoon shows a striking
adaptation which minimizes crowding and expedites the expansion
of the colony into all areas of the substratum surrounding the an-
cestrula. This is illustrated in Plate 13, figure 1 and Plate 14, figure
1, where the stolons growing toward the lower margins of the figures
are markedly longer than their counterparts on the opposite side of
the parent stolon.

No bryozoan resembling C. lagaaiji has been reported in Recent
seas, but the species is known from two widely separated localities
in the Neogene. The zooids of specimens from the middle Miocene
of California are slightly smaller than those of the type specimens

Borinc CTENOSTOMATE Bryozoa: PoHowsky 95

(lower Pliocene, Australia), but no other difference seems to exist.

Family SPATHIPORIDAE, n. fam.

Diagnosis. — Boring Bryozoa with peduncle inserted near or
proximal to midlength of zooid. Zooids inclined to horizontal at “pre-
ferred’ angle, varying with species; and commonly bear frontal vane
with tubulets. Aperture and openings associated with vane typically
form comma-shaped pattern at surface of substratum, at high angle
to stolon and with concave side facing in direction of stolonal growth.
Ancestrula giving rise to two or three stolons from proximal end.
Ovicelled gonozooids present in some species. Principal stolons arise
on both sides of parent stolons but rarely opposite one another.

Range. — M. Jur. (Bathonian or Callovian)-Recent.

Genus SPATHIPORA Fischer, 1866

1866. Spathipora Fischer, Mus. nat. Hist. nat. (Paris), Nouv. Arch., T. 2, pp.
309, 310, pl. 11, figs. 4, 4a.

1880. Non Spatipora Fischer, Seguenza, R Accad. Lincei (Rome), Atti, ser. 3,
vol. 6, p. 128, pl. 12, fig. 17, (nom. null.) 6

1923. Spathipora Fischer, Canu and Bassler, U.S. Nat. Mus. Bull., No. 125, p.
16, pl. 27, figs. 12-14; pl. 47, fig. 3.

1930. Spathipora Fischer, Canu and Lecointre, Soc. géol. France, Mém., n.s.,
T. 6, p. 119, pl. 18, fig. 5.

1938. Partim Spathipora Fischer, Marcus, Inst. Biol. (Sao Paulo), Arq., vol. 9,
pp. 288, 290, 291, text-figs. 1, 3Bs, 6(A-D); mon p. 291, text-figs.
Ti ary 133)

1938. Partim Terebripora @Orbigny, Marcus, ibid., pp. 283, 284, text-fig. 2D.
(Non Terebripora d’Orbigny, 1847, Voyage dans |’Amérique méridionale,
Aas) ptat. ppa zz, 255) pl 10s tags: 165) 175)

1950. Terebripora d’Orbigny, Soule, J. D., Washington Acad. Sci., Jour., vol.
40, pp. 380, 381, text-figs. 1-3

1954. Terebripora d’Orbigny, Bobin and Prenant, Arch. Zool. exptl. gén., T.
91, pp. 133-142, text-figs. 1, 2.

1961. Non Spathipora Fischer, Gorodiski and Balavoine, Bur. Rech. géol. Min.
(Paris), Bull., p. 2, pl. 1, fig. 1-

1962. Non Spathipora Fischer, Voigt, Upper Cretaceous Bryozoa of the Euro-
pean part of the U.S.S.R. and some adjoining areas, [in Russian], Mos-
cow Univ., p. 60, pl. 11, figs. 5-7.

1963. Terebripora d’Orbigny, Soule, J. D., Amer. Mus. Novit., No. 2144, pp.
2225

1966. Spathipora Fischer, Boekschoten, Palaeogeog., Palaeoclim., Palaeoecol.,
vol. 2, pp. 362-364, text-fig. 8.

1967. Spathipora Fischer, Boekschoten, Palaeogeog., Palaeoclim., Palaeoecol.,
vol. 3, p. 319, text-fig. 12.

1968. Non Spathipora Fischer, Miiller, Bohr-Réhren von unbekannten An-

®Neviani (1900, p. 147, pl. 18, fig. 21) repeated Seguenza’s misspelling of
Spathipora.

96 BULLETIN 301

neliden und anderen Organismen in unterdevonischen Brachiopodenklap-
pen aus der Eifel und dem Siegerland (Rheinisches Schiefergebirge),
Univ. Koln, pp. 86, 102, pl. 4, figs. 1, 1a, 2, 2a, 6, 7.

1973. Partim Terebripora (?) d’Orbigny, Voigt and Soule, Jour. Paleont., vol.
47, pp. 26, 27, pl. 2, figs. 2, 3, text-fig. 1.

Type species. —Spathipora sertum Fischer, 1866; S. D., Canu
and Lecointre (1930, p. 119).

Diagnosis. — Bryozoa with the characters of the family, Spathi-
poridae.

Range. —M. Jur. (Bathonian or Callovian)-Recent.

Discussion. — The validity of this widespread and important
genus is in doubt because of the uncertain validity of its type species.
Until the anatomy of S. sertwm is fully understood, the generic af-
finities of the several other species here assigned to Spathipora will
remain uncertain. Should future investigation demonstrate that the
zooids shown in Plate 18, figure 7 do not belong to S. sertwm Fischer
and that this species does not exist — or that the organism described
by Fischer could be any of two or more species — it will be necessary
to regroup most of the species discussed below within a new genus.
Further research may also demonstrate the advisability of dividing
the present group of species on the basis of patterns of stolon pro-
duction observed at the ancestrula (cf. Pl. 17, fig. 2; Pl. 18, figs. 1-4),
and on the presence or absence of ovicells. Ovicelled gonozooids are
present in S. cheethami (Jurassic), and possibly present in S. elegans
(Recent) as well.

The nine species here assigned to Spathipora are conjoined
primarily because of the staggered (vs. opposite) budding of both
stolons and zooids, and the comparable form and orientation of the
latter. Pedunculate sac zooids, and the typical production of three
stolons at the proximal end of the ancestrula are also features shared
by a number of species in the “genus.”

Spathipora sertum ? Fischer, 1866 Pl. 18, fig. 7; Text-fig. 2A

1866. Spathipora sertum Fischer, Mus. nat. Hist. nat. (Paris), Nouv. Arch.,
T. 2, pp. 309, 310, pl. 11, figs 4, 4a.

Material and occurrence. —

Figured: Small colony associated with BMNH 11.10.1 88B
(i.e., next to holotype of “Terebripora” ditrupae Norman, 1907, on
tube of serpulid polychaete), Recent, Shetland. (Tentatively as-
signed to S. sertwm.)

Borinc CTENOSTOMATE Bryozoa: PoHowsky 97

Diagnosis. —Spathipora with peduncle entering zooids at their
tapered proximal end, so that no portion of proximal end is free.
(Based on Fischer’s original, published illustrations. )

Description.— Colony branching; principal stolons straight,
giving rise to other stolons at right angles or nearly so; stolons vary
greatly in length, and sometimes exceed that of parent stolon.
Zooids staggered, elongated, with long and narrow vane; aperture
small, circular. (Based on Fischer’s original description, modified
to employ terminology used in present work.)

Measurements. — Fischer (1866, p. 310) indicated that Lz =
0.5106 mm [sic]. Two of the larger zooids in the colony shown in
Pl. 18, fig. 7 measure 0.31 and 0.36 mm in length.

Discussion. — Unfortunately, Fischer based Spathipora sertum
on a number of syntypes of significantly diverse age and geographic
origin. Included in his “hypodigm” are specimens from the Miocene
of Manthelan (Indre-et-Loire) and Pontlevoy (Loire-et-Cher), as
well as Recent specimens from the Mediterranean, and from La
Rochelle and Arcachon on the Atlantic. For this and other reasons,
discussed below, this species (and consequently, the genus Spathi-
pora) is only tentatively accepted.

Although several species of boring Bryozoa produce comma-
shaped openings in shells, they differ in the site where the peduncle
is typically inserted along the zooid. Without casting, this site can-
not be accurately determined in fossil specimens, unless the substra-
tum is nearly transparent. The available specimens which Fischer
assigned to S. sertwm are preserved in opaque shells, and it seems
improbable that Fischer employed casting in studying of them.

Markedly different species producing similar zooidal openings
occur at the localities cited by Fischer. I have cast topotypic ma-
terial from the Miocene of Manthelan, France, and noted an inser-
tion of the peduncle near the proximal end of the zooids (S. brevi-
cauda, Pl. 16, figs. 1, 2). Bobin and Prenant (1954) reported a
Recent species from Marseille [“Terebripora” comma Soule, Pl. 18,
fig. 8; Text-figs. 2(B-E)] that is commonly attached near the
zooid’s midpoint. It, therefore, seems plausible that several species
of Spathipora — perhaps none of them assignable to S. sertum —
‘constitute the available syntypes of this species, and I regard these
types to be indeterminate species of the genus.

98 BULLETIN 301

Despite these circumstances, the discovery of the specimen
illustrated in Plate 18, figure 7 seems to justify the tentative ac-
ceptance of S. sertum as a valid species, because the point of inser-
tion of the peduncle on the zooids is apparently identical to that
shown in Fischer’s illustration (Text-fig. 2A). It is unfortunate that
this specimen does not display the ancestrular region. Although the
size of the zooids and the general anatomy of the colony differ some-
what from that described by Fischer, these differences may be
features peculiar to the small colony involved. In any case, the
colony from Shetland demonstrates the real possibility that Fischer
examined an organism (preserved in a transparent layer of shell)
which was identical to that shown in his figures. Loss of such a
specimen (or specimens) could easily have gone unnoticed, because
Fischer did not indicate the number of specimens of the various
molluscan substrata he listed.

Admittedly, Fischer’s depiction of zooidal attachment in S.
sertum might be little more than blind speculation, or else fallacious
interpretations based on some other species present among the
presently available syntypes — but one cannot be certain. There
can be no doubt that he recognized the distinctiveness of Spathipora
from all of the other borings (herein assigned to several genera) that
he described in the same publication. It seems undesirable to con-
sider his genus unrecognizable because of the uncertain validity of its
type species.

A holotype for S. sertwm must be selected from among the re-
maining syntypes, but casting will be required to ensure that the
anatomy of the specimen selected conforms with that illustrated
by Fischer. If all available synypes prove to be species other than
S. sertwm, it would probably be best to consider S. sertwm unrecog-
nizable and establish a new genus (or genera) for the remaining
species grouped under Spathipora. Alternatively, a neotype might be
selected from one of the Miocene or Recent localities listed by
Fischer. Until extensive research demonstrates that S. sertuwm can-
not be recognized (7.e., does not exist in Recent seas, or in the Mio-
cene), I suggest that this species and the genus Spathipora be
regarded as valid taxonomic entities. Unless the zooids shown in
Plate 18, figure 7 would subsequently have developed a free proxi-
mal end extending beyond the peduncle, evidence of the existence

Borinc CTENOSTOMATE BryYOzOA: PoHOWSsKY 99

of S. sertum is available.

Spathipora elegans Fischer, 1866 Pl. 15, fig. 4; Text-fig. 6B5

1866. Spathipora clegans Fischer, Mus. nat. Hist. nat. (Paris), Nouv. Arch.,
ais 2 ps0:

Material and occurrence. —

Figured: MNHN 79415-1 (holotype), Recent, coast of Chile.

Type locality and range. — Coast of Chile; Recent.

Diagnosis. —Spathipora with peduncle entering zooids at or
slightly distal to zooid’s midpoint. Autozooids usually inclined at
40-60 degrees to the horizontal. Ancestrula nearly vertical, giving
rise to three stolons.

Additional description. — Autozooids with short vane bearing
one or two tubulets. Aperture circular. Three stolons diverge from
ancestrula at about 120 degrees to one another. All stolons bear
numerous frontal pores or short tubulets. Initial autozooids on the
two stolons diverging laterally from ancestrula, occur on side of
stolon opposite that of ancestrula.

Measurements. — Length from distal end of autozooid to inser-
tion of peduncle on stolon (16) — 0.20-0.23 mm. (Based on PI. 15,
fig. 4).

Discussion. — Spathipora elegans is known only from the holo-
type. Although the substratum bearing this colony is sufficiently
translucent to reveal many of the subsurface features, it is difficult
to be certain that the zooid indicated by the long arrow in Plate 15,
figure 4 is actually an ovicelled gonozooid. If ovicells are present in
S. elegans, it would be worthwhile to obtain more, living specimens
from the coast of Chile in order to cast and section them, and com-
pare the structure of the gonozooid with that of gonozooids in Pene-
trantia. In the event that S. elegans does have ovicells, but lacks an
operculum, this would add to evidence from S. cheethami that ovi-
cells can definitely occur in ctenostomes when adequately shielded
extracoelomic brooding is possible.

Spathipora longirima Canu and Bassler, 1923 Pl. 16, figs. 4, 5, 7

1923. Spathipora longirima Canu and Bassler, U.S. Nat. Mus., Bull., No. 125,
DowlGs ple erie, Se a

1923. Spathipora cucullata Canu and Bassler, :bid., p. 16, pl. 27, fig. 14.

Matenal and occurrence. —

100 BULLETIN 301

Figured: USNM 68394 (holotype), Pliocene (Waccamaw
Marl), Waccamaw River, Horry Co., S. Carolina; UCGM 40076
(RAP 231), Recent, 2 mi. S. of Bethany Beach, near Rehoboth,
Delaware.

Not figured: USNM 68395 (holotype of Spathipora cucullata
Canu and Bassler, 1923), Miocene (Yorktown Fm.), Beulahland,
King William Co., Virginia.

Type locality and horizon. — Waccamaw River, Horry Co., S.
Carolina; Pliocene (Waccamaw Marl).

Range. — U. Miocene-Recent.

Diagnosis. — Spathipora with peduncle entering zooids between
zooid’s midlength and proximal quarter. Zooids usually inclined at
about 30 degrees to the horizontal.

Additional description. — Autozooids with long vane, apparent-
ly without tubulets. Aperture subtriangular to ovoid. Short, widely
spaced tubulets present on a few stolons. Spherical, pedunculate sac
zooids common. Autozooids occasionally inclined at about 45
degrees to the horizontal. Ancestrula not seen.

Measurements. — Lz (6) = 0.32-0.38 mm. (Based on Pl. 16,
fig. 5).

Discussion. — Viewed from the shell surface, the lower Pliocene
holotype and the Recent specimen from Delaware show precisely
the same characters. The estimated angle of inclination of zooids in
the holotype agrees with that seen in casts of the Recent specimen.
The “angle of insertion” referred to by Canu and Bassler (1923, p.
16) is probably the declination of the zooids from the principal sto-
lon, measured in a horizontal plane.

It should be noted that Canu and Bassler (1923, pp. 16, 271,
291) introduced confusion in their use of the term “peduncle” with
reference to S. longicauda and S. longirima. In their description of
the former species (preserved in an opaque shell — PI. 18, fig. 10),
“peduncle” could correspond only to “rimule” in the description
which these authors prepared for S. longirima. The “rimule” is un-
doubtedly the elongated fissure produced by the frontally situated
vane, a feature recognized in this work. Canu and Bassler’s state-
ment that S. longirima lacks a peduncle (sensu Canu and Bassler)
is difficult to interpret. Presumably, they intended to indicate that
attachment of zooids to the principal stolon is direct. Although the
zooids may, in fact, be tangent to the stolons in many cases, many

Borinc CTENOSTOMATE Bryozoa: PoHowsky 101

zooids in the holotype (PI. 16, fig. 5) are attached by means of a
peduncle (as defined in the present study).

Spathipora comma (Soule), 1950 Pl. 18, fig. 8; Text-fig. 2(B-E)

1950. Yerebripora comma Soule, J. D., Washington Acad. Sci., Jour., vol. 40,
pp. 380, 381, text-figs. 1-3.

1954. Terebripora comma Soule, J. D., Bobin and Prenant, Arch. Zool. exptl.
gén., T. 91, pp. 133-142, text-figs. 1, 2.

1963. Terebripora comma Soule, Soule, J. D., Amer. Mus Novit., No. 2144, pp.
2ilee22-

Type locality and range. — Eighteen fathoms, S.W. of Newport
California; Recent.

‘Diagnosis. —Spathipora with peduncle attached to zooids
slightly distal to midlength. Zooids 0.24-0.36 mm long, sometimes
with a few short tubulets arising from a vane between the peduncle
and the aperture. Sac zooids common. (Based on Soule, 1950b;
Bobin and Prenant, 1954).

Discussion. — Bobin and Prenant (1954, p. 139) discovered the
sac zooids (“cénozoécies a sphérules”) of this species and noted that
they are filled with refringent granules (Text-fig. 2C). These authors
did not detect the vane figured by Soule [Text-fig. 2(D, E) here],
but it seems likely that intraspecific variation could account for its
absence in the Mediterranean specimens they examined. Soule
(1950b, pp. 380, 381) noted larvae being brooded in zooids slightly
shorter than, but otherwise externally similar to, some of the auto-
zooids.

?

Spathipora sibirica (Voigt and Soule), 1973

1973. Terebripora (?) sibirica Voigt and Soule, J. D., Jour. Paleont., vol. 47,
pp 26027) plo 2. figss 2.93); text-tie. 1

Material and occurrence. —

Not figured: ZGM 22/9757 (Atabekian coll.). Holotype is
colony (?) of essentially horizontal zooids figured by Voigt and
Soule (1973, pl. 2, fig. 2) occurring on interior of shell measuring
6 x 6.5 cm. Paratype is that colony (?) figured by Voigt and Soule
on plate 2, figure 3, and in text-figure 1.

Type locality and horizon. — Mount Chodsa Kasian, S.W. Scha-
artus, Tadschikistan, U.S.S.R.; U. Cret. (U. Santonian).

Range. — U. Cret. (U. Santonian).

Diagnosis. — Spathipora with peduncle entering zooids between

102 BuLetin 301

zooid’s midlength and proximal quarter. Zooids 0.40-0.48 mm long,
disposed nearly horizontally to slightly less than 45 degrees to the
horizontal. Heterozooids not present.

Additional description. — Apertures subtriangular to subcircu-
lar. Zooids bear long vane; short tubulets present on some primary
stolons.

Discussion.— By study of the two major shell fragments
(measuring 6 & 6.5 cm and 3 & 5 cm) of ZGM 22/9757 it was
possible to locate the same zooids shown in the three illustrations
published by Voigt and Soule. The authors stated that plate 2, figure
2 shows the holotype, and that the same zoarium is illustrated in
plate 2, figure 3. However, this is probably incorrect, because plate
2, figure 3 and text-figure 1 show portions of the 3 & 5 cm shell
encrusting the exterior of the 6 6.5 cm shell illustrated in plate
2, figure 2. There is no visible evidence that any colony on one of
these shells was ever connected with a colony on the other. In view
of this error, some references to specific colonies in the discussion
by Voigt and Soule (1973, p. 26) are confused. Additional confusion
arises because plate 2, figure 3 and text-figure 1 both contain
numerous zooids of a second genus of boring bryozoan.

Examination of the type material reveals that the holotype is
a new species of Spathipora Fischer, whereas the numerous, asso-
ciated circular borings in plate 2, figure 3 and text-figure 1 are
autozooids of Penetrantia Silén. None of the Spathipora colonies
bear sac zooids; the “kenozooecia (?)” described by Voigt and Soule
(p. 26) as “small round holes near the stolons” are merely Pene-
trantia zooids.

Voigt and Soule (p. 27, text-fig. 1) rejected the idea of a second
species being present in deference to a belief that there are transitions
between the two types of zooecia (roughly speaking: horizontal and
vertical). This conclusion is here regarded to be incorrect. No
such transitions are evident in text-fig. 1, and ZGM 22/9757 has
numerous unmistakable zooids of Penetrantia on both the 3 & 5
cm and 6 & 6.5 cm shells. Moreover, the zooids are often isolated
from any which could possibly be assigned to Spathipora.

In some areas of the shells, Penetrantia shows the reniform aper-
ture that is often observed in the genus. One zooid on the 3 & 5 cm
shell (about 5 mm from the muscle scar and 3 mm from the center

Borinc CTENOSTOMATE BryozoAa: PoHowskKy 103

of the shell’s broken edge) shows a clearly visible ovicell. A few
zooids have deviated noticeably from the vertical because they en-
countered an apparently impermeable layer of shell. This can also
be seen in another Cretaceous specimen of Penetrantia (PI. 9, fig. 5).
It is possible that these are the transitional zooids reported by Voigt
and Soule.

In describing their new species, Voigt and Soule (p. 26) ob-
served that the zooids are “. . . subparallel to the surface of the mol-
luse shell, placed irregularly not aligned with the stolonal paths
and .. . joined obliquely to the stolons.” This obviously refers to
Spathipora rather than Terebripora d’Orbigny or Penetrantia Silén.
The “slitlike or sinuous lateral prolongation of the round or ovoid
openings” also describes Spathipora. Despite the misunderstandings
cited above, the fundamental intention of the authors is apparent.
The holotype which they illustrated in plate 2, figure 2 is a new
species, and the first true Spathipora to be described from the Cre-
taceous.

Spathipora sibirica is similar to S. longirima (Canu and
Bassler), but it has slightly longer autozooids and lacks the sac
zooids of the Cenozoic species. Zooids of S. sibirica are shorter than
those of S. cheethami and apparently never have ovicells.

Spathipora cheethami, n. sp. Pl. 15, figs. 1-3

Etymology. — Named in honor of A. H. Cheetham.

Material and occurrence. —

Figured: BMNH D.52318 (holotype) (on BMNH L.20676),
M. Jur. (Bathonian or Callovian; Cornbrash), Thrapston, Nort-
hamptonshire, England; BMNH D.52319 (paratype) (on BMNH
L.69968), M. Jur. (Bathonian or Callovian; Cornbrash), Fengate,
near Peterborough, Northamptonshire, England.

Not figured: BMNH D.52320 (on BMNH L.20689), M. Jur.
(Bathonian or Callovian; Cornbrash), Bletsoe, Bedfordshire, Eng-
land; BMNH D.52321 (on BMNH 20034a), M. Jur. (Bathonian
or Callovian; Cornbrash), Helpstone, England; BMNH_ D.52322
(on BMNH 82429), M. Jur. (Bathonian or Callovian; Cornbrash),
Bournemouth, England.

Type locality and range. — Thrapston, Northamptonshire, Eng-
land; M. Jur. (Bathonian or Callovian; Cornbrash).

104 BuLLeETIN 301

Diagnosis. — Spathipora with peduncle entering zooids between
zooid’s midpoint and proximal quarter. Zooids nearly horizontal.
Colonies with gonozooids bearing globular ovicell near aperture.

Additional description.— Zooids with long vane, apparently
without tubulets. Aperture round to oval. Short tubulets present
on some stolons. Gonozooids slightly shorter than autozooids, and
with ovicell directed laterally. Sac zooids not present. Ancestrula
not seen.

Measurements. — Lz (5) = 0.52-0.61 mm; length of gonozooids
(2) = 0.34-0.48 mm (Based on PI. 15, figs. 1-3).

Discussion. — Spathipora cheethamz is the earliest known repre-
sentative of the genus. Its general morphology is strikingly like that
of younger Spathipora from the Upper Jurassic, Upper Cretaceous
and Cenozoic.

The presence of apparent gonozooids in S. cheethamz is of great
interest and importance. It is evident that this species is either a
Spathipora (or another ctenostome homeomorphic with Spathipora)
which has developed ovicells, or else a shell-penetrating cheilostome
considerably older than Pyrtporopsis portlandensis Pohowsky, 1973
(Portlandian of England), the earliest known cheilostome. On the
basis of anatomical and biostratigraphic information; it seems likely
that S. cheethami belongs with the ctenostomes. This circumstance
considerably weakens arguments for placing Penetrantia Silén with

the Cheilostomata (Soule and Soule, 1969b, pp. 800, 801).
Spathipora brevicauda, n. sp. PIG tic steleee

Etymology. — The specific name refers to the limited extension
of the proximal end of the zooid beyond the peduncle.

Material, occurrence, and range. —

Figured: BMNH D.52324 (holotype) (fragments + SEM
STUB 19), m. Miocene, Manthelan, Indre-et-Loire, France.

Diagnosis. —Spathipora with peduncle entering zooids just
short of zooid’s proximal tip. Zooids nearly horizontal; proximal
end almost never extends across principal stolon.

Additional description. — Proximal tip of zooids curved slightly
in basal direction. Globular, pedunculate sac zooids common. Tubu-
lets lacking on stolons.

Measurements. — Lz (8) = 0.28-0.33 mm (Based on PI. 16,
fig. 1),

Borinc CTENOSTOMATE Bryozoa: PoHowsky 105

Discussion. — The worn condition of the shell bearing the holo-
type precludes accurate determination of the shape of the aperture
and the number of short tubulets which may have been present on
the frontal surface of the zooids.

Spathipora occidentalis, n.sp. Pl. 16, fig. 3; Pl. 17, figs. 1-6; Text-fig. 6B6

Etymology. — The specific name reflects the apparent broad
distribution of this species within the Western Hemisphere.

Material and occurrence. —

Figured: BMNH D.52325 (on BMNH 20793a, shell B), Mio-
cene, Touraine, France; BMNH D.52326 (on BMNH G.13829), al-
most certainly Pliocene, Castel Arquato, Italy; BMNH D.52327 (on
BMNH 68307), 1. Pliocene, Val d’Andona, Piedmont, Italy; BMNH
D.52328 (one of several colonies of this species in gastropod) (on
BMNH G.G.12944), m. Pliocene (Caloosahatchee Fm.), about 2.7
mi. N.W. of bridge, Harney Pond Canal, Glades Co., Florida
(U.S.G.S. loc. 23150); USNM 174673 (on shell with USNM 68392,
holotype of Terebripora pacifica Canu and Bassler, 1923), Pleisto-
cene, San Pedro, California; BMNH D.52329 (holotype) (cast on
SEM STUB 8), Recent, Bay of Santos, Brazil.

Type locality and horizon. — Bay of Santos, Brazil; Recent.

Range. — Miocene - Recent.

Diagnosis. —Spathipora with peduncle entering zooids just
short of zooid’s proximal tip. Zooids nearly horizontal, with proximal
end usually extending across principal stolon, and sometimes slightly
beyond it.

Additional description. — Three stolons arise from proximal end
of ancestrula and subsequently diverge at approximately 120 degrees
to one another. Initial attozooids on two stolons diverging laterally
from end of ancestrula occur on side of stolon opposite that of an-
cestrula. Zooids with long vane bearing few (if any) tubulets. Aper-
ture subtriangular to oval. Tubulets lacking on stolons.

Measurements. — Lz (20) = 0.32-0.45 mm (Based on PI. 16,
fees EL, figs: 2-5):

Discussion. — Only the holotype and the Miocene specimen
listed above have been positively identified by casting. All other cited
specimens are tentatively assigned to this species on the basis

106 BULLETIN 301

of the surface aspect of the borings.

As in S. ambidextra, Haimeina michelim (Terquem), and many
other boring ctenostomes, the pattern displayed by the initial zooids
and stolons in a colony of S. occidentalis is genetically influenced.
Although the order in which the various elements are produced
is apparently subject to some variation (PI. 17, figs. 1, 2), the re-
sulting configuration of features near the ancestrula shows some
definite similarities to those in the specimens shown in Plate 17,
figures 2-5. The first zooids produced on the stolons diverging more
or less laterally from the ancestrula invariably occur on the side
opposite the ancestrula. In addition, the three initial stolons show
a strong tendency to diverge at above 120 degrees from one another.

Because the above characteristics are under genetic control, it
seems possible that the placement of the initial zooid on the medial
stolon may be similarly influenced. Obviously this zooid can occur
on either the right or left side, so it appears that colonies of S.
occidentalis are enantiomorphic in at least their earliest stages. Un-
like Cookobryozoon, dextral and sinistral colonies of Spathipora can-
not be readily differentiated on the basis of the budding pattern in
parts of the colony widely separated from the ancestrula.

Spathipora magnivorticellopsis, n. sp. Pl. 17, figs: 7.06

Etymology. — The specific name refers to the peculiar resem-
blance of the zooidal borings to silhouettes of the protozoan, Vorti-
cella.

Material, occurrence, and range. —

Figured: BMNH_ D.52330 (holotype) (on BMNH 80732),
Pliocene, Colli Astesi, Italy.

Diagnosis. — Spathipora with long zooids (0.42-0.55 mm from
distal end to insertion of peduncle on principal stolon) and large,
triangular or subtriangular apertures.

Additional description.—Zooids with long vane, sometimes
bearing up to eight frontal pores or short tubulets. Vane straight,
evenly curved or sinuous. Frontal pores sometimes present on sto-
lons. Three stolons apparently arise from proximal end of ancestrula
and diverge at about 120 degrees to one another.

Discussion. — Although this species has not been cast, it can
nevertheless be distinguished from similar species on the basis of

Borinc CTENOSTOMATE Bryrozoa: PoHowsky 107

features visible at the surface of the substratum. Sequential stages
in zooidal ontogeny are shown in Plate 17, figure 8.

Spathipora ambidextra, n. sp. Pl. 18, figs. 1-6; Text-fig. 6C3

Etymology. — The specific name refers to the occurrence of
this species in dextral and sinistral colonies.

Material, occurrence, and range. —

Figured: BMNH D.52331 (holotype = dextral colony in PI.
18, fig. 4; 6 paratypes in PI. 18, figs. 1-3, 5,6), [on BMNH G.13829,
Ficus reticulata (Lamarck) ], almost certainly Pliocene (C. P. Nut-
tall, personal communication), Castel Arquato, Italy.

Not figured: BMNH D.52332 (numerous other colonies on same
gastropod, among figured types listed above).

Diagnosis. — Spathipora with ancestrula giving rise to two sto-
lons at proximal end, one of which ends blindly and produces two ad-
ditional stolons just short of its terminus.

Additional description. — Colonies strongly enantiomorphic
near ancestrula, with “blind” stolon (the appendix) occurring on
right or left side. Zooid apertures round to oval. Tubulets lacking
on stolons and vanes.

Measurements. — Length from distal end to insertion of ped-
uncle on stolon (8) = 0.25-0.32 mm. (Based on direct measurement
of colonies in D.52331 and D.52332).

