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ATTI

DELLA

SOCIETÀ ITALIANA

DI SCIENZE NATURALI

E DEL

MUSEO CIVICO

DI STORIA NATURALE DI MILANO

VOLUME CVIII

I. B. A.

INTERNATIONAL BRYOZOOLOGY ASSOCIATION

PROCEEDINGS

of thè

FIRST INTERNATIONAL CONFERENCE ON BRYOZOA

AGIP Direzione Mineraria Paleontological Laboratory S. Donato Milanese

xAugust 12th-16th 1968

Edited by Enrico Annoscia, Conference Chairman

MILANO

31 Dicembre 1968

SOCIETÀ’ ITALIANA DI SCIENZE NATURALI

CONSIGLIO DIRETTIVO PER IL 1968

Presidente :
Vice-Presidenti :

Segretario :

Nangeroni Prof. Giuseppe (1968-69)

Viola Dr. Severino (1968-69)

Conci Prof. Cesare (1967-1968)

De Michele Dr. Vincenzo (1968-69)

Vice-Segretario :
Cassiere:

Consiglieri :
(1968-69)

Bibliotecario:

Rui Sig. Luigi (1967-1968)

Turchi Rag. Giuseppe (1967-1968)

Magistretti Dr. Mario
Marchigli Ing. Giorgio
Moltoni Dr. Edgardo
Ramazzotti Ing. Prof. Giuseppe
SCHIAVINATO Prof. GIUSEPPE

Taccani Aw. Carlo
Schiavone Sig. Mario

MUSEO CIVICO DI STORIA NATURALE DI MILANO

PERSONALE SCIENTIFICO

Conci Prof. Cesare
Torchio Dr. Menico

Cagnolaro Dr. Luigi
De Michele Dr. Vincenzo
Pinna Dr. Giovanni
Leonardi Dr. Carlo

- Direttore (Entomologia)

- Vice-Direttore (Ittiologia e Teutologia),
Dirigente delTAcquario

- Conservatore (Teriologia ed Ornitologia)

- Conservatore (Mineralogia e Petrografia)

- Conservatore (Paleontologia e Geologia)

- Conservatore (Entomologia)

PERSONALE TECNICO

Lucerni Cav. Giuliano - Capo Preparatore
Bucciarelli Sig. Italo - Preparatore (Insetti)

Giuliano Sig. Giangaleazzo - Preparatore (Vertebrati)
Bolondi Sig. Lauro - Preparatore

EDITRICE SETCC. FUSI - PAVIA

Editor : Conference Chairman Dr. Enrico Annoscia

Editorial Board: LB.A. Chairman Dr. Alan H. Cheetham

/. B. A. Secretary Miss Patricia L. Cook
Conference Secretary Dr. Piero Ascoli

The publication of these PROCEEDINGS was possible through
thè f mandai helps of thè following Institutions :

« AGIP Direzione Mineraria », San Donato Milanese (Milan)
« Consiglio Nazionale delle Ricerche », Rome
« Camera di Commercio, Industria, Artigianato e Agricoltura »,
Milan

« Cassa di Risparmio delle Provincie Lombarde » Bank, Milan
« Amministrazione provinciale » of Milan

« Società Italiana di Scienze Naturali » and « Museo Civico di
Storia Naturale », Milan

Note: The discussion following each paper were not printed- in these
PROCEEDINGS owing to space and cost reasons. They will be duplicated
separately. Anybody who is interested to have them is asked to request them
to I.B.A. (c/o Dr. Enrico Annoscia, Via Mincio No. 3, 20139 Milan, Italy).

ATTI

DELLA

SOCIETÀ ITALIANA

DI SCIENZE NATURALI

E DEL

MUSEO CIVICO

DI STORIA NATURALE DI MILANO

PROCEEDINGS

of thè

FIRST INTERNATIONAL CONFERENCE ON BRYOZOA

AGIP Direzione Mineraria Paleontological Laboratory S. Donato Milanese

August 12th-16th 1968

Edited by Enrico Annoscia, Conference Chairman

MILANO

31 Dicembre 1968

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 4. 31-XII-1968
lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

La Società Italiana di Scienze Naturali ed il Museo Civico
di Storia Naturale di Milano sono lieti di poter ospitare nei loro
Atti i Risultati di questo importante Congresso sui Briozoi, il
primo a carattere internazionale dopo V informale Incontro di
Stoccolma del 1965 che dette origine alla costituzione dell’ I.B.A.
(International Bryozoology Association) .

U I.B.A. , seppur così giovane , conta già quasi duecento ade¬
renti, tutti specialisti di un gruppo di animali a torto per V ad¬
dietro trascurati, specie in Italia, da Paleontologi e da Zoologi,
ma che già fanno sentire il loro peso negli studi stratigrafici ed
ecologici.

Vogliamo qui ringraziare il Dr. Enrico Annoscia, organizza¬
tore e Presidente del Congresso, che con particolare cortesia d
ha. offerto V opportunità di pubblicare un così grande numero di
importanti lavori specializzati, permettendoci di offrire ai nostri
Soci un quadro completo dei più moderni studi sui Briozoi, quale
non è dato trovare sulle riviste scientifiche italiane.

The Italian Society of Naturai Sciences and thè Milan Civic
Museum of Naturai History are glad to give hospitality in their
Review to thè Proceedings of this important Conference on Bryo¬
zoa, thè first International one after thè informai Meeting of
Stockholm m 1965, which gave birth to I.B.A. (International
Bryozoology Association).

I.B.A., although so young, already enumerates two hundred
members, all specialized on a group of animais blamely hereto-
fore neglected, especially in Italy, by Paleontologists and Zoolo-
gists, but which are becoming more and more important in stra-
tigraphical and ecological studies.

We wish to thank Dr. Enrico Annoscia, who organized and
presided thè Conference, for having most kindly offered us thè
opportunity to publish so many weight specialized papers, ena-
bling us to offer to our Members a complete picture of thè up-to-
date studies on Bryozoa, which are not easily found in thè Italian
scientific reviews.

Giuseppe Nangeroni - Cesare Conci

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 5-6, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

Enrico Annoscia

CONFERENCE CHAIRMAN ADDRESS

Ladies and Gentlemen, old and new friends,

I am most giaci to welcome you in Sari Donato Milanese, also
on behalf of AGIP Paleontologists and Italian Bryozoologists.

This is thè First International Conference organized by
I. B. A. and thè second on Bryozoa, after thè first informai
meeting held in Stockholm in 1965, when our Association was
founded.

This Conference has been possible through thè help of sere¬
nai bodies, which I want to thank, also on behalf of us all.

First of all I thank AGIP Direzione Mineraria-through thè
persons of General Manager Eng. E. Egidi and Vice-Manager
Dr. D. Jaboli - which generously accepted to gire hospitality oui
Conference, ancl thè May or of S. Donato Milanese, Dr. G. Fiorio,
who is a geologist and whose help was unvaluable for meeting
organization expenses.

Particular thank s are due to AGIP Direzione Mineraria,
to National Research Committee ( C . N. R.), to « Camera di Com¬
mercio, Industria, Artigianato e Agricoltura », Milan, to « Ammi¬
nistrazione provinciale », Milaìi and to « Cassa di Risparmio
delle Provincie Lombarde » Bank, which supplied us with funds
for printing thè Conference Proceedings Volume, and to Prof.
C. Conci, Director of thè Milan Civic Museum of Naturai
History and V ice-Chairman of tire Italian Society of Naturai
Sciences, who generously accepted to print our Confer enee Pro¬
ceedings in thè review « Atti della Società Italiana di Scienze
Naturali e del Museo Civico di Storia Naturale eli Milano ».

E. ANNOSCIA

I also thank thè « E. Mattel » ENI Hydrocarbons Post-Gra¬
duate School, through thè persons of Prof. M. Boldrini and
Eng. E. Camatini, thè ENI Public Relations Office , through thè
persons of Dr. Bellini delle Stelle , Mr. Salvadori and Mr. E osca/ri
and thè Mayor of Possagno , for thè help and hospitality given
to us.

Furthermore , I am deeply grateful to dr. Ascoli , who was
very dose to me in organizing this Conference, to clr. Cheetham,
IBA Chairman, and to thè pretty Secretary, Miss Cook.

Finally , I heartly thank you all for having come bere and
for having appointed me Chairman of this Conference. I wish
this Conference might originate an importuni progress in thè
study of Bryozoa, so that this group of animals - wrongly
forgotten since not long ago - might more and more be widely
applied in thè field of Stratigraphy and Ecology.

I have noia a very sad news to gire you: prof. Ernst Marcus,
75 years old, died on June 30th. This is a great lost for thè Bryo-
zoology. I would propose, in thè Business Meeting, to dedicate
this Conference to his Memory.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 7-12, 31-XT.I-1968

]st I.B.A. IrDernational Conference on Bryozoa, S. Donato Milanese, Aug. 12th-]6th, 1908

Eveline du Bois Reymond Marcus (*)

ERNST MARCUS

8. VI. 1893 - 30.VI.1968

Ernst Marcus was bora in Berlin in 1893. From his child-
hood he loved animals, especially seals and cats. As a school boy
he collected beetles. In 1912 he entered thè University of Berlin to
study Zoology. He was beginning his Doctor’s thesis in thè Ento-
mological Department of thè Berlin Museum, when thè 1914-1918
world war interrupted him. In 1919 he obtained his Doctor’s
Degree. Afterwards, thè Director of thè Museum gave him thè
collection of Bryozoa to study. He had no specialist to initiate him.
He consequently had to make his own way with a rather old li¬
brary and some material classified mainly by Kirchenpauer.

He was entrusted with collections from many expeditions.
When he sent his first manuscript to Sweden, thè Editor, Theodor
Odhner, returned it and told him to translate it into German. The
way it was, it seemed to be translated literally from Latin. Thus,
Ernst Marcus learned to take good care of his style. From his
first publications Dr. 0. Nordgaard - Trondhjem recognized, that
he did not know Levinsen’s fundamental « Morphological Studies
on thè Cheilostomatous Bryozoa » (1909), and gave him thè pre-
cious volume, too expensive for a student during thè years of
inflation.

In 1923 Ernst Marcus obtained thè « Privat-Dozent » and
was appointed assistant of Professor Karl Heider at thè Zoolo¬
gica! Institute of thè University of Berlin. In 1924 we married.

(*) Caixa Postai 6994, Sào Paulo, Brazil.

E. DU BOIS REYMOND MARCUS

He had until then all illustrations far his papers done by a pro¬
fessional, but from then I took on all thè drawings and we stu-
died our Bryozoa together. For some of thè technical details I was
apter, and on such occasions he did thè cooking. Till 1925 we only
had preserved material, but that year we went to thè station of
Biisum and had our first experiences with living marine Bryozoa,
published in 1926. In thè same year we got our first living
freshwater species in a lake near our house. These Plumatella
were extremely rich and produced great numbers of larvae. One
night he kept awake to observe thè alwavs nocturnal birth of
thè larva (1926. Verh. D. Z. G.). We succeeded to stain thè ner-
vous System in thè living larva.

In 1929 Ernst Marcus was appointed Associate Professor.

Sidney F. Harmer in his Presidential Address to thè Linnean
Society London, 28th of May 1931, referred extensively to our
work, which made us very proud.

During thè years 1931 and 1932 we studied a population of
Lophopus crystallinus and went to thè pond where it was thriving
every week (1934).

In 1935 Ernst Marcus was dismissed from thè University
due to thè Nazi laws. By thè Society for thè Protection of Science
and Learning Ltd. (Lord Beveridge) he was recommended for
thè Chair of Zoology at thè University of Sào Paulo, Brazil, which
he occupied from 1936 to 1963, when he had to retire at seventy
years of age. In thè collections of thè Department we found lots
of preserved Bryozoa and on thè coast near Santos there were
many opportunities to study thè living animals and their larvae
(1937-1939). Owing to thè war it became impossible to continue
our marine studies, so we began to work with freshwater mate¬
rial. Our most exciting discovery was thè vestibular pore which
frees thè statoblasts from thè living colony. For a long time we
had suspected that statoblasts are freed, because so many of them
swim on thè surface over thè colony, but we had thought that thè
chironomids feeding upon thè polypids might also have opened
thè way for thè statoblasts. By patient observation we succeeded
to see thè statoblast expelled like an airship from thè hangar
(1941, 1942).

From thè freshwater Bryozoa our attention was then called
to thè accompanying fauna of Oligochaeta and Turbellaria, later

ERNST MARCUS

E. DU BOIS REYMOND MARCUS

to terrestrial and marine Turbellaria, and only now and then we
returned to thè Bryozoa (1946, 1949, 1950, 1953, 1955, 1955, 1957,
1962, 1968).

From 1952 on we were chiefly occupied with Opisthobranch
Gastropods. In thè last years Ernst Marcus’ rhythm of work
slowed down gradually, and in 1968 he weakened visibly, till he
passed away on June 30, aged seventy-five.

We had a lively correspondence with Theodor Mortensen -
Copenhagen, whose collecticns from all thè world contained manv
Bryozoa, during all thè years until he died in 1953. We were
always by letter in contact with thè Bryozoologists S. F. Harmer,
0. Nordgaard, Anna B. Hastings, R. S. Bassler, Raymond
C. Osburn, Mary D. Rogick, Fritz Wiebach, Patricia L. Cook,
and others. In 1956 Libbie H. Hyman carne to see us to prepare
thè volume 5, Smaller Coelomate Groups, of her Treatise of thè
Invertebrates, in which she resumed many of our results.

Ernst Marcus was correspondent member of 9 scientific
Academies and Societies in Brazil, ETSA, Finland, Denmark, Eng-
land, and Germany, and co-editor of thè « Beitràge zur Neotro-
pischen Fauna » (Fischer, Stuttgart) and thè « Monitore Zoolo¬
gico Italiano ».

PAPERS OF PROFESSOR ERNST MARCUS ON BRYOZOA

1. 1919 - Notizen Rber einiges Material mariner Bryozoen des Berliner Zoo-
logisc-hen Museums - SitzBer. Ges. natf. Freunde, Berlin, 1917 (1919),
no. 7, pp. 255-284, Berlin.

2. 1920 - Mittelmeer-Bryozoen aus der Sammlung des zoologischen Museums
zu Berlin - SitzBer. Ges. natf. Freunde, Berlin, no. 2/3, pp. 65-108, Berlin.

3. 1921 a - Bryozoen von den Auckland- und Campbell-Inseln - Papers from
Dr. Th. Mortensen’s Pacific Expedition, 1914-16, VI. Vidensk. Medd.
Dansk nat. For., v. 73, pp. 85-121, pi. 5, 11 text-figs.

4- 1921 b - Bryozoa von den Juan Fernandez-Inseln - In Skottsberg C., ed.,
The naturai history of Juan Fernandez and Easter Island, v. 3 (1).
pp. 93-123, 19 text-figs.

5. 1921 c - Results of Dr. E. Mjòbergs Swedish Scientific Expeditions to
Australia, 1910-13, XXIV, Bryozoen - K. Svenska Vet-Ak. Handl. Stock-
holm, v. 61 (5) (1920), pp. 1-34, 2 pls.

6. 1921 d - Uber die Verbreitung der Meeresbryozoen - Zool. Anz. Leipzig.,
v. 53, no. 9/10, pp. 205-221.

ERNST MARCUS

7. 1921 e - Einiges iiber Bau und Entwicklung der Meeresbryozoen
Schrift. d. Zool. Stat. Bùsum f. Meeresk. no. 3-4, pp. 22-27.

8. 1922 a - Bryozoen von den Aru-Inseln - Abh. Senckenb. Naturf. Ges.
Frankfurt a. M., v. 35, pp. 421-446, pls. 24-25.

9. 1922 b - Indopacifische Bryozoen aus dem Riksmuseum in Stockholm -
Ark. Zool., v. 14 (7), pp. 1-23, 2 pls.

10. 1922 c - Referat iiber die historische und moderne Auffassung des Baues
und der systematischen Stellung der Bryozoengattung Adeona - Verh.
zool. bot. Ges. Wien., v. 72, pp. 42-61.

11. 1922 d - Siidafrikanische Bryozoen aus der Sammlung des Gothenburger
Museums, nebst 1 westafr. Species - Goteborg Vet. Handl., v. 25 (3),
pp. 1-45 ,text figs. 1-22.

12. 1923 - Hydrostatik bei Meeresbryozoen - Verh. D. zool. Ges. Leipzig,
v. 28, pp. 39-41.

13. 1924 - Zur vergleichenden Embryologie der Bryozoen - Mitt. zool. Mus.
Berlin, v. 11 (1), pp. 157-166.

H. 1925 a - Bryozoa - In P. Schulze, ed., Biol. Tiere Deutschlands, pt. 47
(Lief. 14), pp. 1-46, 39 text-figs. Berlin.

15. 1925 b - tìber Stirpariella mortenseni und das Genus Stirpariella - Pa-
pers from Dr. Th. Mortensen’s Pacific Expedition, 1914-1916, XXII. Vi-
densk. Medd. Dansk nat. For., v. 81, pp. 37-55, 12 text-figs.

16. 1925 c - tìber Victorella symbiotica Rouss. (Ectopr. Gymnol. Ctenost.) -
Zool. Anz. Leipzig, v. 62, pp. 129-133, 2 text-figs.

17. 1925 d - Zum Polymorphismus der Bryozoen - Verh. D. zool. Ges. Leip¬
zig, v. 30, pp. 152-159, 6 text.-figs.

18. 1926 a - Beobachtungen und Versuche an lebenden Meeresbryozoen - Zool.
Jahrb. Jena, Syst., v. 52, pp. 1-102, 2 pls., 46 text-figs.

19. 1926 b - Beobachtungen und Versuche an lebenden Siisswasser-Bryozoen
- Zool. Jahrb. Jena, Syst., v. 52, pp. 279-350, 1 pi., 34 text-figs.

20. 1926 c - Bryozoa - In Grimpe, G. and Wagler E., eds., Die Tierwelt der
Nord- und Ostsee. Leipzig, v. 4 (Vile), pp. 1-100, 168 text-figs.

21. 1926 d - Sinnesphysiologie und Nervensystem der Larve von Plumatella
fungosa (Pali.) - Verh. D. Zool. Ges. Leipzig, v. 31, pp. 86-90, 5 text-figs.

22. 1930 - Bryozoa - In W. Junk, Tabulae Biologicae, v. 6 ( = suppl. 2),
pp. 311-327, 5 text-figs.

23. 1934 - tìber Lophopus crystallinus (Pali.) - Zool. Jahrb. Jena Anat., v. 58;
pp. 501-606, 66 text-figs.

2U> 1935 - tìber marine Bodentiere an der Kiiste St. Helenas - Forsch. Fort-
schr. Jahrg. 11, no. 17, p. 228.

25. 1936 a - Sóbre alguns phenómenos da vida dos Bryozoarios Marinhos -
Arch. Inst. Biol. Sào Paulo, v. 7, pp. 203-208, 7 text-figs.

26. 1936 b - Sóbre o systema naturai dos Bryozoarios - Boi. biol. Sào Paulo,
v. 2 (4), pp. 129-135, 2 text-figs.

27. 1937 - Bryozoarios marinhos Brasileiros I - Boi. Fil. Ciènc. Letr. Univ.
Sào Paulo, v. 1, Zool. no. 1, pp. 3-224, pls. 1-29.

28. 1938 a - Bryozoarios marinhos Brazilieiros II - Boi. Fac. Fil. Ciènc.
Letr. Univ. Sào Paulo, v. 4, Zool. no. 2, pp. 1-196, pls. 1-29.

E. DU BOIS REYMOND MARCUS

29. 1938 b - Bryozoarios Perfuradores de Conchas - Arq. Inst. Biol. Sào
Paulo, v. 9, pp. 273-296, 7 text-figs.

30. 1938 c - Bryozoen von St. Helena - Vidensk. Medd. Dansk nat. For.,
v. 101, pp. 183-252, 32 text-figs.

31. 1939 a - Bryozoarios marinhos Brasileiros, III - Boi. Fac. Fil. Ciénc.
Letr. Univ. Sào Paulo, v. 13, Zool. no. 3, pp. 111-353, pls. 5-31.

32. 1939 b - Sawayaella polyzoorum, gen. nov., spec. nov. dos Schizogregari-
naria - Arq. Inst. Biol. Sào Paulo, v. 10 (17), pp. 259-278, pls. 32-33.

33. 1940 a - Mosdyr (Bryozóa eller Polyzóa) - In Danmarks Fauna no. 46,
Copenhagen, pp. 1-221, 401 text-figs. Dansk. Natur. historisk Forening
Kobenhavn.

34. 1940 b - Sóbre a interferencia da propagalo vegetativa na gamogonia -
Ann. Acad. Bras. Sci. Rio, v. 12, pp. 1-16.

35. 1941 a - Bryozoarios Marinhos do Litoral Paranaense - Arq. Mus. Para-
naense, v. 1, pp. 7-36, 34 text-figs.

36. 1941 b - Sóbre Bryozoa do Brasil - Boi. Fac. Fil. Ciènc. Letr. Sào Paulo,
v. 22, Zool. no. 5, pp. 3-208, 18 pls.

37. 1941 c - Sóbre o desenvolvimento do Bryozoario Synnotum aegyptiacum -
Arq. Cir. Clin. Exp. Sào Paulo, v. 5, pp. 227-234, 4 text-figs.

38. 1942 a - Cryptopolyzoon evelinae, a new Ctenostomatous Bryozoan from

thè Brazilian Coast - Proc. 8th Amer. Sci. Congr. Washington, v. 3,

pp. 477-479, 1 pi.

39. 1942 b - Sobre Bryozoa do Brasil II - Boi. Fac. Fil. Ciènc. Letr. Sào
Paulo, v. 25, Zool. no. 6, pp. 57-106, 5 pls.

40. 1944 - Beania cupulariensis Osb. (Bryozoa Cheilost.), nova para o Brasil
- Comun. zool. Mus. Hist. nat. Montevideo, v. 1 (12), pp. 1-3, 4 text-figs.

41. 1946 - On a new Brazilian forni of Fredericella sultana, etc - Comun.

zool. Mus. Hist. nat. Montevideo, v. 2 (31), pp. 1-10, 2 pls.

42. 1949 - Some Bryozoa from thè Brazilian Coast - Comun. zool. Mus. Hist.

nat. Montevideo, v. 3 (53) pp. 1-33, 7 pls.

43. 1950 a - Systematical remarks on thè bryozoan fauna of Denmark - Vi¬
densk. Medd. Dansk nat. For., v. 112, pp. 1-34, 5 text-figs.

44- 1950 b - A new Loxosomatid from Brazil. Boi. Fac. Fil. Ciènc. Letr., Sào
Paulo, Zool. n. 15, pp. 193-206, 2 pls.

45. 1953 - Notas sóbre Briozoos marinhos Brasileiros - Arq. Mus. Nac.,
v. 42, pp. 273-342, 8 pls.

’+ 6 • 1955 - Polyzoa. Percy Sladen Trust Exp. Lake Titicaca - Trans. Linn.
Soc. London ser. 3, v. 1, pt. 3, pp. 355-357.

47. 1957 - Neue Entoprocten aus der Gegend von Santos - Zool. Anz. v. 159,
p. 68-75 text-figs. 1-7.

k8. 1958 - On thè Evolution of thè Animai Phyla - Q. Rev. Biol., v. 33,
pp. 24-58, 1 text-fig.

4-9. 1962 - On some Lunulitiform Bryozoa - Boi. Fac. Fil. Ciènc. Letr. Univ.
Sào Paulo, v. 261, Zool. no. 24, pp. 281-324, 5 pls. [With Eveline du
Bois-Reymond Marcus].

50. 1968 - Neue brasilianische Loxosomen - Zoolog. Beitr. N. F., v. 14,
pp. 203-212, text-figs. 1-11.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 13- 24. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

Piero Ascoli (*) & Patricia L. Cook (**)

CONFERENCE REPORT

The First International Conference on Bryozoa of I.B.A. (Interna¬
tional Bryozoology Association) was opened in thè Conference Hall of E.N.I.
(Italian Hydrocarbons National Company) First Skyscraper in S. Donato
Milanese (Milan, Italy) at 8.30 a. m. on Monday, August 12 th, 1968.

Among thè enrolled 72 I.B.A. members, 49 attended thè Conference ses-
sions. 45 papers were delivered. Owing to lack of tinte, thè papers of thè
non attending members were considered read, since their abstraets
were distributed to all present members in a folder containing many publi-
cations presented by various Institutions. Their complete texts will be pu-
blished, together with thè texts of thè attending members’ papers, in
thè Conference Proceedings.

The Conference Chairman, Dr. E. Annoscia, opened thè Conference
and welcomed thè I.B.A. members on behalf of AGIP Paleontologists and
Italian Bryozoologists.

The floor was taken by thè I.B.A. Chairman, Dr. A. H. Cheetham, who
thanked Dr. Annoscia for his great efforts and contribution in organizing
thè Conference, helped in this by Dr. P. Ascoli, Conference Secretary.

Dr. Cheetham opened thè First Technical Session and gave thè chair
to Dr. R. Lagaaij, for presiding thè Group 1: The Bryozoa in Oil Research.
Three papers were delivered and discussed in this group.

At thè end of papers of thè Group lst, Dr. Lagaaij gave thè chair to
Dr. I. Vigeland for presiding thè 2nd Group: « Anatomy, Morphology and
Skeletal Structure ». Fourteen papers were presented in this group.

The lst Session was interrupted from 12.30 a. m. until 14.30 p. m. and
ended at 17 p. m.

( :) Conference Secretary, AGIP Direzione Mineraria Paleontological La-
boratory - S. Donato Milanese (Italy).

(::::) IBA Secretary, British Museum (Naturai History) - Zoology De¬
partment - London, U. K.

P. ASCOLI - P. L. COOK

The members then visited thè various AGIP Direz. Mineraria Labora¬
tories (Muds-Cements Lab., Chemical Lab., Geochemical Lab., Petrological
Lab. and Paleontological Lab.), stopping particularly in thè latter and exami-
ning its equipment and collections of Bryozoa and other fossils. They then
attended thè cocktail party offered by thè Mayor of S. Donato Milanese,
which took place in thè lobby near thè lst Skyscraper Conference Hall.
At thè beginning of thè party, Eng. E. Merlini welcomed thè I.B.A. members
on behalf of thè AGIP Direz. Mineraria General Manager and wished them
a most successful Conference.

AUGUST 13. The II Technical Session took place under thè chairman-
ship of Dr. G. Larwood in thè morning as well as in thè afternoon, for thè
Group 3: Ecology and Paleoecologv. Seven papers were presented and
discussed.

Afterwards, thè members attended thè banquet offered by thè AGIP
Direzione Mineraria Management, at thè Restaurant of thè Motel Metanopoli.
At thè end of thè banquet, Eng. E. Merlini, on behalf of thè Management,
told he was most happy to give hospitality to thè I.B.A. members and
expressed to them his most sincere wishes for a very successful Conference.
Answering Eng. Merlini, thè I.B.A. Chairman, Dr. A. H. Cheetham, ex¬
pressed to him and to thè AGIP Direzione Mineraria Management his war-
mest thanks for thè hospitality given by AGIP and for all thè facilities
put at disposai of thè members, which enabled them to earry on thè Con¬
ference works in thè best possible way.

AUGUST 14. The Technical Session III (Group 4: Evolutionary Pat-
terns and Systematics) was held under thè chairmanship of Mr. L. Pitt,
in thè morning in thè Conference Hall of thè E.N.I. First Skyscraper, in
thè afternoon by thè E. Mattei Post-Graduate Hydrocarbons School Public
Hall. Nine papers were presented and discussed in this group.

Around 5 p. ni., thè Conference members went to Milan, where they
\ isited thè Civic Museum of aturai History. They were welcomed by
Prof. C. Conci, Director of thè Museum, who with thè help of his assi-
stants Drr. G. Pinna and C. Leonardi, guided them through thè exhibition
halls of thè various sections of thè Museum. At thè end of their visit,
Prof. Conci offered a cocktail party to thè Conference members.

Al GUST 15. The whole day was taken by thè field trip made to Pos-
sagno and Priabona to examine thè Eocene-Miocene outcrops. There was a
full itinerary in thè morning and thè party was entertained to lunch by thè
Mayor of Possagno. In thè afternoon, visits were made to thè Gallery of
plaster casts and thè Templum by Canova at Possagno, followed by further
examinations of thè outcrops at Priabona. On thè return journey, a short
stop was made at Marostica and at Sirmione on thè Garda Lake, where thè
members enjoyed a picnic. All members were grateful to Dr. G. Braga, from
thè Padua Geological Department, who was in charge of thè field-trip.

Fig\ 1. — Ang. 15, 1968. A group of excursionists sampling tne
Eocene clays at Possagno (Treviso province, Venetia): Tavener-
Smith, Lagaaij, Voigt, Braga, Lafrenz, Brood, Sòderqvist, Rucker,
Ghiurca and Schager are visible from left to right.

(Photo A. Debourle)

Fig. 2. — Aug. 15, 1968. A group of excursionists sampling thè
Eocene marls of Priabona (Vicenza province, Venetia): Lagaaij,
Jebram, Labracherie, Prud’homme and Illies are visible from left

to right.