Discussion. —Spathipora ambidextra is particularly interesting
in its marked enantiomorphism and its possession of the unique
“appendix.” This name may be appropriate, for it may someday be
demonstrated that this minute cul-de-sac is indeed a vestigial fea-
ture. In other Spathipora in which the early astogeny is known (S.
elegans Fischer, S. magnivorticellopsis, S. occidentalis), the ancestru-
la produces three stolons in a manner that is difficult to relate to the
configuration seen in S. ambidextra. Perhaps “intermediate” species
will be discovered and assist in explaining the phyletic origin of the
appendix.

It is possible that S. ambidextra may belong to another genus
in which the zooids are merely homeomorphic with those in
true Spathipora. In resolving this issue, it will be necessary to

determine the nature of early astogeny in the type species, S. sertwm
Fischer.

108 BuLLeETIN 301

Spathipora spp. indet. PI. 15, figs. 5-7; Pl. 16, fig: 6; Pl 18, figs; 9/18;
Text-figs. 1F, 3B

1866. Spathipora incerta Fischer, Mus. nat. Hist. nat., Nouv. Arch., T. 2, p. 310.

1923. Spathipora longicauda Canu and Bassler, U.S. Nat. Mus., Bull., No. 125,
Pal6wple aides. 12) 13>

1930. Spathipora sertum Fischer, Canu and Lecointre, Soc. géol. France, Mém.,
TS ln; psp 9 sple W'S, tice 5:

1938. Spathipora sertum Fischer, Marcus, Inst. Biol. (Sao Paulo), Arq., vol. 9,
text-figs. 1, 3Bs, 6(A-D). (Non Spathipora sertum Fischer, 1866, Mus.
nat. Hist. nat., Nouv. Arch., T. 2, pp. 309, 310, pl. 11, figs. 4, 4a).

1938. ?Partim Terebripora ramosa d’Orbigny, Marcus, ibid., pp. 283, 284, text-
fig. 2D; non pp. 281-283, text-figs. 2(A-C). (Non Terebripora ramosa
d’Orbigny, 1847, Voyage dans |’Amérique meéridionale, T. 5, pt. 4, pp.
22525, ple Or tie seulG. li.)

1967. Spathipora sertum Fischer, Boekschoten, Palaeogeog., Palaeoclim., Palaeo-
ecol., vol. 3, p. 319, text-fig. 12.

Owing largely to preservation, further preparation and study
will be required before the species or specimens listed here can be
reliably compared with the Spathipora considered on the foregoing
pages. The specimen of S. sertum illustrated by Canu and Lecointre
(1930, pl. 18, fig. 5) will have to be cast before it can be adequately
compared with the original illustration of that species.

As noted in the discussion of Terebripora d’Orbigny, the speci-
men illustrated by Marcus (1938, text-fig. 2D) is probably a Spathi-
pora (Pl. 18, fig. 9). The following specimens are also assigned to
Spathipora.

Figured: BMNH D.52323 (RAP 302) (fragments + SEM
STUB 24), Miocene, “Lapugy,” Transylvania, Rumania; BMNH
D.52333 (RAP 234), Recent, Bay of Santos, Brazil. (see also PI.
18, figs. 9, 10.)

Not figured: BMNH D.52335 (RAP 319), U. Jur. (probably
Portlandian), Chicksgrove, Tisbury, England. BMNH D.52336 (on
BMNH 1.52581), U. Jur. (L. Portland Beds), Long Crendon,
Buckinghamshire, England; BMNH_ D.52337 (natural cast) (on
BMNH L.52309), U. Jur. (Portlandian, Portland Stone), quarries E.
of “Drill Hall,” near Easton, Isle of Portland, Dorset, England;
BMNH D.52338 (on BMNH G.G.12080), Eocene (probably Clai-
bornian), Alabama; BMNH D.52339 (on BMNH G.G.12083), Eo-
cene, Alabama; BMNH D.52340 (on BMNH L.12460, 12546), Oli-
gocene or Miocene (Santa Cruz Fm.), Santa Cruz, Argentina;
BMNH D.52341 (RAP 320), |. Tertiary, Dax, France; BMNH
D.52342 (RAP 305), Miocene (probably 1., possibly u.), LePoivre,
Bordeaux, France; BMNH D.52343 (on BMNH G.88128), m. Mio-
cene (Helvetian), Manthelan, Indre-et-Loire, France; BMNH

Borinc CTENOSTOMATE Bryozoa: POoHOWSKY 109

D.52344 (on BMNH G.33995), m. Miocene (Vindobonian), Tou-
raine, France; BMNH D.52345 (RAP 308), D.52346 (RAP 318),
m. Miocene (Falunian), Pont-le-Voy, Loire-et-Cher, France; BMNH
D.52347 (on BMNH 45929), Miocene, Touraine, France; BMNH
D.52348 (RAP 309), Miocene, Manthelan, Indre-et-Loire, France;
BMNH_ D.52349 (on BMNH L.L.14860.9), Miocene, Touraine,
France; BMNH D.52350 (on BMNH G.62571), Miocene (York-
town Fm.), west bank of York River, 2 mi. S. of Yorktown, Vir-
ginias BMNH D.52351 (on BMNH G.1011), 1. Pliocene (Plais-
ancian), Biot, near Antibes, Alpes Maritimes, France; BMNH
D. 52352 (on BMNH G.31183), 1. Pliocene (Astian), Altavilla, near
Palermo, Sicily; BMNH D.52353 (on BMNH 13967), 1. Pliocene
(Astian), Asti, Piedmont, Italy; BMNH D.52354 (on BMNH
G.11725), Pliocene (Caloosahatchee Fm.), Florida; BMNH
D.52355 (on BMNH G.11825), Pliocene (Caloosahatchee Fm.),
Florida; BMNH D.52356 (on BMNH G.59332), Pliocene, Piacenza,
Italy; BMNH D.52357 (RAP 306), Pliocene, Artigiana, Italy [?];
BMNH D.52358 (on BMNH L.7522), Pliocene, Colline Sensi, Italy;
BMNH D.52359 (on BMNH G.4046), Quaternary (raised beach),
Latakia, Syria; BMNH D.52360 (RAP 241-3), D5256)". (RAP
235), D.52362 (RAP 238), Recent, Bay of Santos, Brazil.

Family TEREBRIPORIDAE d’Orbigny, 1847

Diagnosis. — Non-pedunculate boring Bryozoa with autozooids
lying horizontally along stolon near distal end but becoming
separated from stolon proximally so that proximal portion extends
“freely” below stolon and nearly parallel to it. Narrow vane some-
times joins stolon to most of “free” portion of zooid. Lateral stolons
arise from stolon, near midlength of zooid.

Range. — Upper Cretaceous - Recent.

Genus TEREBRIPORA d’Orbigny, 1847

1847. Terebripora d’Orbigny, Voyage dans |’Amérique méridionale, T. 5, pt. 4,
hy 4, VSS falls SUD) oS IG, 27

1866. Partim Terebripora d’Orbigny, Fischer, Mus. nat. Hist. nat., Nouv. Arch.,
den 2 ep pes0l 502.

1869. Non Terebripora d’Orbigny, Terquem and Jourdy, Soc. géol. France,
Mém., sér. 2, T. 9, p. 141, pl. 14, figs. 15-18.

1875. Non Terebripora d’Orbigny, Manzoni, I Briozoi del Pliocene antico di
Castrocaro, p. 7, pl. 6, fig. 68.

1877. Non Terebripora d’Orbigny, Dollfus, Soc. Linn. Normandie, Bull., sér.
3, T. 1, pp. 97-99, 102, 103, pl. 1, figs. 2-4.

110 BULLETIN 301

1880. Terebripora d’Orbigny, Jullien, Soc. zool. France, Bull., T. 5, pp. 142-144,
text-figs. 1-3.

1888. Non Terebripora d’Orbigny, Oehlert, Soc. Etud. Sci. Angers., Bull., ‘T. 17,
pp. 108, 109, pl. 10, fig. 3.

1901. Non Terebripora d’Orbigny, Rovereto, Palaeontogr. Italica, vol. 7, p.
221, text-fig. 1.

1907. Non Terebripora d’Orbigny, Norman, Ann. Mag. Nat. Hist., ser. 7, vol.
20, pp. 208, 209, pl. 9, figs. 5-7.

1923. Partim Terebripora d’Orbigny, Canu and Bassler, U.S. Nat. Mus., Bull.
No. 125;"pp. 15; 165 ple 35 figs." 04; 5's pl 27etigs. 155164 plat ometigs
13; non pl. 3, figs. 16, 17.

1938. Partim Terebripora d’Orbigny, Marcus, Inst. Biol. (Sao Paulo) Arq.,
vol. 9, pp. 281-283, 286, 287, text-figs. 2A-C, 4; non text-fig. 2D.

1950. Partim Immergentia Silén, Soule, J. D., Amer. Microsc. Soc., ‘I'rans., vol.
69, p. 366, pl. 2, fig. 3. (Non Immergentia Silén, 1946, Ark. f. Zool., Bd.
38B, pp. 6, 7, text-figs. 9-12.)

1950. Non Terebripora d’Orbigny, Soule, J. D., Washington Acad. Sci., Jour.,
vol. 40, pp. 380, 381, text-figs. 1-3.

1954. Non Terebripora d’Orbigny, Bobin and Prenant, Arch. Zool. exptl. gén.,
Tl. 91, pp. 133-142, text-figs. 1, 2.

1963. Non Terebripora dOrbigny, Soule, J. D., Amer. Mus. Novit., No. 2144,
Dp! 2, 22.

1966. Non Terebripora dOrbigny, Boekschoten, Palaeogeog., Palaeoclim.,
Palzeoecol., vol. 2, p. 360, text-fig. 6.

1968. Non Terchripora dOrbigny, Soule, J. D. and Soule, D. F., S. California
Acad. Sci., Bull., vol. 67, pp. 179, 180, text-fig. 1.

1969. Non Terchripora d’Orbigny, Soule, J. D. and Souie, D. F., California
Acad. Sci., Occas. Pap., No. 78, pp. 7, 8, text-figs. 6-(Sa-e), 14, 15.

1973. Non Terebripora (?) d’Orbigny, Voigt and Soule, J. D., Jour. Paleont.,
vol. 47, pp. 22-28, pls. 1, 2, text-fig. 1.

Type species: Terebripora ramosa dOrbigny; subsequent desig-
nation, Canu and Bassler (1920, p. 842).

Diagnosis. — Terebriporidae with enantiomorphic zooids having
aperture located on right or left side of stolon. Ancestrula produces
stolons proximally, distally, and bilaterally opposite one another
near midpoint of zooid.

Range. — Eocene-Recent.

Discussion. — The erection of Terebripora by D’Orbigny in
18477 marks the outset of the study of boring bryozoans. Although
D’Orbigny clearly recognized the boring habitus and general budding
pattern of his new genus, he neglected to mention or illustrate many
important characteristics, such as the ancestrula, tubulets, and loca-

“Soule (1950b, p. 380) published evidence for accepting 1847 as the date of
publication of the zoophyte section of D’Orbigny’s Voyage dans Amérique
méridionale. The year, 1839, is widely cited in the literature but is apparently
incorrect.

Borinc CTrENOSTOMATE BryozoA: PoHOWSKY Pel

tion of the apertures at the sides of the stolon. Unfortunately, the
generic description presented is applicable to a wide variety of boring
bryozoans, and few subsequent workers seem to have examined the
type specimens to assess the distinguishing features of the genus
before assigning additional species to it. Recently, the assignment
of Spathipora comma (Soule) to Terebripora (Soule, 1950b; Bobin
and Prenant, 1954) was accomplished in apparent disregard for the
illustrated budding pattern of the type species, 7’. ramosa (Text-fig.
1B).

The net result of this is taxonomic confusion. Only six of the
38 species initially assigned to Terebripora are here considered re-
ferable to this genus with certainty. Some of the remainder may be-
long with Terebripora, but inadequate description and illustration,
and lost or poorly preserved types render them unrecognizable. In
brief, the boring habitus of T'erebripora has somehow established this
genus as the post-Paleozoic counterpart of Ropalonaria Ulrich—the
Ordovician “wastebasket” for numerous minute borings of presumed
bryozoan affinities.

Misunderstanding of Terebripora is not confined to paleonto-
logical works. In recent years, several zoologists have concentrated
too restrictively on internal soft parts — thereby overlooking some
critical taxobases inherent in features of the borings. Thus, Marcus
(1938) apparently examined the internal features of the bryozoan
he illustrated in text-figure 2D (Text-fig. 1F) while assigning this
specimen to Terebripora ramosa d’Orbigny. It is evident that the
bryozoan in his figure is probably referable to Spathipora Fischer but
not to Terebripora d’Orbigny. The two zooids shown are far too
closely spaced to lie sequentially along the stolon, and the paired
lateral stolons which invariably arise from the frontal surface of
zooids in Terebripora are curiously absent. A specimen labeled “Tere-
bripora ramosa” from Marcus’s collection (possibly the specimen
shown in his text-fig. 2D) is illustrated in Plate 18, figure 9.

Although some of the specimens figured by Marcus belong in
Terebripora (see synonymies of Terebripora, T. falunica, and T.
miniatura), the colony or colonies whose soft parts he examined cer-
tainly do not. Subsequent assignments of species to Terebripora
made largely on the basis of internal features comparable to those
described by Marcus are of tenuous validity.

112 BuLteTIN 301

It is yet possible that a description of the internal anatomy of a
bona fide Terebripora may actually have been published (un-
suspectingly) by Soule (1950a, p. 366). In conjunction with his
original description of Immergentia philippinensis, Soule presented
three figures, one of which is certainly representative of Terebripora
(Text-fig. 1G). The specimen in that figure shows an ancestrula
and budding pattern much like that of T. ramosa (PI. 19, fig. 1);
moreover, an apparent paratype (AHF 51.2) retains a few well-
preserved zooidal borings in which the aperture is distinctly placed
at the side of the stolon. A small, proximal-lateral sinus opposite the
aperture is also visible. Although part of what Soule called Jmmer-
gentia philippinensis is certainly Terebripora, one cannot be sure that
the soft parts which he described were not those of the apparent
Immergentia he illustrated in plate 1, figure 5. Therefore, the inter-
nal anatomy of Terebripora remains highly uncertain.

As indicated in the generic diagnosis, autozooids of Terebripora
are enantiomorphic. Those zooids with the aperture to the right of
the stolon, in frontal view, are here defined to be dextral; all others
are sinistral.

Terebripora ramosa d’Orbigny, 1847 Pl. 19, figs. 1-4; Text-figs. 1B, 6A2

1847. Terebripora ramosa d’Orbigny, Voyage dans |’Amérique méridionale,
1h Sy fot Ch os 24 2s soll I) ative, a TZ

1938. Non Terebripora ramosa d’Orbigny, Marcus, Inst. Biol., (S40 Paulo)
Arq., vol. 9, pp. 281, 284, text-figs. 2A-D.

Material and occurrence. —

Figured: BMNH D.52364 (RAP 310), Neogene, “Saaret (Saya-
ret), Lycia,” Turkey; BMNH D.52365 (on BMNH G.5247), Plio-
cene (Caloosahatchee group), Florida; MNHN 79572-2 (D’Orbigny
coll. No. 13664) (lectotype), Recent, Arica, Chile.

Not figured: MNHN 79572-2 (two or more paralectotype
colonies within same ink rectangle surrounding lectotype), Recent,
Arica, Chiles MNHN 79415-1 (two or more colonies adjacent to
holotype of Spathipora elegans Fischer), Recent, Chile.

Type locality and horizon. — Arica, Chile; Recent.

Range. — Pliocene - Recent.

Diagnosis. — Terebripora with numerous (10-20) tubulets
arising from frontal surface of autozooids. Lateral stolons typically
arise slightly proximal to midlength of zooid.

Borinc CTENOSTOMATE Bryozoa: PoHowsky 113

Description. — Autozooids bluntly fusiform in frontal view, oc-
curring as enantiomorphs with aperture at right or left side of sto-
lon; frontal surface lies against or slightly basal to stolon throughout
entire length. Aperture subcircular, flattened on side abutting stolon,
and sometimes slightly skewed in distal direction along stolon. Small,
semicircular sinus extends laterally at proximal end of aperture but
on opposite side of stolon.

Heterozooids (sac zooids) sometimes present. Ancestrula_ re-
sembles autozooids, but slightly shorter and lacks tubulets and
lateral stolons; distally produces stolon (leading to autozooid), and
proximally gives rise to autozooid, with little or no intervening stolon.
Stolons subsequently arise from autozooids distally and bilaterally
opposite one another at or (more commonly) slightly proximal to
midlength.

Adventitious stolons sometimes arise laterally from autozooids.
Ten to 20 tubulets extend laterally from medial line on frontal sur-
face of zooid and open at substratum surface. Abundant frontal
pores or extremely short tubulets occur on some stolons.

Measurements. —Lz (8) = 0.30-0.39 mm. (Based on PI. 19,
fig. 1):

Discussion. — D’Orbigny’s description and illustration of 7'ere-
bripora ramosa agree favorably with the several colonies on a gastro-
pod (Calyptraea sp.) mentioned by D’Orbigny and catalogued un-
der MNHN 79572-2. D’Orbigny’s personal catalogue number for T.
ramosa (13664) accompanies the gastropod, and there is no visible
suggestion that the borings within the ink rectangle on the shell are
anything but the type specimens of the first-described species of
boring bryozoan. The largest of the several syntype colonies (PI.
19, fig. 1) is here designated as the lectotype. The neighboring
colonies within the same ink rectangle are paralectotypes.

The type specimens are well-preserved and several (presumed)
ancestrulae are visible. In all cases, the apparent ancestrula (e.g.,
Pl. 19, fig. 1) lacks lateral stolons and seems to give rise to the
proximally situated autozooid with no intervening stolon. In con-
trast, a stolon is obviously present at the distal end of the ances-
trula. The ancestrula differs from the autozooids principally in
lacking lateral stolons and tubulets. One or both of these features
are normally present at the site of an autozooid before it begins its

114 BULLETIN 301

visible differentiation (expansion ) from the stolon (PI. 19, figs. 2, 4).

The subtle aspects of the superficial openings produced by the
various elements of a colony are seen more readily in a fossil speci-
men from Turkey (PI. 19, fig. 4) than they are in the lectotypes. The
small proximal-lateral sinus so evident in this fossil is rarely so well
preserved. This feature has been reported previously in T'erebripora
by Jullien (1880, p. 142) and Marcus (1938, pp. 282, 283). As
noted by Marcus (1938, p. 283) the notch or sinus observed by
Fischer (1866, p. 297; pl. 11, figs. 1, la) was produced by collapse
of the thin layers of shell overlying the zooid. The function of the
proximal-lateral sinus is unknown, but it is tempting to speculate
that it is analogous to that of the poster in the aperture of many
cheilostomes. Marcus (1938, p. 283), apparently discussing this
sinus in what was probably 7. falunica Fischer, seemed to indicate
that this feature is associated with a small sac (“saquinho”), but
the precise nature and location of the structures to which he referred
are not clear. Future examination of the internal anatomy of this
sinus in zooids of Terebripora which have been reliably identified on
the basis of their borings may be revealing.

Terebripora falunica Fischer, 1866 Pl. 19, figs. 5,6; Pl. 20, figs. 1-4;
Pl. 21, figs. 1-6; Text-fig. 1(C-E)

1866. Partim Terebripora orbignyana Fischer, Mus. nat. Hist. nat., Nouv.
Arches Lee2) ps0? on pl. 11, figs..2.) 2a.

1866. Terebripora falunica Fischer, ibid., pp. 301, 302.

1938. Partim Terebripora ramosa d’Orbigny, Marcus, Inst. Biol., (Sa0 Paulo)
Arq., vol. 9, pp. 281-283, 286, 287, text-figs. 2(A-C), 4; mon pp. 283, 284,
text-fig. 2D. (Non Terebripora ramosa d’Orbigny, 1847, Voyage dans
Amérique méridionale, T. 5, pt. 4, pp. 22, 23, pl. 10, figs. 16, 17.)

Material, occurrence. —

Figured: MNHN 79532-1, (lectotype), m. Miocene (Helve-
tian), Manthelan, Indre-et-Loire, France. MNHN 79560-1, m. Mio-
cent (Tortonian), Saubrigues, Landes, France. BMNH D.52366
(fragments + SEM STUB 20), m. Miocene, Manthelan, Indre-et-
Loire, France. BMNH D.52367 (fragment + SEM STUB 4),
Recent, Bay of Santos, Brazil. BMNH D.52368 (RAP 239), Recent,
Bay of Santos, Brazil.

Type locality and horizon.—Manthelan, Indre-et-Loire,
France; m. Miocene (Helvetian).

Range. — M. Miocene-Recent.

Borinc CTENOSTOMATE Bryozoa: PoHOWSKY 115

Diagnosis. — Terebripora with few (0-10) tubulets arising from
frontal surface of autozooids. Lateral stolons typically arise at or
slightly distal to midlength of zooid. Zooids 0.30-0.37 mm long.

Description. — Autozooids like those of 7. ramosa in frontal
aspect and orientation relative to stolon; lying against basal side of
stolon or (more commonly) slightly below it and connected there-
with by narrow vane extending along most of zooid, proximal to aper-
ture. Tapered proximal end extends “freely” basal to stolon, with-
out associated vane. Zooids circular in cross section, except for broad,
lateral swelling arising near proximal end, on side of zooid toward
which aperture is displaced relative to stolon (PI. 21, fig. 3). Distal
one-fourth of zooid strongly flexed toward surface of substratum.
Stolon arises distally, as pronounced ridge on right or left side of
basal surface, near point of zooid flexure. Aperture and associated
proximal-lateral sinus like that of 7. ramosa.

Heterozooids (sac zooids) sometimes present. Ancestrula, ances-
trular budding pattern, and subsequent budding from autozooids
similar to that of 7. ramosa, but with lateral stolons typically arising
slightly distal to midlength of autozooids. Reversed zooids occur in
some specimens.

Paired adventitious stolons sometimes arise from frontal surface
of autozooid, from basal-lateral surface near point of zooid flexure,
or singly from median-distal edge of aperture. Autozooidal tubulets
usually absent, but up to ten occur near median line along frontal
surface in some specimens. Tubulets absent on all stolons except
adventitious stolons arising from basal surface of zooid.

Measurements. — Lz (10) = 0.30-0.37 mm. (Based on PI. 19,
fieaos Els 20, fies 1).

Discussion. — Unfortunately, Fischer’s original description of
Terebripora falunica is vague and not accompanied by an illustra-
tion. Nevertheless, the species is recognized here because the best
preserved of the apparent syntypes in the Muséum national d’His-
toire naturelle (Paris) is a species of Terebripora distinct from T.
ramosa and 7. miniatura. Part of this specimen (PI. 19, fig. 5) lies
within an ink rectangle (drawn by Fischer?) on the second largest
of seven shells catalogued under MNHN 79532-1. It is here desig-
nated to be the lectotype of Terebripora falunica. The accompanying
label indicates that this specimen and the associated bored shells

116 BULLETIN 301

are from Manthelan, the type locality cited in the original descrip-
tion. All of the shells are from the collection of Fischer.

Although preservation of much of the lectotype is poor, portions
lying outside the ink rectangle retain many intact zooids showing
the diagnostic characters of zooid length and dearth of tubulets.
Some characteristics of J. falwnica are better revealed in the topo-
typic colony shown in Plate 21, figures 5, 6. The numerous tubulets
found in 7’. ramosa are clearly absent in this specimen. Other colonies
here assigned to 7. falunica include a m. Miocene syntype of “Tere-
bripora” orbignyana Fischer® (PI. 19, fig. 6) and a Recent specimen
from Brazil (PI. 20, figs. 1-5; Pl. 21, figs. 1-3). The Brazilian colony
and the topotype from Manthelan serve to illustrate intraspecific
variation in the height of the vane.

The well-preserved colony from Brazil also reveals some im-
portant processes in great detail. For example, figure 3 in Plate 20
shows four zooids in ontogentic sequence. Following the development
of the vane, the zooids clearly grow by expansion throughout their
length, rather than by progressive development from one end to
the other. The point of communication with the distally emanated
stolon appears to shift proximally, away from the aperture, as the
zooid expands.

Another noteworthy sequence of events is recorded in Plate 21,
figures 1, 2. Here a stolon executes a spectacular loop around an
immature autozooid, nearly reverses its direction of growth, crosses
one stolon and fuses with the next. Factors influencing the stolon’s
selective fusion are problematic, but it seems possible that the abrupt
return to the surface after crossing the autozooid may indicate a
positive phototrophic reaction in this species. However, in the speci-
men shown, the possibility of a geotropic response cannot be ex-

cluded.

Terebripora miniatura, n. sp. Pl. 20, fig. 5

1938. Terebripora fischeri Jullien, Marcus, Inst. Biol., (Sao Paulo) Arq., vol.
9, pp. 286, 287, text-fig. 4. (Non Terebripora fischeri Jullien, 1880, Soc.
zool. France, Bull., T. 5, pp. 142-144, text-figs. 1-3.)

8“Terebripora” orbignyana was erected before T. falunica, but Fischer’s
description and illustration of the former leave no doubt that the organism he
envisioned belongs with Immergentia Silén. Examination of the best-preserved
syntypes of “T.” orbignyana (e.g., Pl. 24, fig. 6) supports this generic assign-
ment.

Borinc CTENOSTOMATE Bryozoa: PoHoOWwsky ibilyé

Etymology. —It., miniatura, miniature.

Material, range, and locality. —

Figured: BMNH D.52369 (holotype) (RAP 234) (paratype),
Recent, Bay of Santos, Brazil.

Diagnosis. — Terebripora with few (0-10) tubulets arising from
frontal surface of autozooids. Lateral stolons typically arise at or
slightly distal to midlength of zooid. Zooids 0.19-0.24 mm long.

Discussion. — Apart from the smaller size of the zooids, this
species appears to be so similar to 7’. falunica that a complete,
formal description does not seem worthwhile. It may be noted that
7’. miniatura shows evidence of numerous frontal pores or extremely
short tubulets on the stolons. Also, the zooids appear to deviate more
from the horizontal than they do in related species. Marcus’s descrip-
tion and illustration of nearly perpendicular zooids (Marcus, 1938,
p. 286, text-fig. 4) is inaccurate. An optical illusion created by the
nearly opaque substratum of the holotype, the colony occupying
most of Plate 20, figure 5, is responsible for this inaccuracy.

Distally, the holotype collides head-on with a paratype colony,
resulting in a confused proliferation of stolons. It seems possible
that the usual manner of branching has been markedly distorted
by the irregular confluence of conflicting morphogenetic gradients.

Terebripora spp. indet. Text-fig. 1G

1880. Terebripora fischeri Jullien, Soc. zool. France, Bull., T. 5, pp. 142-144,
text-figs. 1-3.

1923. Terebripora parvicella Canu and Bassler, U.S. Nat. Mus., Bull., No.
1258 Fos G55 Ie satecy SS AIS

1923. Tcrebripora sinefilum Canu and Bassler, ibid., p. 15, pl. 3, figs. 14, 15.

1923. Terebripora pacifica Canu and Bassler, thbid., pp. 15, 16, pl. 46, fig. 13
(partim: right side only).

1950. Partim Immergentia philippinensis Soule, J. D., Amer. Microsc. Soc.,
Trans., vol. 69, pp. 366, 367, pl. 2, fig. 3; mom pl. 1, fig. 5.

The species listed above are here assigned to Terebripora, but
their affinities with 7. ramosa, T. falunica, and T. miniatura are un-
certain. On the basis of the scale provided by Jullien (1880), T.
fischeri is probably T. falunica or T. ramosa, but location and study
of the type material are required to resolve the uncertainty. The in-
dicated specimen of Immergentia philippinensts is a Terebripora, but
better, topotypic material will be needed to decide whether this
specimen is distinct from 7. falunica. Available specimens suggest

118 BuLLeTIN 301

that it is probably a new species. The species erected by Canu and
Bassler belong with Terebripora, but their preservation prohibits
further classification. However, a colony on the interior of the shell
bearing the holotype of 7. pacifica suggests that it may be a junior
synonym of 7’. falunica.

The specimens listed below are not illustrated and have not
been examined in detail. Additional study and casting of this ma-
terial may improve our understanding of Terebripora.

BMNH D.52370 (RAP 315), Eocene, Amekia, N. of Umuahia,
FE. Nigeria, BMNH D.52371 (on BMNH G.33995), m. Miocene
(Vindobonian), Touraine, France; BMNH D.52372 (RAP 318),
m. Miocene (Falunien), Pont-le-Voy, Loire-et-Cher, France; BMNH
D.52373 (on BMNH 20793a), Miocene, Touraine, France; BMNH
D.52374 (RAP 324), Miocene, “Lapugy,” Transylvania, Rumania;
BMNH D.52375 (on BMNH G.11725), Pliocene (Caloosahatchee
Fm.), Florida; BMNH D.52376 (on BMNH G.G.12944), Plio-
cene (Caloosahatchee Fm.), about 2.7 mi. N.W. of bridge, Harney
Pond Canal, Glades Co., Florida; BMNH D.52376 (RAP 311), Plio-
cene, Cascale, Italy; BMNH D.52377 (RAP 237), D. 52378 (RAP
241-2), D.52379 (RAP 241-3), D.52380 (RAP 241-4), Recent, Bay
of Santos, Brazil.

Genus MARCUSOPORA, n. gen.

Etymology. — Named in honor of Ernst Marcus.

Type species. — Marcusopora ripleyensis, n. sp.

Diagnosis. — Terebriporidae with bilaterally symmetrical zooids
having apertures located medially along stolon. Ancestrula produces
stolons distally and bilaterally opposite one another near midpoint
of zooid.

Range. — U. Cretaceous (Maastrichtian).

Discussion. — Marcusopora is monotypic and known only from
the Coon Creek Mbr. of the Ripley Fm. in western Tennessee. Its
resemblance to Terebripora d’Orbigny (Eocene?, Miocene - Recent)
suggests that a species of Marcusopora is possibly ancestral to that
genus.

Marcusopora ripleyensis, n. sp. Pl. 7, figs. 5-7; Text-figs. 4B, 6B1

Etymology. — The specific name refers to the formation from

Borinc CTENOSTOMATE Bryozoa: PoHowsky 119

which all known specimens were collected.

Material and occurrence. —

Figured: UCGM 40064 (holotype) (RAP 103), 40063 (para-
type) (RAP 101), 40071 (paratype) (RAP 109), U. Cret.
(Maastrichtian; Ripley Fm., Coon Creek Mbr.), Dave Weeks place,
Coon Creck locality, McNairy Co., Tennessee.

Not figured: UCGM 40100 (RAP 113), U. Cret. (Maastrich-
tian; Ripley Fm., Coon Creek Mbr.), Dave Weeks place, Coon
Creek locality, McNairy Co., Tennessee.

Type locality and horizon.— Dave Weeks place, Coon Creek
locality, McNairy Co., Tennessee; U. Cret. (Maastrichtian; Ripley
F'm., Coon Creek Mbr.).

Range. — U. Cretaceous (Maastrichtian).

Diagnosis. — Same as for the genus, because it is monotypic.

Description. — Zooids resembling those of Terebripora in gen-
eral form and relation to stolon, but bilaterally symmetrical, with
oval aperture disposed medially along stolon. Stolon and distal half
of zooid confluent; vane between stolon and remainder of zooid
totally lacking.

Heterozooids absent. Ancestrula resembles autozooids; produces
stolons distally and bilaterally opposite one another from frontal
surface, at or slightly distal to midlength. Proximal end of initial
zooids more tumid and rounded than that of subsequently produced
zooids. Budding of stolons from autozooids occur as at ancestrula.

Tubulets and adventitious stolons absent. Reversed zooids
present in some specimens.

Measurements. — Lz (8) = 0.29-0.38 mm. (Based on PI. 7, figs.
Grr):

Discussion. — Marcusopora ripleyensis is the only known species
outside of Terebripora d’Orbigny which warrants association with
that genus in the Terebriporidae. This assignment appears to be
justified even though Marcusopora differs markedly from Terebri-
pora in the pattern of budding at the ancestrula (cf. Pl. 7, fig. 7;
Pl. 19, fig. 1). Although this difference and variations in zooid sym-
metry are certainly significant at the generic level, the common
budding pattern and similar aspects of the autozooids in these two
genera suggest that they probably share a closer relationship than
do most other known genera of boring bryozoans.

120 BULLETIN 301

As in Terebripora, zooids of M. ripleyensis begin to grow by ex-
panding the stolon beneath the site of two previously budded lateral
stolons (PI. 7, fig. 6). Colonies may produce broad zones of these
branching stolons distal to the region of developing autozooids (PI.
7, fig. 5). Another feature shared with Terebripora is the occur-
rence in some specimens of reversed zooids, such as the one shown
in Plate 7, figure 6. The anomalous production of unopposing lateral
stolons by two zooids in this same figure is without explanation.

Family IMMERGENTIIDAE Silén, 1946

Diagnosis. — Non-pedunculate boring Bryozoa with zooids es-
sentially vertical in the substratum and joined to one another by
stolonate processes emananting from distal end. Lateral, principal
stolons commonly arise opposite one another along stolons, but never
from zooid body itself. Zooids typically occur in dextral and sinistral
forms distinguishable on basis of aperture.

Range. — L. Miocene - Recent.

Genus IMMERGENTIA Silén, 1946

1866. Partim Terebripora d’Orbigny, Fischer, Mus. nat. Hist. nat., Nouv.
Arch., T. 2, p. 301, pl. 11, figs. 2, 2a. (Non Terebripora d’Orbigny, 1847,
Voyage dans |’Amérique méridionale, T. 5, pt. 4, pp. 22, 23, pl. 10, figs.
Hi, 07/4)

1938. Partim Terebripora d’Orbigny, Marcus, Inst. Biol., (Sao Paulo) Arq., vol.
9, pp. 284-286, text-figs. 3A, 3Bt.

1946. Immergentia Silén, Ark. f. Zool., Bd. 38B, pp. 6, 7, text-figs. 9-12.

1947. Immergentia Silén, Silén, Ark f. Zool., Bd. 40A, pp. 40-47, text-figs. 60,
61.

1950. Partim Immergentia Silén, Soule, J. D., Amer. Microsc. Soc., Trans., vol.
69, pp. 364, 366, 367, pl. 1, figs. 2, 5, 6; pl. 2, fig. 4.

1963. Immergentia Silén, Soule, J. D.. Amer. Mus. Novit., No. 2144, p. 22.

1965. Non Immergentia? Silén, Walter, Soc. géol. France, C. R. fasc. 9, p. 287,
text-figs. a-c.

1966. Terebripora d’Orbigny, Boekschoten, Palaeogeog., Palaeoclim., Palaeo-
ecol., vol. 2, pp. 359-361, text-fig. 6.

1969. Immergentia Silén, Soule, J. D. and Soule, D. F., California Acad. Sci.,
Occas. Pap., No. 78, pp. 8, 9, text-figs. 9-11, 16, 17.

Type species.—Immergentia californica Silén, 1946; O.D.,
Silén (1946, p. 6).

Diagnosis. — Bryozoa with the characters of the family, Im-
mergentiidae Silén, 1946.

Range. — L. Miocene - Recent.

Discussion. — Although Immergentia is perhaps the most com-
mon boring bryozoan in post-Oligocene sediments, its fossil remains

Bor1nc CTENOSTOMATE Bryozoa: PoHowsky 121

have been almost entirely overlooked. Over a century ago, Fischer
(1866, p. 301) erected “Terebripora” orbignyana and included among
the syntypes some colonies of /mmergentia from Asti, Italy (MNHN
79560-4, Pliocene) and Arcachon, France (MNHN_ Di-0207-b,
Recent — PI. 24, fig. 6), but the anatomical distinctiveness of this
genus was not recognized until Silén established the taxon for two
Recent species in 1946. Except for “7.” orbignyana Fischer (MNHN
79560-4), no fossils assignable to Jmmergentia have been described.

The enantiomorphic zooids of this genus have not been re-
ported in extant species, and they seem to be lacking in J. atypica
(Tertiary; Pl. 24, fig. 2). However, their presence is obvious in
many of the colonies examined during the course of this study. When
present, enantiomorphism is always expressed in the shape of the
aperture (PI. 24, fig. 5), and often, in the net deflection of the aper-
ture toward one side of the stolon (PI. 22, fig. 6). The apertures of
typical species are sinuately fusiform; they resemble a slightly
curving, swollen “S,” or the mirror image of that form (cf. various
aperture shapes in Pl. 22, fig. 3; Pl. 24, figs. 1, 5; Text-fig. 3D).
Those zooids in which the attenuated tip of the aperture facing
distally along the stolon points toward the right, as seen from the
shell surface, are here defined to be dextral (e.g., zooid in Text-fig.
3D); all other zooids are sinistral. In those species possessing nearly
circular apertures located medially along the stolon, dextral and
sinistral examples of apparently enantiomorphic zooids may be dif-
ficult to differentiate (PI. 22, fig. 4; Pl. 23, fig. 7). However, when
the apertures of a species have been noticeably deflected toward one
side of the stolon (PI. 22, fig. 6), those zooids placed to the right ap-
pear to be sinistral, as defined above.

The ancestrula and early astogeny of Jmmergentia, heretofore
unknown, are illustrated in some colonies from the Pliocene of Italy
(PI. 23, figs. 1-3). As shown in figure 3, the first lateral stolons arise
slightly distal to the initial autozooids. This is the typical condition
in subsequent astogeny within the genus. In some species, paired
lateral stolons appear to develop just proximal to the autozooids
(I. atypica, I. patagomana). This configuration is perhaps due to
allometric alteration of the processes between the autozooids.

Regarding these processes, it should be noted that the stolons
of Recent Immergentia do not consist of discrete kenozooids. Rather,

122 BuLtetTINn 301

they are highly attenuated portions of the zooids themselves (Silén,
1947, p. 43). This condition may have existed in fossil specimens,
also.

In most (or all) species, the zooids are not vertical in the sub-
stratum. Instead, the entire zooid body is inclined slightly, so that
the proximal end is directed proximally, with regard to the stolon.
In some species, small vanes can be seen in the angles between the
stolon and the distal end of the zooid (PI. 22, fig. 2; Text-fig. 3D).
Apart from the shape and spacing of the autozooids, useful taxobases
include tubulets and adventitious stolons. The former are particu-
larly abundant in J. patagoniana (PI. 24, fig. 5). No gonozooids have
been observed in Immergentia, and larvae are apparently brooded
in autozooids in which the polypide has atrophied (Silén, 1947
p- 45).

Considering the uncertain affinities of J. philippinensis Soule,
either 10 or 11 species of Immergentia are recognized in this study.
In each, the structure and differentiating characteristics of the
borings are discussed in a slightly extended diagnosis, so a descrip-
tion as such is omitted. As indicated in the introduction, Recent
species are considered here only with reference to those features
which are apparently preservable in the fossil record.

bd

Immergentia californica Silén, 1946 Pl. 24, fig. 4

1946. Immergentia californica Silén, Ark. f. Zool., Bd. 38B, p. 6, text-figs. 9,
10.
1947. Immergentia californica Silén, Silén, Ark. f. Zool., Bd. 40A, pp. 40-46
(partim), text-figs. 58, 64-66.
1950. Immergentia californica Silén, Soule, J. D., Amer. Microsc. Soc., Trans.,
vol. 69, p. 364, pl. 1, fig. 2.
1963. Immergentia californica Silén, Soule, J. D., Amer. Mus. Novit., No. 2144,
p. 22.
Type locality and range. — Pacific Grove, California; Recent.
Diagnosis. — Immergentia with zooids about 0.35 mm long and
“evenly pointed” proximally. Zooids tending to be arranged in
straight rows. (Based on Silén, 1946).
Discussion. — An illustration published by Silén (1947, text-
fig. 58) suggests that opposite branching of lateral stolons may not
occur in this species. If this is true J. californica would be readily

distinguishable from all fossil species examined during this study.

Borinc CTENOSTOMATE Bryozoa: PoHowsky 123

Immergentia zelandica Silén, 1946

1946. Immergentia zelandica Silén, Ark. f. Zool., Bd. 38B, pp. 6, 7, text-figs.
LEZ:

1947. Immergentia zelandica Silén, Silén, Ark. f. Zool., Bd. 40A, pp. 40-46
(partim), text-figs. 59, 62, 63, 67-70.

1950. Immergentia zelandica Silén, var. minuta Soule, J. D., Amer. Microsc.
Soc., Trans., vol. 69, p. 367, pl. 1, fig. 6; pl. 2, fig. 4.

1969. Immergentia zelandica Silén, var. minuta Soule, Soule, J. D., California

Acad. Sci., Occas. Pap., No. 78, p. 8, text-fig. 9.

Type locality and range.—Slipper Island, New Zealand;
Recent.

Diagnosis. —Immergentia with zooids about 0.21-0.31 mm
long, and with a short, “finger-shaped” projection at the proximal
end. Zooids tend to be irregularly placed. (Based on Silén, 1946;
Soule, 1950a).

Discussion. — Soule (1950a, p. 367, pl. i, fig. 6) erected J.
zelandica Silén var. minuta. Zooids of this variety are reported to

be 0.207-0.250 mm long, with the proximal, “finger-like” projection
that is diagnostic of the species.

Immergentia suecica Silén, 1947

1947. Immergentia suecica Silén, Ark. f. Zool., Bd. 40A, pp. 46, 47, text-figs.
60, 61.
1950. Immergentia sueica Silén, Soule, J. D., Amer. Microsc. Soc., Trans., vol.
69, p. 364, (nom. null)
Type locality and range. —N. of Flatholmen, Gullmars Fjord,
west coast of Sweden; Recent.
Diagnosis. — Immergentia with zooids 0.31-0.34 mm long, with
blunt proximal end, generally occurring in straight rows. Adventi-
tious stolons sometimes arise from zooids; tubulets sometimes present

on stolons. (Based on Silén, 1947).

Immergentia philippinensis Soule, 1950

1950. Partim Immergentia philippinensis Soule, J. D., Amer. Microsc. Soc.,
Trans., vol. 69, pp. 366, 367, pl. 1, fig. 5; zon pl. 2, figs. 2, 3.
Type locality and range. — Fishery station grounds, Zamboanga
City, Zamboanga, Philippine Islands; Recent.
Discussion. — No diagnosis is presented here because the
anatomy and generic affinities of this species are uncertain. One of
the illustrations accompanying the original description (Soule, 1950a,

124 BuLLeTIN 301

pl. 2, fig. 3, Text-fig. 1G) depicts a species of Terebripora d’Orbigny,
and Soule’s understanding of J. philippinensis was obviously in-
fluenced by that figured specimen. However, the zooid whose soft
parts were illustrated (and described?) (Soule, 1950a, pl. 1, fig. 5)
seems to be referable to Jmmergentia Silén. Pending the publication
of a statement or illustration clarifying the anatomy of the holotype,
the generic affiliation of J. philippinensis Soule will remain prob-
lematic. An apparent paratype (AHF 51.2) contains several zooids
with a well-preserved aperture showing a proximal-lateral sinus much

like that of Terebripora ramosa d’Orbigny (PI. 19, figs. 1-4).

Immergentia angulata Soule and Soule, 1969

1969. Immergentia angulata Soule, J. D. and Soule, D. F., California Acad.
Sci., Occas. Pap., No. 78, pp. 8, 9, text-figs. 9-11, 16, 17.
Type locality and range. — Keaukaha, Hilo, Hawaii; Recent.
Diagnosis. —Immergentia with zooids 0.18-0.20 mm_ long,
, 5 Es
pointed proximally, and “acutely curved at the distal end below
the aperture.” (Based on Soule and Soule, 1969a).

Immergentia boydekina, n. sp. Pl 22 figseiler2a

Etymology. — Middle English, boydekin, dagger.

Maternal and occurrence. —

Figured: BMNH D.52381 (holotype = cast on SEM STUB
23; paratypes = colonies in associated fragments of shell bearing
holotype) (on BMNH G.39306-10), m. Miocene (Balcombian),
Muddy Creek, near Hamilton, Victoria, Australia; BMNH D.52382
(fragments + cast on SEM STUB 15) (RAP 302), Miocene,
“Lapugy,” Transylvania, Rumania.

Type locality and range. — Muddy Creek, near Hamilton, Vic-
toria, Australia; m. Miocene.

Diagnosis. — Immergentia with zooids 0.30-0.32 mm long. Aper-
tures widely spaced, about 0.043 mm across, nearly ovoid, enantio-
morphic and sometimes shifted slightly toward one side of the stolon.
Principal stolons arise opposite one another, just distal to zooids.
Zooids sharply pointed proximally, laterally compressed, and nar-
rowed distally, between well-developed vanes. Tubulets absent.
[Determination of Lz based on direct measurements of six zooids of

holotype (cast) ].

Borinc CTENOSTOMATE Bryozoa: PoHowsKy 125

immergentia lanceolata, n. sp. Pl. 23, figs. 4-6

Etymology.— The specific name refers to the shape of the
zooids.

Material, occurrence, and range. —

Figured: BMNH D.52383 (holotype = cast on SEM STUB 26;
paratypes = colonies in associated fragments of shell bearing holo-
type) (on BMNH G.39704-9, shell B), 1. Pliocene (Kalimnan), Mc-
Donald’s Bank, Muddy Creek, near Hamilton, Victoria, Australia.

Diagnosis. — Immergentia with zooids of same length and gen-
eral form as in J. boydekina, but with broader distal end and larger
aperture (about 0.065 mm across). Adventitious stolons sometimes
arise opposite one another, from edge of zooid facing distally along
stolon (PI. 23, fig. 6), and from various sites on principal stolons.
Paired principal stolons arise as in J. boydekina; tubulets absent.
{Determination of Lz based on direct measurement of seven zooids

of holotype (cast) ].

Immergentia subangulata, n. sp. Pl. 23, figs. 7-9

Etymology. — The specific name refers to the slight flexure that
is commonly observed in the zooids.

Material, occurrence, and range. —

Figured: BMNH D.52384 (holotype, cast on SEM STUB 6),
Recent, Bay of Santos, Brazil.

Diagnosis. — Immergentia with zooids 0.20-0.24 mm long and
gently flexed proximally (relative to the stolon), slightly distal to
midlength. Apertures resemble those of J. boydekina. Zooids oval in
cross section, sometimes with single adventitious stolon arising near
middle of lateral wall (Pl. 23, fig. 9). Paired principal stolons arise
as in J. boydekina. Tubulets absent. [Determination of Lz based on
direct measurement of five zooids of holotype (cast) ].

Immergentia atypica, n. sp. Pl. 24, fig. 2

Etymology. — The trivial name refers to the possession of speci-
fic characters which are rare or unique in the genus.

Material, occurrence, and range. —

Figured: BMNH D.52385 (holotype) (RAP 301), Tertiary,
Lower Waipara Gorge, New Zealand.

Diagnosis. —Immergentia with circular or slightly oval aper-

126 BuLteTIN 301

tures (about 0.10 mm wide) located medially along stolon. Lateral
stolons typically arise opposite one another, just proximal to zooids,
but occasionally just distal to them as well. (Measurement of aper-
tures based on PI. 24, fig. 2).

Discussion. — The illustration of the holotype shows the only
portion of that specimen which retains the stolons. Numerous zooids
are present on other, external parts of the shell, and excavation
around a few of these borings revealed that they are orientated ver-
tically in the substratum.

Despite the apparent absence of apertural enantiomorphism,
the disposition of the zooids relative to the stolons indicates that this
species belongs with Jmmergentia. The production of lateral stolons
just proximal to the zooids is also seen in J. patagoniana.

Immergentia losangelina, n. sp. Pl. 24, fig. 3

Etymology. — The specific name refers to the county from
which the type specimens were collected.

Material, occurrence, and range. —

Figured: BMNH D.52386 (holotype) (on BMNH G.72500-5),
u. Pleistocene (Palos Verdes Sand), Pacific and Oliver Streets, San
Pedro, Los Angeles Co., California.

Not figured: BMNH D.52387 (paratypes on seven shells) (on
BMNH G.72500-5), u. Pleistocene (Palos Verdes Sand), Pacific and
Oliver Streets, San Pedro, Los Angeles Co., California.

Diagnosis. — Immergentia with zooids about 0.20 mm long,
strongly oval in cross section, with rounded proximal end and elon-
gated enantiomorphic apertures (about 0.05 mm wide) separated by
a distance equal to one or two times their length. Paired lateral
stolons arising just distal to zooids. [Determination of Lz based on
direct measurement of three zooids of paratype (cast) ].

Discussion. — The unusually close placement of zooids in this
species produces colonies of exceptional density. Tubulets are prob-

ably lacking.
Immergentia patagoniana, n. sp. Pl, 24, fies 5

Etymology.— The specific name refers to the locality from
which the type specimens were collected.
Material, occurrence, and range. —

Borinc CTENOSTOMATE Bryozoa: PoHOWwsKY 127

Figured: BMNH D.52388 (holotype) (on BMNH 1854.12.4.
466), Recent, Argentina.

Not figured: BMNH D.52389 (paratype) (on BMNH 1854.12.
4.466), Recent, Argentina.

Diagnosis. — Immergentia with stolons bearing numerous short
tubulets. Apertures elongated, placed medially along stolon, and
strongly enantiomorphic. Paired lateral stolons arise just proximal to
zooids and often curve strongly in direction of parent stolon.

Discussion. — An interesting and apparently unique feature of
this new species is the location of the zooids and stolons at the bot-
tom of relatively broad depressions in the surface of the substratum.
These depressions are especially deep around the autozooids, as wit-
nessed by the differential staining of the internal layers of the shell
in Plate 24, figure 5. It seems possible that this unusual condition
reflects an abnormally profuse secretion of the substance(s) respon-
sible for dissolving the shell, but prolonged storage of these speci-
mens in formalin might also have been the cause. The holotype and
paratype are preserved in two gastropods from the collection of
D’Orbigny, and both specimens retain dried zooids within the
borings.

Immergentia spp. Pl. 22) figs: .3),6, 7;, Pl..23,figs. 1-3; Pl. 24, figs, 1, 6;
Text- figs. 3D, 6Al

1866. Terebripora orbignyana Fischer, Mus. nat. Hist. nat., Nouv. Arch., T. 2,
p. 301, pl. 11, figs. 2, 2a.

1938. Tercbripora orbignyana Fischer, Marcus, Inst. Biol. (Sao Paulo), Arq.,
vol. 9, pp. 284-286, text-figs. 3A, 3Bt.

Although the syntypes of “Terebripora” orbignyana are in part
referable to Terebripora d’Orbigny (MNHN 79560-1, Pl. 19, fig. 6),
Fischer’s illustration of the new species leaves no doubt that it be-
longs with Immergentia. However, without casting, “7.” orbignyana
and the specimens listed below cannot be reliably compared with
the other species of Immergentia recognized in the present work.

Material, occurrence, and range. —

Figured: BMNH D.52390 (on BMNH 20793a, shell A), Mie:
cene, Touraine, France; BMNH D.52391 (on BMNH 52415, in
slide), m. Miocene (probably Tortonian), Véslau, Austria, BMNH
D.52392 (on BMNH 81747), Pliocene, Orciana, Toscana, Italy;
BMNH D.52393 (on BMNH 83445), Pliocene, Italy; BMNH
D.52394 (RAP 236), Recent, Bay of Santos, Brazil; MNHN Di-

128 BuLLeTIN 301

0207-b (within ink circle on smaller of two shells) (syntype of
“Terebripora”’ orbignyana Fischer, 1866), Recent, Arcachon,
Gironde, France.

Not figured: BMNH D.52395 (on BMNH G.82116), 1. Miocene
(Langhanian), Lagus, France; BMNH D.52396 (RAP 305), Mio-
cene (probably lower), Le Poivre, Bordeaux, France; BMNH
D.52397 (on BMNH G.33994), m. Miocene (Vindobonian), Tou-
raine, France; BMNH D.52398 (RAP 323), m. Miocene, Manthelan,
Indre-et-Loire, France; BMNH D.52399 (RAP 303), Miocene
(probably middle), “Lapugy,” Transylvania, Rumania; BMNH
D.52400 (on BMNH G.63902), m. Miocene (Vindobonian), De-
linyest, Krasso, Hungary; BMNH D.52401 (RAP 316), m. Miocene
(Vindobonian, probably Tortonian; “2nd Mediterranean Stufe”),
Voslau-Wien, Austria; BMNH DD.52402 (on BMNH 52370), Mio-
cene (probably middle), Grund, Austria, BMNH D.52403 (on
BMNH G.62571), u. Miocene (Yorktown Fm.), W. bank of York
River, 2 mi. 8. of Yorktown, Virginia; BMNH D.52404 (on BMNH
L.L.14860.9), Miocene, Touraine, France; BMNH D.52405 (on
BMNH 45929), Miocene, Touraine, France; BMNH D.52406 (RAP
309), Miocene, Manthelan, Indre-et-Loire, France; BMNH D.52407
(on BMNH G.76529), Miocene, near Zengen, Turkey; BMNH
D.52408 (on BMNH G.70261), Miocene, near Zengen, Turkey;
BMNH D.52409 (RAP 324), probably Miocene, “Lapugy,” Tran-
sylvania, Rumania; BMNH D.52410 (on BMNH G.32492-9), 1.
Pliocene (Plaisancian), Bordighera, N.W. Italy; BMNH D.52411
(fragments + SEM STUB 25) (on BMNH 82698), 1. Pliocene
(Astian), Altavilla, near Palermo, Sicily; BMNH D.52412 (on
BMNH G.G.12307), |. Pliocene (Plaisancian), “Astigiano,” Italy;
BMNH D.52413 (on BMNH G.1011), 1. Phocene (Plaisancian),
Biot, near Antibes, Alpes Maritimes, France; BMNH D.52414 (on
BMNH 83053), 1. Pliocene (Astian), Asti, Italy; BMNH D.52415
(on BMNH 13967), 1. Pliocene (Astian), Asti, Italy; BMNH
D.52416 (on BMNH G.32217), |. Pliocene (Astian), Italy; BMNH
D.52417 (on BMNH G.7930), 1. Pliocene (Astian), Altavilla, near
Palermo, Sicily; BMNH D.52418 (on BMNH 68307), 1. Pliocene
(Astian), Val d’Andona, Piedmont, Italy; BMNH D.52419 (on
BMNH G.39680-4), 1. Pliocene (Kalimnan), McDonald’s Bank,
Muddy Creek, near Victoria, Australia; BMNH D.52420 (on BMNH

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 129

G.72254), Pliocene, Antwerp docks, Belgium; BMNH_ D.52421
(RAP 313), Pliocene, Astigiana, Italy; BMNH D.52422 (on BMNH
G.59323), Pliocene, Piacenza, Italy; BMNH D.52423 (on BMNH
G.59924), Pliocene, Piedmont, Italy; BMNH D.52424 (on BMNH
80732), Pliocene, Colli Astesi, Italy; BMNH D.52425 (on BMNH
L.66250), Pliocene, Piedmont, Italy; BMNH D.52426 (on BMNH
L.7522), Pliocene, Colline Sensi, Italy; BMNH D.52427 (on BMNH
G.52782), Pliocene, Noil Aintie, Timor; BMNH D.52428 (RAP
312), Pliocene, Wanganui, New Zealand; BMNH D.52429 (RAP
321), Pliocene or |. Pleistocene, Piedmont, Italy; BMNH D.52430
(RAP 235), Recent, Bay of Santos, Brazil.

FAMILY UNCERTAIN

Three genera — Foraripora Voigt and Soule (Cretaceous), and
Casteropora and Fischerella (both Paleozoic) — cannot be assigned
with certainty to any of the foregoing families. They are too poorly
known to justify the erection of new families. Foraripora is certainly
a ctenostome, but the Paleozoic genera show features which seem
to set them apart from the other bryozoans considered in this study.
Casteropora and Fischerella are almost certain to be bryozoans,
but if boring hydroids are someday discovered, an immediate reas-
sessment of their affinities will be in order.

Genus FORARIPORA Voigt and Soule, 1973

1973. Foraripora Voigt and Soule, Jour. Paleont., vol. 47, pp. 28-30, pl. 3,
figs. 1-4 ([ ?] figs. 5-7).

Type species. —Foraripora pesavis Voigt and Soule, 1973;
O. D., Voigt and Soule (1973, p. 28).

Diagnosis. —Non-pedunculate boring Bryozoa with tubular,
enantiomorphic zooids orientated horizontally within the substra-
tum. Proximal portion of zooids confluent with stolon; zooids bent
slightly so that distal portion lies free from stolon, on right or left
side thereof. Zooids arise in distal series along principal stolon, and by
paired, opposite budding from proximal portion of other zooids.

Range. — U. Cret. (Campanian, L. Maastrichtian).

Discusston. — Foraripora is monotypic. Its familial relationships
are uncertain, though it shows some characteristics of the Terebri-
poridae and Orbignyoporidae. It seems advisable to allow this issue

130 BULLETIN 301

to rest until we are able to examine additional species and the early
astogeny of I. pesavis.

Foraripora pesavis Voigt and Soule, 1973 Text-fig. 4C

1973. Foraripora pesavis Voigt and Soule, J. D., Jour. Paleont., vol. 47, pp.
28-30, pl. 3, figs. 1-4 ([?] figs. 5-7).

Material and occurrence. —

Iigured: Photo Cat. Voigt No. 3013 (holotype), U. Cret. (U.
Campanian; Chalk), near Lagerdorf, Holstein, Germany. (Only
specimen examined. )

Not figured: Photo Cat. Voigt No. 4717, 5729, 5730, U. Cret.
(Campanian), near Lagerdorf, Holstein, Germany. (Photographs
only examined.)

Range. — U. Cret. (Campanian, L. Maastrichtian).

Diagnosis. — Same as for the genus, because it is monotypic.

Description. — Autozooids strongly elongated, essentially cylin-
drical throughout most of length, but sharply pointed proximally.
Zooids bent laterally at a point one-quarter to one-third of the dis-
tance from proximal end, causing major (distal) portion of zooid to
lie free of stolon, on right or left side. No marked predominance of
dextral or sinistral zooids apparent. Aperture circular to oval, with
width equal to diameter of zooid.

Heterozoids, tubulets, and adventitious stolons absent. Ances-
trula not seen.

Zooids budded ventro-laterally lying close to parent zooid, with
little or no intervening stolon. Those arising in distal series usually
separated by one to four zooid lengths. Stolons exceptionally thin
and nearly always in contact with surface of object bored.

Measurements. —Lz (8) = 1.12-1.38 mm. Zooid diameter
= about 0.075 mm. (Based on direct measurement of holotype).

Discussion. — Foraripora pesavis is distinguished from all other
boring bryozoans by the lateral deflection near the proximal end
of the zooid. The pattern of this deflection to the right or left side
of the stolon is random in a sequence of eight zooids in distal series
in the holotype (Text-fig. 4C). Although Voigt and Soule (1973, p.
29) observed the flexure of zooids in F. pesavis, they did not report
that it caused the distal portion of the zooid to lie free from the
stolon. This omission might be related to their erroneous belief

Bortnc CTENOSTOMATE Bryozoa: PoHowskKY 131

(p. 28) that the stolons of this species are “deeply immersed in the
substratum.”

Genus CASTEROPORA, n. gen.

1888. Terebripora d’Orbigny, Oehlert, Soc. Etud. Sci. Angers, Bull., T. 17, pp.
108, 109, pl. 10, fig. 3. (Non Terebripora d’Orbigny, 1847, Voyage dans
Amérique méridionale, T. 5, pt. 4, pp. 22, 23, pl. 10, figs. 16, 17.)

1965. Partim “Formengruppe C” Jux and Strauch, Senckenbergiana Lethaea,
(Frankfurt a. M.), Bd. 46, pp. 96, 98-100, 113, 114, pl. 9, figs. 15 (a, ¢,
cl), (Leu, (Lele

1968. Partim Cyclopuncta Elias, Miller, Bohr-Réhren von unbekannten Anne-
liden und anderen Organismen in unterdevonischen Brachiopodenklappen
aus der Eifel und dem Siegerland (Rheinischer Schiefergebirge), Univ.
Koln, p. 106, pl. 4, figs. 3-4a. (Non Cyclopuncta Elias, 1958, Jour.
Paleont., vol. 32, pp. 50, 51, pl. 3, figs. 14, 16.)