(Photo A. Debourle)

P. ASCOLI - P. L. COOK

AUGUST 16. This day was mostly dedicated to thè « Business Meeting »,
divided into two sessions . <& Old Business » in thè morning and New

Business » in thè afternoon. Both sessions were presided by thè I.B.A.
Chairman, Dr. A. H. Cheetham, while Miss P. Cook acted as Secretary and
Prof. Y. V. Gautier as interpreter.

At 9.15 a. m. Dr. Cheetham opened thè « Business Meeting », gave a
synopsis of thè agenda and then read thè report of thè Chairman and Se¬
cretary for thè triennium 1965-1968.

The Association was founded at a meeting of 16 paleontologists and
zoologists primarily associated with thè fauna and stratigraphy of thè North
Sea area which took place at invitation of Prof. I. Hessland at Stockholm
University in May, 1965. The University assisted in enabling thè announce-
ment of thè founding of thè Association and its objectives to be sent to 98
Bryozoologists. From thè beginning, membership of thè Association has been
open to all wrorkers on Bryozoa.

Thanks to thè efforts of Dr. E. Annoscia, Prof. T. Perry, Prof. E. Voigt
and Miss E. C. Pope (of thè Australian Museum), other potential members
read published announcements and responded to thè request for a list of
names and adresses of interested workers.

By December 1965 thè list of names totalled 154. It was duplicated with
thè help of thè Smithsonian Institution and thè Louisiana State University
and sent to members with a request for information on research interests,
location of type-specimens and comments on thè feasibility of a conference
in 1968.

The lst International Conference on Bryozoa wras made possible through
thè generosity of thè AGII’ Direzione Mineraria Management, who accepted
to give hospitality to thè Conference and placed their many facilities at
thè disposai of members, and of thè Mayor of S. Donato Milanese, who sup-
plied thè sum to face thè first organization expenses of thè Conference.

At thè end of thè Conference thè num'bers of members had risen to
176, including thè first Honorary Member, Dr. Piero Ascoli, who helped
Dr. Annoscia in organizing thè entire Meeting and in making thè Confe¬
rence successful.

Dr. Schager placed nominations for thè Association Chairman, Prof. Nils
Spjeldnaes, and Secretary, Miss Patricia L. Cook, on behalf of thè Nomi-
nating Committee. There were no nominations from thè floor.

Dr. Cheetham proposed that Prof. Spjeldnaes be Chairman for thè
next triennium of thè I.B.A., seconded by Dr. G. Larwood. Prof. Spjeldnaes
elected by acclamation. That thè position of Secretary continue to be filled
by Miss P. L. Cook, proposed by Dr. R. Tavener Smith, seconded by
Dr. Larwood. Elected unanimously.

Dr. Larwood suggested that thè Chairman of thè Association be hen-
cefoith called thè President, to avoid confusion wTith thè Conference Chairman,
particularly in correspondence. This w^as accepted by thè Chair and by thè
members present.

Dr. Annoscia proposed that thè lst Conference of I.B.A. should be
dedicated to thè memory of thè late Prof. E. Marcus. Accepted unanimously.

CONFERENCE REPORT

He gave also details of thè history of thè arrangements made for publi-
shing thè proceedings of thè Conference. He asked that all papers for in-
clusion be submittd to him by September 15th and reported on thè support
given by thè AGIP Direzione Mineraria Management and thè Mayors of
S. Donato Milanese and Possagno for thè Conference.

Dr. Cheetham thanked Dr. Annoscia for his work and announced that
letters of thanks would be sent to those concerned on behalf of thè Mem-
bers of I.B.A.

Dr. Ryland asked that a vote be taken on thè proposai that a Committee
be formed to study Terminology. Prof. Spjeldnaes suggested that proposals
from members for thè formation of such a Committee should be considered
at thè next Conference.

Dr. R. Tavener Smith asked Dr. R. Boardman for a statement on thè
status of thè Glossaries to be published in thè revision of thè Treatise on
Invertebrate Paleontology. Dr. Boardman stated that thè Treatise revision
is a research endeavour by individuai Authors. Any glossary would therefore
be one of individuai opinion and primarily for terms as used in thè Treatise.
He further considered that we were generations away from enough under-
standing to pioduce a glossary that suggested, consciously or unconsciouslV)
thè fixing of teims. If thè I.B.A. produced a Glossary it would certainly have
authoritative connotations.

Di. T. Schopf suggested that as thè choice and acceptance of terms was
an individuai matter, there was no danger from an authoritative glossary.
Dr. G. Larwood accepted thè possibility of danger, but spoke of thè value
of a Committee considering thè use of terms, particularly those common to
both zoologists and paleontologists. He asked if Dr. Ryland would be willing
to forni an informai investigation group which would report back to thè
I.B.A. Dr. Ryland accepted thè organization of such a group, and stressed
his dependance upon thè co-operation of members.

Dr. Annoscia suggested that thè Glossaries that he and Mrs. J. Prud’
Homme had prepared be made available for any study group to consider
and be made available for a study Committee. He also suggested that one
member of any study group formed should be from thè U.S.S.R.

After considerable further discussion, Prof. Perry suggested that an
informai Committee to discuss 50-100 disputed terms be established, which
would report to thè next Conference and give an estimate of thè size and
scope of a fuller study and thè length of time it would take to produce it.

Dr. Tavener Smith proposed that a study group consisting of Dr. Ry¬
land and other members chosen by thè Chairman institutes a pilot study
on a small number of terms. Seconded by Dr. R. Scolaro. Carried.

Dr. Cheetham gave thè terms of an Advisory Council:

a) to advise thè Chairman on thè time and location of thè next Con¬
ference and on any unforeseen problems, and

b) to provide continuity should any Officer of thè Association stand
down during 1968-1971.

P. ASCOLI - P. L. COOK

The composition of thè Advisory Council was discussed by Prof. Perry,
Dr. Larwood, and Dr. Tavener Smith. It was proposed and accepted to
include Dr. Cheetham in thè Council to ensure continuity and that thè
Council should be proportionally representative in thè sanie manner as thè
Nominating Committee.

Dr. Cheetham suggested that thè new Chairman submit a list of
names after thè closing of thè Conference. This motion carried unanimously.
Dr. Cheetham then asked that thè meeting be closed. Proposed Dr. Rucker,
seconded Dr. Scolaro. Carried.

The meeting closed at 11.23 a. m.

At 5.30 p. m., after thè formai closing of thè Conference, Prof. Spjeld-
naes announced thè names of thè Advisory Council :

Dr. E. Annoscia, Italy (Conference Chairman, 1968).

Prof. G. Astrova U.S.S.R.

Dr. R. Boardman, U.S.A.

Dr. A. Cheetham, U.S.A. (Association Chairman, 1965-1968).

Dr. V. Ghiurca, Rumania.

Dr. R. Lagaaij, The Netherlands.

Dr. G. Larwood, U. K.

Mrs. J. Prud’homme, France.

Dr. S. Sakagami, Japan.

Dr. S. Schager, Sweden.

Prof. E. Voigt, W. Germany.

Additional Members could be chosen (i.e. Conference Chairman and
Secretary) if and when necessary.

Prof. Perry outlined thè probable scope and feasibility of a news-letter
for thè Association. The University of Indiana would be able to provide
secretarmi facilities, but thè question of postage had stili to be investigated.

Prof. Spjeldnaes proposed that thè feelings of thè meeting on thè desi-
rability of a newsletter was indicated by a show of hands. The meeting ap-
proved a newsletter unanimously.

The Meeting closed at 5.45 p. m.

During thè interval between thè two sessions of thè « Business Meeting »,
thè IV Technical Session (Group 5: Biogeography and Biostratigraphy),
under thè chairmanship of Prof. N. Spjeldnaes, was held. Twelve papers
were presented and discussed.

At 6 p. m. thè Conference was officially closed after thè past President
Dr. Cheetham and thè new President Dr. Spjeldnaes and thè whole Assembly
thanked Dr. Annoscia and Dr. Ascoli for having organized thè Conference.

AUGUST 17. In thè morning, about 10 Conference members went to
thè AGIP Direzione Mineraria Paleontological Laboratory, for informally
examining some Bryozoological material at thè microscope and exchanging
ideas about it.

CONFERENCE REPORT

ATTENDING MEMBERS

1. - Dr. Enrico Annoscia - Specialized Paleontologist - AGIP Direzione

Mineraria, Laboratorio Paleontologico, San Donato Milanese (Milan
Italy)

2. - Dr.. Piero Ascoli - Specialized Paleontologist - AGIP Direzione Mine¬

raria, Laboratorio Paleontologico, San Donato Milanese (Milan,
Italy)

3. - Dr. Richard S. Boardman - Curator in Division of Invertebrate Pa-

leontology - Smithsonian Institution, U. S. National Museum, Was¬
hington, D. C. 20560 (U.S.A.)

4. - Dr. Giampiero Braga - Assistant Professor of Paleontology - Istituto

di Geologia e di Paleontologia dell’Università, Via Gotto, 20, Padova
(Italy)

5. - Dr. Krister Brood - Assistant Professor - Geologiska Institutionen,

Universitet i Stockholm, Kungstensgatan 45, Stockholm, Va (Sweden)

6. - Prof. John H. Bushnell - Associate Professor of Biology - Department

of Biology, University of Colorado, Boulder, Colorado 80302 (U.S.A.)

7. - Dr. Alan H. Cheetham - Associate Curator in Division of Inverte¬

brate Paleontology - Smithsonian Institution, U. S. National Museum,
Washington, D. C. 20560 (U.S.A.)

8. - Miss Patricia L. Cook - Senior Experimental Officer in charge of

Recent Bryozoa - British Museum (Naturai History), Zoology De¬
partment, Cromwell Road, London, S.W. 7 (U.K.)

9. - Dr. André Debourle - Geologist - Société Nationale des Pétroles

d’Aquitaine, 5, Rue Bonado, 64 Pau (France)

10. - Dr. Ferdinand D. Flor - Assistant - Geologisches Staatinstitut, Von-

Melle-Park 11, 2000 Hamburg 13 (German Federai Republic)

11. - Prof. Yves V. Gautier - Professor of Cellular and Animai Biology -

College Scientifique Universitaire d’Oran, Fac. des Sciences, Es Senia
B.P. N° 16, Oran (Algeria)

12. - Dr. Virgil Ghiurca - Lecturer of Geology and Paleontology - Catedra

de Geologie-Paleontologie, Universitatea « Babes Bolyai », str. Ko-
gìlniceanu, 1, Cluj (Rumania)

13. - Dr. Reinmar Grimm - Assistant - Zoologisches Staatinstitut und Zoo-

logisches Museum, Von-Melle-Park, 10, 2000 Hamburg 13 (German
Federai Republic)

14. - Dr.. Jean-Georges Harmelin - Oceanographer - Station Marine d’En-

doume et Centre d’Oceanographie, Fac. des Sciences de Marseille,
Rue de la Batterie-des-Lions, Marseille (7e) (France)

P. ASCOLI - P. L. COOK

15. - Mr. Peter J. Hayward - Student in Zoolog’y at University of Reading

- 8, Trinity Court, Trinity Road, London N. 22 (U.K.)

16. - Dr. Gero Hillmer - Assistant - Geologisches Staatinstitut, Von-Melle-

Park, 11, 2000 Hamburg 13 (German Federai Republic)

17. - Mrs. Gisela Illies - Institut fur Geologie der Universitàt - Kaiser-

strasse, 12, 75 Karlsruhe (German Federai Republic)

18. - Mr. Diethardt Jebram - Cand. Rei*. Nat. - Zoologisches Institut der

Universitàt, Hegewischstrasse, 3, 23 Kiel (German Federai Republic)

19.. - Dr. Olgert L. Karklins - Geologist - U. S. Geological Survey, E. 212
U. S. National Museum, Washington, D. C. 20242 (U.S.A.)

20. - Dr. Karl W. Kaufmann - Research Assistant - Marine Science Cen¬

ter, Lehigh University, Bethlehem, Pennsylvania 18015 (U.S.A.)

21. - Miss Monique Labracherie - Research Assistant C.N.R.S.. - Labora-

toire de Géologie, Fac. des Sciences de Bordeaux, 351, Cours de la
Libération, 33 Talence (France)

22. - Dr. Hans R. Lafrenz - Geologist, Curator - Geologisches Staatinstitut,

V on-Melle-P ark, 11, 2000 Hamburg 13 (German Federai Republic)

23. - Dr. Robert Lagaaij - Paleontologist - Bataafse Internationale Petro¬

leum Maatschappij N. V. (BIPM) Carel van Bylandtlaan, 30, ’s-Gra-
venhage (The Netherlands)

24. - Dr. Gilbert Larwood - B. Se., Ph. D., M. A., F. G. S. - Department of

Geology, Science Laboratories, University of Durham, South Road,
Durham (U.K.)

25. - Dr. Frank J. S. Maturo jr. - Associate Professor of Zoology - Depart¬

ment of Biological Sciences, University of Florida, Flint Hall, Gai-
nesyille, 32601 Florida (U.S.A.)

26. - Dr. Noèl Mongereau - Assistant - Faculté des Sciences, Département

des Sciences de la Terre, Université de Lyon, 86, Rue Pasteur, 69
Lyon (7e) (France)

27. - Mr. Osborne B. Nye - Pre-Doctoral Intern - Department of Paleobio-

l°gy> Smithsonian Institution, U. S. National Museum, Washington,
D. C. 20560 (U.S.A.)

28. - Prof. Thomas G. Perry - Professor of Geology - Indiana University.

Department of Geology, Bloomington, Indiana 47405 (U.S.A.)

29. - Mr. Leslie J. Pitt - Amateur - I. Lancaster Road, North Harrow

(Middlesex, U.K.)

30. - Miss Simone Pouyet - Research Assistant C.N.R.S. - Faculté des Scien¬

ces, Départment des Sciences de la Terre, Université de Lyon, 86,
Rue Pasteur, 69 Lyon (7e) (France)

31. - Dr. Neil A. Powell - Curator of Invertebrate Zoology - National Mu¬

seum of Canada, Naturai History Blanch, Ottawa 4 (Ontario,
Canada)

CONFERENCE REPORT

32. - Mrs. Janine Prud’homme - Technical Assistant of Higher Teaching

Laboratoire de Géologie, Fac. des Sciences de Bordeaux, 351, Cours
de la Libération, 33 Talence (France)

33. - Dr. Salvador Reguant - Scientific Assistant C.S.I.C. - Instituto « Jaime

Almera », Catedra de Paleontologia, Universidad de Barcelona
(Spain)

34. - Dr. James B. Rucker - Oceanographer - Director of Laboratory

Branch, U. S. Naval Oceanographic- Office, Washington, D. C. 20390
(U.S.A.)

35. - Dr. John S. Ryland - Leeturer in Zoology - Department of Zoology,

University College of Swansea, Singleton Park, Swansea (Wales, U.K.)

36. - Dr. Sumio Sakagami - Associate Professor, F.G.S.J., F.P.S.J.,

F.S.E.P.M. - Department of Geology, Hokkaido University of Educa-
tion, Hachiman-cho, Hakodate (Japan)

37. - Dr. Sten A. N. Schager - Leeturer, Ph. D. - Geologiska Institutionen,

Universitet i Stockholm, Kungstensgatan 45, Stockholm Va (Sweden)

38. - Dr. Thomas J. M. Schopf - Assistant Professor - Department of

Geological Sciences, Lehigh University Bethlehem, Pennsylvania
18015 (U.S.A.)

39. - Dr. Reginald J. Scolaro - Department of Geology, University of Geor¬

gia, Athens, Georgia 30601 (U.S.A.)

40. - Miss Brigitte Simma-Krieg - Ph. D. - Zoologisches Institut der Uni-

versitàt Wien, Dr. Karl Lueger Ring I, I, A 1010 Wien (Austria)

41. - Mr. Thomas Sòderqvist - Geologiska Institutionen - Universitet i

Stockholm, Kungstensgatan 45, Stockholm Va (Sweden)

42. - Prof. Nils Spjeldnaes - Professor of Chronological Geology - Geolo-

gisk Institut, Aarhus Universitet, 8000, Aarhus (Denmark)

43. - Mr. A. R. D. Stebbing - Department of Zoology, University College

of Swansea, Singleton Park, Swansea (Wales, U. K.)

44. - Dr. Ronald Taverner-Smith - Leeturer in Geology - The Queen’s Uni¬

versity, Department of Geology, Belfast, 7 (N. Ireland, U.K.)

45. - Dr. Antonio Viganò - Assistant Professor - Istituto di Zoologia del¬

l’Università, Via Elee di Sotto, Perugia (Italy)

46. - Prof. Immanuel Vigeland - Research Associate Professor - Zoologica]

Museum, University of Oslo, Sarsgt. 1, Oslo (Norway)

47. - Prof. Ehrhard Voigt - Director of thè Geological Institute, Prof., Dr.,

Dr. h. c., Geologisches Staatinstitut, Von-Melle-Park, 11, 2000, Ham¬
burg, 13 (German Federai Republic)

48. - Dr. Fritz Wiebach - Ph. D., Private Naturalist - Schlossgebiet 15, 232

Plòn (German Federai Republic)

49. - Dr. Bernard Walter - Assistant - Faeulté des Sciences, Département

des Sciences de la Terre, Université de Lyon, 86, Rue Pasteur, 69
Lyon (7e) (France)

P. ASCOLI - P. L. COOK

NON ATTENDING MEMBERS

50. - Prof. Elena Androsova - Research worker - Zoologicheskii Institut

Akademii Nauk S.S.S.R., Leningrad, B/164 (U.S.S.R.)

51. - Prof. Gaiina G. Astrova - Chief of Laboratory - Paleontologicheskii

Institut Akademii Nauk S.S.S.R. Leninskii Prospekt, 33, Moskva
V/71 (U.S.S.R.)

52. - Dr. William C. Banta - University of Southern California, Depart¬

ment of Biology, University Park, Los Angeles, California 90007
(U.S.A.)

53. - Miss Maria M. Barbosa - Geologist Paleontologist - Museu Nacional,

Quinta da Boa Vista, ZC/08, Guanabara, Rio de Janeiro (Brazil)

54. - Prof. Louis David - Chief of « Centre de Paléontologie Stratigraphi-

que » - Université de Lyon, Fac. des Sciences, Département des Scien¬
ces de la Terre, 86, Rue Pasteur, 69, Lyon 7e (France)

55. - Miss N. N. Dunaeva - Geologicheskii Institut Ukrainskoi Akademii

Nauk, Repina, 2, Kiev (U.S.S.R.)

56. - Miss Annie Fey - Collège de France, Laboratoire de Biologie Marine,

Concarneau (Finistère) (France)

57. - Dr. Jean Loup d’Hondt - Muséum National d’Histoire Naturelle, La¬

boratoire de Biologie des Invertébrés Marins, 57, Rue Cuvier, Paris,
5e (France)

58. - Dr. Honnappa - M. Se., F.P.T.C. (Vienna), Lecturer in Geology - Go¬

vernment Arts and Sciences College, 43, lst Main Road, Maruthi
Extension, Srirampuram, Bangalore, 21 (India)

59. - Prof. Tino Lipparini - Ph. D., F.G.S., Chief Geologist, Professor of

Paleontology, Servizio Geologico d’Italia, Largo S. Susanna 13, Roma
(Italy) (until Nov. 1968) or Istituto di Paleontologia dell’Università,
Via delle Cerchia, 5, Siena (Italy)

60. - Miss Geneviève Lutaud - Research Assistant C.N.R.S. - Université de

Paris, Fac. des Sciences, Laboratoire d’Anatomie et d’Histologie Com-
parées, 7, Quai St., Bernard, Paris, 5e (France)

61. - Miss Alice Medioni - Assistant C.N.E.X.O. - Université de Paris,

Biologie Marine, Laboratoire Arago, 66 Banyuls-Sur-Mer (France)

62. - Prof. Iraida P. Morozova - Senior Scientist Worker - Paleontologiche¬

skii Institut Akademii Nauk S.S.S.R,, Leninskii Prospekt, 33, Moskva
V/71 (U.S.S.R.)

63. - Prof. Hugo I. Moyano G. - Universidad de Concepcion - Instituto Cen¬

tral de Biologia, Casilla 1367, Concepcion (Chile)

CONFERENCE REPORT

64. - Prof. Jean Roger - Université de Paris, Fac. des Sciences, Laboratoire

de Paléontologie, Bàtiment 504, 91, Orsay (France)

65. - Prof. June R. P. Ross - Associate Professor in Biology - Western

Washington State College, Dept. of Biology, Bellingham, Washing¬
ton 98225 (U.S.A.)

66. - Mrs. Dorothy F. Soule - Research Associate - Allan Hancock Foun¬

dation, University of Southern, California, Los Angeles, California
90007 (U.S.A.)

67. - Prof. John D. Soule - Professor of Histology - Allan Hancock Foun¬

dation, University of Southern California, Los Angeles, California
90007 (U.S.A.)

68- - Dr. Dante Tedeschi - Paleontologist - Pensione Bella, 17019 Varazzf.
(Genova, Italy)

69. - Miss Mady Thoelen - Universiteit te Leuven, Geologisch Instituut, La-

boratorium voor Stratigraphische Paleontologie en Mikropaleontologie,
St. Michielstraat, 6, Leuven (Belgium)

70. - Dr. Tamara D. Troizkaya - Geologist - Moskva Gosudarstvennii Uni-

versitet, Geologicheskii Facultet, Moskva V.234 (U.S.S.R.)

71. - Miss Lena A. Viskova - Junior Scientist Worker - Paleontologieheskii

Institut Akademii Nauk S.S.S.R., Leninskii Prospekt, 33, Moskva,
V/71 (U.S.S.R.)

72. - Miss Ariadna M. Yaroshinskaya - Obi-Irtishkaya Ekspediziya, Per.

Nakhanovicha, 8, G. Tomsk. 50 (U.S.S.R.)

P. ASCOLI - P. L. COOK

LIST OF

ATTENDING AND NON ATTENDING MEMBERS
ACGORDING TO THE COUNTRIES

Algeria

- Y. V. Gautier

Austria

- B. Simma-Krieg

Belgium

- M. Thoelen

Brazil

- M. M. Barbosa

Canada

- N. A. Powell

Chile

- H. I. Moyano G.

Denmark

- N. Spjeldnaes

Frange

- L. David, A. Debourle, A. Fey, J. G. Harmelin, J. L.
d’Hondt, M. Labracherie, G. Lutaud, A. Medioni, N. Mon-
gereau, S. Pouyet, J. Prud’homme, J. Roger, B. Walter

Germany (West)

- F. Fior, R. Grimm, G. Hillmer, G. Illies, D. Jebram, H. R.
Lafrenz, E. Voigt, F. Wiebach

India

- Honnappa

Italy

- E. Annoscia, P. Ascoli, G. P. Braga, T. Lipparini, D. Te¬
deschi, A. Viganò

Japan

- S. Sakagami

Netherlands

- R. Lagaaij

Norway

- I. Vigeland

Rumania

- V. Ghiurca

Spain

- S. Reguant

SWEDEN

- K. Brood, S. A. N. Schag’er, T. Sòderqvist

United Kingdom

- P. L. Cook, P. J. Hayward, G. Larwood, L. J. Pitt, J. S.
Ryland, A.R.D. Stebbing, R. Tavener Smith

U.S.A.

- W. C. Banta, R. S. Boardman, J. H. Bushnell, A. H. Chee-
tham, 0. L. Karklins, K. W. Kaufmann, F. J. S. Ma¬
turo jr, 0. B. Nye, T. G. Perry, J. R. P. Ross, J. Rucker,
T. J. M. Schopf, R. J. Scolaro, D. E. Soule, J. D. Soule

U.S.S.R.

- E. Androsova, G. G. Astrova, N. N. Dunaeva, I. Moro-
zova, T. D. Troizkaya, L. A. Viskova, A. M. Yaroshinskaya

•J c>

«©

> 3 £S

P. ASCOLI - P. L. COOK

LIST OF

Algeria

Austria

Belgium

Brazil

Canada

Chile

Denmark

France

Germany (West)

India

Italy

Japan

Netherlands

Norway

Rumania

Spain

SWEDEN

United Kingdom

U.S.A.

U.S.S.R.

ATTENDING AND NON ATTENDING MEMBERS
ACCORDING TO THE COUNTRIES

- Y. V. Gautier

- B. Simma-Krieg

- M. Thoelen

- M. M. Barbosa

- N. A. Powell

- H. I. Moyano G.

- N. Spjeldnaes

- L. David, A. Debourle, A. Fey, J. G. Harmelin, J. L.
d’Hondt, M. Labracherie, G. Lutaud, A. Medioni, N. Mon-
gereau, S. Pouyet, J. Prud’homme, J. Roger, B. Walter

- F. Fior, R. Grimm, G. Hillmer, G. Illies, D. Jebram, H. R.
Lafrenz, E. Voigt, F. Wiebach

- Honnappa

- E. Annoscia, P. Ascoli, G. P. Braga, T. Lipparini, D. Te¬
deschi, A. Viganò

- S. Sak agami

- R. Lagaaij

- I. Vigeland

- V. Ghiurca

- S. Reguant

- K. Brood, S. A. N. Scbager, T. Sòderqvist

- P. L. Cook, P. J. Hayward, G. Larwood, L. J. Pitt, J. S.
Ryland, A.R.D. Stebbing, R. Tavener Smith

- W. C. Banta, R. S. Boardman, J. H. Bushnell, A. H. Chee-
tham, 0. L. Karklins, K. W. Kaufmann, F. J. S. Ma¬
turo jr, O. B. Nve, T. G. Perry, J. R. P. Ross, J. Rucker,
T. J. M. Schopf, R. J. Scolaro, D. E. Soule, J. D. Soule

- E. Androsova, G. G. Astrova, N. N. Dunaeva, I. Moro-
zova, T. D. Troizkaya, L. A. Viskova, A. M. Yaroshinskaya

pL. I. _ The Members attendine thè Conference grouped near thè « E. Matte! » Monument in San Donato Milanese.

(Photogr. by « Studio 17, Milan »).

1, Rocker - 2, Basimeli - 3, Labracherie - 4, Sakagami - 5, Prud’homme - 6, Ghmrca - 7, Reguant - 8, Debourle - 9,
Volgi - 10, Lagaaij - 11, Illies - 12, Grimm - 13, Braga - 14, Annoscia - 15, Larwood - 16, Viganò - 17, Lafrenz - 18, Gau-
tier - 19, Nye - 20, Boardman - 21, Scolaro - 22, Tavener-Smith - 23, Jebram - 24, Hillmer - 25, Karklins - 26, Wiebach -

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Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 25 27, 31-XII-1968

j si i.b.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16lh, 1968

1. Group 1 : The Bryozoa in Oil Research.

Enrico Annoscia (*)

PALEONTOLOGICAL AND STRATIGRAPHICAL
RESEARCH CARRIED OUT BY AGIP DIREZIONE
MINERARIA PALEONTOLOGICAL LABORATORY

Riassunto. — L’A. espone brevemente l’attività svolta nel campo della
Paleontologia e della Stratigrafia dal Laboratorio Paleontologico dell’AGIP
Direzione Mineraria negli ultimi quindici anni.

Summary. — A. briefly gives some news about research carried out by
AGIP Direzione Mineraria Paleontologieal Laboratory during thè last fifteen
years in thè field of Paleontology and Stratigraphy.

This report, as announced in thè first program sent to you,
should have been presented to you by Dr. Tedeschi, who was in
charge of thè Paleontologieal Section up to last May. Since
Dr. Tedeschi recentlv left AGIP, I was appointed to substitute
him in this task.

I will briefly illustrate thè activity of thè Paleontologieal Sec¬
tion during thè last 15 years, since thè organization of thè Section
up to 1952 was exhaustively described by Dr. Jaboli in 1952, du¬
ring thè VII National Oil and Gas Congress held in Taormina.

The Paleontologieal Section comprises 18 paleontologists, 5 of
which working at our Laboratories overseas (Persia, Egvpt, Tu¬
nisia and Madagascar).

The activity of thè Section has mostly been devoted to thè
Stratigraphical assistance to wells that AGIP and its associate

(*) AGIP Direzione Mineraria, Servizio Geologico, Laboratorio Paleon¬
tologico San Donato Milanese, Milan, Italy.

E. ANNOSCIA

companies were drilling in Italy and — mostly in thè last years —
abroad, with thè help of Micropaleontology.

In this field thè AGIP Paleontological Laboratory, already
thè most advanced of all in Italy as to thè practical utilization of
Foraminifera in Stratigraphy, published in 1957 an Atlas of Ita-
lian Foraminifera which soon got a world-wide reputation. This
atlas was followed, two years later, by thè atlas of Italian Micro¬
facies, a copy of which is given by AGIP to all Conference mem-
bers. This main activity was afterwards followed by a research
activity devoted to groups of fossils different from Foraminifera
which were commonly used in Italy in thè paleontological and
stratigraphical routine work.

Thus, thè study of Ostracoda, Fusulinids and Paleozoic Me-
gaf'ossils, Mollusca, Brachiopoda, Coelenterata, Graptolithina,
Bryozoa, and finally Algae, Spores, Pollens, Organic Microfossils,
Nannoplankton and Problematica was began by five paleontolo-
gists.