1968. Partim Spathipora Fischer, Miller, ibid., pp. 82, 106, pl. 4, fig. 7. (No
Spathipora Fischer, 1866, Mus. nat. Hist. nat., Nouv. Arch., T. 2, pp. 309,
310, pl. 11, figs. 4, 4a.)

Etymology. — Named in honor of K. E. Caster.

Type species. — Casteropora vetusta (Oehlert), 1888.

Diagnosis. — Boring bryozoans with short, subglobular zooids
disposed vertically within the substratum, along or tangent to sto-
lons. Lateral stolons arise singly from stolons and from distal end of
zooids.

Range. — Lower, Middle Devonian.

Discussion. — Casteropora is presently known from several
occurrences in the Devonian of Europe and New York. Only one
species is recognized at present, though “Formengruppe C” (Jux
and Strauch, 1965) is probably the product of a second member of
the genus.

Casteropora vetusta (Oehlert), 1888 Pl. 14, figs. 4, 5, 7

1888. Terebripora vetusta Oehlert, Soc. Etud. Sci. Angers, Bull., T. 17, pp. 108,
109, pl. 10, fig. 3.

1968. Partim Cyclopuncta Elias, Miiller, Bohr-Réhren von unbekannten Anne-
liden und anderen Organismen jin unterdevonischen Brachiopodenklappen
aus der Eifel und dem Siegerland (Rheinisches Schiefergebirge), Univ.
Koln, p. 106, pl. 4, figs. 3-4a. (Non Cyclopuncta Elias, 1958, Jour. Paleont.,
vol. 32, pp. 50, 51, pl. 3, figs. 14, 16.)

1968. Partim Spathipora Fischer, Miiller, ibid., pp. 82, 106, pl. 4, fig. 7. (Non
Spathipora Fischer, 1866, Mus. nat. Hist. nat. Nouv. Arch., T. 2, pp. 309,
310, pl. 11, figs. 4, 4a.)

Material and occurrence. —
Figured: GLNW Sg II-741, L. Dev. (M. Siegenian, Wildflasser
Zone, Seifen II, Fossil-Bank “a”), Seifen bei Dierdorf, Germany;

132 BuLtetTIN 301

UCGM 40074 (RAP 220), M. Dev. (Marcellus Sh., Cardiff Sh.
Mbr.), hillside quarry on E. side of Swamp Rd., 2.2 mi. N. of Mor-
risville, New York; BMNH D.52431 (SEM STUB 17), M. Dev.
(Marcellus Sh., Cardiff Sh. Mbr.), hillside quarry on E. side of
Swamp Rd., 2.2 mi. N. of Morrisville, New York.

Not figured: UCGM 40095-40099, M. Dev. (Marcellus Sh.,
Cardiff Sh. Mbr.), hillside quarry on E. side of Swamp Rd., 2.2 mi.
N. of Morrisville, New York.

Type locality and horizon. — Saint - Germain - le - Fouilloux,
Mayenne, France; L. Dev.

Range. — Lower to Middle Devonian.

Diagnosis. — Same as for the genus because it is monotypic. Any
future decision that the specimen of Casteropora sp. discussed be-
low is a distinct species would eliminate C. vetusta as a monotype.

Discussion. — Except to say that heterozooids, tubulets, adven-
titious stolons and the ancestrula have not been clearly discerned in
available specimens, a formal description of this species would add
little to what is revealed in the generic diagnosis and in Plate 14,
figures 4, 5, 7.

The most completely preserved specimens of C. vetusta show
a degree of apparent randomness in the budding pattern that 1s
atypical among boring bryozoans. However, the lack of pattern in
the occurrence of unpaired lateral stolons may possibly be a func-
tion of imperfect preservation. If the stolons actually do arise in a
random manner, the system of stolons in older colonies would greatly
resemble the filiform type of hydrorhiza found in some hydroids.
However, despite any possible similarity to a living hydrozoan, our
ignorance of any boring hydroids would seem to assign C. vetusta to
the Bryozoa by default.

Casteropora is totally unlike the other two genera of boring
bryozoans known from the Paleozoic, but it does show a general
resemblance to Jmmergentia Silén. The principal feature in common
is the vertical disposition of the zooids along the stolon. In C. vetusta
the zooids are much less elongated than those of /mmergentia (cf.
Pl. 14, fig. 5; Pl. 22, fig. 2), and the bilaterally opposite budding of
principal stolons — so common in Jmmergentia — is apparently
lacking. While affinity with Jmmergentia cannot be discounted ab-
solutely, the absence of any /mmergentia-like borings between the

Borinc CTENOSTOMATE Bryozoa: PoHowsky 133

Devonian and the Miocene reduces the plausibility of such a rela-
tionship.

Because the location of the holotype of C. vetusta is unknown,
my assignment of specimens to this species is based on Oehlert’s
description and figure. If the indicated magnification of his illustra-
tion is correct, the diameter of zooids in the holotype is several
times larger than that found in the specimens from New York (e.g.,
Pl. 14, fig. 4). However, Oehlert revealed that the surface of the
brachiopod substratum (Uncinulus oehlerti) containing the specimen
was deteriorating, so considerable enlargement of the zooids may well
have occurred. The specific name chosen by Oehlert undoubtedly
refers to the condition of the holotype.

Casteropora sp. Pl. 14, fig. 6

1965. Partim “Formengruppe C” Jux and Strauch, Senkenbergiana Lethaea,
(Frankfurt a. M.), Bd. 46, pp. 96, 98-100, 113, 114, pl. 9, figs. 15(a, c,
Gl), (LPN, (LPAI:

Plate 14, figure 6 shows a topotypic specimen of some Lower
Devonian borings (casts) like those which Jux and Strauch (1965)
described under the heading, “Formengruppe C.” Remarking that
the borings consist of small holes up to about 0.2 mm deep and con-
nected with one another by thin tubes lying near the surface of the
substratum, these authors attributed the problematic remains to
endolithic algae. However, the dimensions of the essentially vertical
holes place them within the size range of bryozoan zooids, and the
disposition of the fine tubes suggests that they could easily be
stolons. Moreover, although further details of the structure of these
borings are unknown, their anatomy appears to be fundamentally
like that of a contemporary bryozoan, Casteropora vetusta —
though on a somewhat smaller scale.

Until further research clarifies the biological relationships of
“Formengruppe C,” it seems that the principal component of these
borings would be more aptly regarded as a species of Casteropora,
rather than an endolithic alga. A new species is not erected at this
time because accurate interpretation of the best-preserved specimens
is obscured by another boring bryozoan in which the zooids are dis-
posed horizontally.

134 BULLETIN 301

Genus FISCHERELLA, n. gen.

1904. Partim Khopalonaria Ulrich, Ulrich and Bassler, Smithsonian Misc. Coll.
(Quart. Issue), vol. 45, p. 272, pl. 66, fig. 11. (Non Ropalonaria Ulrich,
1879, Cincinnati Soc. Nat. Hist., Jour., vol. 2, pp. 26, 27, pl. 7, figs. 24,
24a.)

Etymology. — Named in honor of P. Fischer.

Type species. — Fischerella keokukensis (Ulrich and Bassler),
1904.

Diagnosis. — Boring bryozoans with stolons bifurcating and
growing sinuously. Zooids pedunculate and attached to stolon at
their proximal extremity.

Range. — L. Miss.

Discussion. — Fischerella is monotypic and deserves further
study to determine the details of its poorly known, but unusual
anatomy.

Fischerella keokukensis (Ulrich and Bassler), 1904 Pinions

1904. Rhopalonaria keokukensis Ulrich and Bassler, Smithsonian Misc. Coll.
(Quart. Issue), vol. 45, p. 272, pl. 66, fig. 11.

Material, occurrence, and range.— The lectotype (USNM
43122; Pl. 7, fig. 8), from the Keokuk Ls. (L. Miss.) at Keokuk,
Iowa, is the only known specimen.

Diagnosis. — Same as for the genus, because it is monotypic.

Description. — Autozooids pedunculate, tubular, horizontal, and
attached to stolon at proximal end. Shape of aperture unknown.

Heterozooids unknown; ancestrula not seen. Budding pattern
obscure, but apparently involves bifurcation of sinuous stolons, with
zooids occurring between some points at which stolons divide.

Presence or absence of tubulets and adventitious stolons in-
determinate.

Measurements. —Lz(6) = 0.33-0.40 mm. (Based on PI. 7,
fig. 8).

Discussion. — Fischerella keokukensts is the only boring bryo-
zoan reported from the Mississippian. Only a single specimen is here
assigned to the species, although three items (two borings in corals,
and an artificial cast) are catalogued under USNM 43122, the
number mentioned by Ulrich and Bassler (1904, p. 272). The speci-
men illustrated here is designated to be the lectotype. The biological

Borinc CTENOSTOMATE Bryozoa: PoHowsky 135

affinities of the other items in USNM 43122 are uncertain.

Although this species is poorly known, it is evident that the
sinuous growth and distinct bifurcation of the stolons set it apart
from the other organisms considered in this study. There is no evi-
dence of the pinnate, Ropalonaria-like growth form described by
Ulrich and Bassler (1904). Rather, the relationship of the zooids to
the stolons is more like that which Fischer (1866, pl. 11, figs. 4, 4a)
reported in Spathipora sertwm, but the unique character of the
stolons in F. keokukensis suggests that when better specimens are
collected, the distinctiveness of Fischerella from Spathipora may be
more apparent. Unfortunately, the lectotype is so badly worn that
only the deeper parts of the colony (1.¢., the basal parts of the auto-
zooids) are preserved.

Details in better, topotypic specimens may cast doubt on the
affinities of this genus with the Bryozoa. The peculiar stolons and
possible preferred orientation of the zooids are reminiscent of Protu-
lophila Roverto, a hydroid which lived symbiotically with serpulid
polychaetes (Scrutton, 1973). The mode of life of Fischerella is

almost as uncertain as the details of its anatomy.
STRATIGRAPHIC RANGES OF GENERA

The following is as a summary of the proposed classification of
boring bryozoans, and an aid to their tentative identification, by
means of the indicated plate figures and known range. Descriptions
should be consulted for maximum certainty. The taxa are listed in
order of their appearance within the text; the generic ranges are
shown graphically in Text-figure 5.

Ropalonariidae Nickles and Bassler, 1909

Ropalonaria Ulrich, 1879. U. Ord., ?U. Jur., ?L. Cret. Pls. 1-3
Orbignyoporidae, n. fam.

Orbignyopora, n. gen. ?M. Sil., ?L. Dev., ?M. Dev., ?M. Jur., ?U.

Cret., Paleocene-Pliocene. Pls. 4, 5
Voigtellidae, n. fam.

Voigtella, n. gen. ?Perm., U. Cret. Pl. 6; Pl. 7, figs. 1-4

Penetrantiidae Silén, 1946
Penetrantia Silén, 1946. ?L. Cret., U. Cret.-Recent.
Pl. 9 (except fig. 1), 10-12
Haimeina Terquem and Piette, 1865. U. Trias., L. Jur.
lS SS TAS Ch ayaa TL
Cookobryozoonidae, n. fam.
Cookobryozoon, n. gen. m. Miocene-l. Pliocene.
Pl. 13; Pl. 14, figs. 1-3

136 BULLETIN 301

Rec.

xX @x
Pleist. g pra
3 1
Plio. re)
4
9
Mio. 6 x
i
'
1
t c
' °
' °
t 5S N
t °
1 co >
' o -
Oe e oD a
' o ~
' £ oO
‘ So SY
' °
: ' Q.
° @x o B ex ex 5
1 ' | ' ®
ou ' ro o
n ' ' 1 Ob: CAE
1 : = =
8 ! oy oe) Gy
» Oo 5 2 2
fel OU xX Tc 8
= 9-5
h
Trias. oe to eee Hi: ree he
fou mC) ' © ua Loy
Perm. 3S 2 ° = Oe oo fel fe =
Se) ee Ore oo en 2
oo i oc
Carb. Cos 2 oi
) @x 2 PJ
PIG
ebe 3&
panO siguin >
Hl
A ee

+l

Cam.

TEXT-FIGURE 5

Stratigraphic ranges of boring Bryozoa. Each black disc represents the
approximate stratigraphic position of one or more occurrences of a genus. White
discs indicate occurrences assigned to the genus with doubt. (In Spathipora, the
age and detailed morphology of the type species are uncertain.)

In most cases, only one occurrence of a particular genus is reported in a
given period. However, when two accurately dated specimens are known from

Borinc CTENOSTOMATE Bryozoa: PoHowsky 137

Spathiporidae, n. fam.

Spathipora Fischer, 1866. M. Jur.-Recent. Pls. 15-18
Terebriporidae d’Orbigny, 1847

Terebripora d’Orbigny, 1847. Eocene-Recent. Pls, 19-21

Marcusopora, n. gen. U. Cret. Pl]. 7, figs. 5-7
Immergentiidae Silén, 1946

Immergentia Silén, 1946. 1. Miocene-Recent. Pls. 22-24
Family Uncertain

Foraripora Voigt and Soule, 1973. U. Cret. Text-fig. 4C

Casteropora, n. gen. L. Dev., M. Dev. Pl. 14, figs. 4-7

Fischerella, n. gen. L. Carb. (L. Miss.) lb Zoesnres fe

TAXONOMIC POSITIONS OF SPECIES

The species below appear in their original generic combinations
and in chronological order of their establishment. Those species
erected by Silén and the Soules are best known from their internal
features, but all others were recognized on the basis of borings alone.
The affinities of most of these with the Bryozoa were stated or
strongly inferred in the original publication. Entobia antiqua Port-
lock was presumed to be a “zoophyte” (Portlock, 1843, p. 359) and
Vioa? michelint Terquem was described under the heading, polypiers
[corals], though Vioa Nardo, 1833, was originally conceived to be a
sponge.

After each species appears a notation of its recognized status
within this work. Unless otherwise indicated, all species are boring
ctenostomate bryozoans. Some species are relisted in a new generic
combination. Where no notation appears after a listing, the original
combination is accepted.

Genus Tercbripora d’Orbigny, 1847

. ramosa d’Orbigny, 1847

. irregularis d’Orbigny, 1847; gen. and sp. uncertain
. antiqua d’Orbigny, 1850; gen. and sp. uncertain

. antillarum Fischer, 1866; gen. and sp. uncertain

. pusilla Fischer, 1866; gen. and sp. uncertain

. reticulum Fischer, 1866; gen. and sp. uncertain

Sl Stl sells]

different (lower, middle or upper) parts of a period, both are indicated. A small
dot indicates that the position of a genus within a period is unknown.

An “X” indicates the occurrence of the type specimen(s) of the type
species.

The relative thickness allotted to each period is proportional to the dura-
tion indicated by the Geological Society Phanerozoic time scale (Harland and
others, 1964), except that the Paleocene through Miocene have been thickened
by a factor of 5, and the Pliocene and Pleistocene have been thickened by a
factor of 10.

138

Genus
S.
S.
S.

br Ba eee ge: ee a or ee lp ne er eg le), oe he Ja pha |

BuLLeTIN 301

. orbignyana Fischer, 1866; Immergentia sp. Silén

. falunica Fischer, 1866

. eocenica Fischer, 1866; pics of encrusting cheilostome

. archiaci Fischer, 1866; Orbignyopora archiaci (Fischer)

. contorta Fischer, 1866; pits of encrusting cheilostome

producta Fischer, 1866; gen. and sp. uncertain

arachne Fischer, 1866; Ropalonaria? arachne (Fischer)

propingqua Fischer, 1866; gen. and sp. uncertain

? quenstedti Fischer, 1866; jr. syn. Haimeina michelini (Terquem)

.? portlocki Fischer, 1866; jr. obj. syn. Entobia antiqua Portlock

stellifera Terquem and Jourdy, 1869; probably not a bryozoan

radiciformis Terquem and Jourdy, 1869; probably not a bryozoan

latesulcata Terquem and Jourdy, 1869; not a bryozoan

. hieroglyphica® Terquem and Jourdy, 1869; not a bryozoan

capillaris Dollfus, 1877; Orbignyopora? capillaris (Dollfus)

densa Dollfus, 1877 (nom. nud.)

tenuis Seguenza, 1880; gen. and sp. uncertain—possibly a Terebripora

. fischeri Jullien, 1880; Terebripora sp. d’Orbigny

vetusta Oehlert, 1888; Casteropora vetusta (Oehlert)

manzonti Rovereto, 1901; jr. syn. Orbignyopora archiaci (Fischer)

ditrupae Norman, 1907; Penetrantia sp. Silén

parvicella Canu and Bassler, 1923; Terebripora sp. (d’Orbigny)

sinefilum Canu and Bassler, 1923; Terebripora sp. (d’Orbigny)

elongata Canu and Bassler, 1923; jr. syn. Orbignyopora archiact
(Fischer)

pacifica Canu and Bassler, 1923; Terebripora sp. (d’Orbigny)

robusta Brydone, 1936; encrusting cheilostome

comma Soule, 1950; Spathipora comma (Soule)

eltaninae Soule and Soule, 1968; genus uncertain—not a Terebripora

. varians Soule and Soule, 1969; genus uncertain—probably not a Tere-
bripora

(?) bassleri Voigt and Soule, 1973; Ropalonaria? sp.; possibly a jr.
syn. of R.? arachne (Fischer)

(?) sibirica Voigt and Soule, 1973; Spathipora sibirica

. (?) echinicola Voigt and Soule, 1973; possibly a jr. syn. of Orbignyo-
pora archiaci (Fischer)

Spathipora Fischer, 1866

elegans Fischer, 1866

sertum Fischer, 1866

incerta Fischer, 1866; Spathipora sp. Fischer

Spatipora laxa Seguenza, 1880; (nom. null.), Penetrantia sp. Silén

S.
S.
8.

S.
S.
Genus

longicauda Canu and Bassler, 1923; Spathipora sp. Fischer

longirima Canu and Bassler, 1923

cucullata Canu and Bassler, 1923; jr. syn. Spathipora longirima Canu
and Bassler

indistincta Gorodiski and Balavoine, 1961; pits of encrusting cheilostome

prima Voigt, 1962; Voigtella sp.

Ropalonaria Ulrich. 1879

R. venosa Ulrich, 1879

9The four species of Terebripora erected by Terquem and Jourdy were

also a

ssigned to Talpina von Hagenow in the same publication (pp. 156, 164).

The location of the types of these species is unknown, and their affinities are
here evaluated on the basis of the original descriptions and illustrations. T.
hyeroglyphica Terquem and Jourdy, (1869, p. 164) is a nomen nullum.

Borinc CTENOSTOMATE Bryozoa: PoHowsky 139

. medialis Ulrich and Bassler, 1904; ? jr. syn. Orbignyopora? capillaris
(Dollfus) and jr. obj. syn. Ropalonaria tenuis Ulrich and Bassler

. keokukensis Ulrich and Bassler, 1904; Fischerella keokukensis (Ulrich
and Bassler)

R.? sp., Girty, 1915; not a bryozoan

R. permiana Bassler, 1929; partim Voigtella? timorensis (Bassler), partim
probable boring ctenostome (gen. and sp. indet.)

R. irregularis Fritz, 1944; affinities uncertain, possibly not a bryozoan

R. graphicus Condra and Elias, 1944; not a bryozoan, probably a sponge
boring

R. dendriformis Condra and Elias, 1944; affinities uncertain, probably not
a bryozoan

R. lambtonensis Fritz, 1954; ? jr. syn. Orbignyopora? capillaris (Dollfus)

R. givetiana Kiepura, 1965; encrusting organism of uncertain affinities

Genus Penetrantia Silén, 1946

P. densa Silén, 1946

P. brevis Silén, 1946

P. parva Silén, 1946

P. concharum Silén, 1946

P. sileni, Soule, 1950

P. irregularis Silén, 1956

P. operculata Soule and Soule, 1969

P. gosaviensis Voigt and Soule, 1973; Penetrantia sp.

Genus Immergentia Silén, 1946

I. californica Silén, 1946

I. zelandica Silén, 1946

I. suecica Silén, 1947

I. sueica Soule, 1950a, p. 364 (nom. null.)

I. philippinensis Soule, 1950; genus uncertain (either Jmmergentia or
Terebripora)

I. zelandica Silén var. “minuta” Soule, 1950

I.? lissajoust Walter, 1965; hydroid (see Scrutton, 1973)

I. angulata Soule and Soule, 1969

Miscellaneous genera (listed in order of species’ publication date)

Entobia antigua Portlock, 1843; apparently a boring; possibly a bryozoan.
Bromley (1970, p. 78) indicated that the type species of Entobia (E.
cretacea Portlock, 1843) is a clionid sponge boring.

Talpina pungens Quenstedt, 1848; Voigtella sp. The probable phoronid
affinities of the ichnogenus Talpina von Hagenow, 1840 (type species:
T. ramosa von Hagenow, 1840) are discussed at length by Voigt (1972).

Vioa? michelini Terquem, 1855; Haimeina michelini (Terquem and Piette).

Bascomella gigantea Morningstar, 1922; not a bryozoan; an association of

tubular borings with those of acrothoracican cirripeds. Elias (1957, p.
390) published his concurrence with the opinion of Seilacher that “an
Alcippe-like barnacle rather than a ctenostomatous bryozoan has
probably produced the egg-shaped Bascomella excavations” and pro-
posed “that the generic name Bascomella be applied to the egg-shaped

R. botellus Vine, 1884; encrusting organism of uncertain affinities

R. pertenuis Ulrich, 1886; encrusting uniserial cyclostome (Stomatopora
proutana Miller)

R. ulrichi Vine, 1887b; nom. nud.

R. attenuata Ulrich and Bassler, 1904; ? jr. syn. Orbignyopora? capillaris
(Dollfus) ;

R. robusta Ulrich and Bassler, 1904; ? jr. syn. Orbignyopora? capillaris
(Dollfus)

R. tenuis Ulrich and Bassler, 1904; ? jr. syn. Orbignyopora? capillaris
(Dollfus)

R

R

140 BuLLETIN 301

excavations, and not to their combination with stolon-like excavations
which are occasionally found with them.”

Bascomella fusiformis Condra and Elias, 1944; not a bryozoan; affinities
uncertain.

Bascomella subsphaerica Condra and Elias, 1944; not a bryozoan; affinities
uncertain.

Vinella ulrichi Condra and Elias, 1944; not a bryozoan; possibly a sipuncu-
lid boring. The type species of Vinella Ulrich (V. repens Ulrich,
1890) is an encrusting organism of uncertain affinities.

Heteronema parvula Condra and Elias, 1944; not a bryozoan; probably a
thallophyte boring. The type species of Heteronema Ulrich and Bassler
(H. capillare Ulrich and Bassler, 1904) is an encrusting organism of
uncertain affinities.

Heteronema magna Condra and Elias, 1944; not a bryozoan; possibly a
sipunculid boring.

Graysonia bergquisti Stephenson, 1952 (type species of the genus); not a
bryozoan; an association of tubular borings with those of acrothoracican
cirripeds [conclusion reached by Bromley (1970, p. 58) and Voigt and
Soule (1973, p. 32) ].

Graysonia anglica Casey, 1961; not a bryozoan; an association of tubular
borings with a few vesicular borings [Bromley (1970, p. 58), Voigt
and Soule (1973, p. 32)].

Iramena danica Boekschoten, 1970; almost certainly Penctrantia sp. Silén.

Foraripora pesavis Voigt and Soule. 1973.

EVOLUTION AND PHYLOGENY

Thirteen genera are recognized in this study, but their major
phylogenetic relationships remain obscure, except the probable ties
inferred by uniting two genera within the Terebriporidae and Pene-
trantiidae. While it appears likely that many groups of ctenostomes
assumed the boring mode of life during the long history of the order,
this impression may be largely a reflection of limited collecting and
study. Convincing relationships of ostensibly disparate families may
yet be revealed through further research.

Although the pattern of phylogenesis among boring bryozoans
is still poorly known, a few general observations about the evolution
of these organisms can now be made. All of the species considered
here show evidence of environmental influences on morphology, and
if it were clearly demonstrable that more than one group of cteno-
stomes adopted the boring habitus, the term, “convergent evolution,”
would certainly apply. Silén (1946, 1947) assigned Immergentia to
the Carnosa, while aligning Penetrantia with the Stolonifera. How-
ever, Jebram (1970, and in press) concluded that the distinction
between these suborders is highly artificial. Boring ctenostomes do
present at least one interesting and important example of apparent
convergence with the cheilostomes. The influence of selective pres-

Borinc CTrENOSTOMATE Bryozoa: PoHowsky 141

sures on the colonial anatomy of shell-penetrating species will be
considered first.

Although ensconced in a thick matrix of calcium carbonate, bor-
ing bryozoans are by no means exempt from some of the environ-
mental hazards that plague other members of this sessile, colonial
phylum. All molluscan substrata — and “dead” shells in particular
— are subject to abrasion, boring, burial, fracture, and encrustation
by living organisms, and it is apparent that any of these processes
could have a disastrous effect on any boring or encrusting bryozoan
that might be involved. This fact offers the first of two possible ex-
planations for the highly dispersed arrangement of zooids seen in all
species of boring bryozoans, for it is evident that colonies of this
type would be less susceptible to rapid total destruction by the
above processes than would colonies in which all the zooids were
concentrated in a small area. Larger colonies are more apt to sus-
tain partial damage, while retaining the ability to reproduce. By
having the zooids scattered, a species is assured of the fullest protec-
tion offered by the substratum. If too closely packed, the zooids of
boring species might easily cause supporting pillars of shell to be-
come dangerously weak.

An analysis of the early astogeny of a number of genera sug-
gests that yet another factor may help to produce common attributes
of form among boring bryozoans. Solely on the basis of the number
and orientation of the stolons produced from (or near) the ances-
trula, the species recognized in this study may be divided into five
somewhat artificial groups (Text-fig. 6). These groups, and repre-
sentative taxa are listed below:

2 stolons—/mmergentia sp.

Terebripora ramosa d’Orbigny
3 stolons (type 1)—Marcusopora ripleyensts, n. gen., n. sp.
Cookobryozoon lagaaiji, n. gen., n. sp.
3 stolons (type I1)—Orbignyopora? tridelta, n. gen., n. sp.
Penetrantia sp.
Spathipora elegans Fischer
S. occidentalis, n. sp.
4 stolons—Ropalonaria venosa Ulrich
Haimeina michelini (Terquem)
Spathipora ambidextra, n. sp.
5 or 6 stolons—Penetrantia? sp. (PI. 9, figs. 8-10).

142 BULLETIN 301

oe
z

Al B3
B

A2 Ba

A
4 >t

B2 Bo

TEXT-FIGURE 6

Early astogeny in boring Bryozoa. Taxa are grouped according to the
number and orientation of stolons produced directly from the ancestrula, or
otherwise prior to the appearance of the budding pattern characterizing all sub-
sequent growth in the colony. The groups have the following characteristics:
\, two lines of growth emanate from the ancestrula in opposite directions; B,

Borinc CTENOSTOMATE Bryozoa: PoHOWwsKY 143

I consider it significant that in nearly all of the bryozoans listed
above (with the exception of Marcusopora ripleyensis and Cooko-
bryozoon lagaaiji), the stolons produced at or near the ancestrula
tend to diverge at the greatest possible angle to one another. Thus,
when only two stolons are initially present, they grow in nearly op-
posite directions — though the Immergentia in Plate 23, figs. 1-3
deviates slightly from this rule. In most species producing three
stolons from the ancestrula, the processes form angles of about 120
degrees; in those with four stolons originating near the ancestrula,
the intervening angles approximate 90 degrees, and so on.

This tendency is not entirely fortuitous. It appears likely that
natural selection favors those genotypes producing a colony archi-
tecture that utilizes available space around the ancestrula as ex-
peditiously as possible. A colony in which the initial growth was
strongly unidirectional might encounter unfavorable conditions in
the limited area of the substratum it exploited, and be incapable of
meeting the urgent need to radically redirect its budding. Colonies
possessing a radially symmetrical plan would often be able to rapidly
take advantage of suitable adjoining areas, regardless of their direc-
tion relative to the ancestrula. Evidently the selective pressures
must influence very young colonies, because the subsequent branch-
ing in most species usually produces polydirectional growth.

A force exists that produces polydirectional growth near the

three stolons arise from or near the ancestrula and depart (in figs. B3-B6) at
approximately 120 degrees to one another; C, four stolons arise from or near the
ancestrula and grow at approximately 90 degrees to one another; D, six (some-
times five) stolons radiate from the ancestrula, forming roughly equal inter-
angles.

Taxa: Al, Immergentia sp.; A2, Terebripora ramosa d’Orbigny; Bl,
Marcusopora ripleyensis, n. gen., n sp.; B2, Cookobryozoon lagaaiji, n. gen.,
n. sp.; B3, Orbignyopora ? tridelta, n. gen., n. sp.; B4, Penetrantia sp.; BS,
Spathipora elegans Fischer; B6, Spathipora occidentalis, n. sp.; C1, Ropalonaria
venosa Ulrich; C2, Haimeina michelini (Terquem) ; C3, Spathipora ambidextra,
n. sp.; D, Penetrantia ? sp.

The figures are highly diagrammatic and details of the zooids are not
indicated, except that the ancestrula is shown in black to distinguish it from
the autozooids (white). The arrows indicate the distal direction for horizontal
ancestrulae; those without arrows are orientated vertically, or nearly so.

It should be noted that the various colonies are shown at slightly different
enlargements, and that the illustrations represent portions of “mature” colonies
rather than young colonies in which zooids and stolons appear at the exact
states of development apparent.

144 BuLLeETIN 301

ancestrula, and it is somewhat different from those forces favoring
stolonate colonies with widely separated zooids. It seems possible
that one or two of these three hypothetical factors may have been
influential in determining the colonial anatomy of ancestral, epi-
benthonic ctenostomes. Here the issue becomes complicated how-
ever, because budding in the vertical direction would be possible in
encrusting species.

There are three other features common to a number of boring
bryozoans which may be attributable to the boring mode of life.
These features are tubulets, adventitious stolons, and sac zooids. The
phenomenon of enantiomorphism is also displayed by several genera,
but it apparently occurs sporadically within encrusting bryozoans
(Cummings, 1904, p. 58; Waters, 1924, pp. 594, 595; Cheetham,
1968) and is, therefore, attributable to factors unrelated to the
boring habitus.