To briefly summarize thè work of such a team within 15
years of extensive work, it is not easy.

All these studies, even occasionally being peculiar to pure re¬
search, never forgot thè main point of our Company which is thè
Oil research. Consequently, thè research was devoted to thè aim of
using also groups of fossils different from traditional Foramini¬
fera in thè practical stratigraphical routine work. Therefore, with
thè help of Mollusca, Brachiopoda, Graptolithina, Bryozoa and
organic Microfossils we were able to resolve some important pro-
blems of chronostratigraphy in North Africa.

Bryozoa were widely applied in thè study of African Miocene
(Libya, Egypt, Nigeria) and in resol ving some stratigraphical
problems of thè Cretaceous from Persian Gulf. Furthermore,
most of Central-Southern Italy shows a typical lithofacies of
Bryozoa limestones belonging to Lower Miocene.

Ostracoda were extensively used in dating and correlating in
Italy, North Africa and Iran, thè Mesozoic, Tertiary and Quater-
nary deposits, particularly those scarce or lacking indicative Fo¬
raminifera.

Mollusca and Algae were many times used for thè Mesozoic,
Tertiary and Quaternary Stratigraphy in Italy, North Africa and
Middle-East.

PALEONTOLOGICAL AND STRATIGRAPHICAL RESEARCH CARRIED ETC.

The Richter-Bernburg method has been recently applied to
a regional study of evaporitic cycles in thè North Sea Zechstein.

The Section got a few months ago an electron microscope,
which enabled us to improve thè techniques on research of organic
Microfossils and calcareous Nannofossils according to thè up-to-
date methods of paleontological investigation.

A study on thè application of mathematical models for resol-
ving some paleontological problems is now under way.

The amount of work carried out by thè Paleontological Labo-
ratory may be expressed by thè following data :

from over 2150 wells drilled from 1953 up to day in Italy
and from around 280 wells drilled abroad within thè same pe-
riod of time, 120.000 thin sections, 12.000 bottom and side well
cores, over half a million cuttings, 800 slides and nearly 50 thin
sections of Bryozoa from Paleozoic to Recent, were studied and
kept in collection, beside ten thousand specimens of Foraminifera,
Mollusca, Ostracoda, Spores, Pollens, Organic Microfossils and
other fossil groups.

The Paleontological Section is equipped with a library of
over 5.000 volumes and 10.000 reprints, among which some rare
books by Soldani, Costa, Janus Plancus, and other classic Authors.

Nearly 80 scientific contributions were published within thè
last 15 years.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 28-30, 31-XII-1968

L'f I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

2. Group 1 : The Bryozoa in Oil Research.

Richard S. Boardman (*)

POTENTIAL USE OF PALEOZOIC BRYOZOA
IN SUBSURFACE EXPLORATION

Riassunto. — Studi preliminari sugli strati produttivi ad olio del Simpson
Gioup dell Oklahoma (Ordoviciano medio) indicano che i Briozoi paleozoici
possono essere facilmente identificati fino alla specie nei detriti di perfo-
ì azione (cuttings) e che essi sono sufficientemente abbondanti da permet-
teie un controllo stratigrafico dettagliato all’ interno della formazione.

L A. ì itiene che risultati altrettanto buoni potrebbero essere ottenuti
per tutto il Paleozoico dell’America settentrionale.

Summary. Preliminary studies from thè oil hearing Simpson Group
(Middle Ordovician) ot Oklahoma, indicate that Paleozoic Bryozoa can be
identified readily to species from subsurface cuttings and that they are
abundant enough to provide detailed stratigraphic control within thè Group.

It is anticipated that comparable results would be obtainable generally
throughout thè Paleozoic of North America.

Lse of Paleozoic Bryozoa in subsurface cores or cuttings
is feasible because of their abundance generally in thè strati-
giaphic- column and thè minute size of zooecia in colonies. To my
knowledge, however, Bryozoa have not been used by industry
in subsurface work for anything more than large scale ecologie
interpretations or as horizon markers in a basin where a par-
ticular bed of Bryozoa happens to have distinctive characteris-
tics. Apparently, advantage has not been taken of more detailed
studies that would employ thè classification or evolutionary
trends of thè phylum. Certainly this lack of detailed use is partly

(*) Smithsonian Institution, U. S. National Museum - Washington D C
20560 USA.

POTENTIAL USE OF PALEOZOIC BRYOZOA ETC. 29

due to thè scarcity of specialists and thè resulting lack of mo¬
dera faunal studies that would support detailed biostratigraphic
application.

What is needed from bryozoolcgists before we can present
a convincing inducement to industry is a substantial number of
bryozoan papers that claim to solve stratigraphic problems.
Preferably they would be based on careful collecting of thin,
superimposed stratigraphic units and a population based taxo-
nomy that attempted to deal with morphologic variation as a
continuum through geologie time. Too many of our existing collec-
tions can not include thè evolutionarv intermediates that permit
thè well doc-umented inferences of evolutionary trends and pat-
terns that might be recognized and followed to advantage in
biostratigraphic application.

One of thè more easily solved problems in subsurface use
of Paleozoic Bryozoa is that of preparation of specimens for
study. Preparation from cores, of course, is comparable to techni-
ques used in surface studies. Preparation from cuttings adds
thè problem of working with small fragments. In most Paleo¬
zoic Bryozoa, study from thin sections or peels is required and
thè present classification is based largelv on internai morpho-
lo gy of individuai rather than growth habits or external appea-
rance of thè colony. To prepare sections of small fragments,
thè specimens can be embedded in a plug of polyester resin. The
plug allows handling of thè fragment so that oriented faces can
be obtained bv either grinding or cutting without breakage.
Thin-bladed saws are available that use up a negligible thick-
ness of thè specimen in making a cut. A well oriented cut gene-
rally allows two oriented faces to be made into thin sections
from even thè smaller fragments. Acetate replicas or dry peels
can be more quickly made and are quite adequate for Identifi¬
cation at all taxonomic levels if thè fauna is well known from
thin section studies.

In Paleozoic Bryozoa, a fragment of several zooecia is gene-
rally all that is required to identify a specimen to genus. Most
bifoliate and rhomboporoid crvptostome colonies have branches
of such small widths that nearly all fragments recovered from
cuttings can be considered potentially identifiable at thè species
level. In thè larger stonv Bryozoa such as thè trepostomes and

RICHARD S. BOARDMAN

fistuliporoids, identification of a ramose or frondose forni to thè
species level generally requires a longitudinal section that spans
thè width of thè endozone and at least one side of thè exozone.

In a short study of subsurface cuttings from thè oil hearing
Simpson group of lower Middle Ordovician age in Southern Ok¬
lahoma, 339 fragments of Bryozoa of all kinds were recovered
from thè 300 foot interval of thè top formation. Thirty percent
of these were too small or too poorly preserved to be identifiable.
Of thè remaining 70%, all were identified to genus, 1/3 of these
were cryptostomes and potentially identifiable to species. The re¬
maining 2/3 were stony Bryozoa and half of these were identi¬
fiable to species. Thus, 2/3 of Bryozoa identifiable at thè generic
level were identifiable at thè species leve! and nearly half of all
fragments recovered were considered identifiable at thè species
level.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 31-36, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

3. Group 1 : The Bryozoa in Oil Research.

Yves V. Gautier (*)

BRYOZOA AS MICROFOSSILS
WHICH MAY BE U3EFUL IN OIL RESEARCH

Riassunto. — L’A., richiamandosi ad uno scritto profetico di S. F. Har-
MER (1930) circa l’utilizzazione dei Briozoi nella ricerca geologica applicata,
espone come tale utilizzazione potrebbe eventualmente essere inquadrata nella
ricerca petrolifera..

L’A. si propone semplicemente di provocare una presa di coscienza col¬
lettiva dell’IBA dinanzi a questa possibilità di applicazione.

Summary. — The Author, referring to a prohetical paper by S. F. Har-
mer (1930) about thè use of Bryozoa in economie geological research, ex-
plains how this use might be introdueed in oil research.

The Author, simply proposes to originate a collective consciousness by
IBA with regard to this possibility.

Résumé. — L’Auteur rappelle un écrit prophétique de S. F. Harmer
(1930) concernant l’utilisation des Bryozoaires dans la recherche géologique
appliquée et expose eomment on pourrait envisager éventuellement cette uti-
lisation dans le cadre de la recherche pétrolière. Il essaie simplement de
provoquer une prise de conscience collective de l’IBA devant cette éven-
tualité.

Dear colleagues and friends, ladies and gentlemen, I do not
intend to teli you a long story sinee : firstly, we are about 50 who
have to speak according to thè newsletter of our Conference
Chairman, Dott. Enrico Annoscia; secondly, if my paper is tao
long, it will tire you and a conference must not be tiring.

I intend only to trv to awake a collective conscience among
us and that is why thè shortest is thè best.

(*) Faculté des Sciences d’Oran - Oran, Algeria.

YVES V. GAUTIER

Thanks to our Association Chairman Alan Cheetham
I knew a title for my paper : « Aspects of paleoecology of
Bryozoa » and thanks to my dear colleague and friend Robert
Lagaaij I got two old texts of d’ORBiGNY & Waters giving data
on ecology of Bryozoa.

It seemed to me that there was no need to add more and
more on this subject. Instead of that, I made up my mind to
draw your attention to thè fact that it would be good to try to
see where we are going on and why, to have a synthetic view
of our actual topics and try to elaborate a common or a « con-
certed action » instead of working each of us alone in his lab ;
that is to say that Bryozoa research may become tomorrow an
applied research, although I know there is no difference between
basic and applied research. There was, in this respect, a prophecy
of thè late Sir Sydney Harmer in 1930 alreadv: « it is evident
that many of thè geological formations are well characterized by
their Polyzoa. It is probable that with increasing knowledge,
this phylum will become more important than at present as a
means of correlating thè age of strata, and that thè assistance
of students of thè group will be more sought in connection with
economie problems in Geology ». I raise thè question why this
prophecy did not until to day tura into realisation.

In November 1953, I attended a Congress in Banyuls sur
mer and was told there by Prof. Bourcart, a marine geologist
of thè Sorbonne now retired, that a scientist of Bordeaux had
worked on fossil Bryozoa for thè applied research department
of thè Standard Oil Company; there is no doubt that what was
done in thè past by a man alone can be done to day by our
Association ; there are so many borings all over thè world that
evervbody would have a lot to do, probably too much.

I was brought to this conclusion because every man, when
he knows you work on Bryozoa, asks « what is their use ? » The
same question is raised by thè committee which give grants or
funds for research and thus you dont get enough money for

Fig’. 1. — This figure shows thè way in whieh fragments of Bryozoa
may be assemblee! in special Chapman slides. Slides of this type are
frequently used in routine-work on Foraminifera. (Fig. taken from

Lagaaij & Gautier 1965).

RECENT

RHÓNE DELTA
STR.606

lat. 48° 8' 15" N
long 2° 7' I2"E
depth 50 metres

RECENT

RHÓNE DELTA
STR.606

lat. 48° 8' 15" N
long 2° 7' I2"E
depth 50 metres

RECENT

RHÓNE DELTA
STR.606

lat. 48° 8' 15" N
long 2° 7' I2"E
depth 50 metres

RECENT

RHÓNE DELTA
STR.606

lat. 48° 8' 15" N
long. 2° 7' 12 "E

depth 50 metre6

RECENT

RHÓNE DELTA
STR.606

lat. 48° 8' 15" N
long 2° 7' I2"E
depth 50 metres

RECENT

RHÓNE DELTA
STR.606

lat. 48° 8' 15" N
long 2° 7' I2"E
depth 50 metres

RECENT

RHÓNE DELTA
STR.606

lat. 48° 8' 15" N
long. 2° 7' 12 "E
depth 50 metres

YVES V. GAUTIER

your work. Instead of that, thè atomic research for example is
drawing much money and in this field you can work. We know
of course that in our « brave new world » thè atom is much
more important that thè « lovely group » (as said thè late Mary
D. Rogick) but actually one is looking at us as to mild dreamers
and that is not good for a scientist because if he is neither
dangerous nor useful one does not take note of him.

Therefore I suggest that. one of our main topics would be
to draw thè attention of thè brain trusts of geological research
and to teli them that a team does exist which is expert in
Bryozoa, knowing that these invertebrates are abundant in many
strafa.

In this respect thè best approach would be made by our
colleagues who work already in thè research departments of
Oil societies, E. Annoscia & R. Lagaaij, resp. of thè AGIP and
thè Royal Dutch Shell. They may bave thè opportunity to show
in thè most appropriate place that Bryozoa will be, if we are
helped, studied in thè future as microfossils useful in oil
research.

First of all, geologists have to record all thè strata where
Brvozoa are available and let it know to thè I.B.A. Then,
every specialist of a considered epoch would have to study thè
lot of Bryozoa with thè usuai check up, by a colleague specia-
lised in thè sanie epoch. By these means, age of strata may be
confirmed when necessary. As one may see in thè figure 2, Bryo¬
zoa may be as abundant as benthonic Foraminifera, Mollusca
and Ostracocla and help then in thè determination of thè age of
a strata and also in thè knowledge of thè ecological conditions
in which thè strata was deposited; as one knowsv Bryozoa are
very sensitive to even light changes of these conditions.

The fact that this meeting is held to day proves quite well
that we are not only thè « gallery of rogues » as said with
humour Anna B. Hastings of thè British Museum but also that
we may constitute an expert team in Bryozoa (we may be both
of course).

Since thè Harmer prophecy and in spite of thè paper we
wrote with R. Lagaaij in 1965 on thè « Bryozoa assembiages of
thè Rhóne delta area » (see figs. 1 & 2) it does not seem that

BRYOZOA AS MICROFOSSILS WHICH MAY BE USEFUL IN OIL RESEARCH 35

Bryozoa have been admitted really as useful microfossils ; yet
recent treatises of Paleontology are dealing with them (see
Buge & Duncan in thè bibliography) but only as to a basic
research group. That is whv we have in thè IBA to show that
they may be used as well as Ostracoda and even, sometimes, as
Foraminifera ; what we have to do is to write a treatise ana-
logous of Ellis & Messina’s treatise on Foraminifera: there is
no doubt that this is our duty and there is good hope that it
will be done in thè next ten years. Thank you very much.

OSTRACODA

BENTHONIC

FORAMINIFERA

BRYOZOA

LUSCA

* f - 50m

<o 100

k 75

k 50

RATE OF DEPOSITION

40 cm/yr

Fig. 2. — This figure shows that, in zones where deposition is sìow,
Bryozoa are almost as abundant as Foraminifera, Ostracoda and
Mollusca. Thus, they may be used in addition to these groups to
determine thè age of undated sfrata or to correlate several sfrata.
(Fig. taken from Lagaaij & Gautier 1965).

YVES V. GAUTIER

REFERENCES

Buge E., 1952 - Bryozoaires - In: Traité de Paléontologie dirigé par J. Pi-
VETEAU, T. 1, pp. 688-749, 142 figs.

Duncan H., 1957 - Bryozoans - In: Treatise on marine ecology and paleo-
cology (Ladd edit.), pp. 783-99, Geol. Soc. of America Meni. n° 67.

Harmer S. F., 1930 - Polyzoa - Presid. address in: Proc. Linn. Soc. London,
Sess. 141, pp. 68-118, pi. 1.

Lagaaij R. & Gautier Y., 1965 - Bryozoan assemblages of thè marine Rhóne
delta area (South France) - In: Micropaleontology, voi. 11, n° 1.
pp. 39-58, 34 figs.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 37-42, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
4. Group 2 : Anatomy, Morphology and Skeletal Structure.

Gero Hillmer (*)

ARTIFICIAL MOULDS

FOR STUDYING THE INTERNAL STRUCTURE
OF PALEONTOLOGICAL OBJECTS

Riassunto. — La complicata struttura interna dei Cheilostomata e dei
Cy ciò stornata e di altri oggetti paleontologici può essere studiata per
mezzo della preparazione di impronte artificiali con poliesteri. Questo ancor
poco conosciuto metodo è basato su un’ impregnazione ed una polimerizza¬
zione dei sedimenti a grana fine negli scheletri calcarei dei fossili. Gli sche¬
letri vengono dissolti per mezzo dell’acido cloridrico e quindi l’ interno del¬
l’organismo rimane in ogni dettaglio come un’ impronta tridimensionale ar¬
tificiale con Poliestere.

Per mezzo di una buona preparazione è possibile fare un’esatta valuta¬
zione dei caratteri interni ed esterni ed avere una migliore conoscenza delle
funzioni degli elementi scheletrici.

Summary. — The complicate interior of cheilostome and cyclostome
Bryozoa and other paleontological objects can be studied by thè preparation
of artificial Polyester-moulds. This only little kno\vn study method is based
on an impregnation and polymerization of thè fine-grained sediments in
calcareous skeletons of fossils. Then thè skeleton will be dissolved by hydroch-
loric acid and thus thè interior of thè organism remains in every detail as
a three-dimensional artificial Polyester-mould.

By a successfull preparation it is possible to make an exact valuation
of thè internai and external characters and a better knowledge about former
functions can be obtained.

Résumé. — On peut étudier la structure interne, souvent compliquée, des
Cheilostomes et des Cyclostomes en coulant des moules internes artificielles
de polyester. Cette méthode peu connue consiste en une imprégnation et po-
lymerisation des squelettes fossiles comblés de sediments meubles suivies

(*) Geologisches Staatsinstitut, Von-Melle-Park 11, Hamburg 13, Ger-
many (West).

G. HILLMER

par un dissolution du squelette calcaire à l’acide c-hlorhydrique. On obtient
de cette facon une image en relief des organes du fossile ainsi que d’autres
éléments du squelette cachés à l’observation directe, comme par exemple les
pseudo-pores, les septules etc. On peut y reconnaìtre aussi facilement le par-
cours des tunnels ramifiés des organismes perforants dans le squelette cal¬
caire.

Le nombre des caractères diagnostiques peut étre agrandi chez plusieurs
fossiles à Laide d’une étude des moules internes artificielles ; la fonction
de plusieurs éléments du squelette peut etre identifieé.

For a long tirne thè various methods of preparation have
been used to comprehend thè complicate internai structure of
bryozoa, foraminifers, ostracodes, and other fossils. Therefore
in some institutes various modifications of study methods were
developed, which I shall not take in consideration here.

To study colonies of bryozoa successfully it is necessary in
most cases to have a three-dimensional aspect of thè interior of
thè colony and their zooecia. This is a prime necessity in arder
to get an exact valuation of thè internai and external characters.
In literature many wrong determinations or oversimplified and
erroneous interpretations show us that only those study methods
can be used which are quantitatively and qualitatively exact and
thus are thè supposition for a satisfactory taxonomy. The hi-
therto used and known preparation methods to study thè anatomy
of bryozoa by means of oriented thin sections or serial sections
resp. cellulose acetate technique are mostly time-consuming. But
in many cases those methods are necessary especially for thè
study of Paleozoic stony and recrystallized Bryozoa — Trepo-
stomata, Crvptostomata, etc.

If we find a more delicate material like mìost of thè Mesozoic
and Cenozoic Bryozoa of Cyclostomata and Cheilostomata then
in most cases fossilization is more favourable for thè preparation
of artificial moulds. Here, however, all other study methods di-
rected to thè internai structure of these organisms have some of
thè following disadvantages :

a) The paleontological object will be destroyed by thè
grinding process. Later on nobody can examine thè drawings of
sections, because only thè last polished section will remain as an
evidence. To obtain this evidence we have to make dry peals or

ARTIFICIAL MOULD FOR STUDYING THE INTERNAL ETC.

replicas, fotos and drawings of every oriented polished sections.
And in spite of this effort we only gei an incomplete three-di-
mensional picture.

b) Another disadvantage is, that thè modification of study
method for serial sections of brachiopods by Siehl (1962) will
take great financial and time-consuming pains. A grinding ma¬
chine especially constructed for this purpose is necessary and
much time will be required in thè preparation of polished sec¬
tions, replicas, fotos, and drawings.

In order to reduce time and material for study thè interior
of little paleontological objects, we only have to remember an
about 100 years old method by Beissel (1860, 1865), who made
artificial moulds of foraminifers and bryozoa. Later, VoiGT (1949,
S. 9) points out thè existence of naturai siìicified moulds from
bryozoa in flint-boulders found in northern Germany. Stimulatecl
by these facts Wiesemann (1960) developed a more modern study
method for thè production of Polyester-moulds and this coulcl be
applied with great success. Thus he obtained many data for thè
description of internai structures of thè genus Beisselina Canu
1913.

We will consider this technique further because only little
is known in literature and beside that our own experience made
an improvement of this technique possible. This study method can
be applied to many other paleontological objects.

Preparation of thè specimens.

The most important supposition for thè preparation of satis-
factory artificial moulds is, that skeletons of fossils are filled
with fine-grained and colloidal sediments such as clay, mari,
chalk etc. If we find carbonate skeletons and sediments in dia-
genetic lithification with cementatimi or recrystallization only thè
well-known preparation and handling of thin sections is prac-
ticable. To obtain artificial moulds we are using thè following
procedure :

1) The fossils mav be obtained by carefully washing thè
sediments. We can clean thè separated specimens very simply and

G. HILLMER

quickly by an Ultra-sonic apparatus. If we don’t possess such
an apparatus we can boil fossils for a short time in H20o solution.

2) Much experience with thè various mixtures of Polyester
have shown that thè greatest problem is thè difficulty to reach a
complete impregnation and a slowly polymerization of thè objects.
This procedure is onlv possible by using a very watery Polyester-
mixture and an exact dose. The following mixture conform to
all requirements :

900 mi Vestopal H (Chemische Werke Hiils AG., Mari, Germany)
750 mi Styrol

4,0 mi Co-accelerator EWM, 1% metal.

For polymerization add to 100 mi of this diaphanous and
very watery mixture 45 drops of Methyl-ethyl-keton-peroxyd
(40% solution). Then thè polymerization process will start. Be-
fore doing so thè paleontological objects are placed in thè oriented
position wanted and covered with thè mixture.

The following impregnation takes place in thè vacuum of an
exsiccator until thè mixture is bubble-free. The impregnation
time depends mainly on thè sediments in thè interior of thè tossii
objects. If it is a silty clay matrix thè impregnation in vacuum
will take nearly 4 hours. Immediately after this procedure thè
objects will be taken out and thè polymerization will be finished
in about 1 or 2 days. An acceleration of polymerization with too
much catalyst and heat must be avoided.

3) After this, cut thè hardened Polyester bloc with a dia-
mond-mounted saw in such way, that thè fossil lies in thè middle
of a few mm large bloc. Now you can cut thè object as it is ne-
cessary for your study and put thè sectional piane of thè fossil
in hydrochloric acid solution. The carbonate skeleton itself, very
seldom impregnated by thè Polyester mixture, can be dissolved
partly or totally as you wish. Mostly it is very useful to start thè
dissolution of thè calcareous specimens by dilute hydrochloric
acid and to watch thè procedure under thè microscope. If impor-
tant parts of thè interior with certain pecuìiar structural features
become visible one can stop thè Chemical action of thè acid at
once.

ARTIFICIAL MOULD FOR STUDYING THE INTERNAL ETC.

4) The interior of thè organism remains in every detail
as an artificial Polyester mould when thè whole calcareous ske¬
leton has been dissolved. Now thè student has an excellent three-
dimensional view of thè interior for thè most minute structural
details become visible and can easily be observed. In addition to
that there is a great advantage in always having an impression
of thè outside of an organism, which can be used as a control.

5) Beside this parts of thè interior of their flexible unit
can be separated bv a fine needle under microscope. For example
a bryozoa can be separated in all of their auto- and kenozooecia.

The above shown technique has been developed and metho-
dically improved in dealing with bryozoa. But certainly it can be
applied to foraminifers, ostracodes, brachiopods, ramifying tunnel
Systems of boring organism or other bore cavities in shells, etc.

In this manner Wiesemann (1960) was able to observe on
moulds of thè genus Beisselina Canu 1913 forni, size and position
of thè zooecia and their peristomia, ooecia, hetero- and keno¬
zooecia, various pore channels etc. Extensive studies of our own
specially on Lower Cretaceous Cyclcstomata have enlarged thè
knowledge of thè structure of thè colony, too. Thus details e.g.
can be made about thè interzooecial pores, pseudopores, gono-
zooecia and thè budding of thè Cyclostomata.

It is possible to make an exact valuation of thè internai and
external character and a better knowledge about former func-
tions can be obtained. Therefore thè prepar ation and study of ar¬
tificial moulds is often necessari) for a more naturai systematic.

REFERENCES

Beissel I., 1860 - Darstellung- kiinstlicher Kieselsteinkerne aus organischen
Kalkschalen - Mber. kgl. preuss. Akad. Wiss. Berlin aus d. Jahre
1859, pp. 685-688, Berlin.

Boardman R. S. & Utgaard J., 1964 - Modifications of Study methods for
paleozoic Bryozoa - Jour. Paleontology, voi. 38, n° 4, pp. 768-770.
Koenig J. W., 1954 - Application of cellulose peel technique to fenestrate
sections - Jour. Paleontology, voi. 16, n° 1, pp. 76-78, Text-Fig*s. 4,
PI. 15..

G. HILLMER

Siehl A., 1962 - Eine verbesserte Methode zur Herstellung von Serienan-
schliffen - Palàont. Z. 36, 3/4, S. 268-274.

VoiGT E., 1949 - Cheilostome Bryozoen aus der Quadratenkreide Nord-west-
deutschlands - Mitt. Geol. Staatsinst. Hamburg, 19, S. 1-49, Taf. 1-11,
Hamburg.

W iesemann G., 1960 - Polyester-Steinkerne der Gattung Beisselina Canu
1913 (Bryoz. foss.) - Mitt. Geol. Staatsinst. Hamburg, 29, S. 101-103,
Taf. 10, Hamburg.

PLATE II.

Multizonopora arborea (Koch e Dunker, 1837).

Fig. 1. — Well preserved zoarium lies in a Polyester bloc. A tangential
polished section was only made and in this peripheral region cal-
careous skeleton has been dissolved by hydrochloric acid. Auto-and
kenozooecia connected by interzooecial pores can be seen as ar-
tificial moulds, X 17; Hauterivian of Schandelah, NW-Germany.
Coll. H. Brandes, Geol. Staatsinst. Hamburg.

Fig. 2. — Peripheral region of another zoarium shows auto- and kenozoecia
with interzooecial pores. Obliquely frontal view; X 25; ibid. Coll.
H. Brandes, Geol. Staatsinst. Hamburg.

Fig. 3. — Lateral view from thè sanie species, shows thè centrai and pe¬
ripheral region; x 25; ibid. Coll. H, Brandes, Geol. Staatsinst.
Hamburg.

Multicrescis tuberosa (Roemer, 1839).

Fig. 4. — Peripheral part of a multilamellar zoarium showing a subcolony
(obliquely polished section) and budding; x 17; Hauterivian of
Schòppenstedt, NW-Germany. Coll. H. Brandes, Geol. Staatsinst.
Hamburg.

Ceriopora spec.

Fig. 5. — Artificial moulds of autozooecia and thè interzooecial pores am-
ong them. A centrai part of thè zoarium was not impregnated
by Polyester, therefore internai structure was partly destroyed
by acid; X 12; Hauterivian of Schòppenstedt, NW-Germany. Coll.
H. Brandes, Geol. Staatsinst. Hamburg.

HILLMER G.

Atti Soc.It.Sc.Nat. e Museo Civ.St.Nat.Milano,Vol.CVIII, Pl. II

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 43-53. 31-XII-1968

lst I.B.A. International Conferenc-e on Bryozoa, S. Donato Milanese. Aug. 12th-16th, 1968
5. Group 2 : Anatomy, Morphology and Skeletal Structure.

Ehrhard Voigt (*)

HOMOEOMORPHY IN CYCLOSTOMATOUS BRYOZOA
AS DEMONSTRATED IN SPIROPORA

(Preliminary Report)

Riassunto. — Uno studio dettagliato del genere Spiropora Lamouroux,
1821 ha rivelato che molte differenti linee filetiche sono unite sotto lo
stesso nome.

Per il gonozooide molto caratteristico di Spiropora elegans Lamouroux
viene proposta la nuova famiglia Spiroporidae.

Le altre specie sono sistemate nelle famiglie Entalophoridae Reuss,
1869 insieme al nuovo genere Spirentalophora (specie tipo Sp. bohemica
n. sp.) e Coelospiropora (specie tipo C. hoelderi n. sp.).

Questo è un tipico esempio di omeomorfia nei Bryozoa Cyclostomata.

Summary. — A detailed study of thè genus Spiropora Lamouroux, 1821
revealed thè fact that several different phylogenetic lineages are united
under this name. Bec-ause of thè very peculiar gonozooid of Spiropora elegans
Lamouroux thè new family Spiroporidae is erected.

Other species are placed in thè Fani. Entalophoridae Reuss, 1869 with
thè new genera Spirentalophora (Type species Sp. bohemica n. sp.) and Coe¬
lospiropora (Type species C. hoelderi n. sp.). All this is an impressive exam-
ple for homoeomorphy in cyclostomatous Bryozoa.

Zusammenfassung, — Eingehende Untersuchungen des Genus Spiropora
Lamouroux, 1821 ergaben, dass unter diesem Namen Gattungen versc-hiedener
phylogenetischer Herkunft zusammengefasst wurden. Auf Grund des sehr
abweichenden Baues des Gonozoids von Spiropora elegans Lamouroux wird
die neue Familie Spiroporidae errichtet. Andere Arten werden zu den neuen
Gattungen Spirentalophora (Typspecies Sp. bohemica n. sp.) und Coelospi¬
ropora (Typspecies C. hoelderi n. sp.) gestellt.

Das behandelte Material bietet ein ausgzeichnetes Beispiel fiir eine
homoeomorphe Entwicklung bei cyclostomen Bryozoen.

(*) Geologisches Staatinstitut, Von-Melle-Park 11. Hamburg 13, West
Germany.

E. VOIGT

One of thè fundamental problems in taxonomy of Bryozoa
is thè discrimination of species in thè Order Cyclostomata be-
cause of thè existence of homoeomorphy. Many Cyclostomata,
especially thè suborder Tubuli?) orina, consisting of simple calca-
reous tubes with circular apertures, do not offer essential specific
characters which allow a clear distinction of species in all cases.
The only criteria which thè student can use are thè size and thè
diameter of thè zooecia and thè apertures as well as thè mode
of growth of thè zoaria. It is difficult to distinguish species on
these criteria alone, using conventional methods. Both criteria
are not Constant, that is they vary with ecologie eonditions ; thus,
measurements from different portions of a single zoarium give
variable results. Because of this many authors have defined
species in a very large sense and therefore such « species » have
a long stratigraphical range. For example Entalophora probos-
cidea (M. Edwards 1838) is assumed to range from thè Jurassic
to thè present time. Canu & Bassler (1922 p. 11) however
already suggested that E. proboscidea may be in fact several
species.

Another example is thè well known « Spiropora verticillata»
(Goldfuss 1826 p. 34 pi. 11 fig. 1) of thè Cretaceous. This species
was assumed by later authors to exist from thè Neocomian to
thè Miocene and Waters (1884 p. 686) thought that thè ordo-
vician Mitoclema cinctosa Ulrich (1882 p. 159 pi. 6 fig. 7, 7a),
which is very similar to thè cretaceous form, should belong to
thè same species. Recent studies of thè present author have
shown clearly that under this name « Spiropora verticillata »
there had been united a number of very different species, p. ex.
Sp. neocomiensis d'Orb., cenomana d’Orb., ligeriensis d’Orb., lae-
vigata d’Orb. and some other forms which are regarded now to
be distinct species or subspecies and belonging tò different ge¬
nera. Some of these species were listed by d’Orbigny (1850-1852)
under different names in his prodrome, but they were united
by him some years later in thè « Paléontologie frangaise » (1851-
1854 p. 710) under thè name « Spiropora antiqua » Def rance.

Indeed it is quite impossible to separate these forms on thè
basis of their morphological features. All offer in generai thè
same morphological aspect, that is they appear as rod-like zoaria
with apertures opening in whorls encircling thè rod. They vary

HOMOEOMORPHY IN CYCLOSTOMATOUS ETC.

in thè diameter of thè stems, distance between whorls and thè
number and size of thè peristomes, but these may vary conside-
rably within thè sanie zoarium and thus are undoubtly controlled
by ecological factors as shall be shown in a thesis by F. Flor
(Hamburg"). It must be emphasized that thousands of measure-
ments made by Flor have provided no satisfactory method for
a separation of species because all data give mostly overlapping
values. The possibility of recognizing that there must be repres-
ented severa] species as well as genera was thè discovery of
several different types of « ovicells » (gonozooids). By this it is
evident that many different species have been lumped under thè
name of « Sp. verticillata », so grouped because of their external
conformity.

The gonozooid of thè cretaceous Spiropora verticillata (Gold-
fuss) (Fig. 1 A) agrees in generai features with thè gonozooid of
thè type species of thè genus « Spiropora » which is Spiropora
elegans Lamouroux (Fig. 1 D) from thè Jurassic. Unfortunately
thè oeciostome of thè latter species is not known and therefore
it is incertain if it can be regarded as congeneric with Spiropora
verticillata.

The gonozooid of that species is a long tube embracing thè
rods in several whorls, in contrast to thè simple long baglike
gonozooid of most other cretaceous Spiropora, which ressemble
that of Entalophora. Because of thè fundamental difference
Spiropora must be regarded as representing a new family
Spiroporidae.

The following results are founded upon more than 200 spe-
cimens with gonozooids and thè oeciostome is Constant enough in
each species to be applied as a very trustworthy criterion to
distinguish different species. This study follows Canu & Bassler
in emphasizing thè importance of gonozooids in understanding
thè systematic relationships of Cyclostomata based upon a very
rich collection of more than 5000 specimens.

The following families and genera are now discussed:

I. Family Entalophoridae Reuss 1869.

Genus Spirentalophora n. g.

Type species : Spirentalophora bohemica n. sp., Cenomanian
Kank, CSSR.

E. VOIGT

Diagnosis : Zoarium ìike Spiropora but with gonozooids res-
sembling that of Entalophora which are well defined in their
outlines. Oeciostome ovai or elliptical, terminal. The gonozooid of
this new genus was discussed and illustrated by Canu & Bassler
1922 ( Mecynoecia ( ?) verticillata Goldf. p. 13 pi. 1 figs 16-17).
This was thè first description of a gonozooid of a cretaceous
« Spiropora ». Their belief that this was a specimen of Sp. verti¬
cillata was erroneous however because this specimen is Sp. lige-
riensis d’Orbigny (1851-1854 pi. 615 figs. 13-15).

Stratigraphical range: Valanginian-Santonian.

Spirentalophora bohemica n. g. n. sp.

Fig. i c.

Holotype: Fig. 1 C, Cenomanian Kank, SE of Praha, CSSR.
Cenomanian, Korycan-beds. U.S. Nat. Museum Washington.

Diagnosis: Slender cyìindrical Spirentalophora with regular
whorls built up by 8-14 peristomes. It differs from thè very
similar Spirentalophora ligeriensis (d’Orbigny) 1850 (d’Orbigny
1851-54 pi. 615 figs 13-15), erroneously included in thè text in
Spiropora antiqua (Def rance) by his convex gonozooid which co-
vers thè distance between 1-2 whorls. It is characterized by his
huge oeciostome considerably exceeding thè peristomes in dia-
meter and which is transverse, salient and surrounded by a thick
rim.

Measurements.

Diameter of zoaria
Diameter of peristomes
Diameter of zooecia
Distance of whorls
Length of gonozooids
Width of gonozooids

0,40 - 1,00 mm
0,15 - 0,25 mm
0,15 - 0,30 mm
0,80 - 1,70 mm
1,70 - 2,50 mm
0,40 - 0,55 mm

Stratigraphical Range: Cenomanian, CSSR.

Remarks : This species was probably included in thè syno-
nymy of « Spiropora verticillata » Goldfuss by thè older authors.
It is possible that thè record of Reuss, Nowàk and PocTA from
Saxony and Bohemia represents this species.

HOMOEOMORPHY IN CYCLOSTOMATOUS ETC.

Genus Coelospiropora n.g.

Type species: Coelospiropora hoelcleri n.g. n.sp. Hauterivian
Switzerland.

Diagnosis : Zoarium like Spiropora but with a hollow median
axis showing transverse calcareous partitions (tabulae). Gono¬
zooid ressembling Spirentalophora but with a very small incon-
spicuous terminal oeciostome.

Coelospiropora hoelderi n.g. n.sp.

Fig. 1 B.

Holotype : Fig. 1 B, Mus. Pai. Institut Ttibingen.

Diagnosis : Same as thè genus.

Measurements.

Diameter of zoaria
Diameter of peristomes
Diameter of zooecia
Distance of whorls
Length of gonozooids
Width of gonozooids

1,00 - 1,60 mm
0,15 - 0,25 mm
0,15 - 0,20 mm
0,90 - 1,60 mm
4,00 - 5,00 mm
1,00 - 1,60 mm

Description : The zoarium is bushy with branches about
1,5 mm thick. Whorls are regular and separated by about 1 mm.

The axial canal is thin, about 1/5-1/6 of thè diameter of thè
branches. The gonozooids are very long narrow sacks usuallv
extending over 2-4 whorls and have a very small inconspicuous
terminal oeciopore without protruding oeciostome.

Onlv one large branched zoarium collected by Prof. H. Hòl-
der (Miinster) is known at present.

Range and Distribution : Hauterivian, Landeron (Switzer¬
land).

II. Family Spiroporidae n. fam.

Type genus : Spiropora Lamouroux 1821, Bathonian-Tha-
netian.

Diagnosis : Zoarium cylindrical, branched, solid, often club-
shaped. Apertures arranged in whorls. The gonozooid is a long
tube, which ascends parallel to thè axis of thè zoarium. At thè
apertura] whorl thè gonozooid mostly divides with two arms of
thè gonozooid extending around thè zoarium thus embracing it,

E. VOIGT

and with a third branch ascending distally to thè next whorl, so
that thè gonozooid may extend over many whorls. One to several
oeciostomes may be observed in a single gonozooid. They are small
transverse eyelike slits without protruding rims located on thè
upper rim of thè gonozooid.

Spiropora Lamouroux 1821.

Tvpe species : Spiropora elegans Lamouroux, 1821, Batho-
nian, France.

Diagnosis : Same as family diagnosis.

Stratigraphic distribution : Bathonian-Thanetian.

Remarks : The first figures of gonozooids of that genus were
given by Voigt (1964 p. 223 pi. 2 figs. 3-5) from thè upper Cre-
taceous Spiropora verticillata (Goldfuss). Unfortunately thè gono¬
zooid of thè tvpe species Spiropora elegans (Fig. 1 D) is incom-
pletely known and shows no oeciostome. Therefore thè possibility
cannot be excluded that thè Cretaceous species of Spiropora with
their very peculiar eyelike oeciostome may represent another
genus than thè type-species.

There is no family in which Spiropora could be placed be-
cause of its very unusual gonozooid. Therefore it is necessary to
erect a new family for it. The description of some new forms
and thè discussion of thè synonymy of Spiropora verticillata
(Goldfuss) given by Gregory (1899 p. 256) must await a later

Fig. 1.

gon. = Gonozooid ; oe. p. = Oeciopore.

A. Spiropora verticillata (Goldfuss).

Ai Frontal view, A2 Lateral view of thè gonozooid;

upper Santonian Hannover; Coll. E. Voigt Nr. 3633.

A3 Sketch of a large gonozooid, Santonian, Vallstedt, Germany. Coll.
E. Voigt Nr. 5345.

B. Coelospiropora hoelderi n. g. n. sp. with gonozooid and cross-section at
right.

Hauterivian Landeron ( Switzerland). Coll. Mus. Pai. Inst. Tubingen.

C. Spirentalophora bohemica n. g. n. sp., with gonozooid.

Cenomanian Kank, CSSR. Coll. U. S. Nat. Mus. Washington Nr. 651292.

D. Spiropora elegans Lamouroux with gonozooid. Di-D3 three different views
of thè same specimen Bathonian. Ranville, Calvados, France. Coll.

E. Voigt.

HOMOEOMORPHY IN CYCLOSTOMATOUS ETC

E. VOIGT

publication. However it must be emphasized that Gregory’s syno-
nymy including several different species, which has been followed
by all subsequent authors, is incorrect. The main range of Spi-
ropora is thè late upper Cretaceous and Paleogene, although thè
first occurrence is proved in thè Jurassic. Post Thanetian records
of Spirop. verticillata must be stili verified by thè finding of
gonozooids.

Measurements of Spiropora verticillata (Goldfuss),

(Fi g. 1 A)

Diameter of zoaria
Diameter of peristomes
Diameter of zooecia
Distance of whorls
Length of gonozooids

0,5 - 1,40 mm
0,50 - 0,20 mm
0,15 - 0,20 mm
0,70 - 1,60 mm
may exceed thè length of
more than seven whorls.

Measurements of Spiropora elegans Lamouroux.

(Fig. 1D)

Diameter of zoaria
Diameter of peristomes
Diameter of zooecia
Distance of whorls
Length of gonozooids

1,10 - 2,00 mm
0,15 - 0,25 mm
0,20 - 0,35 mm
0,80 - 1,50 mm
ca. 3,50 mm

Relation of « Spiropora » to « Entalophora ».

The question often discussed in thè past, whether Spiro¬
pora could be included in Entalophora as cne genus or separated
into two genera is now irrelevant. The problem is not if « Enta¬
lophora » and « Spiropora » should be discerned, because very
often thè whorls in Spiropora become irregular and thè distri-
bution of thè apertures offers thè aspect of an « Entalophora ».
The above evidence shows that a single morphologic type « Spi¬
ropora » or « Entalophora » is in fact thè result of convergent
evolution by several lineages. The problem is further compli-
cated because thè species « Spiropora verticillata » of authors
consists of many different forms which must be regarded on thè
basis of gonozooids as several distinct taxa, not only at thè species

HOMOEOMORPHY IN CYCLOSTOMATOUS ETC.

level but at thè generic and family level as well. The task is
now to discriminate all of these convergent and homoeomorphic
forms by looking for their gonozooids and than to arrange them
in a more naturai System.

General Results.

These investigations have revealed that « Spiropora » is a
zoarial growthform which arose at several times in different
phylogenetic lineages. It is very instructive to see that thè same
« Spiropora- type » of growth was realized already in thè Ordo-
vician by thè genus Mitoclema in thè species M. cinctosa Ulrich
(1882, p. 159, pi. 6, fig. 7 and 7 a). The figures of that species
and those from cretaceous « Spiropora » are de facto indistingui-
shable and Waters (1884, p. 681 and 686) thought M. cinctosa
and Spiropora verticillata should be thè same species. The single
difference seems to be that thè paleozoic forms have not yet pro-
du ce d gonozooids.

Homoeomorphy has made it difficult to differentiate taxa
and to trace phylogenetic lineages in many groups of inverte-
brates (brachiopods, corate etc.). Very often internai structures
as seen in sections have provided criteria with which to solve
some of these problems. In thè case of Spiropora thè different
kinds of gonozooids can be observed only in thè fertile specimens.
The specific or generic differences based upon thè character of
thè gonozooid are by no means manifested either in thè external
or in thè internai morphology of thè specimens. This is one of
thè most impressive examples in Paleontology, illustrating thè
fact that an isolated specimen mav not show all of thè potential
morphologic characters which should develop, even though these
characters may be essential to thè taxonomist’s understanding
of that group, much as thè structure of a flower of a particular
plant cannot be known only from observations of thè leaves of
that plant.

On thè other hand it is quite depressing to admit that wi-
thout thè knowledge of thè gonozooids eie facto many specimens
must be left indeterminable. There is no doubt that this same
problem of homoeomorphy exists in many other groups of Bryo-
zoa and it is a function of our present state of knowledge of thè

E. VOIGT

Spiropora
verticillata GOLDF.

Spirent al oph ora
bohemica n.g.n.sp.

Coelospiropora
hoelderi n.g.n.sp.

Spiropora
elegans LAMOUR

Fig. 2. — A) Diameter of thè zoaria (stems) and B) Distanc-e of

thè whorls.

Spiropora
verticillata GOLDF.

Spirentalophora
bohemica n.g.n.sp.

Coelospiropora
hoelderi n.g.n.sp.

Spiropora
elegans LAMOUR .

0,1 0,2 0,3 0,4 0 0,1 0,2 0,3 0,4 mm

Fig. 3. — A) Variation of thè peristome-diameter and B) Width of
thè zooecia of Spiropora elegans Lamour., Spirentalophora bohemica
n. g. n. sp., Coelospiropora hoelderi n. g n. sp. and Spiropora ver¬
ticillata (Goldf.).

HOMOEOMORPHY IN CYCLOSTOMATOUS ETC.

group. Furthermore it would seem that observation of externa]
characters and thè statistica! treatment of measurements are
not always well adapted for thè differentiation of naturai species
groups (Figs. 2-3).

The present author wishes to thank Mr. F. Flor (Hamburg)
for thè drawings and measurements presented here. Mr. Flor
will collaborate with myself in preparing a more complete treatise
on thè same subject to be published soon. He wishes also to thank

Mr. 0. Nye, Smithsonian Institution (Washington) for reading

over thè manuscript.

REFERE N CES

Bassler R. S., 1953 - Bryozoa - In R. C. Moore, Treatise in Invertebrate
Paleontology. Pt. G. Lawrence, pp. 1-253, 175 figs.

Canu F. & Bassler R. S,, 1920 - North American early Tertiary Bryozoa
- Washington, Smiths. Inst. U. S. Nat. Mus. Bull. 106, pp. 1-879,
pls. 1-162.

Canu F. & Bassler R. S., 1922 - Studies on thè Cyclostomatous Bryozoa -
Washington, Proceed. U. S. Nat. Mus. 61, Art. 22, pp. 1-160, pls. 1-28.

Goldfuss A., 1826-1829 - Petrefacta Germaniae - Bonn, Pt. 1, pp. 1-76,
pls. 1-25.

Gregory J. W., 1899 - Catalogue of thè foss. Bryoz. in thè Dept. of Geo-
logy, Brit. Mus. (Nat. History) - The Cretaceous Bryozoa, 1, London,
pp. 1-457, pls. 1-17.

Orbigny A. D. d’, 1850 - Prodrome de Paléontologie stratigraphique Uni-
verselle - Paris, 1, pp. 1-394.

Orbigny A. D. d’, 1850-1854 - Paléontologie frangaise, Description des ani-
maux invértebrés etc. - Terr. Crét., 5, Bryozoaires - Paris, pp. 1-1191,
pls. 600-800.

Ulrich E. O., 1882 - American Paleozoic Bryozoa - Journ. Cincinnati, Soc.
Nat. Hist. 5, pp. 121-175, 232-257, pls. 6-8, 10-11.

VoiGT E., 1964 - A Bryozoan Fauna of Dano-Montian age from Boryszew
and Sochaczew in centrai Poland - Warszawa, Acta Palaeont. Polon.
IX, 4, pp. 419-498, pls. 1-16.

Waters A. W., 1884 - On fossil cyclostomatous Bryozoa from Australia -
Quart. Journ. Geol. Soc., Novemb. 1884 XL. London, pp. 674-697,
pls. XXX-XXXI.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 54-60. 31-XII-1968

lst I.B.A. International Conferenc-e on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
6. Group 2: Anatomy, Morphology and Skeletal Structure.

Karl W. Kaufmann, Jr. (*)

THE BIOLOGICAL ROLE
OF BUGULA- TYPE AVICULARIA ( BRYOZOA )

(Preliminary Report)

Riassunto. — Il ruolo biologico primario degli avicularia di Bugula
simplex e di B. stolonifera nell’area studiata è quella della difesa contro
due specie di Anfipodi tubicoli - Corophium insidiosum e Jassa falcata -
perchè :

a) gli avicularia sono costruiti per catturare questi Anfipodi meglio
che altri organismi capaci di recare danno alla colonia;

ò) gli Anfipodi arrecano un danno apprezzabile alla colonia, ma sem¬
brano essere efficacemente controllati dagli avicularia.

Summary. — The primary biological role of thè avicularia of Bugula
simplex and B. stolonifera in thè area studied is that of defense against
two species of tube-building amphipod, Corophium insidiosum and Jassa
falcata because:

а) The avicularia are better constructed for catching these amphipods
than any other organism liable to harm thè colony;

б) The amphipods do an appreciable amount of damage to thè colony,
but seem to be effectively controlled by thè avicularia.

Introduction.

Since 1555, approximately 1000 papers have been written
concerning thè ecclogy of ectoprocts (Schopf, 1967), but none of
these has dealt specifically with thè biological role of avicularia.
The most widely accepted theory is that thè avicularia are used

(*) Lehigh University, Marine Science Center - Bethlehem, Pennsyl¬
vania, USA.

THE BIOLOGICA!, ROLE OF BUGULA-TYPE ETC.

for defense (Hincks, 1880, p. LXXIX ; Harmer, 1909, p. 720; 1931,
p. 135; Marcus, 1926, p. C58; Hyman, 1959, p. 330). Harmer
suggested that one of thè biological roles of avicularia is that of
defense against larve of encrusting species, particularly those of
other ectoprocts, but this has not been examined experimentally.
Other theories of thè biological role of avicularia are equally
lacking in evidence to support them. One of thè oldest is that
thè avicularia are used to capture food. This theory has been
discredited by Hincks (1880, p. LXXVII) and others who noted,
among other things, that thè zooids cannot use thè type of food
that thè avicularia catch, nor do they have any means of trans-
ferring it to their mouth. It has also been suggested that thè
avicularia aid in respiratimi, presumably by creating a current to
remove thè water that has passed through thè lophophores (Canu
and Bassler, 1929, p. 360). Canu and Bassler also suggested
that thè avicularia of certain Reteporidae distribute thè prey
among thè colony through thè creation of these same water
currents.

The wide variety of different types of avicularia indicates
that they are specialized to fulfill a variety of different biological
roles which vary from species to species. There has yet to be
presented sufficient evidence to prove conclusively that thè avicu¬
laria of any one species fulfills any of thè above biological roles.
This paper provides support for thè defense theory in thè case of
two species of Bugula through a strutturai analysis of their avi¬
cularia and an ecological study of thè interaction of animals found
on thè colony with thè avicularia.

Methods and Procedure.

The two species chosen for intensive study, Bugula simplex ,
and Bugula stolonifera, both grow in Eel Pond, Woods Hole,
Massachusetts. Eel Pond is a circular, nearly enclosed bay ap-
proximately 300 meters in diameter, and is freely communicable
with thè ocean. There is no freshwater runoff into thè bay, so
thè salinity is thè same as that of thè adjacent sea. All of thè
material used in thè investigation was taken from two tires sus-
pended from floating docks. In addition to observations of live

K. W. KAUFMANN

material, extensive use was made of whole mounts in Lakeside
cement for morphologicaì studies.

Defsnitions.

I have adapted Bock and VON Wahlert’s (1965) definition
of function and biological role to apply specifically to avicularia,
A function of an avicularium is defined as a capability which
thè avicularium is mechanically and physiologically able to per¬
forai. A biological role of an avicularium is a role which thè
avicularium plays in acting on its environment. There may be
more than one function, and some of these functions may aid
it in fulfilling a number of biological roles. I shall define defense
as follows : Avicularia can be said to fulfill a biological role of
defense against an organism if (a) that organism is detrimental
to thè colony and if (b) thè avicularia significantly reduce thè
danger which thè animai poses to thè colony.

Structural anaiysis.

To determine what functions thè avicularia could best per¬
forai, a careful structural anaiysis of thè avicularium was made.
The mechanical advantage that thè muscles have in closing thè
mandible was calculated for varying degrees of opening. The
highest mechanical advantage is obtained when thè mandible is
completely closed (Fig. 1, Position A). This advantage rapidly
diminishes to an almost negligible amount as thè mandible opens
to about 90° (Position C), and remains at this low value for thè
rest of thè range of opening, about 180° (Position D). The maxi¬
mum tension that may be developed in an isometric contraction
of thè adductor muscles at different extensions may vary consi-
derably. However, thè difference in mechanical advantage bet-
ween positions completely closed and half-way open (Position C)
means that thè avicularium can hold objects of a small diameter
(less than .1 mm) with a much firmer grasp than larger objects.
The purpose of thè spike on thè end of thè mandible is not to
puncture, but during closing, to more rapidly reduce thè gap

THE BIOLOGICA!, ROLE OF BUGULA-TYPE ETC.

• ) i

between thè mandible and thè rostrum and thus prevent thè
escape of thè prey.

The mean distance between adjacent avicularia on a single
branch is .55 mm for B. simplex and .37 mm for B. stolonifera.
An organism smaller than or even equal in length to these di-
mensions would not be caught nearly so often as an organism
longer than 1 mm that could span several avicularia at thè same
time. The largest organism that was observed to be captured and
held for a moderate length of time (three minutes) was a gam-

Fig. 1. — Sagittal section of avicularium of Bugula simplex with
schematic representation of thè adductor muscles and tendon. The
mandible is shown in four different positions. At position B, thè
mechanical advantage is half that of position A. At positions C
and D, thè mechanical advantage is almost negligible.

K. W. KAUFMANN

marid amphipod 3 mm long, not including thè long antennae.
Animals with many appendages were observed to be caught far
more often than those of similar size and abundance but with
few appendages, such as nematodes. The many small hairy ap¬
pendages increase thè probability that part of thè animai will
come in contact with an avicularium and provide objects of a
small enough diameter that thè avicularia can hold with suf-
ficient force. The avicularia are best able to catch and hold or-
ganisms from 1 to 3 mm long and with many appendages of
small diameter.

Ecological observations.

There are two generai classes of organisms that avicularia
supposedly defend against predators and larvae : especially larvae
of their own kind. No predators were found in Eel Pond that
satisfied thè definition of defense. Hyman (1959, p. 432) and
Marcus (1926, n. C46) list a number of known predators, but
most of them (fish, echinoids, holothurians, prosobranchs, nudi-
branchs) are too large to be effectively hindered bv avicularia.
Observations of smaller animals (amphipods, nematodes, cope-
pods, flatworms) on thè colonies under consideration yielded no
evidence of any of them preving on Ectoprocts. Pycnogonids
have been described as predators of Ectoprocts, but they were
verv rarely seen on thè colonies and could not, therefore, be
considered to do a significar^ amount of damage to thè colonies
in question. Thus, in this particular case, defense against pre¬
dators cannot be said to be a biological role of thè avicularia.
Larvae of both B. simplex and B. stolonìfera are .1 to .2 mm
in diameter and have no appendages or long hairs. Similarly,
thè larvae of other animals found in Eel Pond are either smaller
than thè average distance between avicularia or have few easily
grasped appendages or hairs. Thus, thè avicularia studied are
poorlv suited for capturing larvae.

The animals that were found to best fit thè terms of thè
definition of defense were thè gammarid amphipods, Corophium
insidiosum and Jassa falcata. Both of these amphipods were
present in large numbers and built tubes of detritus and fecal

THE BIOLOGICAL ROLE OF BUGULA-TYPE ETC. 59

pellets among thè colonies. These tubes prevented nearby auto-
zooids from feeding by clogging up thè proximal parts of thè
colonies. The avicularia, however, effectively limited tube buil¬
ding by grabbing amphipods that wandered among thè branches
and holding them for varying amounts of time (minutes to
hours). The size of thè amphipods ranged from a minimum of
.5 mm up to 5 mm. They had many small appendages, making
it easy for thè avicularia to grab and hold them. 51% were in
thè optimum size range of 1-3 mm.

Conclusion.

Because thè two species of amphipods fit thè terms of thè
definition both in being a threat to thè colony and in being
effectively controlled by thè avicularia, and because thè avicu¬
laria are better designed to capture them than any other orga¬
nismi on thè colony, thè primary biological role of thè avicularia
of Bugula simplex and B. stolonifera in Eel Pond is that of
defense against C. insidiosum and J. falcata. The wiclespread
distribution of both tube-building organisms and species with
Bugula- type avicularia make it probable that this is not a unique
relationship.

Acknowledgements.

Dr. Thomas J. M. Schopf, Department of Geological Sciences and Marine
Science Center, Lehigh University, suggested thè study and provided f man¬
dai assistance through NSF grant GB-7325. Dr. Schopf ’s encouragement is
greatly appreciated. Dr. F. J. S. Maturo, Jr. identified B. stolonifera.
Mr. Allan Michael, Dalhousie University, identified thè amphipods. The
work was carried out at thè Marine Biological Laboratory, Woods Hole,
Massachusetts Contribution number 59 of thè Marine Science Center, Lehigh
University.

This extended abstract merely summarizes thè results and line of reaso-
ning of a paper now being prepared.

K. W. KAUFMANN

REFERENCES

Bock W. J. & von Wahlert G., 1965 - Adaptation and thè form-function
complex - Evolution, 19: 269-299.

Canu F. & Bassler R. S., 1920 - North American early Tertiary Bryozoa -
Smithsonian Inst. U. S. Nat. Mus. Bull. no. 106., Washington D. C.,
pp. i-x, 1-879, pls. 1-162.

Canu F. & Bassler R. S., 1929 - Bryozoa of thè Philippine region - Smith¬
sonian Inst. U. S. Nat. Mus. Bull. 100, voi. 9, Washington, D. C.,
pp. i-xi, 1-685, pls. 1-94.

Harmer S. F., 1909 - Address to thè zoological section - Brit. Assoc. Adv.
Sci. Rep. 78th meeting (1908, Dublin), pp. 715-731.

Harmer S. F.. 1931 - Recent work on Polyzoa, Presidential Address - Proc.
Linn. Soc. London 1930-1931, sess. 143, pp. 113-168.

Hincks T., 1880 - A history of thè British marine Polyzoa, voi. I - John
van Voorst, London; pp. i-cxli, 1-601.

Hyman L. H., 1959 - The Invertebrates, voi. V - McGraw-Hill Book Company
Ine., New York; pp. 1-783.