As suggested by Marcus (1938) and Silén (1947), tubulets un-
doubtedly serve for the exchange of dissolved substances between
the stolons and the external environment. Presumably, those species
with stolons located essentially tangent to the substrate surface have
similar metabolic requirements and also communicate with the ex-
terior. A number of such species show definite evidence of simple
openings (frontal pores) on either or both stolons and zooids.

Adventitious stolons are found in several boring genera, and
their occurrence is presumably a means of providing alternative
routes for the exchange of materials between zooids in the event
that some of the principal stolons cease to function. The fact that
they are common and often arise far below the surface in species
such as Penetrantia irregularis Silén and P. souler suggests that
these bryozoans may be adapted for life in environments wherein
abrasion or boring are particularly serious hazards. [One or both of
these dangers may explain why P. densa Silén secretes calcium car-
bonate (PI. 11, fig. 2), and it is probably to avoid abrasion that the
operculum of some species of Penetrantia is countersunk slightly
beneath the shell surface.

Sac zooids are known in only three, seemingly diverse genera.
Presumably, the sac zooids of Ropalonaria Ulrich and Terebripora
d’Orbigny also contained (or contain) the “refringent granules” re-
ported by Bobin and Prenant (1954) in Spathtpora comma (Soule).

Borinc CTENOSTOMATE Bryozoa: PoHowsky 145

Although the function of these granules is unknown, the presence
of sac zooids in Ropalonaria and Terebripora is evidence that these
genera may be more closely related to one another and to Spathipora
than is apparent in view of the significant differences in age and
anatomy which separate them. Because sac zooids have not been
observed in epibenthonic ctenostomes, it is tempting to speculate
that they may have evolved in response to some special require-
ment(s) of shell-penetrating species.

The fact that many species of boring bryozoans show similar
adaptations in apparent response to the same selective pressures
is perhaps overshadowed in significance by the near certainty that
a few of these ctenostomes (or, with regard to Penetrantia, prob-
able ctenostomes) have evolved some important features typically
associated with the Cheilostomata. Unfortunately, the soft-part
anatomy of Terebripora d’Orbigny may be uninvestigated, and it is
now impossible to say with certainty that the proximal-lateral sinus
in this genus (PI. 19, fig. 4) serves a function analogous to that of
the poster in the aperture of some cheilostomes. However, the need
for a passage to permit the exchange of water between the exterior
and a cavity surrounding the zooids of boring species is obvious, be-
cause the protrusion and withdrawal of the lophophore of the cteno-
stomes is accomplished by a process fundamentally like that em-
ployed by the cheilostomes (Harmer, 1930, pp. 92-99). The peculiar
sinus in the aperture of Terebripora could conceivably assist in this
process.

While it is clear that the function of structures in some bryozoan
borings is uncertain, there is little reason to doubt that the globular
bodies at the distal end of some zooids of Spathipora cheethami (M.
Jur.; Pl. 15, figs. 1-3) are ovicells. This species occurs in sediments
somewhat older than those of the earliest definite cheilostome
(Pyriporopsis portlandensis Pohowsky, 1973; Portlandian of Eng-
land), and the presence of ovicells does not argue convincingly
against its apparent affinities with the Ctenostomata. Ovicells may
also be present in a Recent boring ctenostome, Spathipora elegans
Fischer.

Although Penetrantia is here referred to the Ctenostomata with
slight reservation, its considerable resemblance to Haimetna miche-
lint (Terquem) (U. Trias., L. Jur.) is evidence that this assignment

146 BULLETIN 301

(first proposed by Silén in 1947) may be correct. If it is, then it is
clear that a boring ctenostome has evolved yet another feature
characteristic of the Cheilostomata — the operculum. Moreover, in
some species of Penetrantia the operculum articulates with the aid
of small calcareous processes analogous to the cardelles of the cheilo-
stomes (Soule and Soule, 1969b, p. 799).

The ordinal affinity of Penetrantia is a matter of considerable
importance. If it eventually becomes clear that Penetrantia is a
ctenostome, a question will be raised vis-a-vis the common ancestry
of species perfunctorily assigned to the Cheilostomata on the basis
of their possession of one or more of the following features: 1. ovi-
cells, 2. opercula, 3. a calcareous exoskeleton. There is no doubt that
all three of these cheilostomatous characters are present in P. densa
Silén.

Any inference that the Cheilostomata could be polyphyletic is
sobering at this stage of our knowledge, but some suggestions pro-
vided by the boring Bryozoa indicate that one should be prepared
to consider this possibility. The principal suggestion is that extra-
coelomic brooding (via ovicells) is usually of selective advantage
only in those species which can provide the more vulnerable, “ex-
ternally” situated larva with protection beneath a solid calcareous
shield. Although the majority of living ctenostomes are epibenthonic,
none of these have evolved the ability to secrete calcium carbonate,
and none have ovicells. On the other hand, the boring ctenostomes
and the predominantly calcified Cheilostomata can provide ample
protection for extracoelomically brooded larvae, and these groups
display ovicells in a few of their members. Although it is more dif-
ficult to explain why well-developed opercula occur principally in
groups in which the zooids are typically surrounded by calcium
carbonate, this nevertheless seems to be so.

The important implication of these observations is that an un-
calcified ctenostome which evolved the ability to secrete calcium
carbonate would be more likely to give rise to a lineage of ovicelled,
operculate bryozoans than if it remained uncalcified. This reasoning
is by no means an assertion or demonstration that the order, Cheilo-
stomata, is polyphyletic, but it does suggest that selective pressures
may exist to expedite the development of additional cheilostomatous
features once mutations permit the acquisition of a calcareous exo-

Borinc CTENOSTOMATE Bryozoa: PoHowskKY 147

skeleton. It seems possible (in fact, probable) that more than one
group of ctenostomes developed the capacity to dissolve shells. Inso-
far as Penetrantia or its boring ancestors undoubtedly did not give
rise to the encrusting cheilostomes, it appears likely that at least two
groups of ctenostomes have evolved the ability to secrete calcitum
carbonate. The Cheilostomata may, therefore, have arisen from
more than one lineage of epibenthonic ctenostomes, and any means
of evaluating this possibility should be investigated rigorously.

TOPICS FOR FURTHER INVESTIGATION

It would not be fitting to conclude this study without directing
attention to a few problems which warrant additional research. The
following, annotated list is by no means complete, but it does give
some indication of the wide variety of topics that remain to be in-
vestigated. Other subjects in need of study will be apparent to
specialists in diverse areas of zoology and paleontology, and revision
or refutation of the opinions expressed herein will in many cases
contribute to a better understanding of boring bryozoans and an-
cillary subjects.

TOPICS

1. The means by which bryozoans bore.

There is no question that these organisms dissolve their cal-
careous substrata by chemical means, but the substance(s) involved
are problematic. Evidently, all boring bryozoans are able to pene-
trate, in addition to calcium carbonate, the organic tissues of shells
and their own body walls. Results obtained during the present,
cursory investigation of this problem raise doubts about some of
the conclusions drawn by Silén (1947).

2. The means by which boring bryozoans remain near the sur-
face of the substratum.

Although it seems possible that tactile sensations involving
tubulets or frontal pores may be responsible for controlling the depth
at which stolons typically penetrate, the looped stolon in Plate 21,
figure 2, suggests that other factors are probably involved. Schneider
(1963, p. 369) observed phototropic responses in Bugula avicularia
Oken (Cheilostomata) and several other species, but reports of
boring bryozoans at depths in excess of 400 m (Soule and Soule,

148 BuLLeETIN 301

1969b, p. 795) raise serious doubts about the importance of photo-
tropism in directing the boring process in some species.

3. Factors inducing the development of reversed zooids and
double polypides in boring bryozoans.

There is no question that reversed zooids constitute a normal
attribute of the budding pattern in Cookobryoxzoon lagaaiji, n. sp.,
but they seem to be anomalous in other genera. A detailed analysis
of the occurrence of reversed zooids in C. lagaaii, Terebripora
d’Orbigny, and Ropalonaria? arachne (Fischer) may shed light on
the origin of these features.

Among boring bryozoans, zooids which presumably contained
two polypides are known only in R.? arachne, and their orientation
in opposite directions within the zooecia of these species suggests
that they may have arisen through a process fundamentally different
from that which formed the double polypides that Waters (1924; p.
598) observed proximal to the ancestrula of Electra pilosa (Linné)
(Cheilostomata, Recent).

4. Origin and significance of enantiomorphic zooids and colonies.

Enantiomorphism appears to offer little or no adaptive ad-
vantage to boring bryozoans, yet the phenomenon is observed in
several groups in the Cenozoic. The origin of dextral and sinistral
members of a species has been studied most extensively in pulmonate
gastropods (Diver and Andersson-Kotté, 1938; Raven, 1958, pp. 69,
104), and it would be interesting to compare and contrast conclu-
sions drawn from studies on snails with observations made on culti-
vated bryozoans. Evidence of enantiomorphism at the ancestrula of
some common, encrusting species has been cited by Cummings (1904,
p. 58) and Waters (1924, pp. 594, 595). Conceivably, ratios of dex-
trally and sinistrally budding ancestrulae may be influenced by en-
vironmental factors, because temperature is a decisive factor in
determining the coiling ratio of some Foraminifera (Bandy, 1960).
Readers interested in a broadly based, modern account of the
phenomenon of left and right handedness in nature should consult
Fritsch (1968).

5. Pattern formation in boring bryozoans and other Cteno-
stomata.

Waters (1924, p. 602) suggested that “a comparative study of
the ancestrula and early stages of the Bryozoa is likely to help us

Borinc CTENOSTOMATE Bryozoa: PoHowsky 149

much in classification . . .” and Medd (1966) stressed the need to
consider the development of the colony as a whole. This propitious
approach to the study of bryozoans will undoubtedly benefit from
the application of the interesting analytical methods which Braver-
man (1963, 1971) and Braverman and Schrandt (1966) used to in-
vestigate colony development in hydroids.

Very recently, Boardman and Cheetham (1973) prepared a de-
tailed analysis of polymorphism, astogeny, and colonial integration
in bryozoans, but their treatment of the gymnolaemates dealt ex-
clusively with the more diversified order, Cheilostomata. A few
species of boring ctenostomes are sufficiently complex to invite
mathematical analysis of their growth, as well.

6. Phylogenetic relationships among the several families of bor-
ing bryozoans.

Paleontological evidence must play a major role in establishing
the course of evolutionary differentiation and convergence in these
organisms. Much collecting and study now lie ahead, but the fossils
examined in the present work provide little or no indication that the
species united by Soule (1953, p. 751) in the Terebriporina are a
monophyletic unit. The boring habitus may well have been assumed
by several groups of ctenostomes, and the coherence of the Terebri-
porina is probably not appreciably increased by the removal of
Penetrantia to the Cheilostomata (by Soule and Soule, 1969b, p.
801).

7. The ordinal position of Penetrantia Silén.

Penetrantia may be a cheilostome, but the discovery of species
linking Havmeina michelim (Terquem) (U. Trias., L. Jur.) with
Penetrantia in the Cretaceous will help to affirm its probable affinity
with the ctenostomes. The establishment of this relationship will
demonstrate that three important characters of the Cheilostomata
(the ovicell, operculum, and calicified body wall) have arisen in-
dependently in more than one lineage of bryozoans.

8. The taxonomic positions of “Terebripora” eltaninae Soule
and Soule, “7.” varians Soule and Soule, and Immergentia philip-
pinensis Soule.

Immergentia philippinensts is either an Immergentia or a Tere-
bripora, but the familial affinities of “7.” eltaninae and “T.” varians
are uncertain. “7.” eltaninae has been found only in the coenecium

150 BuLLeTIn 301

of the pterobranch, Cephalodiscus, and may be only distantly related
to shell-penetrating bryozoans.

9. The anatomy, planktonic life, and settling habits of boring
bryozoan larvae.

Virtually nothing is known about this aspect of shell-penetrating
bryozoans and it is possible that research in this area would be use-
ful in evaluating relationships among the four extant families. In
addition, a comparison of these larvae with those of encrusting cteno-
stomes may provide hints about the ancestry of boring species.

10. Boring bryozoans of the Paleozoic.

Our understanding of Paleozoic shell-penetrating Ctenostomata
is particularly inadequate. The possibility that Ropalonaria venosa
Ulrich (U. Ord.) gave rise to Mesozoic species questionably assigned
to this genus is one of many questions that must eventually be re-
solved. The discovery of ctenostomes predating R. venosa might re-
sult from a study of calcareous substrata from the Ordovician.

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Abh., Bd. 125, pp. 401-422, 6 text-figs., pls. 33-37.

Eine fossile Art von Arachnidium (Bryozoa, Ctenostomata) in der
Unteren Kreide Norddeutschlands. Neues Jahrb. Geol. Pal., Abh.,
Bd. 132, pp. 87-96, 4 text-figs., pl. 7.

Uber Talpina ramosa v. Hagenow 1840, ein wahrscheinlich zu den
Phoronidea gehériger Bohrorganismus aus der Oberen Kreide,
nebst Bemerkungun zu den iibrigen bisher beschriebenen kreta-
zischen “Talpina”-Arten. Akad. Wiss. Gottingen, Nachr. II. Math.-
Phys. Klasse, Nr. 7, pp. 93-126, 5 pls.

Vinelloidea Canu, 1913 (angeblich jurassische Bryozoa Cteno-
stomata) = Nubeculinella Cushman, 1930 (Foraminifera). Pal.
Abh. (Berlin), Abt. A, Bd. 4, pp. 665-670, 1 pl.

Voigt, E., and Soule, J. D.

1973"

Walter, B.
1965.

Waters, A. W

1879.

1904.
1913.

1924.

Cretaceous burrowing bryozoans. Jour. Paleont., vol. 47, No. 1,
pp. 21-33, 1 text-fig., 4 pls.

Un bryozoaire perforant de l’Oxfordien: Immergentia? lissajousi
nov. sp. (Ctenostomata). Soc. géol. France, C. R., Fasc. 9, pp. 286,
Asiatic:

On the Bryozoa (Polyzoa) of the Bay of Naples. Ann. Mag. Nat.
Hist., ser. 5, vol. 3, pp. 114-126.

Bryozoa. Rés. Voy. Belgica (Zool.), pp. 1-114, 3 text-figs., 9 pls.
The marine fauna of British East Africa and Zanzibar from col-
lections made by Cyril Crossland, . . . in the years 1901-1902.
Bryozoa—Cheilostomata. Zool. Soc. (London), Proc., pp. 458-537,
text-figs. 79-82, pls. 64-73.

The ancestrula of Membranipora pilosa L., and other cheilo-
stomatous Bryozoa. Ann. Mag. Nat. Hist., ser. 9, vol. 14, pp. 594-
612, pls. 18, 19.

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Borinc CTENOSTOMATE Bryozoa: PoHowsky 159

PLATES

Note: Indicated magnifications refer to the original plates, measuring
240 X 178 mm. To obtain the true magnification of the reduced figures shown
herein, multiply the indicated magnification by 0.675.

“Specimens under polish” have been coated with transparent, colorless
fingernail polish to improve the visibility of the borings. Those “under ink”
have been photographed beneath a thin coating of wet, washable blue ink. In
specimens “treated with ink, under polish,” the ink was allowed to dry, and the
surface was subsequently coated with fingernail polish. “Dry” specimens have
not been treated in any way.

160

Figure

1. Ropalonaria venosa Ulrich, 1879

BuLtetTIN 301

EXPLANATION OF PLATE 1

Syntype, showing budding pattern somewhat altered by

2-7. Ropalonaria venosa Ulrich, 1879

diagenesis and weathering. Specimen dry. In Streptelasma
sp. U. Ord. Richmond Gp., Waynesville Fm.; Clarksville,
Ohio. USNM 43115 (on smallest of 3 corals); X 12.5.

On Rafinesquina sp. U. Ord. Richmond Gp., Waynesville Fm.,

2.

Blanchester Mbr.; at base of dam, Acton Lake, Hueston
Woods State Park, ar. Oxford, Ohio.

Surface of uncrowded, distal portion of colony, showing
budding pattern and zooidal ontogeny. Arrows indicate
developing sac zooids. Specimen under polish. UCGM
40062 (RAP 202); x 42.

Arrow indicates stolon joining proximal ends of ancestrula
and of one of initial autozooids in colony. The two zooids
are indistinguishable. Specimen under polish. UCGM 40066
(RAP 206); X 27.

Oldest part of colony, showing sac zooid (center) between
ancestrula and first proximal] autozooid. Ancestrula identi-
fication uncertain. Specimen under polish, UCGM 40077
(RARI2IA) ee a27-

. Portion of well-preserved colony with numerous sac zooids

(arrow). Specimen under polish, UCGM 40061 (RAP
201); X 18.5.

SEM of polyester cast. Three sac zooids in top half of
figure. Pits in zooids are sites of post-mortem calcite boring
fillings. BMNH D.52264 (SEM STUB 11); x 55.

SEM of polyester cast. Same colony as in fig. 6, showing
proximal and lateral aspects of several autozooids. Frag-
mentary sac zooid distal to autozooid in central foreground
with apparent post-mortem calcite filling. BMNH D.52264
(SEM STUB 11); xX 47.

oe ee eee COO COOOSOCOOSOSOOOOSOOC ICO O OS eT eT TTT

POee CEES UEOOOOOOOOOOOOOOOO OSS T eee ee reer rey

BULL. AMER. PALEONT., VOL. 73 PLATE 1

BULL. AMER. PALEONT., VOL. 73 PLATE 2

Figure

Borinc CTENOSTOMATE Bryozoa: PoHowsky

EXPLANATION OF PLATE 2

1-6. popalauenia: amachmes (MISCHET) sl SEG ieee ccc ncneas conccecsseocevacevers

. Lectotype. Colony preserved as hollow borings, illuminated
from lower right. Specimen dry. In Ostrea marshii, J.
Sowerby. U. Jur. Callovian, (fide Fischer, 1866: p. 303) ;
likely Oxfordian (fide E. Buge, pers. comm.); Villers-
sur-Mer, Calvados, Fr. (Negative courtesy of E. Buge.)
MNHN R-50375; X 22.

. Distal portions of two colonies, showing pronounced ex-

tension of stolons distal to fully developed autozooids.
Stolons within each colony apparently terminating growth
(fusing) upon contact, but stolons from different colonies
apparently crossing one another without interruption or
communication. Arrow indicates zooid with proximal and
distal apertures. Specimen treated with ink, under polish.
In Gryphaea sp. M. or U. Jur. Callovian or Oxfordian;
Popilani, Lithuania. BMNH D.52265 (on BMNH L.12957) ;
Sal:

Surface, worn colony. Photographic negative reversed to
match cast in fig. 4. Arrow indicating adventitious stolon
arising near frontal surface of one of two zooids it con-
tacts; shadows of tubulets visible at corresponding position
in fig. 4. Specimen treated with ink; under glycerine. In
Gryphaea dilatata J. Sowerby. U. Jur. Oxfordian; Argiles
oxfordiennes de Dives; Dives-sur-Mer, Calvados, Fr.
BMNH D.52266 (on BMNH 65752); X 20.

. Polyester cast of specimen in fig. 3. Arrows indicating two

of the several autozooids with adventitious stolons pro-
duced from their basal surfaces. These features are com-
monly hidden in fig. 3. Several sac zooids present. BMNH
D.52266 (SEM STUB 7); x 20.

. Surface of colony cast in fig. 6. Arrows in figs. 5 and 6

correspond. Specimen under glycerine. In Gryphaea sp. U.
Jur. U. Oxfordian; Ampthill Clay; excavation for Ampt-
hill sewage works, 0.75 mi. S. of Ampthill, Bedfordshire,
Eng. GSM 113444; x 32.

. SEM of polyester cast of specimen shown in fig. 5. Arrows

in figs. 5, 6 correspond. GSM 113444 (SEM STUB 13); x
70.

161

162

Figure

1-6. pedir roan ! arachne (Fischer), 1866

BuLLETIN 301

EXPLANATION OF PLATE 3

SEM of polyester cast, showing basal view of colony. In
Gryphaea sp. U. Jur. U. Oxfordian; Ampthill Clay; ex-
cavation for Ampthill sewage works, 0.75 mi. S. of Ampt-
hill, Bedfordshire, Eng. GSM 113439; x 50.

. Teratological zooid with two apertures. In context of sur-

rounding zooids, larger aperture (toward bottom of figure)
appears supernumerary. Pairs of bilaterally opposite stolons
produced distal to both apertures. Treated with ink; under
polish. In Gryphaea sp. U. Jur. Callovian or Oxfordian;
Popilani, Lithuania. BMNH D.52265 (on BMNH L.12957) ;
x 64

. Portion of colony of fig. 2. Autozooid on right with two

apertures; apparent supernumerary aperture near center
of figure. Pairs of stolons distal to both apertures, with two
pairs forming distal to aperture on right. One sac zooid.
Specimen under polish; X 64.

. Portion of colony in figs. 2 and 3. Central autozooid has

producéd its aperture along lateral stolon budded from
distal end of autozooid at upper right. Specimen under
polish only. x 64.

. Lateral stolon originating distal to zooid at bottom has

induced development of dwarf zooid lying basal and distal
to autozooid near center, causing autozooid to form left-
skewed aperture. Two other dwarf zooids in lower left-
hand corner. Treated with ink, under polish. Encrusting
Gryphaea dilatata J. Sowerby. U. Jur. Oxfordian; Argiles
oxfordiennes de Dives; Dives-sur-Mer (Calvados), France.
BMNH D.52266 (on shells encrusting BMNH 65752); x
64.

. Portion of advanced, complexly branched colony or

colonies. Specimen treated with ink, under polish. In
(Liostrea delta (W. Smith) ). U. Jur. Kimmeridgian; Kim-
meridge Clay; locality unknown (shell part of Sowerby
coll., purchased by British Museum in 1861). BMNH
D.52267 (on BMNH 43357); xX 8.1.

rigidum J. Sowerby. U. Jur. U. Callovian; Argile de Dives
(‘“‘vaches noires’’); Dives-sur-Mer, Calvados, Fr. BMNH
D.52271 (on BMNH 65990); xX 41.

PreeeereeCESO ECCS eesti

Page

7. Ropalonaria? bugei,. 0. (SPs occccsossccsesecccescssscsecunosuvvosbtversavecucanreneee 55
Holotype. Treated with ink; under polish. In Plagiostoma

BULL. AMER. PALEONT., VOL. 73 PLATE 3

PLATE 4

BULL. AMER. PALEONT., VOL. 73

Figure

Borinc CTENOSTOMATE Bryozoa: PoHowsky

EXPLANATION OF PLATE 4

1-7. eireuroparad capillaris CD OVEUS) 2 EBT 'G \ccstssnesivscdhttanstesasadsnste

. Best-preserved portion of holotype of Rhopalonaria tenuis
Ulrich and Bassler, 1904. Specimen under glycerine. In
brachiopod. M. Dev. Hamilton Gp., lower shales (“Arkona
beds”) ; Thedford, Ont. USNM 43119; x 14.6.

. Best-preserved specimen known, showing details of exter-

nal zooidal anatomy. Laterally disposed tubulets arising
from frontal surface of autozooids. Under polish. In Glos-
selettia triqguetra (Conrad). M. Dev. Hamilton Gp. Mar-
cellus Sh., Cardiff Sh. Mbr.; hillside quarry on E. side
Swamp Rd., 2.2 mi. N. of Morrisville, N.Y. (Gift, B. W.
Cameron.) UCGM 40068 (RAP 221); x 64.

. SEM of polyester cast, showing large sac zooid (top,

right) produced from stolon budded laterally from auto-
zooid in background. Arrow indicates distal end of auto-
zooid. Small mound at lower right is zooid of Casteropora
vetusta (Oehlert). In Glosselettia triguetra (Conrad). M.
Dev. Hamilton Gp. Marcellus Sh., Cardiff Sh. Mbr.; hill-
side quarry on E. side of Swamp Rd., 2.2 mi. N. of Mor-
risville) NY. BMNH D.52277 (SEM STUB 17); xX 59.

. Natural cast on concave external mold of brachiopod; low

angle photograph showing lateral profile of some zooids.
Autozooids expanded proximally. Arrow indicating possi-
ble sac zooid. Specimen dry. L. or M. Dev. (Camden Fm.) ;
Camden, Tenn. USNM 35089 (On one of 3 fragments ac-
companying holotype of Ropalonaria robusta Ulrich and
Bassler, 1904. Ulrich and Bassler (1904: 269) indicated
knowledge of only one colony); X 22.

. Portion of holotype of Ropalonaria lambtonensis Fritz,

1954. Natural cast (pyrite) on coral (Microcyclus discus
Meek and Worthen). Specimen dry. M. Dev., Hamilton
Gp.; Thedford, Ont. ROM 27119; x 15.

. Natural cast showing bilaterally opposite branching near

midlength of zooid. Specimen dry. On mold of Schizophoria
provularia. L. Dev. Siegenian, Wildflaser zone, Seifen II,
Fossil-Bank “a”; Seifen bei Dierdorf, Ger. GLNW Sg
II-322; x 14.5.

. Syntype of Ropalonaria attenuata Ulrich and Bassler, 1904

(Ulrich and Bassler, pl. 66, fig. 5). Specimen dry. In frag-
ment of gastropod. M. Sil. Rochester Lms.; Lockport, N.Y.
USNM 43116 (in one of 24 whole specimens and frag-
ments); < 19.

163

164

Figure

1-5. Srnlsnyepe 2 archiaci (Fischer), 1866

BuLLeTIN 301

EXPLANATION OF PLATE 5

Holotype. Shcwing budding pattern. Specimen dry. In
Ostrea archiaciana d’Orbigny. L. Tertiary (“Zone of
Serpula spirulaea’”’); Brassempory, Landes, France.
MNHN 79512-1; xX 10.5.

Holotype, showing evidence of numerous laterally disposed
tubulets along frontal surface of autozooids. Specimen dry;
ass

Holotype, Terebripora elongata Canu and Bassler, 1923.
Weathering resulting in loss of shell overlying zooids.
Specimen dry. In gastropod. Miocene. Bowden Marl;
Bowden, Jamaica. USNM 68391; x 12.5.

Single autozooid showing essentially perfect preservation.
Laterally disposed tubulets arising obliquely from frontal-
lateral surface of zooid. Circular aperture disposed
medially along stolon. Unpaired adventitious stolon arising
from left side of zooid; al] laterally budded stolons
growing to surface a short distance from autozooid. Speci-
men under polish. In Ranella marginata G. B. Sowerby
II?. Probably Pliocene. Astian. Italy. BMNH D.52274
(on BMNH G.598); xX 64.

Specimen in translucent shell, showing budding pattern
and outline of zooids in frontal view. Treated with ink;
under polish. In Ostrea sp. U. Miocene or Pliocene; hills
near “Bythmia,’ Candia, Crete. BMNH D.52273 (RAP
307); X 8.1.

rise to rows of autozooids proximally and medial-laterally.
Distal end of ancestrula directed up in figure. Profuse thal-
lophyte borings partially obscuring colony. Treated with ink,
under polish. In Pycnodonta cochlear (Poli). L. Pliocene.
Near Ayias, Simeous, Cyprus. BMNH D.52278 (on BMNH
L.65483) ; X 12.

polish. In Plagiostoma sp. M. Jur. Bathonian or Callovian
(Cornbrash); Fengate, near Peterborough, Northampton-
shire, Eng. BMNH D.52280 (on BMNH L.69968); x 40.

POU eeTeeeeeOeOOOrer errr ere i iti r rs)

6. Orbignyopora? tridelta, 1s SP: o..ctcccc.<tecsececccneg sce eco avonnes seceaneare nace 65
Holotype, showing central portion of colony. Ancestrula giving

7. Orbignyopora? cornbrashica, 0. (SP. <0s.:cccsssescnes--0-oce-canceseroseees 66
Holotype, in transparent shell. Treated with ink; under

BuLu. AMER. PALEONT., VOL. 73 PLATE 5

BuLL. AMER. PALEONT., VOL. 73

Figure

iB

Zod; Woigtella regalis, 1. SP. ...........scccc.ccscsssressencsneseeecnceasnescenceesnsenees
2. Part of colony figured and assigned to Spathipora prima

Borinc CTENOSTOMATE Bryozoa: PoHOWSKY

EXPLANATION OF PLATE 6

NOIGF GNA) SIT a TOC tarts ne. fee tacks <vacteavccestsnvesta Waviennetictacvesaccecctes
Holotype, Spathipora prima Voigt, 1962, chalk-filled borings

in belemnite rostrum. Thin outer layer containing stolons
worn away; only autozooids preserved. Specimen dry. U.
Cret. L. Maastrichtian; Vol’sk (Saratov Province), U.S.S.R.
MGU 8046-5c; X 23.3.

by Voigt (1962, p. 61; pl. 11, fig. 7), showing portion on
specimen clearly revealing relationship of zooids and sto-
lons. Aperture of fifth zooid visible at far left. Specimen
dry. In Gryphaea vesicularis Lamarck. U. Cret. U.
Maastrichtian. Trans-Caspian Province, U.S.S.R. MGU
672-b; xX 35. ;

Well-preserved colony (or colonies) showing budding pat-
tern and numerous autozooids, principal stolons, and ad-
ventitious stolons or thallophyte borings. Arrows on
proximal sides of 2 stolons that undergo astogenetic change
from budding of zooid-stolon pairs to production of stolon-
stolon pairs. Specimen under water. On belemnite rostrum.
(Gift, D. P. Najdin.) U. Cret. L. Maastrichtian; Sengiley,
Uljanovsk Province, U.S.S.R. UCGM 40069 (RAP 227);
Se IA

. Area on belemnite shown in fig. 3. Bilaterally opposite

stolons producing zooid-stolon pairs at left. Specimen
under water; X 23.