Marcus E., 1926 - Bryozoa - In G. Grimpe and E. Wagler (eds.), Die Tierwelt
der Nord- und Ostsee, Teil VII, pp. C 1 - C 100.

Schopf T. J. M., 1967 - The literature of thè phylum Ectoprocta: 1555-1963 -
Syst. Zool. 16 (4), pp. 318-327.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 61-63. 31-XII-1968

lst I.B.A. International Conferenc-e on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
7. Group 2: Anatomy, Morphology and Skeletal Structure.

Natalie N. Dunaeva (*)

ON THE MODE OF SEXUAL REPRODUCTION
OF SOME TREPOSTOMATOUS BRYOZOA

(Preliminary Report)

Riassunto. — L’abbondanza di cisti negli zooecia di molte colonie di
Aisenvergia cylindrica Dunaeva e di T 7 olnovachia distincta Dunaeva, pro¬
venienti dal Carbonifero inferiore del Bacino del Donetz, viene considerata
come una prima indicazione del modo di riproduzione sessuale nei Treposto-
mata.

Summary. — The abundance of cysts in thè zooecia of many colonies of
Aisenvergia cylindrica Dunaeva and V olnovachia distincta Dunaeva from
thè Lower Carboniferous of Donetz Basin is considered as a slight indication
of thè mode of sexual reproduction by T repost ornata.

In thè sfrata of thè Lower Carboniferous of Donetz basin
occur some peculiar bryozoans — Aisenvergia cylindrica Dun.,
V olnovachia distincta Dun. — , referred to a new family Aisen-
vergiidae Dunaeva (Dunaeva, 1964). The main feature of these
bryozoans are thè sygmoidally curving of zooecial walls and thè
dose compression of thè zooecial cavities in exozone which in thè
most exciting structure of g. Aisenvergia result in forming a cy-
lindrical wall between endozone and exozone.

Apart from this unique inner structure thè Aisenvergìidae
from Donetz basin proved to be verv interesting in some other
ways.

(*) Akademiya Nauk Ukrainskoi S.S.R., Institut Geologicheskikh Nauk,
Kiev (G.), Ukraine S.S.R.

N. N. DUNAEVA

Many colonies of both genera possess small sphaerical to ir-
regulary globular hollow bodies in zooecia. These bodies were
observed more than in 160 thin-sections in different number —
sometimes isolated, sometimes very numerous (fig. 1). In thè last
case they are often constricted. The bodies are about 30-80 tu in
diameter and have definite walls consisting usually of two la-
yers — thè inner dark and thin, and thè outer more thick, light
and laminated. According to their position and size thè sphae¬
rical bodies look like eggs in thè zooecia of some living Bryozoa
( Electra pilosa, Membranipora membranacea).

Similar bodies, though never in such abundance, were men-
tioned in some Trepostomatous bryozoans by R. S. Bassler
(Bassler, 1911) and R. S. Boardman (Boardman, 1960) as cysts.

Fig- 1- — V olnovachia distincta Dunaeva. Transverse section show-
ing many cysts in thè zooecia. ( x 60)

Donetz Basin, Lower Carboniferous, Zone Ci at.

ON THE MODE OF SEXUAL REPRODUCTION ETC. 63

No definite explanation was given about thè nature of these for-
mations.

The unusual abundance and position of thè cysts in thè
zooecia of Aisenvergiidae cause thè assumption of their connec¬
tion with thè reproductive functions of colonies. This is confirmed
by thè faci that all thè specimens of both species were collected
in a small place (less than 20 m-) in thè same layer of limestone
and most likely represent thè colonies from thè same population
which grew simultaneously and were suddenìy buried in thè stage
of sexual reproduction.

According to thè investigations on recent Bryozoa (Harmer,
Borg, Silén) thè sexual reproduction of these animals may go
on different ways. Two main types of sexual reproduction may
be indicated by thè recent Bryozoa of order C beilo stornata, Cte-
nostomata and Cy do stornata: 1) thè ova develop in special brood-
chambers (gonozooecia or ovicella); 2) thè ova develop in thè sur-
rounding water where they are evacuated from thè body cavity
through thè intertentacular organ or through thè genital pore.

The ways of sexual reproduction of extinct Bryozoa (order
T r epo stornata, Cystoporata and Cryptost ornata) are almost quite
unknown. Some analogies with thè brood-chambers were noticed
in some genera of Cryptostomata (by genera Polypora and Fe-
nestella). No evidence of ovicella are indicated up to day in
Trepostomata.

The observations discussed above may serve as a slight in-
dication of thè mode of sexual reproduction of these extinct
Bryozoa (at least of thè group of them belonging to thè family
A is env ergiìdae ) .

REFERENCES

Bassler R. S., 1911 - The early Paleozoic Bryozoa of thè Baltic Provinces
- U. S, Nat. Mus. Bull., 77.

Boardman R. S., 1960 - Trepostomatous Bryozoa of thè Hamilton Group of
New York State - Geol. Surv. Prof. Paper, 340.

Dunaeva N. N., 1964 - Novye mshanki otrjada Trepostomata iz nisznego
karbona Donezkogo baseina - Paleontolog. jurn., N. 2.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 64-70. 31-XII-1968

ist I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
8. Group 2: Anatomv, Morphology and Skeletal Struc-ture.

Gero Hillmer (*)

ON THE VARIATION OF GONOZOOECIA
OF ENCRUSTING « BERENICE A »-FORMS
(LOWER CRETACEOUS) ( BRYOZOA )

(Preliminary Report) (**)

Riassunto. — Vengono studiati su colonie incrostanti di forme del gruppo
« B erenicea » (Hauteriviano della Germania settentrionale) la variazione e
il valore tassonomico dei gonozooecia.

Il rapporto tra l’accrescimento dei gonozooecia e degli zooecia vicini è
secondo Canu & Bassler (1920, 1922) un criterio sistematico di primaria im¬
portanza per le famiglie Diaperoeciidae Canu, 1918, Plagioeciidae Canu,
1918 e Oncousoeciidae Canu, 1918.

Osservazioni morfologiche e sezioni lucide seriate praticate attraverso
i gonozooecia hanno mostrato che questo rapporto negli accrescimenti non
è un buon criterio sistematico per definire una famiglia.

Le famiglie Diaperoecidae, Plagioeciidae e Oncousoeciidae dovranno es¬
sere invalidate allorquando un nuovo concetto sistematico sarà elaborato.

Summary. — Variation and taxonomic value of gonozooecia of encrusting
colonies of thè « Berenicea »-form-group are studied. The classification of
Canu (1918, 1919) and Canu & Bassler (1920, 1922) are discussed. The
investigations show, that these authors have depended too much on thè
character of gonozooecia. In encrusting « Berenicea » colonies thè gonozooecia
are not a distinguishing family character. We must reject thè families
Diaperoeciidae Canu, 1918, Plagioeciidae Canu, 1918 and Oncousoeciidae
Canu, 1918, if we can establish a more naturai systematic concept based on
more exact defined taxonomic characters. We can realize this only by mono-
graphic investigations of exactly encircled smaller groups of forms.

(*) Geologisches Staatsinstitut - Hamburg, Germany (W.).

(**) The final paper will be published in thè Review: « Palàontologische
Zeitsc-hrif t » .

ON THE VARIATION OF GONOZOOECIA OF ENCRUSTING ETC.

Résumé. — La variation et la valeur systematique des gonozoécies ont
été étudiés sur des colonies encroutantes de « Berenicea » ( Hauteriviens de
l’Allemagne du Nord). Le rapport entre la croissance des gonozoécies et des
zoécies voisines est d’aprés Canu (1918) et Canu & Bassler (1920, 1922)
un critère systematique de premier ordre pour la famille des Diaperoeciidae
Canu 1918, Plagioeciidae Canu 1918 et Oncousoeciidae Canu 1918.

Des observations morphologiques et des polissages en sèrie à travers les
gonozoécies ont montré que ce rapport de croissance n’est pas un bon critère

systematique pour définir une famille.

Les familles Diaperoeciidae, Plagioeciidae et Oncousoeciidae devront ètre
rejetes dés qu’un nouveau concepte systématique sera élaboré.

During my studies of thè Lower Cretaceous cyclostomatous
Bryozoa from some classic localities of North Germany (Schan-
delah, Schoppenstedt, Berklingen, Gr. Vahlberg and Achim) — a
complete revision of these Bryozoa is in preparation — I had oc-
casion to study many different specimens with gonozooecia. In
this report I only will discuss thè variation and thè systematic-
taxonomic value of gonozooecia of encrusting colonies of thè Be¬
renicea form-group.

My effort aimed at testing thè classification of Canu (1918,
1919) and Canu & Bassler (1920, 1922) of this group and we
will see, that thè gonozooecium of some « Berenicea »-forms is
not a very trust-worthy and Constant character. These results are
in contrary to thè investigations of homoeomorph specimens of
thè « Spiropora-group » by E. Voigt (1968), who demonstrated
in this form-group, that we cannot separate these growth forms
on thè basis of their conventional morphological features but only
on thè different types of their gonozooecia. By means of volumi-
nous fossil material Voigt could demonstrate, that shape, size and
developement of thè gonozooecia and thè ooeciostome referred to
thè ooeciopore is Constant enough in each species to be applied
as a very trustworthy criterion to distinguisi! different specimens.
In this case he followed thè systematic concept of Canu & Bass¬
ler, which is mostly based on thè character of thè gonozooecium.

We know that thè principles of classification following zoarial
characters and gonozooecia are overlapping and that this is thè
main reason of thè partly very unnatural systematics.

G. HILLMER

Canu & Bassler (1920) wrote, that a more naturai syste-
matics should mainly be based on thè fact, « that thè distinction
between thè families of Cyclostomata, like thè other orders of
Bryozoa, is or should be based on their larvai forms, each family
beeing characterized by a special larva. The larvae of thè Cyclo¬
stomata are very similar to each other and difficult to discrimi¬
nate, but fortunately they show their differences by thè evolu-
tion of thè embryos in ovicells of very different size, shape and
position ».

According to this, only size, shape and position of thè gono¬
zooecia are thè main characters for a separation of specimens.
In spite of thè zoological criticism of Borg (1936) many cyclo-
stomatous families — like Diaperoeciidae Canu 1918, Plagioecii-
clae Canu 1918 and Oncousoeciidae Canu 1918, — are based only
on this character.

There is no discussion, that quite generally in some cyclo-
stomatous families thè zoarial characters show much more varia-
bility as thè gonozooecia or zoarial brood-chambers and their
ooeciostomes, which are by fact thè most Constant characters. But
in special groups thè brood-chambers, however, vary so much,
that it is impossible to establish a classification by using only
this distinguishing character.

Canu & Bassler have discriminated and described a large
number of different types of brood-chambers, which often differ
only very slightly from one another as for example in some « Be-
renicea » -forms. Thus, for instance, thè families Diaperoeciidae,
Plagioeciidae and Oncousoeciidae are separated according to thè
shape and thè position of thè gonozooecium and thè time relation
between thè growth of thè gonozooecium and zooecial tubes. These
are thè most import ant characters for thè diagnoses.

Species of « Berenicea » preserving gonozooecia are referred
to severa! distinct genera and families. Some of them belong to
thè genus Plagioecia but others to Diaperoecia or Oncousoecia.

Colonies without brood-chambers belong futhermore to thè
genus Berenicea Lamouroux, 1821, because thè type species Be¬
renicea prominens has no gonozooecium.

Canu, 1918, gave thè following family diagnosis, which are
accepted in thè Treatise (1953), of which I will briefely give thè
first-class character:

ON THE VARIATION OF GONOZOOECIA OF ENCRUSTING ETC. (>7

a. The globular or transverse sac-like gonozooecium of thè
family Diaperoeciidae is formed after thè calcification of thè
distai tubes and therefore is placed among many tubes which
Project without disarrangement on thè gonozooecium itself.

b. The gonozooecium of thè family Plagioecìiclae is formed
before thè calcification of thè neighboring tubes, thè formation
of which it hinders. The longitudinal axis of thè brood-chambers
is perpendicular to thè zooecial tubes.

c. The gonozooecium of thè family Oncousoeciidae is pa-
rallel to that of thè tubes and is developed at thè same time as
thè adjacent zooecia, which are not disarranged in their respec-
tive positi on.

A great number of morphological very different colonies are
united in these families. The reason is, that students quite gene-
rally believe that thè mcrphology of thè brood-chamber and thè
arrangement of thè zooecia in relation to it shows thè systematic
relationships of these cyclostomatous species better than thè very
variable zoarial growth form. As we know it is quite right for
some groups, but it is not a trustworthy criterion for others.

Thus, for instando, thè seemingly well known ‘ÌDiaperoecia
polystoma (Roemer, 1839).

I had thè occasion to study thè type-species Cellepora poly¬
stoma Roemer, 1839 and many conspecific colonies with gono-
zooecia.

Canu & Bassler, 1922, referred these colonies with brood-
chambers in thè family Diaperoeciidae , because thè gonozooecium
is formed after thè calcification of thè surrounding tubes. Con-
trary to this meaning, my material of this species from thè type-
locality Schoppenstedt, NW-Germany, must increase thè confu-
sion, because some colonies show a gonozooecium of thè Plagioe-
cia- type, others of thè Diaperoecia- type. In this relation a very
grotesque example is, that we can recognize in one and thè same
encrusting colony two very different types of gonozooecia. This
could give rise to thè very unnatural separation of one part of
this colony to thè family Diaperoeciidae and thè other part to
thè family Plagioeciidae.

G. HILLMER

Thus, mv material gene-rally shows, that size and shape of
thè gonozooecia varying considerably from an elliptical transver¬
sai sac to a heart-shaped extension. They are also more or less
convex. The mostly terminal situated oeciostome is small and less
than thè zooecial diameter and adjacent to a zooecial aperture.

The oeciopore is mostly orbicular; only in two cases it is a
little more elliptical. The time relation between thè growth of thè
gonozooecium and thè neighboring zooecia shows also great va-
riation. At several gonozooecia we can recognize, that some tubes
Project through thè centrai and peripheral region of thè brood-
chamber.

According to thè systematic concept this finding shows, that
thè gonozooecia developed after thè calcification of thè tubes. In
contrary to that, we can see, that other gonozooecia are not tra-
versed by thè tubes and therefore they must have developed be-
fore thè calcification of thè surrounding zooecia. Thus, just study-
ing thè morphology we can observe, that thè gonozooecia of ex-
actly conspecific specimens from thè same locality with very si-
milar ecologie conditions vary in size and form and developed
not only before but also after thè calcification of thè surround¬
ing tubes. Thus, we could arrange some colonies in thè family
Plagioeciidae and others in Diaperoeciidae. The colonies without
gonozooecium we have to unite under thè zoarial genus Berenicea
Lamouroux.

We can examine thè character of time relation between thè
growth of thè brood-chamber and thè surrounding zooecial tubes
also by means of serial sections. The preparation of gonozooecia
where no tubes traversed thè roof of brood-chamber shows, that
thè development of gonozooecia and surrounding tubes occurred
nearly at thè same time and differences are mostly based on eco¬
logie factors.

Results.

The results of my observations of encrusting colonies of thè
« Berenicea » form-group show us, that Canu and Bassler have
depended too much on a single character. Gonozooecia surround¬
ing peristomes or not, exist to a more or less extent in many other

ON THE VARIATION OF GONOZOOECIA OF ENCRUSTING ETC.

f>9

genera and it is not a distinguishing family character. The de-
velopment of gonozooecia and surrounding zooecial tubes occurred
nearly at thè same time. Shape and size of thè gonozooecium can
show also great variation. Till now I was disappointed in my
hope, that thè gonozooecia show severa] tvpes of oeciopores
which may eventually result in thè separation of these forms. All
brood-chambers of encrusting « Berenicea » forms which I have
seen, usually show, isolated terminal and ± median oeciostomes
situated verv near to a peristome in a directly continuation of thè
fertile zooecium. There exists only little variation in thè shape of
thè oeciopore, which is mostly round and only sometimes a little
elliptical. But we can hope, that more observations in tossii ma¬
terial will confirm thè zoological statement of Osbìtrn (1953,
S. 616), that thè position and form of thè oeciopores and their
oeciostomes are fairly Constant and usuable for exact determi-
nation.

These results demonstrate, that we must reject thè families
Diaperoeciidae, Plagioeciìdae and Oncousoeciidae, if we can es-
tablish a more naturai systematic concept based on more exact
defined taxonomic characters. This finding exists for some other
cyclostomatous families, too. In my opinion we have to work out
a new systematics for thè Order Cy do stornata mostly indepen-
dent from thè old one. We can realize this only by monographic
investigations of exactly encircled smaller groups of forms.

REFERENCES

Borg F 1926 - Studies on Recent Cyclostomatous Bryozoa - Zool. Bidr.

Uppsala, 10, pp. 181-507, Figs. 1-109, Pls. 1-14, Uppsala.

Bassler R. S., 1953 - Bryozoa - In: Treatise Invertebr. Paleont. (edit.

R. C, Moore), Part G, pp. GI-G 253, 175 Figs., Lawrence.

Canu F., 1918 - Les ovicelles des Bryozoaires cyclostomes. Études sur quelques
families nouvelles et anciennes - Bull. Soc. Géol. France (4), 16
pp. 324-335, Paris.

Canu F., 1919 - Études sur les ovicelles des Bryozoaires cyclostomes (2e con-
tribution). Ibid. (4), 17, pp. 345-347, Paris.

Canu F. & Bassler R. S., 1920 - North American Early Bryozoa - Smiths
Inst. U. S. Nat. Mus., Bull. 106, 879 pp., 279 Figs., 162 Pls., Washington.

G. HILLMER

Canu F. & Bassler R. S., 1922 - Studies on thè Cyclostomatous Bryozoa -
Proc. U. S. Nat. Mus., 61, Art. 22, pp. 1-160, Pls. 1-28, Washington.

Canu F. & Bassler R. S., 1926 - Studies on thè Cyclostomatous Bryozoa -
Proc. U. S. Nat. Mus., 67, Art. 21, pp. 1-93, Pls. 1-31, Washington.

Gregory J. W., 1909 - Catalogue of thè tossii Bryozoa in thè Dept. of Geo-
logy, British Museum, London - The Cretaceous Bryozoa - Voi. I
I-XIVa, 1-457, 1899; Voi. II, I-XLVIIa, 1-346, London.

Roemer F. A., 1839 - Die Versteinerungen des Norddeutschen Oolithen-
gebirges - Nachtrag: pp. 1-59, Pls. 1-5, Hannover.

VoiGT E., 1968 - Homoeomorphy in Cyclostomatus Bryozoa as demonstrated
in Spiropora - (Preliminary report) Proceed. 1 st. IBA Intera. Conf.
Bryozoa, S. Donato M. 1968, in Atti Soc. It. Se. Nat. & Mus. Civ.
St. Nat. Milano, pp. 43-53, Figs. 1-3, Milan.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 71-74. 31-XII-1968

lst I.B.A. International Conferenee on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
9. Group 2: Anatomy, Morphologv and Skeletal Structure.

Gisela Illies (*)

ON THE GONOZOOECIUM OF
COLLAPORA STRAMINEA (Phillips)

( Bryozoa Cyclostomata)

Riassunto. — Collapora straminea (Phill.), un Cyclostomata eretto, ap¬
pare nel Bajociano medio della Regione dell’Alto Reno (strati a Briozoi).
I suoi gonozooecia, sconosciuti finora, vengono qui descritti e illustrati.

Summary. — Collapora straminea (Phill.), an erect Cyclostome, appears in
thè Middle Bajocian of thè Upper Rhine Region, forming so-called Bryozoa
Beds. Its gonozooecium, which was unknown till now, shall be described.

Zusammenfassung. — Collapora straminea (Phill.), eine freiwachsende
cyclostome Bryozoe, tritt im mittleren Bajocium des Oberrheingebietes
gesteinsbildend auf. Das bisher unbekannte Gonozooecium dieser Art wird
beschrieben.

In 1925 Deuss described a Bryozoa Bed within thè Bajocian
strata of south western Germany. The layer is intercalated in
marly succession containing thè guide ammonite Otoites sauzei
d’ORB. The form described here was collected on thè « Galgen-
berg » (height 313,7 m) near Niederrimsingen W Freiburg i. Br.

According to Deuss (1925, p. 13) thè Bryozoa Bed consists
of colonies of Pustulopora quenstedti Waagen, which is equalized
(p. 66) with Millepora straminea Phill.

(*) Geologisches Institut der Universitàt - Karlsruhe, Germany (W).

G. ILLIES

Collapora straminea (Phillips, 1829)

(PI. Ili, fig. 1-6)

Synonymy :

Millepora straminea Phillips 1829, 2nd. ed. 1835, pp. 115, 121,
pi. IX, fig. 1.

Pustulopora quenstedti Waagen 1867, p. 641, pi. 32, fig. 10.
Cricopora acutimargo Waagen 1867, p. 641, pi. 33, fig. 7.
Collapora straminea (Phill.) Quenstedt 1881, pp. 223-225, pi. 151,
figs. 49-56.

Haplooecia straminea , (Phill.) Gregory 1896, pp. 159-161, text
figs. 11-12.

Haplooecia straminea (Phill.) Canu & Bassler 1922, p. 97, text
fig. 25, pi. 14, figs. 14-15.

Collapora straminea (Phill.) Walter 1967, p. 45, pi. 11, fig. 13.

The erect colonies contain numerous gonozooecia. The visible
part of a gonozooecium is many times longer than thè visible
part of a zooecium and its width is stili more than thè doublé
cune of a zooecium (pi. Ili, figs. 1-5). The gonozooecium is narro-
wing towards thè distai oeciopore, until its width is about thè
same of a normal peristome, and forms an oeciostome. The frontal
piane of thè gonozooecium is flattened or slightly arched. It is
possible that thè gonozooecia are budding like thè zooecia as a
very small and thin tube within thè centre of thè round stems.

The tube of thè zooecium is widening in diameter thè more
it comes to thè frontal layer (corresponding to thè zooecial regions
situated more or less along a radiai line of thè coneshaped gro-
wing zone at thè end of thè stem). Thereby thè zooecial tube will
be displaced by several younger generations of zooecia from thè
centre to thè frontal piane. Therefore thè length of thè non-visible
part of thè tube is essentially longer than that of thè visible part.
The origin of a zooecium could not be ascertained precisely till
now. The proximal part is very small.

Some observations lead to thè assumption that thè non-visible
parts of gonozooecia and zooecia do not differ at all from each
other. (1) There is no indication of a growing gonozooecium
within a stem’s cross section, situated proximal to its visible part.

ON THE GONOZOOECIU M OF COLLAPORA STRAMINEA (PHILLIPS) 7,‘}

(2) Injured gonozooecia show thè equivalence of thè inner tube
of gonozooecia and zooecia at thè transition from thè inner to thè
outer region.

Within thè frontal layer thè gonozooecium is overgrowing
thè distai zooecia. Some of those overgrown zooecia will not be
able any more to reach thè frontal piane. The zooecia growing
laterally beside thè gonozooecium are mostly undisturbed. Small
differently shaped frontal walls without peristomes will not often
be observed.

Dimensions at thè frontal piane. Gonozooecia: (a) Length
1.4-3. 2 mm, (b) maximal width 0.45-0.85 mm, (c) depth (rectan-
gular to (a) and (b)) 0.15-0.20 mm. Width of thè ellipsoidal oecio-
pore 0.10-0.30 mm. Zooecia (situated beside thè gonozooecia):
(a) Length 0.40-0.70 mm, (b) width 0.20-0.30 mm. Peristome’s
width 0.14-0.20 mm.

The same or at least very similar stems of Bryozoa with
equiformed gonozooecia were collected, too, from thè Upper Aale-
nian and thè Upper Bajocian of thè same region.

REFERE N CES

Canu F. & Bassler R. S., 1922 - Studies on thè Cyclostomatous Bryozoa -
Proceedings of thè United States National Museum. 61 (22), pp. 1-160,
pls. 1-28. Washington.

Deuss F., 1925 - Der untere Dogger am westl. Schwarzwaldrand - Ber. Na-
turf. Ges. Freiburg i. Br., XXV, pp. 1-86, pls. 1-4.

Gregory J. W., 1896 - The Jurassic Bryozoa - Catalogue of thè tossii Bryozoa
in thè Dept. of Geology, British Museum, London. 239 p., 22 text.
figs., pi. 1-11.

Phillips J. 1835 - Illustrations of thè Geology of Yorkshire or a description
of thè sfrata and organic remains. Part. I, The Yorkshire coast -
London, 2nd. ed. (lst. ed. 1829), pp. I-XII, 1-184, pls. I-XIV, maps.

Quenstedt F. A., 1881 - Petrefactenkunde Deutschlands. VI. Korallen -
Leipzig, pp. 1-1093. Atlas pls. 143-184.

Waagen W., 1867 - tìber die Zone des Ammonites Soiverbyi - Geogn.-Palàont
Beitr. Dr. E. W. Benecke 1868, Mùnchen, I ( III), pp. 507-668, pls. 32, 33

Walter B., 1967 - Révision de la fauna de bryozoaires du Bajocien superieur
de Shipton Gorge (Dorset, Grande-Bretagne) - Trav. Lab. Géol. Fac.
Sci. Lyon, N.S. no. 14, pp. 43-52, pls. 10-11.

EXPLANATION OF PLATE III

Figs. 1-2. — Collapora straminea (Phill.) 1829. Gonozooecium with one
oeciostome. Middle Bajocian, zone of Otoites sauzei d’ORB., Gal-
genberg near Niederrimsingen W Freiburg i. Br., Germany.
Fig. 1 x 12, fig. 2, thè sanie gonozooecium x 25. Collection
G. Illies N° Kl.

Fig. 3. — Collapora straminea (Phill.) 1829. Gonozooecium with one
oeciostome. Middle Bajocian, zone of Otoites sauzei d’ORB., Gal-
genberg near Niederrimsingen W Freiburg i. Br., Germany.
X 12.. Collection G. Illies N° K2.

Figs. 4-5. — Collapora straminea (Phill.) 1829. Type specimen of Cricopora
acutimargo Waagen, 1867 (in Benecke, 1868, I (III) ), p. 641,
pi. 33, fig. 7 a-b., Lower Bajocian, zone of Sonninia so-
werbyi Mill., Gingen, Wiirttemberg, Germany. Figs. 4, 5 each
stem with one injured gonozooecium, about X 12. Bayer.
Staatssammlung f. Palàontol. u. hist. Geol., Munchen. N° AS
XXII 26.

Fig. 6. — Collapora straminea (Phill.) 1829. Type specimen of Pustulo-
pora quensteclti Waagen, 1867 (in Benecke, 1868, I (III), p. 641,
pi. 32, figs. 10 a-b., Lower Bajocian, zone of Sonninia sowerbyi
Mill., Gingen, Wiirttemberg, Germany, about X 12. Bayer.
Staatssammlung f. Palàontol. u. hist. Geol., Munchen. N° AS
XXII 18.

ILLIES G

Atti Soc. It. Se. Nat. e Museo Civ.St.Nat.Milano,Vol.CVIII,

Pl. Ili

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 75 -76. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16'h, 1968
10. Group 2 : Anatomv, Morphology and Skeletal Struct.

Brigitte Simma-Krieg (*)

ON VARIATION AND SPECIAL REPRODUCTION HABITS
OF AETEA SICA (Couch) ( BRYOZOA )

(Preliminary Report) (**)

Riassunto. — L’A. ha presentato un rapporto preliminare del suo studio
che è diviso in quattro parti: 1. habitus; 2. tipi di variazione; 3. modo di
riproduzione; 4. conclusioni.

L’inusitata e grande capacità di variazione di Aetea sica (Couch) è
stata divisa in quattro tipi, tre dei quali possono essere distinti l’uno dal¬
l’altro da speciali formazioni chiamate «sacculi» (prodotti della riprodu¬
zione asessuale).

Dopo aver riferito sulle possibili modificazioni di Aetea sica, l’A. af¬
fronta la questione della posizione deg’li Inovicellata nei Gymnolaemata.

Summary. — This study deals with four points. The habitus of Aetea
sica (Couch), thè types of variation, thè reproduction habits, and a discus-
sion of questions arising from these observations.

The habitus of A. sica was defined by thè usuai qualitative and quan¬
titative criteria. Examination of numerous colonies showed that four types
of variation occur.

Three of thè types of zooidal varieties developed different asexual
reproduction produets, called sacculi, for thè forms associated with zooidal
types A and B, and apparently consisting of free autozooids for type C.
The sacculi and thè autozooids can be homologized, and their origin and
development can be compared. The variation of thè zooids appears to be
related to thè type of substratum.

(*) I. Zoologisches Institut der Universitàt, Wien, Austria.

(**) The final paper will be published in: Cahier s de Biologie
Marine.

B. SIMMA-KRIEG

Zusammenfassung. — Die vorlieg’ende Arbeit behandelt vier Punkte. Den
Habitus der Aetea sica (Couch), die Variationstypen, die Reproduktions-
formen und eine Diskussion von Fragen, welehe aus den vorangegangenen
Beobachtungen resultieren.