Area on belemnite shown in figs. 3, 4. Zooid buds on
proximal side of stolons. In one (arrow), usual orientation
of zooid-stolon pair is reversed. Specimen under water;
x He

6. Voigtella? timorensis (Bassler), 1929 00.0.0... ceeeesseeeeeeeeene

i

Holotype, showing relationship of zooids to stolons. Stolons

budding opposite one another (arrow), subsequently bearing
inclined, pedunculate zooids on proximal sides. Zooids com-
monly occurring on distal side of stolons as well. Borings
enlarged by weathering. Specimen dry. In crinoid colum-
nals. Permian. Noil Boewan, Timor. GPIUB Bassler Nr.
YA BS e135),

extending at near right angles from both sides of stolon;
stolon passing horizontally through center of figure. Stolons
connecting zooids in vertical rows not preserved. Specimen
dry. In crinoid columnals. Permian. Noil Boewan, Timor.
GPIUB Bassler Nr. 1; X 15.4.

165

Page
77

69

Worgtel la? Srset Gets eae sal ficcdkcnens es cates tase ent Seats piSinkes ete scanvanets 77
Holotype, Ropalonaria permiana Bassler, 1929. Rows of zooids

166 BuLLeETIN 301
EXPLANATION OF PLATE 7
Figure
1-4: Voigtolla secunda, 0; ‘SPs: s:ccccccrcscasncslecncseecaces iets -nvsceners eecmeebecede
1. Surface of colony, showing bilaterally opposite budding

of stolons from principal stolon that extends horizontally
near center of figure (distal end at right). Zooids forming
on either side (or both sides) of stolons, which produce
only stolon-stolon pairs in apparent astogenetically mature
zones. Specimen dry. In Cucullaea vulgaris Morton. U.
Cret. Maastrichtian. Ripley Fm., Coon Creek Mbr.; Dave
Weeks Place, Coon Creek, McNairy Co., Tenn. UCGM
40065 (on UCGM 32771, RAP 106); X 21.

Holotype. Under glycerine. In Exogyra cancellata Stephen-
son ?. U. Cret. Maastrichtian. Ripley Fm.; exposures in
Bogue Chitto Creek at Rt. 22, Dallas Co., Alas UCGM
40070 (RAP 216); X 19.

Portion of colony (or colonies) shown in fig. 2, regular
and irregular aspects of budding pattern. Tubulets proxi-
mal to aperture of some zooids. Treated with ink; under
polish; x 42.

Portion of colony (or colonies) in figs. 2, 3, showing ex-
tremes in aperture shape variation. The orifice for poly-
pide extension evidently occupied only small segment of
some apertures. Treated with ink; under polish; x 42.

Page
75

5-7. Marcusopora ripleyensis, N. ZeN., 1. SP. ........eecseeeeceeeeeteeceeeeees 118

OF

a |

8. Fischerella keokukensis (Ulrich and Bassler), 1904

Paratype, in opaque shell, showing budding pattern and
pronounced development of stolons distal to zone of zooid
formation. Specimen dry. In Crassetellites vadosus (Mor-
ton). U. Cret. Maastrichtian. Ripley Fm., Coon Creek
Mbr.; Dave Weeks place, Coon Creek, McNairy Co.,
Tenn. UCGM 40063 (on UCGM 32817, RAP 101); X 9.6.
Holotype. Specimen in translucent shell. Proximal ends of
zooids free, apertures located medically along stolon.
Young autozooid (arrow) forming at origin of bilaterally
opposite stolons. Younger developing zooid directly above.
One of two zooids separated by “x” is reversed. Speci-
men under water. In Exogyra costata Say. U. Cret.
Maastrichtian. Ripley Fm., Coon Creek Mbr.; Dave Weeks
place, Coon Creek, McNairy Co., Tenn. UCGM 40064
(RAP 103) (on UCGM 32787); X 42.

Paratype, weathered, translucent shell. Ancestrula (arrow
at proximal end) producing two lateral and one distal
stolons, these bearing obvious jnitial autozooids with
bulbous proximal ends. Treated with ink; under polish.
In Exogyra costata Say. U. Cret. Maastrichtian. Ripley
Fm., Coon Creek Mbr.; Coon Creek, McNairy Co., Tenn.
UCGM 40071 (on UCGM 6361, RAP 109); x 43. (See
text-fig. 4B).

Holotype. Anatomy best left of center. Substratum worn,

causing loss of colony structure. Irregular stolons and evi-
dence of preferred zooid orientation suggesting this puta-
tive bryozoan may be a hydroid that lived commensally with
coral in which it is embedded. Specimen under water. L.
Miss. Keokuk Ls. Keokuk, Ia. USNM 43122; x 15.

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BULL. AMER. PALEONT., VOL. 73 PLATE 8

Borinc CTENOSTOMATE Bryozoa: PoHowsky

Figure

EXPLANATION OF PLATE 8

1-8. Haimeina michelini (Terquem), 1855 2.00.0... eee eeeeee

1.

Central portion of colony showing excellent preservation in
nearly transparent shell. Arrow indicates ancestrula. Under
polish. In Plagiostoma gigantcum J. Sowerby. L. Jur. L.
Lias. Mickleton, Gloucestershire, Eng. BMNH D.52284
(on BMNH L.6537); xX 23.

Ancestrula, nearly vertical in shell, stolon extending from
proximal end to substratum surface. In shell shown in fig.
ae 1653

Central part of two overlapping colonies. Arrows indi-
cate ancestrulae. Near center stolon from left colony con-
tacts stolon of other colony but continues to grow, sug-
gesting non-fusion. In shell shown in fig. 1; x 37.

Central portions of 3 overlapping colonies. Arrow indicates
ancestrula of colony which has developed on only one
side. In shell shown in fig. 1; X 23.

Stolons and autozooids of one colony, showing ribbon-like
adventitious stolon arising from principal stolon (bottom,
right). Small aperture near autozooid at top left is from
ancestrula of another colony. In shell shown in fig. 1; xX
36.

Distal part of a colony, showing development of widely
spaced pairs of autozooids in different stages of ontogeny.
In shell shown in fig. 1; X 50.

SEM of polyester cast. Tubulet on stolon (bottom, left)
and low ridge arising slightly distal to proximal tip of
autozooids, on side opposite peduncle. In Plagiostoma
giganteum. L. Jur. M. Lias Marlstone; Stroud, Glou-
cestershire, Eng. BMNH D.52285 (SEM STUB 14), (on
BMNH L.17606), X 90.

Another part of cast shown in fig. 7; 46.

167

168

Figure

Ae

2-10. Penetrantia Spp. indet. .............:ccsessescseseessesestecesessesnesnenneneeneenees

8-10.

Haimeina michelini (Terquem), 1855

BULLETIN 301

EXPLANATION OF PLATE 9

SEM of polyester cast, showing 5 zooids in various stages of

2.

a |

ontogeny. (cf. Penetrantia densa Silén, Pl. 12, fig. 3.) In
Plagiostoma giganteum. L. Jur. M. Lias Marlstone; Stroud,
Gloucestershire, Eng. BMNH D.52285 (SEM STUB 14),
(on BMNH 1.17606); x 97.

Colony in nearly opaque shell showing zooid apertures
and evidence of tubulets on stolons. Specimen dry. In
Exogyra costata. U. Cret. Maastrichtian. Ripley Fm.,
Coon Creek Mbr.; Dave Weeks place, Coon Creek, Mc-
Nairy Co., Tenn. UCGM 40067 (RAP 102), (on UCGM
32787); X 44.

Portion of colony near that shown in fig. 3. Uppermost
layers of substratum removed, causing loss of stolons, and
truncating gonozooids (double holes) at level of ovicell.
Four autozooids also visible. Large boring at upper left
not a bryozoan. Specimen dry; X 49.

Colony showing ancestrula (arrow )and staggered branch-
ing of stolons. Reniform apertures have convex side facing
distally, in direction of stolonal growth. Specimen under
water. In Exogyra costata. U. Cret. Maastrichtian. Ripley
Fm., Coon Creek Mbr.; Dave Weeks place, Coon Creek,
McNairy Co., Tenn. UCGM 40072 (RAP 107, colony A),
(on UCGM 32782); xX 13.3.

. Part of colony showing opposite and staggered branching

of stolons. Proximal end of some zooids lies nearly horizon-
tal (beneath stolon), suggesting zooids may have been
unable to penetrate underlying layer of shell. Illumination
from lower right. Treated with ink; under polish. In
Exogyra costata. U. Cret. Maastrichtian. Ripley Fm., Coon
Creek Mbr.; Dave Weeks place, Coon Creek, McNairy
Co., Tenn. UCGM 40073 (RAP 105), (on UCGM 32782) ;
x 64.

Part of colony on shell shown in fig. 5. Arrow indicates
minute, horizontally-directed protrusion of zooid wall.
Zooid near top has not established communication with
shell surface, its distal] end bears numerous short protru-
sions. Treated with ink; under polish; xX 56.

Central part of another colony on shell shown in fig. 5.
Arrow indicates ancestrula. Treated with ink; under
polish; X 27.

Young colonies of a species of Penetrantia ? spp. differing
from that in figs. 4, 7. In shell shown in fig. 5. Treated with
ink; under polish.

8.

10.

Ancestrula with 5 radially directed stolons. Stolons orig-
inate well within substratum, grow upward to establish
communication with surface of shell; x 46.

. Ancestrula with 6 stolons, most showing evidence of tubu-

lets; X 30.
Ancestrula with 6 stolons, and nearby larger ancestrula
(different species?) with one stolon initiating develop-
ment; X 30.

87

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BULL. AMER. PALEONT., VOL. 73 PLATE 10

Borinc CTrENOSTOMATE Bryozoa: PoHowsky

Figure

fs Peneirantia SP MOC bei ec... 2h sete caesar sateen schsncomonaneuwacarcceoceszeoshas
i.

EG a ONO IATA SOMIEN TSP 0 ot 02. ocn ccc cennnrsesnneoscovss vareaceeaneoatose-cescessus
5:

PIMEIIPEVRESETANIEES) | STAD MMTDIOLC tot ceases fact cee to scars sack ons cer scocecaucsdescosndesounsenne

EXPLANATION OF PLATE 10

Surface of colony in shell cast in fig. 2. Distal end of
zooids flared, producing countersunken appearance of
aperture (most evident at right). Apertures bearing 2
sinuses. Specimen dry. In Cyfraea sp. Miocene. Touraine,
Fr. BMNH_ D.52294 (SEM STUB 12), (on BMNH
20793'a)) i> <3

SEM of polyester cast of colony shown in fig. 1. Tubulets
on stolons, peduncles extending to zooids, and immature
zooid at bottom, right. Zooids flared distally and pointed
proximally; x 81.

Surface of colony in shell fragment cast in fig. 4. Specimen
dry. In Leporemax sp. Pliocene. Wanganui, North Island,
N.Z. BMNH D. 52295 (SEM STUB 22); xX 23.

SEM of polyester cast of colony illustrated in fig. 3, show-
ing autozooids and one gonozooid. Numerous stolons
partially concealed by profuse thallophyte borings; x 51.

Paratype. Surface of colony in interior of shell cast in fig.
6. Rows of shallow, ovoid pits produced by encrusting
cheilostome — probably Electra. Specimen dry. In Neptunia
contraria Linné. Plio-Pleistocene. Kaloot, S. Walcheren,
Nether. BMNH D.52293 (on BMNH G.70412); xX 23.
Holotype. SEM of polyester cast of colony on exterior of
shell illustrated in fig. 5. Adventitious stolons arising from
autozooids and gonozooid (top, center). Adventitious
stolons producing bilaterally opposite stolons near point of
origin, all 3 processes then growing toward substratum sur-
face. BMNH D.52292 (SEM STUB 28), (on BMNH
G.70412) ; X 78 (approx.).

Holotype, Terebripora ditrupae Norman, 1907. Note tubulets

8. Penetrantia concharum Silén, 1946

on stolons, irregular shape of apertures. Specimen dry. On
tube of Ditrupa arietina. Recent; Shetland. BMNH 11.01.1
88B, xX 35.

Autozooid extracted from boring. Outline of operculum, in

oblique view, visible at distal end. Lophophore and diges-
tive tract occupying most of zooid interior. Retractor muscle
origin visible at proximal tip. Unsupported on glass slide,
orientation of stolons different from that encountered in
borings. Operculum may be deflected relative to other parts
of autozooid. Specimen in 70% alcohol. Recent. Gullmars
Fjord, forty-five miles N. of Flatholmen, west coast of
Sweden. NHR 16.8.1946; X 125.

169

Page
87

86

87

170

BuLtetIn 301

EXPLANATION OF PLATE 11

Figure Page

1-7. Penetrantia densa Silén, 1946. ..................ccssssscsssssssesnsorcesessessas 81

Paratypes on about 36 gastropods, Burnupena delalandi
(Kiener). Recent (bryozoans and gastropods apparently col-

lected alive); near shore, “at the lighthouses,” Cape of
Good Hope, S. Afr. NHR Typsaml. No. 2351.

1. Surface of borings in shell fragment treated with sodium
hypochlorite solution to remove soft parts of bryozoan.
Prior to gold coating for SEM study, white carbonate de-
posits of bryozoan (along stolons and around most zooids)
stand in marked contrast with darker substance of mollusk
shell. Long arrow corresponds to arrow in fig. 2; short
arrow corresponds to arrow in fig. 3. Specimen dry. NHR
Typsaml. No. 2351b (SEM STUB 10); xX 37.

2. SEM of surface of colony. Arrow corresponds to long ar-
row in fig. 1, directed toward aperture of small autozooid
containing horseshoe-shaped calcareous structure which
serves to strengthen operculum, but is probably an in-
completely formed lid for sealing zooid during regenera-
tion. Two gonozooids having ovicells; both chambers of
gonozooid near top have established communication with
stolons. Autozooid at lower right has two concentric layers
of bryozoan carbonate deposits, suggesting it has under-
gone regeneration. NHR Typsaml. No. 2351b (SEM STUB
10); X 130.

3. SEM of surface of colony. Arrow corresponds to short ar-
row in fig. 1, is directed toward autozooid with incipient
device for closure. Small denticle in aperture may serve as
support for articulation of operculum, absence of similar
feature near other extremity of “horseshoe” controverts
this interpretation. Closed autozooid at lower right may
be undergoing regeneration. Presumed closure device in
zooid at top may be undergoing resorption after regenera-
tion. NHR Typsaml. No. 2351b (SEM STUB 10); xX 210.

4. Fragment of same shell appearing in figs. 1-3. Arrows
indicating two zooids in which developing closure device
has fallen down due to removal of soft, supporting tis-
sues; one at right is more advanced than those in figs.
2, 3. Specimen dry. NHR Typsaml. No. 2351b (RAP 243) ;
eh

5. Surface of colony with soft parts in place (perhaps not
in exact life position). Specimen under 70% alcohol. NHR
Typsaml. No. 2351c (RAP 244, specimen 1); X 23.

6. Untreated colony showing fairly regular opposite branch-
ing of stolons. Specimen in 70% alcohol. NHR Typsaml.
PIC NEVE SSS TIGAEE)-

7. Area near aperture of gastropod, showing effect of en-
croaching mantle upon bryozoan. Top half: unaltered
colony. Central zone: empty zooids; stolons absent due to
resorption of outermost layers of shell. Bottom: zooids
partially filled with new shell deposits. Specimen in 70%
alcohol. NHR Typsaml. 2351a; X 12.5.

BuLuL. AMER. PALEONT., VOL. 73 PLATE 11

BULL. AMER. PALEONT., VOL. 73 PLATE 12

Borinc CTENOSTOMATE Bryozoa: PoHowskKy

Figure

1-3. Penetrantia densa Silén, 1946

EXPLANATION OF PLATE 12

SEM of polyester cast of shell fragment of same gastropod

ib

from which fragment shown in PI. 11, figs. 1-4 was ob-
tained. Colony probably another part of colony illustrated
there. Recent; near shore, “at the lighthouses,’ Cape of
Good Hope, S. Afr. NHR Typsaml. No. 2351b (SEM STUB
10).

Distal view. Long arrow corresponds to arrow in fig, 2.
Short arrow shows zooid indicated by arrow in fig. 3.
Tubulets visible on some stolons. Developing gonozooid
occurs above “x” at lower right. Ovicell on right side
distal, relative to stolonal growth); 15 (approx.).
Developing zooids at four ontogenetic stages. cf. Haimeina
michelini (Terquem), Pl. 9, fig. 1. Arrow corresponds to
long arrow in fig. 1 and indicates zooid nearing mature
length, proximal tip more blunt than in mature zooids in
fig. 3. Note constriction in peduncle, may be site of septum
on interior. Principal stolon flattened laterally; Xx 127
(approx.).

Some mature zooids in lateral profile. Low ridge on distal
side of zooids (facing direction of stolonal growth), begin-
ning slightly distal to proximal end. Arrow indicates zooid
shown by short arrow in fig. 1. Two gonozooids in lower
lefthand quadrant of figure. Gonozooid nearer center of
figure apparently mature, having pointed tip extending
beyond ovicell. Ovicells on distal side of zooids; x 32

(approx.).

POeeeeerIeEPOrrrrrer irri iri rrr rrr r irri rir ii)

171

Ce GME CMI SOP VOU Le | 5.555, .ascareessotes sesastsesasses cvaadercdssoacceateseencces 87
In gastropod. Recent; Bay of Santos, Brazil. (Gift, Mrs. E.

Marcus.)

4. Surface of colony in translucent shell, in fragment of same

6.

shell cast in figs. 5, 6. Numerous tubulets on stolons. Ar-
row indicates one of several gonozooids. Treated with ink;
under polish, BMNH D.52296 (RAP 241, shell B); xX 64.
SEM of polyester cast. Borings in shell shown in fig. 1 and
from same colony. Four or five gonozooids visible. Thin
sheets of casting material in background represent fis-
sures within shell. BMNH D.52296 (SEM STUB 5);
xX 110 (approx.).

Enlarged view of autozooid visible at bottom of fig. 5.
Note flared aperture, stolonal fusions, and long tubulets.
Thin tubulet at right of autozooid aperture not yet at
surface of substratum. Peduncle of autozooid hidden; that
of nearby gonozooid visible at upper left; * 210
(approx.).

172

Figure

BuLLETIN 301

EXPLANATION OF PLATE 13

1-9. Cookobryozoon lagaaiji, N. ZEN., NM. SP. ......ecseeessecesecereeeeeeeens
In Polinices sp. L. Pliocene (Kalimnan). McDonald’s Bank,

5-9.

1.

Muddy Creek, near Victoria, Austr.

Holotype (large colony occupying most of figure) and all
or part of three paratypes. Arrows point to ancestrulae.
Holotype, sinistral, having zooids on left side of stolon pro-
ceeding proximally from ancestrula. Colony with ances-
trula at top of figure dextral. Fusion of stolons within (but
not between) colonies. More advanced development of sto-
lons on right side of sinistral holotype. Young stolons
usually growing more rapidly on side of parent stolon
where zooids occur.

Two short adventitious stolons near center of figure
on media! stolon of holotype.

Normal zooids growing with distal end facing distally
along stolon; those on other stolons consistently have a
reversed orientation. Specimen treated with ink, under
polish, BMNH D.52315 (on BMNH G.39704-9, shell C) ;
es
Paratype. Surface of colony in shell fragment selected for
casting. Arrow as in figs. 3, 4. Specimen dry. BMNH
D.52316 (SEM STUB 21), (on BMNH G.39704-9, shell
A); x 20:

Page
93

SEM of polyester cast of shell in fig. 2. Arrow as in figs.

2, 4. Zooid apertures at side of stolon; most reversed, with
aperture directed proximally along stolon; < 20 (approx.).
Enlargement of zooids shown in fig. 3. Arrow as in figs.
2, 3. Stolons may loop over other stolons or zooids or may
appear to fuse with or transect one another. Many zooids
showing attenuated proximal tip and slightly flared distal
end; x 48 (approx.).

Paratypes. Young colonies at five sequential astogenetic
stages. Treated with ink, under polish, BMNH D.52317 (on
BMNH G.39704-9, shell D); x 26.

D

6.

ie

Two ancestrulae, initiating development of proximal stolon,
but not showing left- or right-handedness.

Sinistral colony with zooid bud on left and stolon bud on
right.

Sinistral colony, slightly more advanced than in fig. 6.
Dextral colonies, each with ancestrula and one autozooid.
Stolon from a third colony entering figure at bottom.
Dextral colony with ancestrula and 3 autozooids. Develop-
ment of stolons more advanced on left. Stolons from
another colony entering figure at top.

BULL. AMER. PALEONT., VOL. 73 PLATE 13

PLATE 14

BuLL. AMER. PALEONT., VOL. 73

Figure

1-3.

Borinc CrENOSTOMATE Bryozoa: PoHowsky

EXPLANATION OF PLATE 14

173

Page

Cookobryozoon lagaaiji, N. ZEN., N. SP. oo... eeeeeeeeeeeeeeneeeeeees

1. Holotype. Stolons and zooids arising ultimately from
initial stolon budded on left side of colony, distal to proxi-
mal end of ancestrula (near top of figure). Greater de-
velopment of stolons on left (lower) side of aforementioned
“parent” stolon expedited expansion of colony into new
areas of substratum. Long arrow indicating reversed dex-
tral zooid on stolon dominated by normal, sinistral zooids.
Short arrow indicates normal, dextral zooid on stolon
dominated by normal, sinistral zooids. Treated with ink;
under polish. In Polinices sp. L. Pliocene (Kalimnan).
McDonald’s Bank, Muddy Creek, near Victoria, Austr.
BMNH D.52315 (on BMNH G.39704-9, shell C); x 8.1.

2. Slightly weathered colony cast in fig. 3. Specimen dry. In
Polinices sp. M. Miocene. Temblor Fm., Olcese Sand Mbr.;
near Barkers Ranch, 1.5 mi. N.E. of “Kern River Park,”
Kern Co. ?, Calif. BMNH D.52314 (SEM STUB 18), (on
BMNH G.90134); xX 15.5.

3. SEM of polyester cast of colony shown in fig. 2. Zooids
slightly smaller than in types, but colony showing all fea-
tures diagnostic of species; X 42 (approx.).

Casteropora, n. gen.
Casteropora vetusta (Oehlert), 1888 .............cceeceeeeeeeeeeeeeee
Well-preserved colony showing budding pattern and variation
in situation of zooids along stolon. Unusual anatomy of
colony suggests this species may not be a bryozoan. Specimen
under polish. In Glosselettia triquetra (Conrad). M. Dev.
Hamilton Gp. Marcellus Sh., Cardiff Sh. Mbr.; quarry
on E. Side of Swamp Rd., 2.2 mi. N. of Morrisville, N.Y.
(Gift, B. W. Cameron.) UCGM 40074 (RAP 220); x 12.2.

Casteropora vetusta (Oehlert), 1888 00.00.00... eee cceeeeceeeeee
SEM of polyester cast of colony resembling that shown in
fig. 4. On Glosselettia triquetra (Conrad). M. Dev. Hamil-
ton Gp. Marcellus Sh., Cardiff Sh. Mbr.; hillside quarry
on E. Side of Swamp Rd., 2.2 mi. N. of Morrisville, N.Y.
BMNH D.52431 (SEM STUB 17); x 43.

GASTEKOPOMAS Ps cecoccectaesss-:sscssecsssessservecescuassvesouceeass Swed sass évssosasaseeees

Natural casts in mold of brachiopod. Zooids more densely

spaced and apparently smaller than in fig. 4. Specimen dry.

L. Dev. U. Siegenian. At large stone bridge, S.E. of Unkel-
Miihle bei Eitorf/Sieg, Ger. GIK 759; x 12.5.

Casteropora vetusta (Oehlert), 1888 0.0.0... cceeeeeeesseeeessees
Natural cast in mold of brachiopod. Specimen dry. L. Dev.
M. Siegenian (Wildflasser Zone, Seifen II, Fossil-Bank
a”); Seifen bei Dierdorf, Ger. GLNW Sg II-741; x 10.5.

93

133

174 BULLETIN 301

EXPLANATION OF PLATE 15

Figure Page

1-3) -Spathipora:‘cheethami; Te SDs :i:hscc-cncsee--soceeeeess erence eee eee 103

1. Paratype, in transparent shell. Arrow indicates gonozooid

with ovicell. External anatomy of zooids may be partially
obscured by filling with sediment. Long cleft extending
proximally from aperture often meets it tangentially; may
represent poorly preserved row of discrete tubulets on fron-
tal edge of vane. Treated with ink; under polish. In
Plagiostoma sp. M. Jur. Bathonian or Callovian Corn-
brash; Fengate, near Peterborough, Northamptonshire,
Eng. BMNH D.52319 (on BMNH L.69968); x 64.

2. Holotype, in translucent shell. Arrow indicates gonozooid
with ovicell. Darker mineral (pyrite?) in proximal end
of zooids. Note staggered branching of stolons. Specimen
under xylol. In Plagiostoma sp. M. Jur. Bathonian or
Callovian Cornbrash; Thrapston, Northamptonshire, Eng.
BMNH D.52318 (on BMNH L.20676); x 33.

Portion of holotype, showing autozooid (left), gonozooid
with ovicell (right) and stolon with tubulets (bottom,
center). Treated with ink; under polish; x 64.

4. Spathipora: elegans, Fischer, 1866 <.-:/ccs:cco----scercecoseseesrer ees 99
Holotype, in translucent shell. Short arrow indicates ances-
trula, orientated nearly vertically in substratum. Long ar-
row indicates zooid apparently bearing ovicell. Note stag-
gered branching of stoions and evidence of tubulets. Speci-
men dry. In Calyptraea radians (Deshayes). Recent; Chile.
MNHN 79415-1; X 30.

5:7. -Spathipora ‘spp. iindet. 2s.c0eec. cet ecto ee 108

5. Portion of colony showing 5 zooids with somewhat longer
vane and more horizontal orientation than those of S.
elegans (fig. 4). Treated with ink; under polish. In
Ancillaria inflata Deshayes. Miocene; ‘“Lapugy,’”’ Transyl-
vania, Rumania. BMNH D.52323 (RAP 302); x 45.

6. Another portion of colony shown in fig. 5. Apparent zooid
at far left is boring of acrothoracican cirriped. Stolons,
mature zooid, and zooid bud at far right also shown in
fig. 7. Extremely thin networks of tubes are thallophyte
borings. Specimen under ink. BMNH D.52323 (SEM STUB
+ ee aE

7. SEM of polyester cast of some zooids visible in fig. 6
(right side). Note zooid bud in foreground, and tubulets on
stolon. Inclination of mature zooid is apparently somewhat
less than in holotype of S. elegans, but greater than in §.
brevicauda (PI. 16, fig. 2). Note comparatively greater
freedom of proximal end; X 220 (approx.).

wo

BULL. AMER. PALEONT., VOL. 73 PLATE 15

BULL. AMER. PALEONT., VOL. 73 PLATE 16

Borinc CTENOSTOMATE Bryozoa: PoHOWwsKY 175

EXPLANATION OF PLATE 16

Figure Page

Toi: Spears Brewicalicdayy BSD rei sccsk scscets hts ee tavactcanatoghes 104
Holotype, showing surface of colony in slightly weathered
shell fragment cast in fig. 2. Specimen dry. In Venus subro-
tunda Defrance. M. Miocene. Manthelan, Indre-et-Loire,

Fr. BMNH D.52324 (SEM STUB 19); x 21.

2. SEM of polyester cast of shell fragment in fig. 1. Arrow
indicates one of 2 sac zooids. Zooids are nearly horizontal
in substratum. Short segment of proximal end free, proxi-
mal tip not extending beyond (across) principal stolon (cf.
S. longirima, fig. 5); X 65.

Gs SPATMIPONG OCCLGOMPAlIS, Tl. SPs: ..2c4-nccseccecssssecsccssscscsseaccoesescsoseess 105
Surface of colony with vanes somewhat longer than in holo-
type of 8. brevicauda, Proximal end of zooids often extend-
ing across principal stolon. Zooids nearly horizontal, as in S.
brevicauda. Specimen dry. In Cypraea_ sp. Miocene.
Touraine, Fr. BMNH D.52325 (on BMNH 20793a, shell B) ;
x ZB-

4,5. Spathipora longirima Canu and Bassler, 1928 ....................0 99
Holotype, in translucent shell. Specimen under water. In
pelecypod. L. Pliocene. Waccamaw Marl; Waccamaw
River, Horry Co., S. Car. USNM 68394.
4. General view; X 14.5.
5. Detailed view, showing zooids with longer free segment
of proximal end compared to S. brevicauda (fig. 2). Proxi-
mal end frequently crossing beneath principal stolon. Ar-
row indicates sac zooid; another sac zooid at lower right;
S< She

Wp ee SP METSEPION ASU PUIG e Eg tee snes Pate cos ctcces sence cncostucd tecdacsbcssdcoasedes 108

Colony with horizontally disposed ancestrula (arrow) sig-
nificantly shorter than most autozooids. Location of proxi-
mal end of zooids uncertain. Triangular apertures and
tubulets on stolons and frontal edge of vanes. Stolons of
Terebripora miniatura enter figure at right. Specimen
labeled “Spathipora sertum Fisch.” by Marcus. Treated with
ink; under polish. In gastropod (fragment). Recent; Bay of
Santos, Brazil. BMNH D.52333 (RAP 234); x 43.

7. Spathipora longirima Canu and Bassler, 1923 ....................000+ 99
Colony in translucent shell. Casting reveals numerous sac
zooids, confirms zooid-stolon relationship is as in holotype.
Specimen inked. In gastropod. Recent. Two mi. S. of
Bethany Beach, near Rehoboth, Del. (Gift, W. C. Banta and
G. Gautier.) UCGM 40076 (RAP 231); X 12.5.

176 BuLtetin 301

EXPLANATION OF PLATE 17

Figure Page

1-6... Spathipora occidentalis, (ti. Sp. 2 iesiese arene ccecccteeeere se cettaesacee nee 105

(Visible features and dimensions of specimens in figures 1-4

are similar to those in holotype (fig. 5), but as specimens
have not been cast, species assignment is tentative.)

1. Young, sinistral colony showing ancestrula with proximal
stolon, autozooid on left side, stolon bud on right. Speci-
men under polish. In Ficus reticulata Swainson. Pliocene
(fide C. P. Nuttall, pers. com.). Castel Arquato, Italy.
BMNH D.52326 (on BMNH G.13829); X 40.