Der Habitus der Aetea sica wurde durch die gebràuchlichen qualitativen
und quantitativen Kriterien definiert. Eine Prufung zahlreicher Kolonien
zeigte, dass vier Variationstypen vorkommen.

Drei der vier Typen der zooidalen Varianten entwickelten verschiedene
asexuelle Reproduktionsprodukte, welehe fiir die Formen die mit den zoo¬
idalen Typen A und B korreliert sind, Sacculi genaannt werden und fiir
den Typus C aus freien Autozooiden bestehen. Die Saceuli und die Auto-
zoide des Typus C kònnen homologisiert werden und ihr Ursprung und
ihre Entwicklung kann verglichen werden. Die Variation der Zooide scheint
mit dem Substratypus in Beziehung zu stehen.

The study presented deals with four points. I. The habitus,
II. thè types of variation, III. thè reproduction habits of Aetea
sica (Couch) and IV. a discussion.

As to I., thè habitus of Aetea sica was defined by thè so far
usuai criteria, which comprise qualitative and quantitative fea-
tures. Concerning point II., it was found, after examination ot
numerous colonies of thè species, that they show four types ot
variation, which coincide only partly with thè known qualitative,
but not with thè quantitative features. Furthermore it was out-
lined that also within one colony, representing a special type,
thè rate of variation of thè quantitative features was very high.

Point III. thè reproduction habit, stated, that three of thè
four types of variation, develope different reproduction produets,
which can be homologized. Fot each of these formations, which
were named « sacculi » for thè type A and B and consist of an
autozoid free, and not attached with its basai part, for type C,
it was shown A. thè habitus, B. thè possible positions in relation
to a colony and C. summarising, origin, development and ma-
turitv of a colony and its ways of reproduction by thè sacculi
A and B and thè free autozooid, type C.

The hypothetical stages for thè free type C correspond with
veritable stages of thè sacculi type A and B.

The discussion which follows as point IV., deals with, A. thè
assumption thè sacculi constitute asexual reproduction produets,
B. thè question after thè species Aetea sica and possible site
modifications as well a C. thè position of thè Inovicellata in thè
System of thè Gy muoia e mata.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 77-84. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
11. Group 2: Anatomy, Morphology and Skeletal Structure.

Olgerts L. Karklins (*)

ZOOECIAL BOUNDARY PATTERNS
IN THE MIDDLE ORDOVICIAN GENERA
OF THE FAMILIES RHIN1DICTYIDAE ,
STICTOPORELLIDAE AND PTILODICTYIDAE

( Bryozoa )

Riassunto. — Un nuovo metodo viene usato nell’ interpretazione delle
strutture zoariali dei Cryptostomata. Esso mette in risalto le scure zone
confinarie e la loro sistemazione in Stictopora Hall e in alcune specie di
Stictoporella Ulrich e di Pachydictya Ulrich. Stictopora è caratterizzato dal¬
l’avere gli zoaria a disposizione lineare in cui gli zooecia adiacenti sono sepa¬
rati per mezzo di « range boundaries » lateralmente e per mezzo di « zooecia!
boundaries » longitudinalmente.

In Stictoporella angularis Ulrich gli « zooecial boundaries » sono poligo¬
nali in sezione tangenziale ; gli zooecia non sono in file distinte e i « range
boundaries » mancano. In Pachydictya f oliata Ulrich gli « zooecial bounda¬
ries » descrivono una forma cilindrica nell’esozona e sono approssimativa¬
mente ovali in sezione tangenziale. Le pareti tra gli zooecia adiacenti nel¬
l’esozona contengono numerose zone scure, ma non vi sono « range bounda¬
ries ». Pachydictya acuta (Hall) è caratterizzata dall’avere «range parti-
tions » nell’esozona che si estendono per tutto lo zoarium tra zooecia allineati
longitudinalmente e sono quasi ad angolo retto con la superficie zoariale.
Gli « zooecial boundaries » sono come quelli di P. f oliata ma i « range boun¬
daries », simili a quelli di Stictopora , sono sistemati lungo la mezzeria delle
« range partitions ». La mancanza di « boundary pattern » nell’esozona è ca¬
ratteristica in Escharopora Hall e Graptodictya Ulrich, che mostrano diffe¬
renze nella configurazione delle laminae parietali zoeciali. (Translation into
Italian from thè Author’s English summary by. E. Annoscia. Since thè
terms « zooecial boundary », « range boundary », and so on are new and
bave not yet equivalent terms in Italian, thè translator preferred to use
thè originai English terms in inverted commas).

(*) Publication authorized by thè Director, U. S. Geological Survey -
Washington D. C., USA.

0. L. KARKLINS

Summary. A new approach is used in thè interpretation of cryptostome
zoarial structures that emphasizes thè dark boundary zones and their spatial
arrangement in Stictopora Hall and in some species of StictoporeUa Ulrich
and Pachydictya Ulrich. Stictopora is characterized by having zoaria with
approximately linear ranges in which adjacent zooecia are separated by
« range boundaries » laterally and by « zooecial boundaries » longitudinally.
In StictoporeUa angularis Ulrich thè « zooecial boundaries » are polygonal in
tangential views; zooecia are not in distinct alignment and thè range boun¬
daries are lacking. In Pachydictya l'oliata Ulrich thè « zooecial boundaries »
describe a cylindrical forni in thè exozone and are approximately ovai in tan¬
gential views. The walls between adjacent zooecia in thè exozone may contain
numerous dark zones, but there are no « range boundaries ». Pachydictya
acuta (Hall) is characterized by having «range partitions » in thè exozone
that extend throughout zoaria between longitudinally aligned zooecia and are
about at right angle to zoarial surface. The « zooecial boundaries » are like
those in P. f oliata but thè « range boundaries », similar to those in Stictopora,
are located along thè middle of thè «range partitions». Lac-k of «boundary
pattern » in thè exozone is distinctive in E scharopora Hall and Graptodictya
Ulrich which show differences in thè configuration of thè zooecial wall
laminae.

Zusammenfassjjng. — Ein neuer Einstellungsversuch ist angewendet fùr
die Darstelìung der allgemeinen Zoariumstrukturen der cryptostome Bryo-
zoen. Diese Darstelìung hebt die dunklen Grenzen und ihre ràumliche Anord-
nung innerhalb der Gattung Stictopora Hall und bei manchen Arten der
Gattung StictoporeUa Ulrich und Pachydictya Ulrich hervor. Die Zooecien
stehen bei Stictopora ungefàhr in regelmàssigen Làngsreihen. Diese Zooecien
sind seitlich durch die Grenzen der Langsreihen und der Lànge nach durch
die Grenzen der Zooecien abgetrennt. Bei StictoporeUa angularis Ulrich sind
die Grenzen der Zooecien vieleckig; die Zooecien befinden sich nicht in regel¬
màssigen Reihen und es fehlen die Grenzen der Langsreihen. Bei Pachydictya
t'oliata Ulrich werden die Grenzen der Zooecien in der verdickten Skeletzone
rohrenfòrmig und ungefàhr ovai innerhalb des Tangentialschnittes. Die
Wànde zwischen den Zooecien in der verdickten Skeletzone konnen gelegen-
tlich zahlreiche dunkle, unregelmàssige, kurze grenzartige Ziige erhalten,
aber es fehlen die Grenzen der Làngsreihen. Bei Pachydictya acuta (Hall)
sind die Làngsreihen der Zooecien in der verdickten Skeletzone des Zoarium
durch Scheidewànde abgetrennt. Diese Scheidewànde erstrecken sich durch
die Zoarien und sind ungefàhr rechtwinklig zu dessen Oberflàche orientiert.
Die Grenzen der Zooecien sind dieselben wie in Pachydictya t'oliata, und die
Grenzen der Làngsreihen sind àhnlich wie bei Stictopora, aber sie befinden
sich in der Mitte, entiang der Scheidewand. Bei den Gattungen Escharopora
Hall und Graptodictya Ulrich fehlt ein deutliches Muster der Grenzen in
der verdickten Skeletzone. Diese Gattungen unterscheiden sich hinsichtlich
der Gestaltung der Zooeciumlaminae in der verdickten Skeletzone.

ZOOECIAL BOUNDARY PATTERN S ETC.

A study of thè Middle Ordovician genera of thè families
Rhinidictyidae Ulrich 1895, Stictoporellidae Nickles and Bassler
1900, and Ptilodictyidae Zittel 1880 indicates that there are se-
veral problems in thè interpretation of thè zoarial and zooecial
wall structures. In order to solve these problems a new approach
is used in which I have emphasized dark boundary zones and their
spatial arrangement in zoaria as distinct morphological features
in Stictopora Hall 1847, and in some species of Pachydictya Ul¬
rich 1882 and Stictoporella Ulrich 1882 or lack of them in Escha-
ropora Hall 1847, and Graptodictya Ulrich 1882.

The dark boundary zones are formed by abutting or adjoi-
ning zooecial laminae and, when present, they outline zooecia or
other structural elements in zoaria. In thin sections thè bounda-
ries appear as dark lines representing thè edge views of planar
to curved boundary zones between zooecia that extend for diffe-
rent lengths throughout zoaria. These dark boundaries, when
viewed in three dimensions, separate thè laminate zoaria into
well-defined segments. Some of thè boundaries are associated with
thè individuai zooecia but thè others are zoarial features. These
two kinds of boundaries taken together indicate a pattern of zoa¬
rial secretion which appears common to more than one genus in
a family. Therefore I found that thè boundary zones are useful
in describing and regrouping thè different genera.

Four distinct zooecial boundary patterns and two different
configurations of laminae in thè zooecial walls are described
briefly. These structural features in zoaria together with other
morphological features not discussed here are useful in grouping
of genera and may result in revision of thè concepts on which thè
definitions of thè cryptostome families are based. The diverse
boundary patterns appear to show evolutionary trends, for exam-
ple in Pachydictya , and thus have a potential value in stratigra-
phic work.

In Stictopora, for example, S. nicholsoni (Ulrich) 1882 from
thè Tyrone Limestone, Kentucky, and S. mutabilis Ulrich 1886
from thè Decorah Shale, Minnesota, U.S.A., and in related genera
having zoaria with approximately linear zooecial ranges, thè
zoarial structure is characterized by two boundary zones. Both
boundaries are similar in structure and begin at thè mesotheca,
but they differ in their relationships to thè zooecia of a zoarium.

0. L. KARKLINS

One of these boundaries is located between thè longitudinally
adjacent zooecia and it is here named thè « zooecial boundary ».
The other boundary separates thè laterally adjacent zooecia and
is continuous throughout thè entire length of a zoarial branch.
This boundary demarcates thè zooecial ranges and therefore it is
here named thè « range boundary ». Both boundaries commonly
carry short, rodlike structures which begin in thè inner exozone.
These structures are here described as thè murai tubuli (orai com-
munication, R. S. Boardman, 1966). The two sets of thè bounda¬
ries form a distinct pattern that characterizes Stictopora, Phyllo-
dictya Ulrich 1882, Ptilotrypa Ulrich 1890, and probably Eury-
dictya Ulrich 1890 and Dicranopora Ulrich 1882.

Another pattern of zooecial boundaries is shown in several
Stictoporella species such as S. angularis Ulrich 1886 from thè
Decorah Shale, Minnesota, and S. frondifera Ulrich 1886 from
thè Decorah Shale, Minnesota, Iowa, and Wisconsin, U. S. A.
In these species thè dark zooecial boundaries are polygonal in tan-
gental view and are readily discernible in longitudinal and trans¬
verse views showing thè walls in thè exozone.

In comparing thè boundary zone pattern in Stictoporella an¬
gularis and in other related species with that in Stictopora, thè
following differences are noted. In Stictoporella angularis thè
zooecia are not aligned in distinct ranges as are those in Sticto¬
pora species. Consequently, there are no range boundaries in
S. angularis. The zooecial boundaries divide thè walls between
adjacent cavities into two parts that are approximately equal in
Stictoporella angularis, but not in Stictopora in which thè zooecial
boundaries are within thè upper part of thè walls between thè
longitudinally adjacent zooecia. Thus each zooid secretes on each
side of itself about an equal quantity of calcite in Stictoporella
angularis. In Stictopora, however, a larger amount of calcite is
secreted distally and laterally than proximally. Furthermore, thè
zooecial boundaries appear to be approximately hexagonal or po¬
lygonal in Stictoporella angularis whereas in Stictopora thè zoo¬
ecial boundaries are crescent shaped, convex proximally. There
are no murai tubuli in zooecial boundaries of Stictoporella angu¬
laris and thè lack of thè range boundaries was already noted.
The species of these genera differ also in thè generai appearance

ZOOECIAL BOUNDARY PATTERN S ETC.

of thè zooecial wall laminae ; in Stictopora thè laminae are poorly
defined whereas in Stictoporella they are distinct.

The zoaria of species discussed above show well-developed
boundary zones separating thè laminate structural segments. For
purposes of comparison it might be appropriate to note here that
in another large group of thè cryptostome bifoliates thè zooecial
walls between adjacent cavities are constructed by apparently con-
tinuous and well-defined laminae. However, thè boundary zones
in thè exozone zooecial walls have not been observed in this group
of genera. In generai, thè pattern of thè wall laminae and thè
lack of thè boundaries seems to distinguisi! thè genera of this
broad group. The configuration of thè wall laminae in section is
generally sinuous. In Escharopora subrecta (Ulrich) 1886 from
thè Decorah Shale, Minnesota, U.S.A., thè laminae of thè walls
are approximately M-shaped with broad crests as observed in
transverse views. In Graptodictya simplex (Ulrich) 1886, also
from thè Decorah Shale in Minnesota, thè curves of thè laminae
are more V-shaped and commonly form three pointed crests bet¬
ween adjacent cavities. On thè zoarial surface these crests may
appear as slightly raised flexuous ridges. The wall structures in
Escharopora and Graptodictya have been redescribed by Ross
(Phillips, 1960, p. 17, 19; Ross, 1960, p. 859; 1964, p. 941) in
greater detail.

Several zooecial boundary patterns are observed among thè
many species that are currently assigned to Pachydictya Ulrich
1882. Two of these boundary patterns, both of which differ from
that shown in thè type of thè genus, Pachydictya robusta Ulrich
1882 (Phillips, 1960, p. 14) from thè Middle Ordovician strata
of Tennessee, U.S.A., are briefly discussed below.

In Pachydictya f oliata Ulrich 1886, from thè Decorah Shale
of Minnesota, U.S.A., thè zooecial boundaries are constructed si-
milarly to those in Stictopora and Stictoporella angularis, but thè
zoarial arrangement is fundamentally different. Unlike Sticto¬
pora, thè zooecial boundaries in P. follata describe a cylindrical
form in exozone and appear approximately ovai in tangential
view ; they enclose thè zooecial cavities and a part of thè adjoining
wall. There are no range boundaries in P. f oliata, because thè
zooecia are not aligned in distinct ranges. The zooecial boundaries
begin at thè mesotheca and are characteristically indistinct in thè

0. L. KARKLINS

QO
o n

endozone. At thè base of thè exozone thè proximal segments of
thè boundaries curve and together with thè distai part of thè
sanie boundary form a cylinder in thè exozone. The part of thè
zooecial wall between thè cavity and thè boundary consists of
indistinct, gently curving laminae. At thè zooecial boundary these
laminae abut or adjoin with those that form thè part of thè walls
between thè boundaries. The latter cannot be associated with any
individuai zooecium but appear to be secreted by thè adjacent
zooids of a zoarium. The laminae in thè common tissue are broadly
curved and are convex to thè zoarial surface. The laminae bet¬
ween thè boundaries contain dark, thin, intermittent zones that
are approximately perpendicular to thè zoarial surface and that
trend in thè generai direction of thè zoarial growth. Because of
this trend thè zones are most observable in thè transverse views
in which thè piane of thè thin section cut is approximately at
right angles to them. The same zones generally are not obser¬
vable in thè longitudinal views because in these views thè piane
of thè thin section is commonly parallel or slightly oblique to thè
zones but not in their piane. However, thè zooecial boundaries are
always visible in longitudinal views because of their cylindrical
form, but they must not be confused with thè intermittent dark
zones in thè same view. In thè areas of maculae or monticules thè
dark zones are especially abundant.

Another zooecial boundary pattern is seen in Pachydictya
acuta (Hall) 1847, P. fimbriata Ulrich 1895, P. elegans Ulrich
1895, all from thè Decorah Shale, Minnesota, U.S.A., in P. am¬
bigua Ross 1961 from thè Ellis Bay Formation, Anticosti Island,
Canada, and in related Pachydictya species from thè Middle and
Upper Ordovician strata of thè U.S.A. The boundary zones in
Pachydictya acuta are similar in construction to those in P. fo¬
llata, but thè zoarial arrangement is modified.

The zooecial boundary encloses thè zooecial cavity with thè
adjacent part of thè zooecial wall like that in Pachydictya f oliata.
Unlike P. f oliata, thè zooecia are aligned in approximate ranges
in thè direction of thè zoarial growth. These zooecial ranges are
demarcated by range boundaries as in Stictopora. However, un
like Stictopora, thè range boundaries are not shared in thè exo¬
zone by thè laterally adjacent zooecia but are formed along thè

ZOOECIAL BOUNDARY PATTERNS ETC.

middle of a wedge-shaped feature. This wedge-shaped feature is
secreted in thè exozone between thè linear zooecial ranges, and it
is here named thè range partition.

The range partition begins at thè base of thè exozone and
forrns skeletal mass between thè zooecial ranges. Externally this
partition may appear as a slightly elevated and flexuous ridge.
The range partition is demarcated on both sides by dark bounda-
ries that appear as lines in transverse and tangential view. Along
these boundaries thè laminae of thè range partition and those of
zooecial walls adjoin or abut so that thè apexes of these adjoining
laminae point toward thè endozone.

The structural relationships between thè range partitions
and thè zooecial walls are seen best in thè transverse thin sections.
In these views of thè exozone, five dark and distinct boundaries
can be discerned. These are thè edge views of thè boundaries which
are cut perpendicular to thè thin section. These boundaries out-
line thè zooecia, their ranges and thè range partitions. The same
boundaries can be recognized in tangential views if thè transverse
view is kept in mind. In longitudinal section thè boundaries of thè
range partitions are not visible because in these views thè piane
of thè thin section is approximately parallel to thè boundaries.
However, in an oblique cut they might be visible. The zooecial
boundaries are observable in all three views because they have
thè cylindrical form in thè exozone. Not uncommonly thè boun¬
daries are obscured by impurities in or between thè lamine or by
murai tubuli. However, by keeping in mind thè three dimensionai
aspect of thè boundaries these morphological features can be
readily distinguished.

The boundary patterns in Pachydictya f oliata and P. acuta
are thè only two of this genus which I have discussed in some
detail. Further studies indicate that there are at least three other
* distinct patterns. These patterns can be observed in P. robusta
from Tennessee, P. bromidensis Loeblich 1942 from thè Bromide
Formation, Oklahoma, and in P. splendens Ulrich 1890 from thè
Upper Ordovician of Illinois, U.S.A.

0. L. KARKLINS

REFERENCES

Hall J., 1847 - Descriptions of thè organic remains of thè lower division of
thè New York System - New York Nat. History Survey, Palaeontology
of New York, part vi. v. 1, pp. 1-338, pls. 1-87.

Loeblich A. R. Jr., 1942 - Bryozoa from thè Ordovician Bromide Formation,
Oklahoma - Jour. Paleontology, v. 16, no. 4, pp. 413-436, pls. 61-64.

Nickles J. M. & R. S. Bassler, 1900 - A synopsis of American fossil
Bryozoa including bibliography and synonymy - U. S. Geol. Survey
Bull. 173, pp. 1-663.

Phillips J. R. P., 1960 - Restudy of types of seven Ordovician bifoliate
Bryozoa - Palaeontology, v. 3, pp. 1-25, figs. 1-2, pls. 1-10.

Ross J. R. P., 1960 - Re-evalution of thè type species of Arthropora Ulrich -
Jour. Paleontology, v. 34, no. 5, pp. 859-861, 1 pi.

Ross J. R. P., 1961 - Larger cryptostome Bryozoa of thè Ordovician and Si-
lurian, Anticosti Island, Canada, pt. 2 - Jour. Paleontology, v. 35,
pp. 331-344, pls. 1-5.

Ross J. R. P., 1964 - Morphology and phylogeny of early Ectoprocta
(Bryozoa) - Geol. Soc. America Bull., v. 75, pp. 927-948, figs. 1-10.

Ulrich E. O., 1882 - American Paleozoic Bryozoa - Cincinnati Soc. Nat.
History, Jour. v. 5, pp. 121-175, pls. 5-8.

Ulrich E. O., 1886 - Report on thè Lower Silurian Bryozoa with preliminary
descriptions of some of thè new species - Minnesota Geol. and Nat.
History Survey, Ann. Rept. 14, pp. 57-103.

Ulrich E. O., 1890 - Paleontology of Illinois, Pt. 2, sect. VI, Palaeozoic
Bryozoa - Illinois Geol. Survey, v. 8, pp. 283-688, figs. 1-18, pls. 29-78.

Ulrich E. O., 1895 - On Lower Silurian Bryozoa of Minnesota - Minnesota
Geol. and Nat. History Survey, Final rept, v. 3, pt. 1, pp. 96-332,
figs. 8-20, pls. 1-28.

Zittel K. A., 1880 - Molluscoidea - Handbuch der Palaentologie, erste Band,
Druck und Verlag von R. Oldenbourg, Mùnchen und Leipzig, pp. 575-
641, figs. 412-472.

Atti Soc. It. Se. Nat, e Musco Civ. St. Nat, Milano - 108: 85-92. 31-XII-1968

lst I.B.A. International Conferenee on Bryozoa. S. Donato Milanese. Aug. 12th-16th, 1963
12. Group 2: Anatomy, Morphology and Skeletal Structure.

Ronald Tavener-Smith (*)

SKELETAL STRUCTURE AND GROWTH
IN THE FENESTELLIDAE ( BRYOZOA )

(Preliminary Report) (**)

Riassunto. — Le pareti della branche dei Briozoi Fenestelliclae hanno
un piano di costruzione a tre foglietti: uno strato granulare mediano, fian¬
cheggiato da tessuto laminato, sottile all’ interno e denso all’esterno. Lo sche¬
letro granulare si formava durante un unico continuo periodo di deposizione,
mentre il tessuto laminato risultava da accrescimenti regolari successivi.

Bastoncini scheletrici si originavano dallo strato granulare e si irradia¬
vano attraverso lo scheletro laminato. Questi bastoncini sono strutture solide
e non c’è nessun indizio che siano state mai perforate.

Lo strato granulare si formava prima del tessuto laminato che lo fian¬
cheggiava ed è quindi giustificabile l’uso dei termini « formazione primaria »
e « formazione secondaria ». La zona di formazione primaria (granulare) e
quella esterna di formazione secondaria erano secrete da un mantello esterno
o coloniale, mentre il tessuto interno di formazione secondaria veniva deposto
dall ectoderma zooidale. E’ quindi evidente che i Fenestelliclae avevano una
struttura parietale composta di due elementi, paragonabile a quella dei Cyclo-
stomata Horneridae (Borg, 1926). Il mantello esterno era probabilmente ori¬
ginato come un’estroflessione ectodermale della regione vestibolare dell’ance-
strula. Questo mantello era associato strettamente con lo sviluppo di tutte
le strutture coloniali e formava un involucro completo esterno, perforato
soltanto dalle aperture zoeciali. L’epithelium interno del mantello secerneva
la maggior parte dello scheletro coloniale e, come nei Brachiopodi (Wil¬
liams, 1968), è dimostrato che questo secerneva diversi prodotti nelle diverse
fasi della crescita.

(*) Department of Geology, Queen’s University - Belfast, N. Ire-
land, U. K.

(**) The talk on this subject to be given at thè Milan Conferenee is
based on a paper shortly to appear in « Palaeontology ». The following is a
summary of thè main points dealt with in that paper, and readers are re-
ferred to it for a fuller explanation and for illustrations.

R. TAVENER-SMITH

La sistemazione delle pareti in nodi carenali, dissepimenti ed escrescenze
spinose, è simile a quella delle branche, a parte il fatto che non c’è lo strato
secondario interno. Queste strutture non avevano nessuna comunicazione in¬
terna con le cavità zoeciali e venivano deposte interamente dalPepithelium
interno del mantello. Sostegni coloniali massicci, come quelli di Lyropora e
di Archimedes, consistono interamente di tessuto secondario formato da una
secrezione massiccia localizzata proveniente dal mantello esterno. La deposi¬
zione di calcite di questo tipo contribuiva efficacemente alla riparazione dei
danni alla struttura retiforme.

Summary. — Branch walls of fenestellid bryozoans have a three-fold
construction : a middle, granular layer, flanked by inner (thin) and outer
(thick) laminated tissue. The granular skeleton was formed by a single,
continuous depositional episode, while laminated tissue resulted from regular
incrementai additions. Skeletal rods originate from thè granular layer and
radiate through thè laminated skeleton. These are solid structures, and there
is no evidence that they were ever perforate.

The granular layer pre-dates thè laminated tissue flanking it, and use
of thè terms primary and secondary is therefore justifiable. The primary
(granular) and outer secondary (laminated) zones were secreted by an
external (or colonial) mantle, while thè inner secondary tissue was laid
down by thè zooidal ec-toderm. It is therefore evident that fenestellid bryo¬
zoans had a « doublé » wall structure comparable to that in hornerid
cyclostomes (Borg, 1926). The external mantle probably originated as an
ectodermal evagination from thè vestibular region of thè ancestrula. It was
closely associated with thè growth of all colonial structures, and formed a
complete external envelope pierced only by zooecial apertures. The inner
mantle epithelium laid down most of thè colonial skeleton and, as in brachio-
pods (Williams, 1968) there is evidence that this secreted different produets
at different stages of growth.

The wall arrangement in carinal nodes, dissepiments and spiny out-
growths is similar to that of branches, but thè inner secondary layer is
absent. These structures had no internai communication with zooecial cham-
bers, and were laid down entirely by thè inner mantle epithelium. Massive
colonial supports, such as those of Lyropora and Archimedes, consist entirely
of secondary tissue formed by massive, localised secretion from thè external
mantle. The formation of calcite deposits of this kind also played an effective
part in thè repair of structural damage to thè meshwork.

1. Skeletal morphoiogy.

Branch walls in fenestellid bryozoans are of three-fold con¬
struction : a middle granular layer is flanked by inner (thin) and
outer (thick) laminated tissue. The middle layer has always been
considered thè fundamental wall componenti it is invariably

SKELETAL STRUCTURE AND GROWTH IN THE FENESTELLIDAE ETC.

8 7

present as a continuous investment around zooecial chambers
and extends abeve them as thè core of thè carina. Electron
micrographs show that it has a distinctive granular texture
without trace of lamination.

The outer laminated zone is generally well developed, espe-
cially on thè reverse of branches. Each lamina is a sheet-like
mosaic of calcite plates, and adjacent laminae are clearly defined.
Laminae of this kind are known to form by incrementai growth,
and Williams (1968) suggested that in brachiopods a diurnal
periodicity may be represented. If successive laminae were
formed during equal time intervals, then width variations bet-
ween them show that thè rate of calcite secretion through time
was not Constant. Neither was it aìwavs Constant from place to
place even within thè same time interrai, for some laminae
thicken locally into lenses. In these thè platy structure of thè
mosaic is replaced by a granular one similar to that of thè middle
wall layer. If thè presence of laminae is due to thè addition of
skeletal layers by increment, it is logicai to suppose that their
absence (i. e. granular texture) indicates continuous deposition.
Also, thè granular material appears to have formed at a relati-
vely accelerated rate, as shown by lenses in thè outer laminated
skeleton. In spite of their distinctive textures, thè granular and
outer laminated wall zones show a perfect gradational contact,
which must represent a transition from one mode of deposition
to thè other.

The inner wall element, lining zooecial chambers, is of
similar appearance and structure to thè outer laminated zone,
though notably thinner. Development appears to have been
checked when thè chamber lining had achieved a certain thick-
ness. The presence of this layer in chambers dose to « young »
brandi tips shows that it is a true wall component and not
merely a late-stage accretion characterising senility. The contact
between inner laminated and granular wall zones is non-gra-
dational.

The outer (but not thè inner) laminated skeleton incorpo-
rates rod-like elements radiating from thè granular layer. These
are best seen in transverse sections of branches, but are also
present in dissepiments and carinal nodes. Skeletal rods form
minute prominences at thè surface, and these are commonly ar-

R. TAVENER-SMITH

ranged in rows along thè crests of ridges (or « striae ») on thè
reverse side. Electron micrographs and other evidence show that
thè skeletal rods were always solid structures, contrary to thè
supposition of earlier authors. It is also certain that they are
integrai parts of thè fenestellid skeleton, and not of algal origin
as Elias & Condra (1957) suggested. The rods consist of gra¬
nular skeletal tissue and must have resulted from continuing
growth at an infinity of points on thè outer surface of thè
granular layer. Their purpose is not obvious, but it may be signi-
ficant that they are identica! in structure and situation with thè
taleolae of strophomenide brachiopods (Williams 1968).