2. Dextral colony at slightly more advanced developmental
stage than in fig. 1. Aperture not developed on autozooid at
top of figure. Under polish. In Echinophoria intermedia
(Gmelin). L. Pliocene, Astian, Val d’Andona, Piedmont,
Italy. BMNH D.52327 (on BMNH 68307); X 40.

3. Sinistral colony. Arrow indicates ancestrula. Stolon and
several reniform apertures of Penetrantia Silén visible at
right of Spathipora. Specimen dry. In Calyptraea floridana
(Olsson & Petit). Pliocene. Caloosahatchee Gp.; about 2.7
mi. N.W. of bridge, Harney Pond Canal, Glades Co.,
Fla. BMNH D.52328 (on BMNH G.G.12944, colony A-3) ;
xX 14.4.

4. Weathered colony with longer and more densely spaced
zooids than in holotype (figs. 5, 6). Shell collapsed at
ancestrula (arrow). Colony occurs next to holotype of
Terebripora pacifica Canu and Bassler, 1923, was figured
by these authors. Specimen dry. In pelecypod. Pleistocene.
San Pedro, Calif. USNM 174673 (on shell with USNM
68392) xX 1756;

5. Holotype, showing surface of dextral specimen cast in fig.
6. Arrow indicates immature autozooid. Note ancestrula.
Specimen inked. In Crefidula sp. Recent. Bay of Santos,
Brazil. (Gift, Mrs. E. Marcus.) BMNH D.52329 (SEM
STUB 8); -X 21.

6. SEM of polyester cast of specimen in fig. 5. Photographic
print reversed for comparison with previous figure. Proxi-
mal end of zooid often extends over or slightly beyond prin-
cipal stolon; X 21.

7,8. Spathipora magnivorticellopsis, ND. SP. ..........:cccccseeseeseeseeeees 106

Specimen dry. In Nassa mutabilis Linné. Pliocene. Colli
Astesi, Italy. BMNH D.52330 (on BMNH 80732).

7. Holotype, possible ancestrula indicated by arrow. Slightly
longer zooid (nearby, right) may be true ancestrula; x 18.

8. Portion of holotype, showing zooids in various stages of
ontogeny. Note triangular aperture, staggered budding,
and evidence of tubulets on vanes and stolon; x 40.

BuLuL. AMER. PALEONT., VOL. 73 PLATE 17

BULL. AMER. PALEONT., VOL. 73

PLATE 18

Borinc CTENOSTOMATE Bryozoa: PoHowskKy 177

EXPLANATION OF PLATE 18

Figure Page

1-6: Spathipora ambidextra, 0: (Sp: ).fe..cccd.bssessseecsisdededdvecdceenesecesbecdee 107

Holotype (fig. 4), 6 paratypes. Colonies in single, opaque

shell. Under polish. In Ficus reticulata (Lamarck). Pliocene
(fide C. P. Nuttall, pers. com.). Castel Arquato, Italy.
BMNH D.52331 (on BMNH G.13829); X 64.

1-3. Young sinistral colonies in successive stages of astogeny.
Ancestrula producing two stolons from proximal end;
that on left terminating in cul-de-sac (the appendix —
see arrow), subsequently giving rise to another stolon,
whose origin defines the proximal end of the appendix.

4,5. Dextral colonies (appendix on right) in successive stages
of astogeny. Colony in fig. 4 apparently older than
sinistral colony in fig. 3. Configuration of zooids varies,
even though both colonies are dextral. Between stages
represented in figs. 3, 4, a stolon arises from near
proximal end of appendix (? on basal side), and
another stolon grows beside ancestrula (on left, as in
dextral colonies).

6. A dextral and sinistral colony in close proximity and
at similar stages of development. Each colony produced
a stolon that was about to collide with the appendix of
the other colony.

7. Spathipora sertum? Fischer, 1866 ..................ccccccccessscceesseceeees 96

Two zooids of small colony occurring at small end of serpulid
polychaete tube (Ditrupa arietina) bearing holotype of
Terebripora ditrupae Norman, 1907. Immature zooid at
right giving rise to thin adventitious stolon near insertion on
principal stolon. Both zooids attached to stolon by tapered
proximal tip, so that no free end exists. Specimen dry.
Recent. Shetland. (With BMNH 11.10.1 88 B); x 105.

8. Spathipora comma (Soule), 1950 ......2...........cccesscssscsescsssesseevess 101
Holotype of Terebripora comma Soule, 1950, showing surface
of borings. In Polinices draconis (Dall). Recent; 18 fathoms,
S.W. of Newport, Calif. Specimen figured by Soule (1950b:
text-fig. 1). (Negative, court. of J. D. Soule). AHF No.
IS P< GE

Sra CSP LHIPONG (SOP UIE baie ese-coe ccc eran caches ca ctk du aceas nsec cysucdsspasuacdsante 108
Colony (?) examined and described as Terebripora ramosa
d’Orb. by Marcus (1938). Mounted on glass slide (by
Marcus) ; photographed by transmitted light. Recent. Bay
of Santos, Brazil. BMNH D.52334 (RAP 240) (Slide labeled
“Dept. Zoologia — S. Paulo; Terebripora ramosa d’Orb.;
917 Santos”); X 26.

Lie SOMTROLA (SDD INGELS so5ceisrs..~s svnreerdencvacaens wacasecave tee nee aerate 108
Holotype of Spathipora longicauda Canu and Bassler, 1923.
Specimen dry. In pelecypod? Miocene. St. Mary’s Fm.;
Bowlers Wharf, Middlesex Co., Va. USNM 68393; x 22.

178

Figure

BuLteTIN 301

EXPLANATION OF PLATE 19

1-4. Terebripora ramosa d’Orbigny, 1847 20.0.0... ccecceceseeseeeeeeeeees

1. Lectotype, showing portion of colony produced from proxi-

mal end of ancestrula (long arrow). Short arrow indicates
sac zooid. Ancestrula buds only proximally and distally,
autozooids have laterally opposite stolons diverging from
point slightiy proximal to midlength. Zooids enantio-
morphic, with apertures on right or left side of stolon.
Proximal-lateral sinus preserved in some zooids of holo-
type, this feature more evident on adjacent colonies (para-
lectotypes) and in topotypic specimens of Spathipora ele-
gans Fischer. Portion of paralectotype colony enters fig-
ure at bottom (right of center). Specimen dry. In Calyg-
traea sp. Recent. Arica, Chile. (Negative, courtesy of E.
Buge.) MNHN 79572-2 D’Orb. coll. No. 13664); xX 23.
Enlarged view of lectotype, showing zooidal ontogeny and
tubulets on zooids and stolons. Zooids initiating develop-
ment with laterally directed tubulets or stolons or both
from segment of principal stolon; X 46.

Colony with zooids shorter than in lectotype. Note proxi-
mal-lateral sinus (better preserved in fig. 4) and de-
veloping zooid at left. Treated with ink; under polish.
In Porphyria sp. Pliocene. Caloosahatchee Gp.?. Fla.
BMNH D.52365 (on BMNH G.5247); X 64.
Well-preserved colony, zooid length about as in lectotype.
Proximal-lateral sinus (arrow) and tubulets (on zooids
and stolons) evident. Bilaterally opposite branching along
some stolons indicating initiation of autozooid development.
Development of lateral tubulets in absence of branches
(bottom, right) perhaps related to zooid formation. Treated
with ink. In Ancilla sp. Neogene. “Saaret (Sayaret),
Lycia,” Turkey. BMNH D.52364 (on RAP 310); xX 64.

5,6. Terebripora falunica Fischer, 1866 ................cccccccesseceeesseeeees

5. Lectotype. Colony worn, but suggesting rarity, reduction,

or absence of tubulets on zooids. Branching of stolons fre-
quently occurring at or distal to zooid midlength. Zooids
enantiomorphic, as in 7. ramosa d’Orb. Specimen dry. In
gastropod (Conus sp.). M. Miocene, Helvetian; Manthelan,
Indre-et-Loire, France. (Negative, court. E. Buge.) MNHN
79532-1 (within ink rectangle on second largest of 7 shells
or shell fragments); xX 18.

Syntype of Terebripora orbignyana Fischer, 1866. Speci-
men dry. In Conus sp. M. Miocene, Tortonian; Saubrigues,
Landes, Fr. MNHN 79560-1; x 14.

PLATE 19

BuLuL. AMER. PALEONT., VOL. 73

BULL. AMER. PALEONT., VOL. 73 PLATE 20

Borinc CTENOSTOMATE BRYOzOA: POHOWSKY 179

EXPLANATION OF PLATE 20

Figure Page

1-4. Terebripora falunica Fischer, 1866. ............::ccccsseeseeseteeneens 114
1. Surface of colony in shell cast in figs. 2-4. Long arrow
(same as long arrow in fig. 2 and Pl. 21, fig. 1) indicates
reversed, sinistral zooid. Short arrow (near top) corre-
sponds to arrow in fig. 3. Specimen treated with ink. In
gastropod. Recent. Bay of Santos, Brazil. (Gift, Mrs. E.
Marcus.) BMNH D.52367 (SEM STUB 4, shell C); X 23.
2. SEM of polyester cast of colony shown in fig. 1. Long

arrow (similar to iong arrow in fig. 1 and Pl. 21, fig. 1)

indicates reversed, sinistral zooid. Short arrows indicate

sac zooids; X 26.

SEM of polyester cast of colony shown in fig. 1. Arrow

corresponds to short arrow in fig. 1, indicates proximal-

lateral sinus of sinistral zooid. Four zooids (a-d) in

sequential stages of ontogeny. First three dextral; zooid d

sinistral. Zooid 6 with single lateral stolon at typical locus

of branching (slightly distal to midlength of zooid), and
development of a supernumerary pair near its proximal end

(? to compensate for deficiency); x 55.

4. Enlargement of zooid c in fig. 3, showing origin of lateral
stolon from vane (at former level of basal surface of
stolon). Little of immature zooid’s proximal tip extending
freely beyond vane. Four tubulets arising from vane and
expanding frontally; x 243.

ve

5. Terebripora miniatura, 1. SP. .......ccccccccceeesseseeseessessessesseasneeees 116

Holotype and portion of paratype (top). Colonies resembling
those of T. falunica, but zooids commonly about half the
length in that species. Confused development of stolons at
top of figure resulting from collision of holotype and para-
type. Fusion between stolons of the two colonies common.
Erratic budding of stolons may be reflection of conflicting
morphogenetic gradients. Specimen labeled “Terebripora
fischeri Jul.” by Marcus. Treated with ink; under polish.
In gastropod (fragment). Recent. Bay of Santos, Brazil.
BMNH D.52369 (RAP 234); x 64.

180

Figure

BuLLETIN 301

EXPLANATION OF PLATE 21

1-6. Terebripora falunica Fischer, 1866 .0.....0....cccccceccceseseeeeeeeeeeee

1.

SEM of polyester cast of colony in Pl. 20, fig. 1. Arrow

corresponds to long arrow in that figure, indicates re-
versed, sinistral autozooid. Proximal tip of zooid extending
beyond vane, far from stolon. In gastropod. Recent. Bay of
Santos, Brazil. BMNH D.52367 (SEM STUB 4); xX 85.

Proximal view, showing 3 zooids from near center of fig.
1. Stolon entering figure at lower left looping across auto-
zooid, crosses one stolon and fuses with next; xX 165

(approx.).

. Zooid in colony shown in preceding figures. Note pro-

nounced lateral bulge near proximal end, and paired ad-
ventitious stolons arising near distal end and giving rise
to tubulets as they approach surface. Stripes encircling
zooid are reflection of shell microstructure; xX 250
(approx.).

Central portion of colony, showing ancestrula (arrow)
and budding pattern. Shell overlying ancestrula and
several autozooids partially collapsed. Zooid length diffi-
cult to determine and specimen may be TJ. miniatura.
Specimen labeled “Terebripora ramosa d’Orb.” by Mar-
cus. Treated with ink. In shell plate of cirriped. Recent.
Bay of Santos, Brazil BMNH D.52368 (RAP 239);
xX 46.

Surface of colony in shell fragment cast in fig. 6. Arrow
corresponds to arrow in fig. 6, indicates reversed, dextral
autozooid. Specimen dry. In Venus subrotunda Defrance.
M. Miocene. Manthelan, Indre-et-Loire, France. BMNH
D.52366 (on SEM STUB 20); X 20.

SEM of polyester cast of colony in fig. 5. Arrow cor-
responds to arrow in that figure and indicates reversed,
dextral autozooid. Letters “x” near zooids producing
adventitious stolons from basal-medial surface of distal
end. Two sac zooids present; that near base of figure
represented in fig. 5 by small diagenetic opening. Num-
erous smaller saccate bodies attributed to algae or fungi;
x INE

_
N
&
&
a
Ay

BuLu. AMER. PALEONT., VOL. 73

BULL. AMER. PALEONT., VOL. 73 PLATE 22

Bor1nG CTENOSTOMATE Bryozoa: PoHowsky 181

EXPLANATION OF PLATE 22

Figure Page

1,2,4,5. Immergentia boydekina, n. Sp. ..........c.cccccceesscceceeessenscceerseeensens 124

1. Holotype. Surface of colony in shell cast in fig. 2. Bi-
laterally opposite branching occurring distal to zooid
apertures. Treated with ink; under polish. In Conus sp.
M. Miocene, Balcombian. Muddy Creek, near Hamilton,
Victoria, Austr. BMNH D.52381 (SEM STUB 23), (on
BMNH G.39306-10); x 47.

2. SEM of polyester cast of another portion of colony in
fig. 1. Vanes filling angles between stolons and distal
end of zooid body. Distal end narrower than in J. lanceo-
lata (cf. Pl. 23, figs. 5, 6); X 110 (approx.).

4. Surface of colony in shell cast in fig. 5. Specimen dry. In
Ancillaria inflata Deshayes. Miocene. “Lapugy’, Transyl-
vania, Rumania. BMNH D.52382 (SEM STUB 15, RAP
302); X 43.

5. SEM of polyester cast of another portion of colony in fig.
4. Thin sheets of casting compound draped from zooid in
background represent fissures in shell; & 110 (approx.).

Gee MURTRESION JENN Nl) “SPP0 foe..s.ceeseas.cessncseescveazcestucesvaocs«buesestenossssssccsceccseede 127

3. Surface of colony in slightly weathered shell. Apertures
more attenuated than in fig. 1, due to solution of sub-
stratum along adjoining portion of stolon. Casting reveals
zooids like those of holotype. Specimen dry. In Cypraea
sp. Miocene. Touraine, Fr. BMNH D.52390 (on BMNH
20793a, shell A); X 29.

6. Surface of colony resembling JI. boydekina, with dif-
ferentiable enantiomorphic zooids; 11 of 13 shown, sinis-
tral. Numerous adventitious stolons. Treated with ink;
under polish. In Ancillaria glandiformis Lamarck “var.”
monstrosa. M. Miocene (probably Tortonian, fide C. P.
Nuttall, pers. com.). Véslau, Austria. BMNH D.52391 (on
BMNH 52415, fragment in slide); > 40.

7. Surface of colony resembling J. boydekina, showing bud-
ding pattern in relatively uncrowded peripheral region.
Treated with ink; under polish. In Priamus helicoides
Brocchii. Pliocene. Orciano, Toscana, Italy. BMNH
D.52392 (on BMNH 81747); x 11.7.

182 BuLtetin 301

EXPLANATION OF PLATE 23

Figure Page

Aad, lrmmmerqgeniia: SPDs. sec 2525 <0ceenesenee ae corsencecononseeesnceeeee == nye emereeeeeee 127

Young colonies, showing budding pattern at ancestrula. Sto-
lons diverging from opposite sides of ancestrula growing
(fortuitously?) to form obtuse angle, with ancestrula at
apex. On fragment of Ranella marginata (Gmelin). Under
polish. Pliocene. Italy. BMNH D.52393 (on BMNH 83445) ;
Bil

1. Four colonies with stolons, without mature autozooid. Ar-
rows indicating ancestrulae which have just begun to pro-
duce stolons. Largest colony (top, left) shows slight expan-
sion of stolon perhaps representing developing autozooid.

2. Two colonies. Larger one produced one autozooid (top,
center) with paired lateral stolons arising slightly distal
to it.

3. Colony with ancestrula (arrow) and 3 autozooids. Paired
stolons arising distal to autozooids near ancestrula.

#6: Immergentia lanceolata, 0. SP: i:2-<.s20.<<.-rcrcee ese oe 125

Holotype. On Polinices sp. L. Pliocene (Kalimnan); Mc-

Donald’s Bank, Muddy Creek, near Hamilton, Victoria,
Austr. BMNH D.52383 (SEM STUB 26), (on BMNH
G.39704-9, shell B).

4. Surface of colony in shell cast in figs. 5, 6. Apertures large
in comparison with J. boydcekina (cf. Pl. 22, fig. 1). Speci-
men dry; X 23.

5. SEM of polyester cast of shell in fig. 4. Zooids similar to
I. boydekina, distal end stouter, strongly flared in some
specimens. Bilaterally opposite principal stolons arising
distal to zooids, and numerous adventitious stolons
emanating from principal stolons; x 50 (approx.).

6. Another portion of cast shown in fig. 5. Autozooid at
right producing adventitious stolon, this growing toward
surface and fusing wih distal end of zooid in center of
figure; X 90 (approx.).

7-9. Immergentia subangulata, N. SP. ..........cceeccceeeeeeeeeereeeeeneeeenaees 125

On Crepidula sp. Recent. Bay of Santos, Brazil. (Gift, Mrs.

E. Marcus.) BMNH D.52384 (SEM STUB 6, shell D).

7. Surface of colony in shel] fragment cast in figs. 8, 9. Ar-
row corresponding to arrow in fig. 8, indicating zooid in
center of fig. 9. Specimen inked; xX 25.

8. SEM of polyester cast of colony shown in fig. 7. Arrow
similar to arrow in fig. 7, indicating central zooid in fig.
9. Proximal end of zooids leaning proximally along stolon.
Zooids commonly fiexed in that direction, laterally, or
both. Paired lateral stolons diverging distal to 3 zooids
near bottom of figure; xX 42.

9. Enlarged view of cast in fig. 8, seen from opposite direc-
tion. Central zooid (indicated by arrow in fig. 8) pro-
ducing adventitious stolon, this growing toward surface
and fusing with distal end of zooid in foreground. Small
saccate bodies at upper right of algal or fungal origin;
x 125 (approx.).

PLATE 23

BuLuL. AMER. PALEONT., VOL. 73

BuLu. AMER. PALEONT., VOL. 73 PLATE 24

Figure

Borinc CTENOSTOMATE Bryozoa: PoHowsky

EXPLANATION OF PLATE 24

PINION OME Lag SD DP saccceaceorctas sccceaccestavssvecc ccerewete cocci caSetacesceztesioneceuesces

Surface of colony, resembling J. boydekina and I. subangulata,

Three of 9 zooids sinistral. Treated with ink; under polish.

In gastropod. Colony labeled “Terebripora orbignyana

Fisch.” by Marcus. Recent. Bay of Santos, Brazil. BMNH
D.52394 (RAP 236); x 40.

ImmergentiaratypiCa, 1; SP.) sccscceccccossvsnssscoccsscesevsccceessececesseccseee
Holotype. Surface of best-preserved portion of colony show-
ing bilaterally opposite branching of stolons, these just
proximal to apparently monomorphic autozooids with nearly
circular apertures situated medially along stolon. Specimen
dry. In Maoricrypta sp. Tertiary. Lower Waipara Gorge,
N.Z. BMNH D.52385 (RAP 301); xX 23.

Immergentia losangelina, 1. SP. ...........:::cccceceessenseeeeeeseesrseeeeesens
Holotype, showing surface of large and densely spaced zooids.
Apertures rarely separated by more than twice their length.
Specimen dry. In Olivella biplicata Swainson. U. Pleisto-
cene, Palos Verdes Sand. Pacific and Oliver Streets, San
Pedro, Los Angeles Co., Calif. BMNH D.52386 (on BMNH
G.72500-5); x 24.

Immergentia californica Silén, 1946 oo... eee eeeeeeeeeeeeee
In Tegula ligulata Menke. Recent. Tidal pool, Whites Point,
Calif. (Negative court. of J. D. Soule.) Coll. Soule; x 50.

183

Page

127

125

126

Immergentia patagoniana, 1. SP. .............ccceceesseeeseesesessteeeseennens 126

Surface of holotype, showing profuse development of tubu-
lets, adventitious stolons, strongly enantiomorphic zooids.
About half of zooids dextral. Zooids lying in shallow de-
pressions indicated by differentially stained, deeper shell
layers. Treated with ink; under polish. In Buccinanops
cochlidium Kiener. Recent. Argentina. BMNH D.52388 (on
BMNH 1854.12.4.466); xX 56.

DIMMS bbay SPD Sac sssseccees os sa aco oeas coc ece Seco sceetvssiscconcessvesessossaxeenesonas
Syntype of Terebripora orbignyana Fischer, 1866, showing 4
zooids (2 dextral, 2 sinistral) in translucent shell. Specimen
dry. In pelecypod. Recent. Arcachon, Gironde, France.
MNHN Di-0207-b (within ink circle on smaller of 2 shells) ;

x Si.

127

INDEX

NUMBER 301
Note: Light face type refers to page numbers. Bold face type refers

to plate number.

A

abscondita, Bulbella .. 1
NCTOR: oer erceccrctesesseeseaes 18, 50
AHF (Allan Hancock

Foundation) ............ pa alr alee
Alabama A 108

Dallasy Cos ett: 75, 89, 166
Alcippen 2 se oes 139
Alcyonidium ................ 54
ambidextra,

Spathipora .......... 18 106, 107, 141,

143,177

Ampthilli@laysen ee 52, 161, 162
Anca Nee 178
AN Ci arias 174, 181
anglica, Graysonia ...... 140
angulata, Immergentia 124, 139
antillarum,

TELeDEIPONAL ..c.c20cce: 137
antiqua,

Binito pia eee ee 137-139

Merebriporay) =. 67, 68, 137
arachne,

Ropalonaria ............ 40

Ropalonaria? ...... 2,3 22, 47, 52-57,
138, 148, 161,

162

Terebripora ............ 52, 53, 138

Arachnidiimie..e 8, 50

archiaciana, Ostrea .... 164
archiaci,

Orbignyopora ........ 5 17, 26, 27, 58-
63, 65-67, 138,

164
Terebripora ............ 59, 60, 138
Argentinian 127, 183
Santa) Cruz #.2c2-ccsss- 108
argile de Dives
(“vaches noires”’) .. 56, 162
argiles oxfordiennes
Ge! Dives ance 52, 161, 162
arietina, Ditrupa ........ 169, 177
“Arkona beds,” lower
shales of Hamilton
| oe ears Sea tes abr 62, 163
ASCOGICELYV ON eens 8
attenuata,
Rhopalonaria .......... 61
Ropalonaniay jccccse 64, 139, 163
atypica,

Immergentia ........ 24 121, 125, 183

ANISUrallial eee e 95
Victoria 93, 124, 125,
IPSS Pa ITB}.

181, 182
Austria ere 78

GTI iad cee eesseeeae 89, 128

Voslau-Wien ............ 127, 128, 181
avicularia, Bugula ...... 147

B
iBascomellaye 139, 140
bassleri,

Terebripora (7?) ...... 47, 57, 78, 88,

it
Belgium,

Antwerp Docks ...... 129
berquisti, Graysonia .. 140
biplicata, Olivella ...... 183
Blanchester Mbr.,

Waynesville Fm. .... 47, 160
BMNH (British

Museum of

Natural History) .... 22, 29, 47, 52,

54-56, 59, 65,

67, 69, 86, 89.
91, 93, 96, 103-
109, 112, 114,
117, 118, 124-

129, 132, 160-
164, 167-169,
171-183
botellus, Ropalonaria.. 49, 139
Bowden! Marl 59, 164
Bowerbankia .............. Sala

boydekina,
Immergentia ...... 22 124, 125, 181-
183

brandesi,

Arachnidium .......... 8
|i 4 | Lee ee oa a 116
Bay of Santos .......,.. 89, 90, 105,
108, 109, 114,
117, 118; 125.
127,129, 171,
175-177, 179,
180, 182, 183

brevicauda,
Spathipora .......... 16 = 37, 97, 104,
174, 175

brevis, Penetrantia .... 79, 84, 139

184

INDEX

Buccinanops .............6. 183
bugel,
Ropalonaria? ........ 3 47, 55, 56,
162
BUS UNA: sss.ceccsesteeeeceee 147
Bulbellla: -3...<.cceccestsecers=s of
Bundenbach ................ 11
BUEeeSS “Sha ese ill
BULNUPeCNA s.2.2-22000-05-2- 170
(e
GalihoOrnialers.sser8 -see-e= 94
ern ON es esses 93, 173
ING WDOnte eee cceee es 101, 177
Pacific Grove .......... 122
San Pedro, Los
Angeles Co. ............ 105, 126, 176,
183
Whites Point .......... 183
californica,
Immergentia ...... 24 81, 120, 122,
139, 183
Caloosahatchee Fm. .. 89, 105, cer
(Ct RASS pee eee 112, 176,178
CalyptTaea: .....2:2c:..<.... 113, 174, 176,
178
Gam@envhim:, sacevcecceee:-- 62, 163
eancellata, Exogyra .. 166
capillacea,
Terebripora ............ 61
capillaris,
Orbignyopora .......... 17, 64

Orbignyopora? ...... 4 37, 58, 61, 63-
65, 138, 139,

163
merepripora--e iyi ake}, (UE
138

Cardiff Sh. Mbr.,
Marcellus Sh. .......... 62, 132, 163,
173
Gasteropora sone 14 32,33, 129,
131-133,137,
138, 163, 173
Cephalodiscus ............ 150
Chaetophorites ............ 46, 52, 55
Chaetopterus. .............. u
Chalke ene: 130

cheethami,

Spathiporas 22.2... 15 37, 81, 96, 99,
103, 104, 145,
174
CUD ARO i Aovsesectuee 81, 99, 174
PATI CAL seestcceessettessseatsees 112, 178
Cincinnatian Series .. 48

cochlear,

By cnodontar....2 164

cochlidium,
Buccinanops ............ 183
comma, Spathipora 18 16, 17, 19, 27,
34, 37, 43, 51,
77, 81, 101,
111, 138, 144,
bee
Terebripora ............ 97, 101, 138,
177

concharum,
Penetrantia .......... 10 24, 39, 78, 79,
85, 87, 139,
169
contorta, Terebripora.. 19, 138
contraria, Neptunia .. 169
ConuSw = ee 178, 181

Cookobryozoon ..13, 14 40, 41, 92-94,
106, 135, 141,
148, 148, 172,

173
Coon Creek Mbr.,
J27h 0) | 2h) 010 Eee 75, 89, 118
119, 166, 168
Cormbrash\ =. 37, 67, 103,
164, 174
cornbrashica,

Orbignyopora?....5 66-68, 164
costata, Exogyra ........ 166, 168
Crassetellites .............. 166
Crepidulay (5.2..cccessenstess 176, 182
cretacea, Entobia ...... 139
Crete, Bythmia,

Candiage es .ox. 59, 164
@ryptomonas, ~.....5-.... 55
Cryptopolyzoon. .......... 23, 93
Curcullaecaiy te 166
cucullata,

Spathipora <.ncccccoseess 99, 100, 138
Cyclopunctaye 58, 61, 131
Cy pra@ aise cc..se eee 169, 175, 181
Cyprus, Ayias,

SIIMECOUSie sete ee 65, 164

D
danica, Iramena ........ 78, 87, 140
delalandi, Burnupena 170
Delaware, Bethany

Beach, Rehoboth .... 100, 175
delta, Liostrea ............ 162
dendriformis,

Ropalonaria’ 2.2... 139
Denmark, Fakse ........ 78
densa,

Penetrantia ....11,12 9, 28, 29, 31,

185

INDEX

32, 36, 38, 39,
78, 79, 81-85,

87, 88, 92,
139, 144, 146,
168, 170, 171

Merebriporay cac.---- 138
dilatata, Gryphaea .... 161, 162
discus, Microcyclus .... 163
distans, Hippothoa .... 18
IDMWADH OE) dessecooncactasass RO: 169, 177
ditrupae, Terebripora 87-89, 96,

138, 169, 177
ditrupiae,

Merepriporac.------ 87
divaricata, Hippothoa 7
draconis, Polinices .... 177
duplex, Alcyonidium.. 54

E
echinicola,

merepriporay es... 59, 61, 138
Echinophoria ............-. 176
THGRIEY peste bcoceccsdbouce 7, 29, 148,

169

elegans, Spathipora 15 27, 37, 81, 96,

99, 107, 112,

138, 141, 148,

145, 174, 178

elongata, Terebripora 59, 60, me

WASOPOLA secestsesttereees 8
eltaninae,

Terebripora ............ 19, 138, 149
eam Ol Peeccerccssesteteccess 78, 92, 104

Bedfordshire .......... 52, 103, a

Bournemouth .......... 67, 103

Chicksgrove,

SPAS BUY irceccceoecees eee 108

Chideock, Bridport.. 91

Easton, Isle of

Dorset, Dorset ........ 108

Paring QO ssc. 2 88

Helpstone ................ 67, 103

Long Crendon,

Buckinghamshire 108

Lyme Regis, Dorset 90

Mickleton,

Gloucestershire ...... 90, 167

Peterborough,

Northamptonshire .. 67, 103, a

PLODADLY seers a eee 52

Stockton,

Warwickshire ........... 90

Stroud,

Gloucestershire ...... 90, 167, 168

SUkiolk: o5.42.2.0c ae 52

Thorpe, St. Andrew,

Norwich, Norfolk .. 69

Thrapston,

Northamptonshire .. 103, 174

WOrKSHITNG| a cesses 90
HNCODIaae- eeecerrseeeceeee 137-139
eocenica, Terebripora 19, 138
HSUTODE: s.sc.csescessceeesees 92
EXOPYTA ee 166, 168
expansa,

Hypophorella .......... Lbs PA IU

FE

falunica, Tere-

bripora....19, 20, 21 15, 19, 41, 66,
111, 114-118,
138, 178-180
Marella .cstsssscrcee ee 31
BiCus 72 ee 107, 176, 177
Hischerellawess 7 129, 134, 135,
137, 139, 166

fischeri,
Terebripora ............ 116, 117, 138,
179

Florida

Bg dosteceen sestesovees 109, 112, 118,
178

Harney Pond Canal,

GladesCon es ..2:.-- 89, 105, 118,
176
floridana,

Calyptraea .............. 176
Wlastrellidnray 80
MOrariporal eee 60, 70, 129,

130, 137, 140
“Formengruppe C’”’ .... sil, ils38°
Fossil-Bank “a’’,
Seifen II, Wild-
HassersZONC wees 61, 62, 131,
163, 173
France,
Antibes, Alpes
Maritimes) 22---c-c 109, 128

Arcachon, Gironde... 121, 128, 183
Barneville-sur-

Mer, Manche .......... 62
Brassempory,

WANES wens ese 59, 164
SSCUTCECY, ) y2itecteetreees ee 91
| B Fb: cape ane ee ne 108
Dives-sur-Mer,

GalvadOS) @2.c221.00:5-5-

52, 56, 161,
162

Gan, Basses-
IPVEGNCES’ icc. secsscresins 59
Hettange, Moselle .. 91

186

INDEX

Manthelan, Indre-

OCUEOING. soscscesssdssesees 92, 104, 108,
109, 114, 116,
128, 175, 178,

180

AGU Shy oe ectcterccccceas cass 128

Saubrigues, Landes 114, 178

LePoivre, Bordeaux 108, 128

EAN CAN: OF. sevcenceceee ates: 67, 68

Marseilles <.cs--:-: 97

Perpignan,

Pyrénées

Orientales) ==. 90

Pont-le-Voy,

Loire-et-Cher .......... 97, 109, 118

Saint-Germain-le-

Fouilloux, Mayenne 132

Touraine 89, 105, 109,
11S) 120.128;

169, 175, 181

Trouville-sur-Mer,

WalVaAGOS) xeccccetet. -sc--s 52

Villers-sur-Mer,

CallVadOS e dsccccses000 500% 52, 161
fusiformis,

Bascomeliay s.......-.-. 139

G
Germany,

Lagerdorf, Holstein 130

Marmorgraben

bei Mittenwald ...... 90

Seifen bei Dierdorf 62, 131, 163

Stuttgart-Degerloch 91

Unkel-Miihle bei

Bitorf£/Sieg. «.;.......sc 173
Georgia, Lumkin,

Stewart) Cone. 89
gigantea, Bascomella.. 139
giganteum,

Plaeiostoma 167, 168
GIK (Geol. Inst.

inivs. Koln): ....:wxé 22, 173
givetiana,

Ropalonaria ............ 139
glandiformis monstrosa,

AnGillaniauy-.seectet: 181
GLNW (Geol. Landes.