2. Reconstruction of secretory tissues.

Calcareous skeletal tissues are secreted by epithelial layers,
and a hypothetical reconstruction of these facilitates understan-
ding of thè way in which colonies functioned and grew.

The gradational contact between thè two outer wall zones
of a fenestellid branch, their relative positions, and thè fact that
thè skeletal rods grew outward from thè granular layer through
thè laminated tissue as this formed, indicate thè earlier age of
thè former. The structure of inter-zooecial walls shows equally
clearly that thè granular layer pre-dated thè inner laminated
chamber lining. Therefore thè granular tissue was first formed
(primary), and thè inner and outer laminated skeleton was sub-
sequently added (secondary). The presence of secondary tissue
on either side of thè granular layer indicates secretion from two
epithelial layers : thè inner being thè zooidal ectoderm and thè
outer an external mantle which must have enveloped thè entire
colony. Other lines of evidence also point to thè existence of an
external mantle : laminae of thè outer secondary skeleton must
have been added from thè exterior during growth ; thè sealing
of zooecial apertures in thè proximal parts of old colonies and
formation of massive colonial holdfasts can only have been ef-
fected from thè exterior. Also, thè skeletal structure of carinal
nodes and dissepiments can only be reasonably interpreted in
terms of calcite deposition from an external membrane. Such
an arrangement has already been reported (Borg, 1926) in thè

SKELETAL STRUCTURE AND GROWTH IN THE FENESTELLIDAE ETC.

Horneridae, and thè writer has verified this and noted many
similarities in thè skeletal structure of hornerid and fenestellid
colonies. As in H ornerà, thè fenestellid external mantle probably
incorporated two secretory epithelia separated by a slit-like
cavity (thè « hypcstegal coelcm » of Borg). The outer mantle
epithelium secreted an external periostracum, thè inner one was
thè main calcite-secreting surf ace of thè colony. The hypostegal
coelomic space communicated with thè body cavities of zooids
beneath each zooidal aperture. Skeletal rods, supposed by
Shulga-Nesterenko (1941) to be tubular ducts, possibly pro-
vided at their outer extremities (pustules) attachments for ten-
dons maintaining thè outer mantle epithelium in position.

Three epithelia therefore contributed to skeletal formation.
The first wa s thè zooidal ectodermi, which secreted thè inner
laminated wall. The second and third epithelia bounded thè
external mantle, a membraneous investment of thè whole colony.
The second (or inner mantle) epithelium secreted thè primary,
and later thè outer secondary tissue and was therefore responsi¬
ve for thè major part of thè colonial skeleton. The third (or
outer mantle) epithelium produced an external cuticle only.

It is now known that before thè commencement of calca-
reous deposition epithelia produce a proteinous layer upon which
subsequent crystal seeding takes place. Where two secretory epi¬
thelia are in juxtaposition it is therefore expected that they will
be separated by a cuticular layer, possibly doubled. This must
have been thè case in thè fenestellid skeleton between thè first
and second epithelia, before formation of thè calcareous wall
commenced. It probably accounts for thè non-gradational contact
between thè inner secondary and primary skeletal zones.

3. Skeletal formation and growth.

For a hypothetical growth pattern to be acceptable, it must
be possible to trace thè secretory tissues from their earliest
appearance in thè ancestrula. Derivation of thè innermost
(zooidal) epithelium is not in doubt, for it must have been a
direct extension by budding from thè ancestrular ectodermi. The
origin of thè external mantle is more obscure : it probably arose

R. TAVENER-SMITH

as a peripheral evagination of ectodermal epithelium from thè
vestibular region of thè ancestrula. The « flap » so formed
consisted of a doubled epithelial layer (second and third epi-
thelia) with a slot-like extension of thè body cavity between.
It covered thè ancestrular surface and extended into thè adja-
cent substrato. As development proceeded thè external mantle
extended to form a continuous colonial investment pierced only
by zooecial apertures.

In fenestellid colonies, as in modern fenestrate bryozoa,
growth was mainly from thè tips of branches, and in that situa-
tion thè proliferation of epithelial cells and initial formation of
cuticle took place. It is probable that thè outer cover of zooidal
buds at thè branch tip was of cuticle, and that rigid calcareous
walls only formed after thè attainment of aduìt size and shape.
At that stage a change of physiological activity in thè second
(inner mantle) epithelium led to thè deposition beneath thè cu¬
ticle of granular calcite. This primary wall was laid down in a
clearly defined zone dose behind thè tip of a growing branch.
As forward growth preceeded a further modification affected
thè same epithelial layer, and thè deposition of calcite particles,
previously continuous, became intermittent and partirle shape
changed from granular to platy. As a result, thè transition from
primary to outer (laminated) secondary skeleton took place. It
seems that, by physiological adaptation, a single epithelial layer
secreted different products at successive growth stages. A simi-
lar « conveyor belt » arrangement has been noted by Williams
(1968) in thè Brachiopoda.

4. Formation of other skeletal elements.

Dissepiments and carinal nodes show basically thè same
construction. Each has a primary core of granular tissue enve-
loped in laminated outer secondary material. The latter is pene-
trated by a System of skeletal rods radiating from thè granular
core and giving (in conjunction with thè laminae) a « spiders
web » pattern in transverse seetion. The inner secondary skeletal
layer is not present in these structures, nor is there an axial
canal to suggest thè former presence of internai protoplasmic

SKELETAL STRUCTURE AND GROWTH IN THE FENESTELLIDAE ETC.

substance, or communication with zooecial chambers. However,
an axial trail of dark granules (traceable to thè junction between
zooecial lining and primary skeleton in thè adjacent branch) may
record thè earlier existence of a cuticular strand on which pri¬
mary skeletal depositimi took place.

Dissepiments were formed by thè union of paired out-
growths from adjacent branches. It is probable that dissepi-
mental buds were initiated at thè grcwing tips of branches,
for they were already developing vigorously while neighbouring

•V **

zooidal walls were stili in thè cuticular stage : zooecia at thè bases
of dissepiments are commonly distorted in a wav that would have
been possible only if their walls were flexible.

Carina! nodes rise from thè keel at more or less regular
intervals. Their structure shows no indicaticn of thè former pre-
sence of internai soft parte, or of communication with zooecial
chambers. There is no evidence that thè nodes housed acantho-
pores, though there seems little doubt that they served a protec-
tive purpose. In some genera (e. g. Hemitrypd) thè distai ends
of carinal nodes branch, and thè branches unite into a geometri-
cally patterned superstructure screening zooecial apertures. The
superstructure bars are of identical construction to carinal nodes
and, like them, were undoubtedly secreted by an enveloping
membrane.

Proximal parte of old colonies are commonly thickened and
show an encrusting calcareous holdfast which attac-hed thè colonv
to its substrate. Formation of thè holdfast was initiated by thè
secretimi of primary tissue from thè lcwer mantle surface where
this extended over thè substratum. Secondary tissue was subse-
quentlv added, resulting in a laminated texture and thè attain-
ment of massive proportions.

Colonial meshwork supports in such genera as Lyropora,
Anastomopora and Archimedes resulted from sustained localised.
deposition of secondary calcareous substance from thè inner
mantle epithelium. In thè first two genera thè secretimi of exces-
sive laminated tissue on branches at thè margins of a F enestella-
like meshwork caused thè sealing of zooecial apertures, plugging
of fenestrules and expansion of branches until these fused to
forni thè V-shaped colonial support. In Archimedes a spirai

R. TAVENER-SMITH

mesh of thè same basic type is supported by an axial screw of
laminated secondary tissue. The colonia] meshwork is continuous
through thè screw, and although thè primary skeleton of bran-
ches shows no change, thè laminated outer tissue thickens prò-
gressively towards thè axis, with which it finally merges.

REFERENCES

Borg F., 1926 - Studies on Recent cyclostomatous Bryozoa - Zool. bidrag.
fran Uppsala, 10, 181.

Elias M. K. & Condra G. E., 1957 - Fenestella from thè Permian of West
Texas - Meni. Geol. Soc. Amer., 70.

Shulga-Nesterenko M. I., 1941 - Lower Permian Bryozoa of thè Urals -
Akad. Nauk. S.S.S.R., Paleont. Inst., Paleont. U.S.S.R., 5., (5). Russian
with English summary.

Williams A., 1968 - Evolution in thè shell structure of articulate brachiopods
- Spec. Pap. Paleont., 2., Pai. Assoc.

Atti Soc. It, Se. Nat. e Museo Civ. St. Nat. Milano - 108: 93-96. 31-XII-1968

lsfc I.B.A. International Conferenc-e on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
13. Group 2: Anatomy, Morphology and Skeletal Structure.

William C. Banta (*)

THE BODY WALL OF THE ENCRUSTING CHEILOSTOME
WATERSIPORA NI ORA (Canu and Bassler)

( Bryozoa )

(Preliminary Report)

Riassunto. — Le sezioni con epon e metacrilato di Watersipora migra
e altri Cheilostomata incrostanti rivelano che :

1. - la calcificazione è inizialmente intracuticolare ;

2. - le pareti laterali e gli organi di comunicazione sono più complessi
di quanto non si conoscesse;

3. - gli organi laterali di comunicazione sono gemme di zooidi abortiti ;

4. - la parete frontale è criptocistale.

Vengono poi discussi gli altri aspetti della morfologia e dell’evoluzione
della cistide.

Summary. — Epon and methacrylate sections of Watersipora migra and
other encrusting cheiiostomes reveal: (1) calcification is initially intracu-
ticular; (2) lateral walls and communication organs are more complex than
previously reported; (3) lateral communication organs represent aborted
zooid buds; (4) thè frontal wall is cryptocystal. Other aspeets of thè mor¬
phology and evolution on thè body wall are discussed.

Resumen. — Las secciones de epon y methacrylate de Watersipora migra
y de otro Cheilostomata incrustante demuestran : (1) que al principio la

calcificación es intracuticular ; (2) que las paredes laterales y los órganos
de comunicación son mas complejos que los reportados anteriormente; (3) que
los órganos de comunicación laterales son brotes de zoides abortados; (4) que
la pared frontal es un cryptocysto. Otros aspectos de la morfologia y evo-
lución del cistidio son discutidos.

(*) University of Southern California, Department of Biological Scien¬
ces, Los Angeles, California, USA.

W. C. BANTA

This is a preliminary report of research in progress at thè
Allan Hancock Foundation, University of Southern California,
Los Angeles. When completed, thè results will comprise a disser-
tation, to be presented to thè graduate faculty of thè University
of Southern California in partial fulfillment of thè degree of
Doctor of Philosophy. Most of thè work has been prepared for
publication as a series entitled « The body wall of cheilostome
Bryozoa » (Banta, in press).

Results are based primarily on gluteraldehyde-osmium fixed
material embedded in epon or methacrylate and sectioned at one-
half micron for viewing with thè light microscope. Approxima-
tely twenty species have been examined in detail ; I have espe-
cially emphasized Watersipora nigra (Canu and Bassler). The
following is a list of thè more important results.

1) Silén (1944: 436) was justified in distinguishing two
categories of walls in cheilostome Bryozoa, « external walls » and
«internai walls», but they must be redefined as follows: an
external wall is a reinforced portion of thè « ectocyst », an acel-
lular secretion of epidermal cells produced by intussusceptive
expansion of thè cuticle of thè ancestrula. An internai wall is a
ledge-like partition which grows by apposition from thè inner
face of an external wall.

2) In Watersipora, external walls generally consist of thè
following: (a) an outer «cuticle», (b) a layer of calcium car¬
bonate deposited on an organic matrix containing acid mucopoly-
saccharide, and (c) a previously undescribed structure, thè « ske-
letal membrane », which develops as a differentiation of thè
organic matrix of thè skeleton.

3) Lateral walls are external ; they consist of thè follo¬
wing: (a) a centrai cuticular layer, thè «intercalary cuticle».
This layer is continuous with frontal and basai cuticles and re-
presents an invaginated portion of thè ectocyst. (b) A pair of
calcareous laminae, and (c) a pair of skeletal membranes. A distai
(transverse) wall is an unpaired calcareous lamina surrounded
by a pair of skeletal membranes, sometimes absent. This arran¬
gement aceounts for thè observations of Levinsen (1909: 26)
and Silén (1944: 435) that incinerated or KOCl-treated cheilos-
tomes often tend to break up into longitudinal rows of zoecia.
Failure to do so is sometimes due to calcification of thè inter¬
calary cuticle.

THE BODY WALL OF THE ENCRUSTING CHEILOSTOME ETC.

4) Matrices of wall layers overlap. Their relations with
one another, particularly near an uncalcified window in thè basai
wall, indicate that calcium carbonate is an intracuticular deposit.

5) The annulus (pore ring) of a lateral communication
organ is not continuous with a calcareous wall, but is actually
a thickening of edge of a ruptured portion of thè intercalary
cuticle.

6) Rosette cells of both lateral and transverse communi¬
cation organs possess a morphological polarity similar to that
observed by Bobin (1958) in Bowerbankia and other ctenostomes.
« Special cells » plugging communication pores are borne on thè
side of thè septula facing thè more proximal of thè two zooids
sharing it. Polarity of lateral communicafion organs is also ma-
nifested by thè position of thè annulus.

7) Each communication pore is surrounded by a gasket-
like ring of PAS-positive material with a centrai hole through
which special cells protrude. This ring, thè « pore cincture » may
represent an intracellular accumulation within epidermal cells.

8) In some species of Membranipora, thè annulus and pore
piate of young specimens are modifications of thè lateral wall,
which is initially one-layered. Older, more heavily calcified spe¬
cimens of thè same species have a structure more compar able to
that described for W ater sip ora nigra, This observation supports
thè theory that calcification is intracuticular and that many dif-
ferences between species in thè structure of septulae can be attri-
buted to differences in thè degree of calcification.

9) In thè species studied by me, development of lateral
septulae differs from thè descriptions of SilÉn (1944: 456) and
Lutaud (1961: 211). Most important, thè lateral wall of thè sep-
tular area remains uncalcified until formation of thè pore piate.
The lateral wall is represented at this time by an unpaired,
uncalcified ectocystal layer continuous with thè intercalary cu¬
ticle. The ectocyst ruptures after thè pore piate is established.

10) These findings are consistent with thè view of SilÉn
(1944: 475) that lateral septulae represent aborted zooid buds and
that pore plates are homologous to transverse walls.

11) In some cheilostomes, lateral and transverse septulae
play an important part in «reparative budding», a regeneration-
like phenomenon described here for thè first time. Reparative

W. C. BANTA

buds are produced by zooids bordering dead regions of thè colony.
These buds, which mav coalesce with similar buds from other
zooids, produce new zooids within old zooecia. Since a complete
new ectocyst is produced, this process may account for thè so-
called « regeneration » of whole zooids described by Levinsen
(1907) and others.

12) The frontal wall of Watersipora nigra is an internai
wall, which develops (by apposition) underneath thè frontal
ectocyst. The ascus develops as an invagination of thè ectocyst
proximal to thè operculum. Parietal muscles differentiate and
attach to thè ascus in serial sequence from thè distai to thè
proximal end.

13) The frontal wall is pierced by four multiporous porè
plates, provided with special cells and pore cinctures.

14) In Watersipora thè lining of thè hypostega consists
of a single layer of cells. It is probable, however, that thè peri-
toneal lining has been secondarily lost and that thè hypostega is
a compartment of thè coelom.

15) It is concluded that thè frontal wall of Watersipora
is a cryptocyst and that thè affinities of thè genus are with thè
Cryptocijstidea , probably thè Coilostega.

REFERENCES

Banta C., 1968 - The body wall of cheilostome Bryozoa, I. The ectocyst of
Watersipora nigra (Canu and Bassler) - Journal of Morphology,
voi. 125, no. 4, 10 pp., pi. 1, figs. 1-6; in press.

Bobin G., 1958 - Structure et genèse des diaphragmes autozoéciaux chez
Boiverbankia imbricata (Adams) (Bryozoaire cténostome, vésicularine)
- Arch. Zool. Exp. Gén., voi. 96, pp. 53-100, figs. 1-9.

Levinsen M., 1907 - Sur la régénération totale des Bryozoaires - Overs.

Forhand. Kong. Danske Vidensk., (for 1907), no. 4, pp. 151-159, 1 pi.
Levinsen G. M., 1909 - Morphological and systematic studies on thè cheilo-
stomatous Bryozoa - Nat. Forfatt. Forlag, Copenhagen, vii -f- 364 pp.,
pls. 1-27, figs. 1-6.

Lutaud G., 1961 - Contribution a l’étude du bourgeonnement et de la crois-
sance des colonies chez Membranipora membranacea (Linné) Bryo¬
zoaire c-hilostome - Ann. Soc. Roy. Zool. Belgique voi. 91, no. 2,
pp. 157-300, pls. 1-8, figs. 1-28.

Silén L., 1944 - On thè formation of thè interzoidal Communications of thè
Bryozoa - Zool. Bidrag Uppsala, voi. 22, pp. 433-488, pi. 1, figs. 1-59.

Atti Soc. It. Se. Nat. o Museo Civ. St. Nat. Milano - 108: 97-100. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
14. Group 2 : Anatomy, Morpkology and Skeletal Structure.

Gilbert P. Larwood (*)

FRONTAL WALL STRUCTURES OF CRETACEOUS
AND RECENT CRIBRIMORPHA
AND OTHER CHEILOSTOME BRYOZOA

(Preliminary Report)

Riassunto. — Le strutture delle pareti frontali di alcuni Briozoi Cribri-
morpha cretacici sono comparate con quelle dei generi Membraniporella e
Cribrilaria ( Cribrimorpha recenti). Sono state prese in considerazione anche
le strutture frontali dei generi Hiantopora, Petalostegus e Cancla.

Summary. — The structures of thè frontal walls of some Cretaceous cri-
brimorph bryozoans are compared with those of thè Recent cribrimorph ge¬
nera Membraniporella and Cribrilaria. The frontal structures of Hiantopora,
Petalostegus and Cancla are also considered.

Résumé. Les structures frontales de quelques bryozoaires cribrimorphes
du Crétacé sont comparés avec ceux des genres cribrimorphes actuels Mem¬
braniporella et Cribrilaria. Les structures frontales des genres Hiantopora,
Petalostegus et Cancla sent aussi examineées.

In their evolution from membranimorph precursors in thè
early Cenomanian thè cribrimorph Bryozoa evolved a number of
distinctive struct ural patterns in thè frontal wall. The frontal
walls of Recent Cribrimorpha resemble those of manv less heavily
calcified Cretaceous forms. Both thè less marked frontal calcifi-
cation of some Recent non-cribrimorph cheilostomes and thè ex-

(*) LTniversity of Durham, Department of Geology, Science Laborato¬
ries - Durham (U. K.).

G. P. LARWOOD

tensive tertiary frontal wall calcification of some later Creta-
ceous cribrimorphs may be interpreted as features relating to thè
whole zoarium.

Early Upper Cretaceous cheilostome bryozoans include ge¬
nera with marginai spines which arched over thè chitinous frontal
membrane (thè primary frontal wall) but which were not fused
along thè mid-line of thè zooecia. Anaptopora and Anotopora from
thè Cenomanian are examples of such genera (Lang, 1916, 1921).
Morphologically such genera demonstrate thè derivation of cribri-
morph costate secondary frontal walls from a membraniporid con-
dition (Lang, 1921; Larwood, 1962).

Some Cenomanian cribrimorphs have divided intercostal
spaces. Poly cerato por a euglypha shows this condition but thè pre¬
cise nature of thè lateral costai fusions is not clear. The Recent
genus Membraniporella is most closely comparable to early Cre¬
taceous cribrimorph genera of simple structure in which a few
irregular lateral costai fusions are developed. Membraniporella
nitida has these features but M. marcusi and M. aragoi demons¬
trate thè formation of a costate secondary wall from marginai
spines which branch distally in one piane. In Cretaceous cribri¬
morphs thè secondary frontal wall appears always to be formed
by unbranched spines.

Among post-Cenomanian Cretaceous cribrimorphs different
species of Pelmatopora demonstrate thè principal complications
of thè costate secondary frontal wall (Larwood, 1962).

An additional, though by no means invariably developed, fea-
ture of cribrimorph costae is thè presence of pores on thè upper
surface. These lumen pores are visible in some Recent cribri¬
morphs as small uncalcified areas which are occupied in life by
soft tissue. Similar pores in thè costae of fossil cribrimorphs
may be termed pelmata and pelmatidia (large and small lumen
pores respectively). All thè species of Pelmatopora display pel¬
mata or pelmatidia in thè upper walls of thè costae. In species
with no lateral costai fusions a single pelma is situated near thè
distai (inner) end of each costa. In species with a well developed
series of lateral costai fusions a graded series of pelmata and pel¬
matidia occurs with thè pelmata opposite each lateral costai fusion.
In both fossil and Recent cribrimorphs pelmata and pelmatidia

FRONTAL WALL STRUCTURES OF CRETACEOUS ETC.

may be absent as in Membraniporella nitida and Cribrilaria ra¬
diata. In some fossil genera pelmata and pelmatidia occur in some
species of a genus but not in others.

Among later Cretaceous cribrimorphs Castanopora jurassica
exemplifies a marked development of pelmata, pelmatidia and
lateral costai fusions (Larwood, 1962), and species of Ubaghsia
such as U. reticulata and U. ornata demonstrate features deve-
' loped by some heavily calcified forms in which there are very
few pelmata on each costa and a small number of robust lateral
costai fusions.

Although there are minor variations thè basic pattern of
this type of secondary frontal wall is thè same in Cretaceous and
in many Recent cribrimorphs, but thè structure of thè costae in
some Recent cribrimorphs appears to be different. Cribrilaria ra¬
diata has a distintive and different frontal wall structure not
seen in other Recent genera and, with thè possible exception of
Corbulipora, not known fossil. In Cribrilaria thè costae rise steeply
from thè margins of thè frontal wall forming a peripheral ring
of near-vertical hollow spines. At thè level of thè secondary
frontal wall each of these spines branches inward to form costae
which converge on a median-distal mucro . Lateral costai fusions
join thè costae which lack pelmata or pelmatidia.

Numerous genera of later Cretaceous cribrimorphs develop a
tertiary frontal wall of abundant calcareous tissue above thè se¬
condary costate frontal wall. Tertiary frontal walls are well di-
splayed by Tricephalopora , Phracto por ella, Polycephalopora, Coe-
lopora, Steginopora, Disteginopora and Ubaghsia. In such genera
as Ubaghsia this extra calcification forms an irregular robust and
raised lattice of calcareous tissue above thè generai level of thè
zooecial secondary frontal walls. The extensive development of
such tertiary frontal walls has no dose parallel in Recent cribri-
morph genera. The scale of olocystal or tremocystal calcification
in some ascophorans may be comparable with that of thè tertiary
frontal walls of some later Cretaceous cribrimorphs but its mode
of formation is different.

Functionally, thè significance of a well developed tertiary
frontal wall would seem to relate to thè colony as a whole rather
than directly to individuai zooecia. Its development affords pro-
tection for thè more delicate subjacent costate frontal walls of

100

G. P. LARWOOD

zooecia and for their contained polypides. It acts as a coarse outer
filter to thè zoarium precluding penetration by larger organisms
or by coarse detritus and it may even be effective in retaining a
certain amount of graded detritus forming a further protection
over thè surface of thè zoarium.

A similar interpretation could be made of frontal structures
of some much less calcified C hello stornata. Recent species of Hian-
topora ( H . ferox and H. intermedia) demonstrate thè overgrowth
of branched marginai spines in association with prominent avi-
cularia combining to form a frontal shield over each zooecium.
Since these shields are developed by adjacent zooecia they form a
protective barrier for thè whole colony and a filter in which thè
largest openings are located over thè orifices of thè zooecia.

The complex tertiary frontal walls developed in Cretaceous
cribrimorphs are a specialised example of a zoarial filter and
protective lattice.

An illustrated and extended account of thè matters discussed
in this paper will be published elsewhere.

REFERENCES

Lang W. D., 1916 - A revision of thè « Cribrimorph » Cretaceous Polyzoa.
Ann. Mag. Nat. Hist., London (8), XVIII, pp. 81-112, 381-410.

Lang W. D., 1921 - Catalogue of thè Fossil Bryozoa (Polyzoa) in thè De¬
partment of Geology, British Museum (Naturai History). The Creta¬
ceous Bryozoa (Polyzoa), III The Cribrimorphs, Pt. I, pp. i-cx, 1-269,
pls. 1-8.

Larwood G. P., 1962 - The Morphology and Systematics of some Cretaceous
Cribrimorph Polyzoa ( Pelmatoporinae). Bull. Brit. Mus. (Nat. Hist.)
Geol. VI (1), London, pp. 1-285, figs. 1-132, pls. 1-23.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 101-110, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
15. Group 2 : Anatomy, Morphology and Skeletal Structure.

James B. Rucker (*)

SKELETAL MINERALOGY OF CHEILOSTOME BRYOZOA

Riassunto. — Un’ indagine sulla costituzione mineralogica dello scheletro
di 61 specie di Cheilostomata è stata condotta usando i raggi-X a diffra¬
zione e particolari tecniche di colorazione.

La maggior parte delle 32 specie di Anasca si sono mostrate intera¬
mente calcitiche. Le specie con struttura mineralogica aragonitica o mista
ei ano caratterizzate da colonie lunulitiformi liberamente viventi. Come la
maggior parte degli Anasca , la sola specie di Acanthostega esaminata — Cri-
brilaria radiata — era interamente calcitica.

Gli Ascophora sono apparsi essere caratterizzati da uno scheletro car-
bonatico con costituzione mineralogica mista, sebbene siano state trovate
specie monominerali sia con costituzione aragonitica che calcitica. Tra quelle
specie con costituzione mineralogica mista, gli strati scheletrici primitivi for¬
manti le pareti basali, laterali e distali e gli strati interni delle pareti fron¬
tali sono calcitici. La calcificazione aragonitea susseguente si ha tipicamente
come un ulteriore ispessimento sulla superficie esterna della parete frontale.

La quantità di aragonite presente è apparentemente in relazione, in
parte, con la maturità della colonia, che può essere, a sua volta, regolata
entro certi limiti da parametri ambientali come la temperatura dell’acqua.

Summary. — A survey of thè skeletal mineralogy of 61 species of Cheilo¬
stomata was conducted using X-ray diffraction and staining techniques. A
majority of thè 32 species of Anasca were wholly calcitic. Those species of
aragonitic or mixed mineralogy were characterized by a free-living, lunuliti-
form colony. Like most Anasca, thè single species of Acanthostega examined,
Crihrilaria radiata, was entirely calcitic.

Ascophora appear to be typified by a skeletal carbonate of mixed mine¬
ralogy, although monomineralic species both of aragonitic and of calcitic
composition were found. Among those species of mixed mineralogy, thè pri-
mary skeletal layers forming thè basai, lateral, and distai walls, and thè
inner layers of thè frontal wall are calcitic. Subsequent aragonitic calcifi¬

ca U. S. Naval Oceanographic Office - Washington D. C., USA.

102

J. B. RUCKER

cation typically occurs as additional thickening on thè outer surface of thè
frontal wall. The amount of aragonite present is apparently related, in part,
to thè maturity of thè colony, which may be, in turn, regulated to some
extent hy environmental parameters such as water temperature.

Skeletal mineralogy of cheilostome Bryozoa.

Previous studies indicate that thè carbonate exoskeletons of
cheilostome Bryozoa ore composed either of calcite, of aragonite,
or of a mixture of these two calcium carbonate minerals. No
comprehensive survey of thè taxa had previously been made,
however, and little was known regarding thè relationship bet-
ween thè carbonate mineralogy and thè fundamental elements
of skeletal morphology. Schopf and Manheim (1967) conducted
an exhaustive search of thè published data on thè elemental
Chemical composition of Bryozoa, and determined thè geoche-
mical and mineralogie composition of several species. Stili, most
data reported on thè minor-element chemistry of thè skeletal
carbonates, have not been accompanied by mineralogie studies
(Dodd, 1967).

In this study, thè carbonate mineralogy of thè calcareous
exoskeletons of 61 species was determined using X-ray diffrac-
tion methods. Differential staining techniques were employed to
determine thè location of aragonite in bimineralic species, using
Feigl’s solution as thè staining agent, A 45 minute exposure to
thè stain at 45°C. produced a fine-grained, black precipitate on
thè aragonite, and left thè calcite unstained.

Fig. 1. — General configuratimi of thè three suborders of Cheilostomata,
showing lateral and transverse views. For simplicity, polypides, muscles, and
various calcifying tissues are all shown by gray tone ; non-calcifying, flexible,
chitinous membranes are shown by heavy black lines ; and calcareous zooecial
walls are represented by a striped pattern. The Anasca have a calcifying
epithelium in contact with thè zooecial walls. The frontal surface is covered
by tough, chitinous frontal membrane. The Acanthostega differ in having a
costular shield composed of partially fused, hollow spines which arch over thè
elastic frontal membrane. The Ascophora have calcifying epithelial tissue in
contact with thè basai and lateral walls; it is possibly in contact also, at
least in some Ascophora, with thè basai primary laminae of thè frontal wall
during’ early stages of zooecial development. Subsequent calcification occuis
on thè outer surface of thè frontal wall, secreted by epithelial cells beneath

thè epi-frontal membrane.