Nord. Westf.) .......... 22, 61, 62,

131, 163, 173
GIODIBeTINA: 5....0..s500<-0-0- 40
Glosselettial)........c..<.<-:.. 163, 173
gordiana, Polyzoa ......
gosaviensis,
Penetrantia .............. 78, 87, 88,
139

GPIUB (Geol.-Pal. Inst.

inivawbOnn) es. 22, 73, 74

165

gracilis, Bowerbankia ail ae
graphicus,

Ropalonaria ............ 139
GEAYSONIAY secre 140
Grunder Schichten? .. 89
Gryphaeal cocccccvsctss<cc0s 161, 162, 165
GSM (inst. Geol. Sci.,

NEOTIGON) ees. ecco oss 22,02, Lois

162
H
IBEYCNEDGC) — Gasccaeaoeeeen 8,9 17, 38, 39, 81,
88, 90-92, 106,
135, 138, 139,
141, 143, 145,
149, 167, 168,
val
HamiltonuG ps eee 62, 63, 163,
173
Harmeriellaly...---c Uf
Hawaii,

Haena Bay, Kauai .. 86

Keaukaha, Hilo ...... 124
helicoides, Priamus .. 181
Heteronema ................ 140
hieroglyphica,

Terebripora ............ 138
ELI PPO LO dee 7, 18, 49
Hudson River Gp. ......

Hungary, Delinyest,

KE aASSOmse ee reer 128
hyeroglyphica,

Terebripora ............ 138
Hypophorella .............. The PAU Bel

Immergentia 22, 23,24 9, 15,17, 19,
23, 25, 26, 30,

32, 40, 42, 57,

81, 110, 112,

116, 117, 120-

127, 132, 137-

141, 143, 149,

181-183
Immergentia? .............. 42
incerta, Spathipora .... 108, 138
Indiana, Hanover ........ 48
Versatile ics cicoscceccsss 48
indistincta,
SPALOIPOLAl <.. 6.000022 19, 138
inflata, Ancillaria ...... 174, 181

187

INDEX

intermedia,

Echinophoria .......... 176
Towa., Keokuk <.s.c.c.:--- 134, 166
TPATIVO MA eeccccteesesesterees oe 78, 87, 140
irregularis,

Penetrantia ~2:2:0%.- 85, 87, 139,

144

Ropalonaria ............ 139

Terebripora ............ 137
Tally NS eee 59, 88, 121,

127, 128, 164,
182

PATA VIE | ooceceperorcence 109

COASHIPIANAT, | cceescces=c 128, 129

Asti, Piedmont ........ 89, 109, 121,

128

BOrdighera vreess.s-:s:-- 89, 128

Gascale ge rescccssscssesee2e 118

Castel Arquato ........ 89, 105, 107,

Gs

WolHVAStES! cscs <-scc2 106, 129, 176

Colline Sensi ...::.c..:: 109, 129

Orciana, Toscana .... 127, 181

IPTACENZA eects caseereen= 89, 109, 129

Piedmont, eee 129

Val d’Andona,

IPIEAMONE eeecreteeseeee= 89, 105, 128,

176
J
Jamaica, Bowden ........ 59, 164
K
keokukensis,
Rischerella) -.......-.-- 7 134, 135, 139,
166

Rhopalonaria ........... 134

Ropalonaria ............ 139
Keokuk Tis? ices. ccsescesses 134, 166
Kimmeridge Clay ...... 52, 162
Koéssener Schichten .. _ 90

L
lagaaiji, Cooko-
bryozoon ........ 13, 14 41, 92-94,
141, 143, 148,
y+ 4B}
lambtonensis,

Rhopalonaria .......... 61

Ropalonaria ............ 139, 163
lanceolata,

Immergentia _...... 23) 125 181 SZ
latesulcata,

Terebripora <...2::.00. 138

laxa, Spatipora ............ 87, 88, 138
Leporemax: 2223s: 169
levinseni,

Tubiporella _............ 7
ligulata, Tegula .......... 183
iostrea: cesses 162
lissajousi,

Immergentia? _........ 42, 139
Lithuania, Popilani .... 52, 161, 162
longicauda,

Spathiporass 100, 108, 138,

bs Li?
longirima,

Spathipora .......... 16 37,99, 100,

103, 138, 175
losangelina,

Immergentia ...... 24 126, 183
Lower Portland beds.. 108
lutheri, Monochrysis.. 35

M
magna, Heteronema .. 140
magnivorticellopsis,

Spathipora .......... 17 106, 107, 176
manzonii,

Térebriporay © .si.2:.2-.<- 59-61, 138
Maorierypta. 2::..0%....<¢: 183
Marcellus Sh) =. 62, 132, 163,

173
Marcusodictyon .......... 8
Marcusopora ............... if 57, 66, 70,

118-120, 137,
141, 143, 166

marginata, Ranella .... 164, 182
Marlistone? 3. 90, 167, 168
marshii, Ostrea .......... 161
Mazon? Creek 2... .20 iGl
medialis,
Rhopalonaria .......... 61
Ropalonaria ............ 64, 139
Mediterranean ............ 97, 101
San Antonio,
Ibiza, Baleares ........ 84
Mexico, San Benito
Islands, Baja
Californiaee a 85
MGU (Moscow State
WNIiVErsity) meee 22, 69, 165
michelini,
Haimeina _.......... 8,9 17, 38, 39, 81,
90-92, 106,
138, 139, 141,
143, 145, 149,
167, 168, 171
VIG Aes. seco 90, 137, 139
ET CLOGCY CLUS merer steers: 163

188

INDEX

miniatura,
Terebripora ........ 20 15, 111, 115-
117, 175, 179,
180
MNHN (Mus. nat. Hist.
Mate ALS) eee 22, 52, 59, 67,

99, 112-115,
121, 127, 161,
164, 174, 178,

1

83
Monobryozoon ............. 93
Monochrysis ................ 55
monostachys, Electra.. 1
mucronata, B.,

AON C# OLAS casacssesesnsessss 69
mutabilis, Nassa ........ 176
N
INASS2 Sikes orcees ste casesevesvevss 176
ING DUNE 2-4-...000200000<0505 169

Netherlands, Kaloot,

S. Walcheren .......... 86, 169

IN GW AY. OLK» ... cscoccsseeessses 58, 63, 64,
133

Hubbardsville .......... 62

BOCK DOLRte ret eee 61, 62, 163

IMIGTEEIS VAN @peeasececcess- 62, 132, 163,

173
News Zealand soccscccc-ces. 87

“Fossil Creek”,

Maraekakaho,

Hawkes Bay ............. 90

Lower Waipara

GON PCr trcccssstsoese cases 125, 183

Otago Peninsula,

Little Papanui ........ 85

Moko Hinau Island,

aura Gillitgeessssee 84

Slipper Island ........ 123

Wanganui, North

TSland”.....o0tcesesscosseess 89, 90, 129
NHR (Naturh. Riksmus.,

Stockholm) <icxssc:.! 22, 82, 84,

169, 170, 171
Nigeria, Eastern,

(UlsTThelow ey peeeeerccpocee 118
North America .......... 88
INV GMMILES Wee .-..2-c:-<scesee 68, 77

ce)
occidentalis,

Spathipora ....16,17 105-107, 141,
143, 175, 176

oehlerti, Uncinulus .... 133

Ohio,
Acton Lake, Hueston
Woods State Park,

Neat Oxfordies 47, 48, 160

Ginemmnatiieeccs cs 47, 51

Clarksvill eigecesc sso 47, 160

OTEZONIAL: «.c:..ccccs-seze8 48

Waynesville ............ 48
Olecese Sand Mbr.,

Memblons Hm) ce-c-cee 93, 173
QUAY OH ae d2i5..coscccesisnceseone 183
OMEATION ee crcccscsecensecee 63

A HEOLOUG, | «.sccecessveverns- 62, 163
operculata,

Penetrantia .............. 36, 86, 139
orbignyana,

Terebripora ............ 114, 116, 121,

127, 128, 138,

178, 183

Orbignyopora ............. 5 17, 26, 27, 45,
57-62, 64-67,

135, 138, 164
Orbignyopora? ...... 4,5 37, 60, 62-68,
138, 139, 141,

143, 163, 164
OStROA, cccccessscctesissssvesees 161, 164
P
pachyderma,
Globigerina ............ 40
pacifica,
Terebripora ..........:. TOS Zee:
138, 176
paessleri, Watersiana U
Palos Verdes Sand .... 126, 183
Parasmittina: ......-.....- 80
parva, Penetrantia .... 84, 139
parvicella,
Terebripora ............ 117, 138
patagoniana,
Immergentia _...... 24 121, 122, 126,
183
IRE CECI i: se ecssesscssosedeeevese 24
Pene-
trantia ..9,10,11,12 7, 17, 23-33,
36, 38, 39, 43,
77-89, 92, 99,
102-104, 135,
138-141, 143-
147, 149, 168-
171, 176
permiana,
Rhopalonaria .......... yi
Ropalonaria ............ 14, 10500;
139, 165
pertenuis,
Ropalonaria ............ 19, 49, 139

189

pesavis, Foraripora ....

Philippine Islands,
Zamboanga City,
Zamboanga

philippinensis,
Immergentia

pilosa, Electra
Plagiostoma

Polinices) -....-2
Polyz0ar...... cote
ERonphynidiee see
portlandensis,
iPyriporopsis) ...-.....-
Portland Stone
portlocki,
Terebripora?
Priamus

eee eee eeeeweeeeeeeeeee

Proboscidactyla
producta,
Terebripora
propinqua,
Terebripora
Protulophila
proutana,
Stomatopora
provularia,
Schizophoria
Psilonotenkalk
pungens,
Nygmites
Talpina
pusilla,
Terebripora
Pycnodonta
Pyriporopsis

eee e eee eeeeeeeeeee

quenstedti,
Terebripora

radians,
Calyptraea
radiciformis,
Terebripora
Rafinesquina
ramosa,
Terebripora

eases’ 19

INDEX

60, 70, 129,
130, 140

123

9, 15, 19, 112,
117, 122-124,
139, 149

29, 148

92, 162, 164,
167, 168, 174
L273 177,
182

7

178

37, 92, 104,
145

108

138

1$1

69, 72, 77,
138, 165
42

138

138
42,135

49, 139
163

91

77

72, 77, 139
137

164

37, 92, 104,
145

90, 138

174

138
160

9, 14, 15, 17-

19, 36, 49, 50.
54, 108, 110-
117, 124, 137,
139, 141, 143,
177, 178, 180

Ranella 164, 182

RAP (Robert A.
Pohowsky reference

HUMES)! cece ere 22, 59, 62, 69,
75, 82, 89-91,
100, 108, 109,
112, 114, 117-
119, 124, 125,
127-129, 132,
160, 163-166,
168, 170, 171,
173-175, 177-
181, 183
regalis,
WOlctellamen ec 6 38, 39, 68-70,
72, 73, 75-77,
165
repens, Farella ............ 31
Vinellay execs 140
reticulata, Ficus .......... LOT, V6 ie
reticulum,
Terebripora ............ il7/
Rhopalonaria .............. 46, 47, 58, 61,
62, 68, 73, 77,
134, 163
Rhopalonaria? ............ 46, 53
Richmond Gp. ............ 47, 48, 160
rigidum, Plagiostoma 162
Ripley Fim. <2.<:.:2e52, 75, 89, 118,
119, 166, 168
ripleyensis,
Marcusopora .......... 7 70, 118-120,
141, 143, 166
robusta,
Rhopalonaria .......... 61, 62
Ropalonaria .ti:2.8. 64, 139, 163
MerebDEMpOLay ees. 19, 138
Rochesterslss- 61, 62, 163
ROM (Royal Ontario
Museum)! 2202... 22, 62, 163
Ropalonaria .............. 1 14, 15, 17-20,
37, 40, 45-54,
56, 58, 63, 64,
66, 68, 69, 74,
(ey 7 bul
134, 135, 138,
141, 143-145,
150, 160, 163,
165
Ropalonaria? ........ 2,3 22, 52-57,
138, 139, 148,
161, 162

190

INDEX

Rumania, “Lapugy”,

Transylvania .......... 89, 108, 118,
124, 128, 174,
181
S

St. Mary’s nly -...----...- IGE
Santa @ruzeimine....-.--- 108
Schizophoria ................ 163

“Ind Mediterranean

Ste? e.cccccteesosesevese<s 128
secunda,

Voirtella.. ;..:..:.c..<.:. 7 69, 71, 74-77,
septemradiatus,

IPGCTGMe eee ecceee 24
CLE, Coeeeeeree teecerecert 59
sertum,

Spathipora .......... 18 16, 17, 96-99,

107, 108, 135,
ays ee ie |
Shetlands wee eceres: 89, 96, 98,
169, 177
sibirica,
Spathipora .............. 78, 88, 89,
101, 103, 138

Terebripora? .......... 78, 101, 138
Sicily,

IBUCCHEET i .cee0e.cessssse 89

TRE ST S100) cspceceeesooudooc 89, 109, 128
sileni, Penetrantia ...... 85, 139
sinefilum,

mere briponac.-------- 117, 138
Skaneateles Sh. .......... 62
Solnhofe nies -teeeeee- see 11
Soule Collection .......... 183
soulei,

Penetrantia ........ 10 385-87, 144,

169

South Africa,
Cape of Good Hope
Port Nolloth)-~....-----
South Carolina,
Waccamaw River,

82, 170, 171
82

lei (Gy, eaxereeenaccocce 100, 175
Spathi-
pora ....15, 16, 17, 18 10, 15-17, 19,

26, 27, 32-34,
37, 43, 45, 51,

58, 61, 68, 69,

y PA a ss)

88, 89, 95-

104, 106-108,

1195119, 131.

135-138, 141,

143-145, 165,

174-178
Spatipora 77, 87, 88, 95

spirulea, Serpula,

ZONCy Of keecdeeccsoesceoe 59, 164
stellifora,

Merepriporadececcces---- 138
Stomatopora ..............+ 49, 139
Streptelasma ............ 160
subangulata,

Immergentia ......23 125, 182, 183
subrotunda, Venus .... 175, 1
subsphaerica,

Bascomella .............. 139
suecica, Immergentia.. 123, 139
suecia, Immergentia .. 123, 139
Sweden, Flatholmen,

Gullmars Fjord ...... 85, 123, 169
Syria, Latakia .............. 59, 109
ai
4 Moy aC oatctecteenserconcoseococee 68, 72, 77

138, 139
Pec utlal eieceicesccceeneeee-nn=-e2 183
“ueraloloye IM, sscceeconconce 93, 173
MENNESSCEN ceccccresssseoesenes 118

(CHTTVGKETE copsocnseececoccanec 62, 163

Dave Weeks Place,

Coon Creek,

MeNairy Co. ............ 75, 89, 119,

166, 168
tenuis,

Chaetophorites ........ bya)

Rhopalonaria .......... 61, 163

Ropalonaria ............ 64, 139

Terebripora «.........+. 138
Menenelilaweeecceces:-cusesosee Tf
terebrans,

Harmeriella ............. 7
Terebripora 19, 20,21 9, 10, 14, 15,

17-19, 34-37,

40, 41, 45-46,

49, 50, 52-54,

57-61, 66-68,

77, 87-90, 95-

97, 101, 103,

105, 108-121,

124, 127, 128,

131, 137-139,

141, 143-145,

148, 149, 164,

169, 175-180,

183

Terebripora (?) .......... 47, 57, 88
Ulta (Ot licaeotercdcseccroce

Noil Boewan ............. 73, 129, 165
timorensis,

Rhopalonaria .......... 73

Ropalonaria ............ 74, 139

Voictella? v2.00... 6 69, 72-74, 76,

165

191

INDEX

tridelta,
Orbignyopora? _....5 58, 60, 65, 66,
141, 143, 164
triquetra,

Glosselettia .............. 163, 173
MubIpOrellagseseecseses ee 7
TULK CW) esse A keisiocsnsess 114

“Saaret” (Sayaret),

EQOA. eck ceccesostceeeees 112, 178

ACNE CNY esa. acsotees 128

UCGM (Univ. Cin-
cinnati Geol. Mus.).. 22, 47, 52, 62,

69, 75, 89, 91,
100, 119, 132,
160, 163, 165,
166, 168, 173,
175
ulrichi,
Ropalonaria ............ 139
Vinella eee 140
Oncmultisse eee 133
United! States 78
“upper Graywacke of
Manche, graywacke
with Spirifer” ........ 62
USGS (United States
Geological Survey).. 22, 105
USNM (National
Museum of
Natural History) .... 22, 48, 57, 59,
61, 62, 64,
100, 105, 134,
135, 160, 163,
164, 166, 175-
177
WES Sta eee 78, 88
Chvalyusk,
Saratov Province .... 69
eISOSMInSk ee 52
Mt. Chodsa Kasian,
S. W. Schaartus,
Tadschikistan .......... 89, 101
Sengiley, Ulja-
novsk Province ...... 69, 165
Trans-Caspian
TOVINCE Peo oscsennc: 69, 165
Vol’sk, (Saratov
PTOVinee) ee 165
UVvanValkeriage PAT OATF
Vv
vadosus,
Crassetellites .......... 166
Valkeriat 495 5.3.2o..05.:00: PH BW

varians, Terebripora .. 19, 138, 149

venosa,
Ropalonaria .......... 1 14, 15, 17, 18,
37, 46-54, 56,
138, 141, 143,
150, 160
venosum,

Rhopalonaria .......... 47
VENUS reece ee ee 175, 180
vesicularis,

Grypnaen: (2255 we 165
vetusta,

Casteropora ........ 14 131-133, 138,

163, 173

Terebripora ............ 131, 138
Winelia (5 ee ee 140
Mineloide@a. secccscccoecnecess 8
WiO0al ee eee 90, 137, 139
Virginia,

Beulahland, King

William: Co. 2.....::..:. 100

Bowlers Wharf,

Middlesex Co. ........ 177

VWOPKCOWN | ccnsseossaccsese 109, 128
Voirtellaw 6,7 38, 39, 68-70,

72-77, 135,
138, 139, 165,
166
Voistella? 2.3.0 6 69, 72-74, 76,
139, 165
Voigt, Photo

Catalogue of ............ 130
VOrticellay. co ce 106
vulgaris, Cucullaea .... 166

Ww
Waccamaw Marl] ........ 100, 175
Watersiana -2h.cs.c0
Waynesville Fm. ........ 47, 48, 160
“Wurmlocher”’ ............
id
Yorktown! Hm 2 100, 109, 128
Zz
zelandica,

Immergentia _.......... 123, 139

minuta,

Immergentia ............ 123, 139
ZGM (Central Geol.

Mus., Leningrad) .... 22, 89, 101,

102
Zone of Serpula

SUNPUIED oasis 59, 164

Zone of B. mucronata 69

192

LII. (Nos. 233, 236). CH yeh oetee, ey fe) Eh et Ale ee a

LITI. (Nos. 237-238). ARSED D4 OM Sager eat eee ee mi
Venezuela Bryozoa, Kinderhookian Brachiopods.
LIV. (Nos. 239-245). SIOMDD > OM psig eee eee ee es oe
Dominican ostracodes, Lepidocyclina, mollusks.
LV. (Nos. 246-247). G57 DD OO PIS <n ee ee ss
Cenozoic corals, Trinidad Neogene mollusks.
LVI. (Nos. 248-254). BUDD 149 GDISS wees teecescccsre test aks ue eecencaaen
Forams, North Carolina fossils, coral types, Cenozoic
Echinoids, Cretaceous Radiolaria, Cymatiid gastropods
LVII. (Nos. 255-256). B27 D DMO amples creer ee ee aes
Jurassic ammonites.
LVIII. (Nos. 257-262). BO Sip Die S oe DIS emesc re eaae ee ee ee
Cretaceous Radiolaria and Forams, Pacific Silicoflagellates,
North American Cystoidea, Cyclonema, Vasum.
LIX. (No. 263). BSA Ts Da errr
Bibliography of Cenozoic Echinoidea.
LX. (Nos. 264-267). BS Sar D Dyk OSS eet te ee ens Scarce
Radiolaria, cirripeds, Bryozoa, palynology.
LXI. (Nos. 268-270). S65 ppc Sis plse ences eee se =
Mollusks, Murex catalogue, Cretaceous Radiolaria.
LXII. (Nos. 271-274). ST SED see BD Ss cree cee Se
Trace fossils, ammonoids, Silicoflagellates, microfauna.
LXIII. (Nos. 275-277). BAO De S00 Use ee
Chitinozoa, Spumellariina, Mexican Ammonites
LXIV. (Nos. 278-281). CJ SY FS 9 weet 1B) 0) Kc) pee ete een eee
Palynology, corals, echinoderms, Foraminifera, and crinoids.
LXV. (No. 282). SH eit, GE IRS oe 2
Ostracode Symposium.
LXVI. (Nos. 283-286). G39 iD py AOD MPS Spe tac sas sees tase ee esece ca enemns =
Crinoids, gastropods, corals, ostracodes.
LXVII. (No. 287). A'S Gs DD GON PSs, estates ce mesa cane ee eesenece
Misc. Paleozoic
LXVIII. (Nos. 288-290). DAME DP tao e oP isin eee ee eee es
Paracrinoidea, ostracodes, cirripeds.
LXIX. (No. 291). DOE Di She plan cae ls Pee ees
Bryozoa.
LXX. (Nos. 292-294). AGAR Ty DLA BAD Site cee eee are cscs aecceeeatne
Turrids, gastropods, forams.
LXXI. (No. 295). B7oenp? SUiupl Sethe et st ee eee uae

New Zealand forams, Stromatoporoidea, Indo-Pacific, Mio-
cene-Pliocene California forams.

Paleocene Nigeria

LXXII. (Nos. 296-300). CACY 0) SERIE Stal 8) Ke pete ee eg RR ae ee

Volume 1.

II.

III.

Vill.

Crinoids, barnacles, forams, Stanford catalogue.

PALAEONTOGRAPHICA AMERICANA
See Johnson Reprint Corporation, 111 Fifth Ave., New York,
N. Y. 10003
Monographs of Arcas, Lutetia, rudistids and venerids.
(Nos. 6-12). SME 37), PUSS cect he ek ee
Heliophyllum halli, Tertiary turrids, Neocene Spondyli,
Paleozoic cephalopods. Fasciolarias, sponges.
(Nos. 13-25). SESH DDS 6 Lip Sepa ees ee Se
Cephalopods, siphonophores, Devonian fish, gastropods,
crinoids, Cretaceous jellyfish, brachiopods, bivalves.

(Nos. 26-33). AOD DD a7 25D Sete ccare een ee nee

Devonian _lycopods, Ordovician eurypterids, mollusks,
brachiopods.

(Nos. 34-47). 445) pe LOM DIG ene oar Rae

Pelecypods, Cretaceous Gulf Coastal forams.

(Nos. 38-41). BA NSD) 5S AUR f sane eccentrics

Pennsylvanian plants, Venericardia, Carboniferous crinoids,
Trace fossils.

(Nos. 42-46). Cog iy DW) opp ake eels ee Sea ee

Trilobites, rudists, crinoids, gastropods.

(Nos. 47-50). 33/7) PD.1360 DIS es eet an eere
Gastropoda, Devonian plants, brachiopods, Bivalvia.

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Vol. I-XXIII.

XXIV.

XXV.

XXVI.

XXVII.
XXVIII.
XXIX.

XXXVII.
XXXVIII.
XXXIX.
XL.

XLI.
XLII.
XLIII.

XLIV.

XLV.
XLVI.
XLVII.
XLVIII.

XLIX.

1 Us

LI .

(No. 225-230).

(Nos. 231-232).

BULLETINS OF AMERICAN PALEONTOLOGY

See Kraus Reprint Corp., 16 East 46th St.,

N. Y. 10017. U.S.A.

(Nos. 80-87). JY WA of o owe 47 a 0) (peer oemrm est fatelt eo

Mainly Paleozoic faunas and Tertiary Mollusca.

(Nos: 88-948): 306) pp3730) (pls. eee

Paleozoic, Mesozoic, and Miocene fossils.

(Nos:95-100).. 4204pp:, 58: pls:0 2 ee

Florida Recent, Texas and South America Cretaceous,
Cenozoic fossils.

(Nos) e101=108) 20/376 pp: .s6npls: =.

Tertiary mollusks, Paleozoic Venezuela, Devonian fish.

(Nos: 1092114). 412" pp: 34 pls ee

Paleozoic cephalopods, Cretaceous Eocene, forams.

GNos: -215-116)s) 738) pp), 52) pls: (2 eee ee ee

Bowden forams and Ordovician cephalopods.

(Non SUEZ). e563. pps 65. plea tec carcscs meee oe ee eee

Jackson Eocene Mollusks.

(Nos saG=128) 5 458 pps 12 7) ap lsiyc. ts aero ee

Mollusks, crinoids, corals, forams, Cuban localities.

(Noss 1295133))2 2942 Pps 39) piss ees accccoe cece eee

Silurian cephalopods, crinoids, Tertiary forams, Mytilarca.

(Nos: 4134-159). 448) pps SL Spl ssa nee ee ee ee

Devonian annelids, Tertiary mollusks, Ecuadoran strati-
graphy paleontology.

(Nos: 140-145) 400 pp\, 19) pls:.2.228 es ee

Forams, cephalopods, ostracods, conularid bibliography.

(Nos: 2146-154), SS6mpps 310 pis) sete ee

Forams, cephalopods, mollusks, ostracods.

(INos co 1552160) ian B12 = pp 5153) pS. .-ctesten tee ee

Forams, Eocene fish, rudists.

(Nos. 161-164): 486. pp., 37 \pls...2.2 ee

Cretaceous rudists, Foraminifera, Stromatoporoidea.

(Nos. 165-176). 447 pp., 53 pls. ....

Forams, ostracods, mollusks, Carriacou, fossil ‘plants.

(Nos. 177-183). 448 pp. 36 pls. <.-.-

South American forams, Panama Caribbean mollusks.

(No; /184). (4.996 pp. pl... eee

Type and Figured Specimens P.R.I.

CNos23185=192)0 9 381 Sppis So (pls. caccca se Soe ee.

Forams, mollusks, carpoids, Corry Sandstone.

(No. 193)... 673: pp., 48) pls; oe a

Venezuelan Cenozoic gastropods.

(Nos, 194-198). 427 pp., 29. pis,

Ordovician stromatoporoids, Indo-Pacific camerinids, Mis-
sissippian forams, Cuban rudists.

(Nos:199-203). 365: spp, "68 iplss 22 ee

Puerto Rican, Antarctic, New Zealand forams, Lepidocy-

clina, Eumalacostraca.

Oo se reeneweee je eccceccecrcccccewccccece

(IN0.204) 9 564pps 163'(pls. ake see ee eee Ets
Venezuela Cenozoic pelecypods.

(Nos) 205-211) 7) 1419 pp. 70) pl ss a ee ee
Forams, Crustacea, brachipods, Recent mollusks.

(Nos? e212=217):) S84 pp. 83) ples. cscs ee at

Forams, mollusks, polychaetes, ammonites.

(Nos2t8)s ClOSStipps, 5eplss cis ne ee ee eee

Catalogue of the Paleocene and Eocene Mollusca of the
Southern and Eastern United States.

(Nos. 219-224). 671 pp., 83 pls.

Peneroplid and Australian forams, North American car-
poids, South Dakota palynology, Venezuelan Miocene mol-
luska, Voluta.

Aone eeneewneecne sent encneeccesccescsccesaccceses

SIS (pp: 42. play eA eee ee eee

Venezuela, Florida cirripeds, forams, Linnaean Olives,
Camerina, Ordovician conodonts.

420° DD; lO Up ss y-2e-e ee cee

Antarctic bivalves, Bivalvia catalogue.

New York,

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