SKELETAL MINERALOGY OF CHEILOSTOME BRYOZOA

LATERAL

TRANSVERSE

W\\\vsr AA \ XXX \ w

104

J. B. RUCKER

One hundred specimens representing 61 species belonging
to thè three suborders of Cheilo stornata were studied : thirty
two species of Anasca, one species of Acanthostega, and 28 spe¬
cies of Ascophora. The results of this survey are indicated in
Table 1 ; several generalizations regarding thè calcification
within each suborder may be made.

Anasca.

The fundamental anascan skeletal elements are shown in
Figure 1. The Anasca are characterized by zooecia having car¬
bonate basai, lateral and distai walls, but lacking a true frontal
wall. Instead, they have a flexible frontal membrane. Of thè 32
species studied, 25 were entirely calcitic. Six of thè seven anascan
species having mixed mineralogy belong to families which, for
thè most part, have a discoidal or freeliving zoarial form.

The similar aragonitic skeletal mineralogy of Cupuladria
and Discoporella (both lunulitiform genera) tends to confirm
thè dose relationship between them, which has been suggested
by previous authors cn thè basis of morphologic similarities
(Cook, 1965). Minor quantities of calcite, approximately five
percent, were detected in Discoporella. Using staining techni-
ques, it was determined that thè tubercles on thè basai zoarial
surface were at least partially calcitic. Like thè other lunuliti¬
form species, Setosellina goesi was essentially aragonitic.

The lunulitiform genus Lunulities (both modera and Eocene
species) was found to be of mixed calcite-aragonite mineralogy.
The more soluble carbonate, aragonite, formed thè thick basai
wall, while thè more insoluble carbonate, calcite, formed thè
lateral and distai walls.

Fig. 2. — Photographs of Schizoporella unicornis showing different degrees
of calcification of thè frontal wall, with thè corresponding percent arago¬
nite, up 33% aragonite, low 72% aragonite (determined by subsequent X-ray
analysis of these sanie samples). The specimen having thè lower aragonite
content is characterized by a uniformly thin frontal wall, with numerous
tremopores. With increasing aragonitic calcification on thè outer surface,
thè frontal wall thickens and becomes more irregular, while thè number of

pores decreases.

SKELETAL MINERALOGY OF CHEILOSTOME BRYOZOA

105

J. B. ROCKER

10(3

The only other anascan found to be of mixed mineralogy
was Canda retriformis, a species having an erect cellariiform
habit. Insufficient material was available, however, to determine
thè site of aragonite deposition with staining tests, or to elimi¬
nate thè possibility of sample contamination.

Acanthostega.

The suborder Acanthostega is somewhat more complex than
Anasca. Acanthostega species are characterized by a frontal
costular shield of partially fused spines, rising from thè murai
rim that arches over thè frontal membrane (Figure 1). Discus-
son regarding this suborder must be postponed since, to date,
only a single species has been analyzed.

Because of thè basic similarities of most Acanthostega
species to thè membraniporiform Anasca, one would suspect
that Acanthostega species might also have calcitic skeletal com-
position. The single species analyzed, Cribrilaria radiata, proved
to be entireìy calcitic ; on this limited evidence, however, it would
be premature to speculate that a calcitic skeletal composition is,
in faci, characteristic of this suborder (Table 1).

Ascophora.

Ascophora is thè most advanced suborder of thè Cheilosto-
mata. This suborder is characterized by species having a well-
developed calcerous frontal wall (Figure 1), although it is reco-
gnized to d.evelop in more than one way (Harmer, 1957).
Twenty-eight species belonging to this group were analyzed ;
twelve species were found to be wholly calcitic, four species
were aragonitic, and twelve were of mixed mineralogy (Table 1).

Species of mixed mineralogy were stained to determine thè
site of aragonite deposition. Invariably thè aragonitie was res-
tricted to thè outer frontal wall.

Thirteen samples of a ubiquitous encrusting species, Schizo-
porella unicornis (sensu lato), from eight localities were studied.
This species characteristically was of mixed skeletal mineralogy.
The percent aragonite ranged from 25 to 72, and appeared to
be directly related to thè degree of frontal wall thickening
(Figure 2). The degree of thickening of a frontal wall depends

SKELETAL MINERALOGY OF CHEILOSTOME BRYOZOA

107

upon thè age of thè individuai zooecia. The frontal walls of new
zooecia at thè growing edge of a colonv are generally devoid of
aragonite and are less heavily calcified than individuals in thè
centrai (older) portion of thè sanie colony. The rate at which
individuals thicken their frontal walls by aragonite deposition
may be related to their growth rate, and may be controlled, in
part, by various environmental parameters.

A temperature effect in thè mineralogie skeletal composition
of thè bryozoan species, Schizoporella unicornis, from Bermuda
was documented by Lowenstam (1954). He found chat thè
amount of aragonite increased as thè water temperature in-
creased; similar results were noted in this studv.

A plot of percent aragonite against thè mean annual tem-
peratures (taken from thè Coast and Geodetic Surface Water
Temperature and Salinity Summaries) at sample locations, indi-
cated a positive relationship between temperature and aragonite
content. No trend was noted between annual salinity and percent
aragonite or percent MgCO^ .

Many of thè monomineralic species reported are represented
by a single analysis of a single specimen ; it would be imprudent
to discuss these taxa further, until more is known about their
range of compositional variations.

Several specimens of two Metrarabdotos species were
studied. One species, M. tenue was consistantly wholìy calcitic.
A closely related species, M. unguiculatum was of mixed mine¬
ralogy. The wall structures and mineralogy of these species were
compared in detail by Cheetham et al. (In Press). It was found
that thè two species were quite similar in terms of both zooecial
ontogenv and zooecial wall structure, in spite of thè differences
in mineralogy. Both species were composed of smooth, calcitic,
primary skeletal layers forming thè basai, lateral, and distai
walls, and thè inner layers of frontal wall of thè zooecia. A su-
perficial layer of deposited carbonate material was noted on thè
outer surface of thè frontal wall ; this layer was of a radiating,
fibrous, aragonitic nature in M. unguiculatum , and of a wavv-la-
mellar, calcitic nature in M. tenue. This superfic-ial material ap-
pears to be deposited from thè epi-frontal tissue that characteris-
tically covers thè frontal wall of thè Ascophora.

108

J. B. RUCKER

Table 1. - Skeletal mineralogy .

Species

Mineralogy

Calcite Aragonite Calcite & Aragonite

ANASCA

Eucratea loricata

Membranipora aurita

M. hastingsae

M. unicornis

M. tuberculata

Bif lustra s avarili

Electra anomala

E. pilosa

E. tenella

Flustra foliacea.

Aplousina gigantea

Chaperia condylata

Steganoporella magnilabris

Thalamoporella granulata

T. distorta

T. falcifera

Setosellina goesi

Cupuladria canariensis
Discoporella doma

D. umbellata

Lunulites capulus

L. jacksonensis (Eocene)
Nellia tenella

Bugula californica

B. neritina

B. simplex

Dendrobeania murrayana

Cellaria bassleri

Canda retriformis
Scrupocellaria regularis

S. maderensis

Caberea ellisi

Cribrilaria radiata

ACANTHOSTEGA

SKELETAL MINERALOGY OF CHEILOSTOME BRYOZOA

109

( segue Table 1)

Species

Mineralogy

Calcite Aragonite Calcite & Aragonite

ASCOPHORA

T remo gaster ina granulata
T. lanceolata

Gemelliporella prevailae X

Parasmittina spathulata
Smittoidea prolifica

Codonellina montf errandii X

Retoporellina marsupiata X

Cryptosula pallasiana X

W atersipora subovoidea X

Hippopodina feegeensis X

Hippoporina pertusa X

Harmerella dichotoma X

Mamillopora cupula X

Hippo t'ho a hya Un a X

Escharoides praestans X

Schizoporella unicornis (Sensu lato)

Stylopoma spongites X

Adeona cellulosa

Metrarabdotos tenue X

M. unguiculatum

Gemelliporina glabra

Microporella umbonata X

Celleporaria albirostris

C. vagans

C. granulosa X

C. aperta

Celleporina costazii X

Hippopetraliella marginata

Minor quantities of calcite were detected on thè tubercles of thè basai
surface.

Twenty percent aragonite was detected on a single X-ray analysis of this
species. However, insufficient material was available to do follow-up stain-
ing to determine thè site of aragonite deposition, and to eliminate thè
possibility of contamination.

110

J. B. RUCKER

REFERENCES

Cheetham A. H., Rucker J. B. & Carver R. E., 1969 - Wall structure and
mineralogy of thè cheilostome bryozoan, Metrarabdotos - Jour. Paleon-
tology (in press).

Cook Patricia L., 1965 - Polyzoa from West Africa: The Cupuladriidae
(Cheilostomata, Anasca) - Bull, of thè British Museum (Naturai Hi-
story) Zoology, v. 13, No. 6, pp. 1-3, 4 text-figs.

Dodd J. R., 1967 - Magnesium and strontium in calcareous skeletons - A
review, v. 41, No. 6, pp. 1313-1329.

Lowenstam H. A., 1954 - Factors affecting thè aragonite: calcite ratios in
carbon-secreting marine organisms - Jour. Geology, v. 62, pp. 284-322,
15 text-figs.

Schopf T. J. M. & Manheim F. T., 1967 - Chemical composition of Ectoprocta
(Bryozoa) - Jour. Paleontology, v. 41, pp. 1197-1225, 6 text-figs.

Atti Soc. It. Se. Nat. e Museo Civ St. Nat. Milano - 108 : 111-114, 31-XII-1968

lst I.B.A. International Conference cn Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
16. Group 2: Anatomy, Morphology and Skeletal Structure.

OSBORNE B. NYE (*)

ASPECTS OF MICROSTRUCTURE
IN POST-PALEOZOIC CYCLOSTOMATA

(Bryozoa)

Riassunto. — Nei Cyclostomata post-paleozoici è possibile identificare
diaframmi basali, intermedi e terminali.

Questi diaframmi sono distinti per la loro posizione all’ interno dello
zooecium e per la direzione verso cui le laminae si flettono quando incon¬
trano il rivestimento della parete zoeciale. La secrezione dei diaframmi è
in relazione con la connessione del tessuto interzooidale attraverso i pori
interzooidali. La circolazione così aumentata attraverso i pori interzooidali,
non posseduta dalla maggior parte dei Briozoi paleozoici, costituisce un adat¬
tamento vantaggioso per i Briozoi post-paleozoici.

Summary. — Basai, intermediate and terminal diaphragms can be iden-
tified in post-Paleozoic cyclostomes. These diaphragms are distinguished
on their position within thè zooecium and thè direction in which thè la¬
minae flex when joining thè lining of thè zooecial v/all. The secretion of
thè diaphragms is related to thè connection of interzooidal tissue through
interzooidal pores., Increased circulation through interzooidal pores, not
possessed by most Paleozoic Bryozoa may provide an adaptive advantage
to most post-Paleozoic Bryozoa.

Résumé. — Parmi les Cyclostomata du Secondaire et Tertiaire on peut
distinguer des diaphragmes basai, intermédiaire et terminal. Les diaphrag-
mes sont determinés par leur position dans le zooécium et la direction
d’ inclinaison des laminae du diaphragme quand ils se jointent à la partie
interieure de la paroi zoéciale. La mode sécrétoire des diaphragmes est liée
à la jonction de l’épithelium interzoidal à travers les pores interzoidals.

(*) Smithsonian Institution, U. S. National Museum - Washington
D. C. USA.

112

0. B. NYE

L’aug'mentation de circulation à travers les pores interzoidal (la plupart
des bryozoaires du Primaire ne demontré pas ce trait) a été un avantage
pour l’adaptation des bryozoaires du Secondaire et Tertiaire.

Interzooidal pores are characteristic morphologic structures
common in cyclostomes. Most Paleozoic bryozoans have nonpo-
rous walls with thè exception of some Ordovician and Silurian
ceramoporoids, but thè murai pores of ceramoporoids do not ap-
pear to relate structurally to thè interzooidal pores of post-Pa-
leozoic cyclostomes. Most pcst-Paleozoic bryozoans characteristi-
cally develop porous walls; however Borg, 1926, and Silén, 1944
showed that interzooidal pores of cyclostomes are different ana-
tomically from thè communication pores of Ctenostomata and
C hello stornata.

Examination of thè microstructure of thè zooecial walls in
cyclostomes shows that thè laminae lining thè wall generally pa-
rallel thè zooecial cavity until thev reach thè locus of thè pore.
Here thè laminae do not stop abruptly but deflect and contour
thè outline of thè pore. Deflection of thè laminae indicates that
calcite was deposited bv a secretory epithelium which lined thè
pore, therefore thè pore is considered a primary structure.

The biologie role of interzooidal pores is suggested by
microstructure of diaphragms of which three types, basai,
intermediate and terminal, can be identified in post-Paleozoic
cyclostomes.

Basai diaphragms lie within thè zooecial cavity in an aboral
position. They are usually thin and non-porous and have been
observed in exozone and endozone portions of thè zooecium. The
laminae of this diaphragm curve orally as thè diaphragm joins
thè zooecial wall and continue orally as a zooecial lining. The
orai flexure of thè laminae requires that thè depositing epithe¬
lium was on thè orai side of thè diaphragm.

Terminal diaphragms (Borg, 1933, p. 290) are deposited at
or dose to thè orai extremity of a single zooecium as a zooecial
cover piate. This diaphragm is porous and relatively thick with
laminae which flex aborally as thè diaphragm joins thè zooecial
wall.

Intermediate diaphragms have a laminar configuration like
that of thè terminal diaphragms in that thè laminae flex aborally

ASPECTS OF MICROSTRUCTURE ETC.

113

to parallel thè zooecial wall. The intermediate diaphragm is dis-
tinguished from thè terminal diaphragm because it lacks pores,
is usually thinner and is aboral in position.

The manner in which thè laminae of thè terminal and inter¬
mediate diaphragms join thè zooecial lining requires that thè
soft tissues which deposited thè laminae lay on thè aboral side
of thè diaphragm. Soft tissues engaged in metabolic activities
such as thè deposition of calcareous tissue require a supply of
nutritive and respiratory substances, and thè means to eliminate
toxic metabolic byproducts. This in tura requires either a Storage
facility or a direct communication with tissues able to supply
these requirements. When thè first laminae of thè intermediate
diaphragm is completed, a chamber is formed sealed off from
thè overlying zooecial cavity. This effect is essentially thè same
in thè case of thè porous terminal diaphragm because there is
no zooid orai to thè diaphragm. In all cases observed, however,
thè chamber is connected laterally to adjoining zooecial cavities
by interzooidal pores. The evidence presented supports Borg’s
observations (1926, p. 201-202) that celi layers passed un inter -
rupted through thè pores and his hypothesis that coelomic fluide
carrying nutriente could be exchanged through interzooidal pores.

In most Paleozoic bryozoans thè secretion of diaphragms
within a zooecia formed a series of closed chambers. Living soft
tissues were confined to a zone at thè periphery of thè zoarium,
defined and underlain proximally by thè last formed diaphragm.
This skeleton would seem to have provided only a supporting
function analogous to that of a coralline calyx with a relatively
small protettive potential. In post-Paleozoic cyclostomes, howe¬
ver, living tissues capable of metabolic activities could be sup-
ported throughout thè zoarial framework, because of thè commu¬
nication System of interzooidal pores. This tissue may provide a
temporary internai reservoir in time of stress when external con-
ditions might be unfavorable to thè existence of most feeding
polypides. Under more favorable conditions, these underlying tis¬
sues might support thè proliferation of new feeding polypides
allowing thè survival of thè cyclostome colony. Thus post-Paleo-
zoic bryozoans, provided with interzooidal Communications, have
a flexibility in reacting to environmental changes not possessed
by most Paleozoic bryozoans.

114

0. B. NYE

Whether thè development of interzooidal pores appeared in
severa! lineages of Bryozoa which led to a polvphyletic group,
or whether post-Paleozoic cyclostomes are monophyletic, can not
be answered at present. However, it would seem that interzooidal
pores provide one of thè keys to an understanding of thè extinc-
tion of most Paleozoic tubular Bryozoa and thè successful adap-
tion of post-Paleozoic Cyclostomata to their environment.

Many of thè ideas expressed in this paper evolved from generai discus-
sions of thè bryozoan seminar group at thè U.S.N.M. Responsibility for
application of these ideas to thè Cyclostomata however is mine.

REFERENCES

Borg F., 1926 - Studies on Recent Cyclostomatous Bryozoa - Zool. Bidrag.

Bd. 10, Uppsala, pp. 181-507, figs. 1-109, pls. 1-14.

Borg F., 1933 - A Revision of thè Recent Heteroporidae (Bryozoa) - Zool.

Bidrag. Bd. 14, Uppsala, pp. 253-394, figs. 1-29, pls. 1-14.

Silén L., 1944 - On thè Formation of thè Interzooidal Communications of
thè Bryozoa - Zool. Bidrag. Bd. 22, Uppsala, pp. 433-488, figs. 1-59,
pi. 1.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 115-118, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
17. Group 2: Anatomy, Morphology and Skeletal Structure.

S. Thomas Soderqvist (*)

OBSERYATIONS ON EXTRACELLULAR
BODY WALL STRUCTURES IN CRISIA EBURNEA L.

( Ectoprocta , Crisiidae )

Riassunto. — Crisia eburnea ( Ectoprocta , Crisiidae ) quale briozoo Cy-
clostomata primitivo è stato studiato per mezzo del microscopio elettronico
a scansione. La parete corporea extracellulare è risultata composta di una
sottile cuticola organica, un sottile strato esterno ed un più spesso strato
interno*

Lo strato esterno è composto da fasci di minuti prismi mentre lo strato
interno ha una struttura lamellare, essendo composto da cristalli poligonali,
tubulari, sovrapposti.

Viene discussa la struttura della parete corporea extracellulare e ven¬
gono date alcune definizioni corrette.

Summary. — Crisia eburnea ( Ectoprocta , Crisiidae) as a « primitive »
cyclostomatous bryozoan has been investigated by means of scanning elec¬
tron microscopy. The extra-cellular body wall is composed of a thin or-
ganic cuticle, a thin outer and a thicker inner calcareous layer. The outer
layer is composed of bundles of minute prisms while thè inner layer has
lamellar structure, being composed of polygonal, tabular, superimposed
crystals. The structure of thè extra-cellular body wall is discussed and
some revised definitions are made.

Zusammenfassung. — Crisia eburnea ( Ectoprocta , Crisiidae ) als « pri¬
mitive!’ » cyclostomate bryozoe ist mit Raster-Elektronen Mikroskopie unter-
sucht worden. Das Aussenskelett ist aus einer dùnnen ausseren und dickeren
inneren Kalk-Schicht aufgebaut. Die àussere Schicht ist aus Bundeln kleiner
Prisma zusammengesetzt, wàhrend die innere Schicht lamellare Struktur
aufweist und ist aus polygonale, in Dachziegelschichtung angeordnete Kris-
tallen, aufgebaut. Einige Definitionen der Aussenskeett sind diskutiert.

(*) Geologiska Institutionen och Zoologiska Institutionen, Stockholms
Universitet, Stockholm, Sweden. Present address: Geologiska Institutionen,
Stockholms Universitet, Box 6801, 113 86 Stockholm, Sweden.

11(3

S. T. SODERQVIST

Introduction.

Present knowledge of thè structure of thè body wall in
cyclostomatcus bryozoa (Ectoprocta; Cyclostomata) is based pri-
marly on thè works of Borg (1923, 1926) which are generally
adopted by standard text-books (e. g. Hyman, 1959). According
to Borg thè body wall is made up of four layers: cuticle, calca-
reous layer, ectoderm and mesoderm (see also Calvet, 1900).

In this report preliminary results of an investigation with
a scanning electron microscope on thè extra-cellular body wall in
C risia eburnea L. and some other cyclostomatous bryozoa are
presented. In a forthcoming paper thè results will be compared
with biochemical and transmission electron microscopical data in
order to reveal thè ontogenv and morphology of thè body wall.

Material and Methods.

Live colonies of Crisia eburnea L. were either fixed imme-
diately or first trypsin digested in order to eliminate proteina-
ceous material from zooids, and then fixed. In order to obtain
fresh wall structures thè material was crushed and then imme-
diately coated with carbon or gold and examined in a Cambridge
« Stereoscan » scanning electron microscope. Micrographs were
recorded in magnifications from 500 X to 20,000 X.

Body wall in ’ Crisia eburnea’.

The extra-cellular parts of thè body wall were found to
consist of three layers: 1) a thin cuticle, 2) a thin outer calca-
reous layer and 3) a thick inner calcareous layer.

1) The cuticle is preserved in non-digested preparations
thereby indicating its proteinaceous nature. The cuticle shows no
specific structures except for scattered, indistinct depressions and
elevations, part of which might reflect thè uneven, underlying
crvstal surface. The longitudinal, parallel folds (fig. 1) are arti-
facts caused by shrinkage of thè cuticle in vacuimi treatment.
The cuticle is thinner (one tenth to one fifteenth of thè wall)
than that assumed by Borg (one fourth to one fifth; 1926).

2) The outer calcareous layer consists of bundles of cry-
stals, each bundle comprising 20-50 crystals (fig. 1). At higher
magnifications these crystals appear as prisms without any in-
tracrystalline structure. Borg’s (1926) observations that thè body

OBSERVATIONS ON EXTRACELLULAR BODY WALL STRUCTURES ETC.

117

wall is composed of « parallel, longitudinal strips/with/minute
particles . . . parallel to thè longitudinal axis of thè bud » is cor-
rect only insofar as thè outer surface is considered.

3) The inner calcareous layer consists of polygonal, tabu¬
lar crystals (fig. 3), stacked like roofing-tiles. In transverse views
(fig. 2) thè same crystals are arranged as lamellae with approxi-
mately uniform thickness. Around thè pores thè crystals are def¬
lected outwards indicating that thè pore is a primary formation
and has not been formed by thè resorption of precipitated crystals.

The interzoidal wall, septum, dividing thè common bud into
two new zooids is constructed of lamellae of thè same type. Seen
in transverse view thè septum has a lamellar structure with no
« hyaline » middle zone (cf. Diplosolen below). This is probably
due to thè fact that thè Crisia septum has a comparatively nar-
row growing front and crystals non-parallel to thè growth direc¬
tion are either entirely absent or too few crystals are present in
this deflected region to be detectable under thè technique used.

In four other recent species investigated, Stomatopora sp.,
Diplosolen intricarius (Smitt), Idmonea atlantica Johnston and
Heteropora pelliculata Waters, thè inner part of thè calcareous
wall has thè same architecture as in Crisia , i.e. superimposed, ta¬
bular, polygonal crystals. Diplosolen and Heteropora exhibits a
broad « hyaline » zone of deflected crystal arrangement in thè
middle of thè interzooidal wall. In Heteropora thè « hyaline » zone
is very thick and thè lamellar zone is restricted to a few lamellae.

No indications of organic material were found in thè calca¬
reous layers.

Discussion.

The body wall is a functional unity consisting of those parts
of thè zooid involved in thè protection and physical support of thè
zooids and colony. The cuticle and calcareuos layers are, by ana-
logy to molluscs (Wilbur and Simkiss, 1967) secreted by thè epi-
thelium of thè zooid. During ontogenythe epithelium first secretes
thè cuticle as a terminal membrane and as a cuticle proper (cf.
periostracum in molluscs). The cuticle is here defined as a non-
mineralized, extra-cellular organic layer. Internai to thè cuticle
thè outer and inner calcareous layers are then deposited. It is as-
sumed that these two layers consist of calcium carbonate and
small amounts of other minerals (Schopf and Manheim, 1967)
in conjuntion with an organic matrix of probably heterogeneous

118

S. T. SODERQVIST

nature. Both thè minerai and organic matrices are secreted by
thè epithelium into a hypothetical narrow space between thè cu-
ticle and thè epithelium, here termed thè extraepithelial fluid
space by analogy to molluscs. In this space one can assume that
thè crystals grow as polycrystalline aggregates, since carbon rep-
licas of thè inner surf ace of this layer in Crisia show this type of
intracrystalline surface structure. Comb-like edges, as visible in
fig. 3, might be indications of earlv stages of new crystals. Board-
man and Towe, in an unpublished investigation, have found thè
sanie type of crystal intrastructure in Heteropora pelliculata by
means of carbon replicas (personal communication).

REFERENCES

Borg F., 1923 - On thè structure of cyclostomatous Bryozoa - Arkiv Zool.,
15, pp. 583-598.

Borg F., 1926 - Studies on recent cyclostomatous Bryozoa - Zool. Bidrag
Uppsala, 10, pp. 181-507.

Calvet L., 1900 - Histoire naturelle des bryozoaires ectoproctes marins -
Trav. Inst. Zool. Montpellier, Ser. 2, Mém. 8.

Schopf T. J. M. & Manheim F. T., 1967 - Chemical composition of Ecto-
procta (Bryozoa) - J. Paleontol., 41, pp. 1197-1225.

Wilbur K. M. & Simkiss K., 1968 - Calcified shells - In: Florkin, M. (ed.),
Comprehensive Biochemistry, 26 A, pp. 229-295, Elsevier, Amsterdam.

Plate IV

Fig. 1. — Crisia eburnea autozooid. Outside view with outer calcareous layer
(OCL) and cuticle (CU). Longitudinal folds in cuticle are arti-
facts caused by shrinkage in vacuum treatment. 1310 x.

Fig. 2. — Crisia eburnea autozooid. Transverse view. Cuticle conceals outer
calcareous layer. Note deflection of thè lamellae of thè inner
calcareous layer (ICL) around thè pore (P). 5290 X-

Fig. 3. — Crisia eburnea gonozooid. Oblique inside view of tabular, poly-
gonal crystals of inner calcareous layer. Note crystal deflection
around thè pore and comb-like edges on some crystals. 3260 X-

Fig. 4. — Stomatopora sp. autozooid. Inside view of tabular, polygonal
crystals of inner calcareous layer. Pulpy appearance in lower right
corner is probably due to remaining cellular material. 1730 X.

SÒDERQVIST S. T.

Atti Soc. It. Se. Nat. e Museo Civ.St.Nat.Milano,Vol.CVIII, Pl. IV

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 119-128. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

18. Group 3: Ecology and Paleoeeology.

Diethardt Jebram (*)

A CULTI VATION METHOD FOR SALTWATER BRYOZOA
AND AN EXAMPLE FOR EXPERIMENTAL BIOLOGY

Riassunto. — Un metodo di coltivazione proposto da Grell, Schneider,
Kaissling e da Hauenschild e modificato, si applica molto bene ai Briozoi
salmastri e di acque poiialine. Per qualche specie assolutamente marina è
necessaria una separazione del cibo dalla sua soluzione nutritiva. Come nutri¬
mento per parecchie specie di Bryozoa si sono mostrate buone Oxyrrhis
marina (Dinoflagellata) e Cryptomonas sp. (Cryptomonadina).

Per ottenere più colonie di specie incrostanti per mezzo della riprodu¬
zione asessuale, è stato sviluppato un nuovo metodo. I Briozoi sono lasciati
crescere da un vetrino copri-oggetto all’altro. Questi vetrini copri-oggetto
sono fissati ad un vetrino porta-oggetto per mezzo di sottili tubicini di
polivinile.

Nelle condizioni di coltivazione usati, Conopeum reticulum (L.) sviluppa
polipidi negli spazi triangolari interopesiali allargati. Dopo queste osser¬
vazioni, queste strutture furono riconosciute essere eterozooidi (« reticulo-
zooidi »). Le pareti laterali dei vecchi zooidi crescono strato su strato verso
l’alto. Per confronto con i reticulozooidi di Conopeum , le spine e i tubercula
di Membranipora Blainville furono identificati come eterozooidi.

Summary. — A cultivation method, modified after Grell, Schneider,
Kaissling and Hauenschild proved effective for Bryozoans from brackish
and polyhaline waters. For some typical marine species a separation of thè
food from its nutrient solution is necessary. As food for several Bryozoan
species, Oxyrrhis marma (Dinoflagellata) and Cryptomonas sp. (Cryptomo¬
nadina) were effective. In order to obtain, by asexual means, more colonies
of thè incrusting species, a new method was developed, in which thè Bryo¬
zoans were allowed to grow from one coverslip to another. These coverslips
were held fast on glass slides by means of slit pieces of polyvinyl-tubing.

(*) Zoologisches Institut und Museum der Universitat, Kiel - Ger-
many (w.).

120

D. JEBRAM

Under thè eultivation conditions used, Conopeum reticulum (L.) builds
in enlarged « triangular, interopesial eavities » polypids. From these obser-
vations, these formed structures are recognized to be heterozooids (« reti-
culumzooids »). The lateral walls of old zooids grow layer by layer upwards.
By comparison with thè retieulumzooids of Conopeum, thè spines and tuber-
eula of thè genus Membranipora Blainville are identified to be likewise
heterozooids.

Résumé. — Une méthode de culture modifiée après Grell, Schneider,
Kaissling et après Hauenschild s’applique bien aux Bryozoaires d’eau
saumàtre et polyhaline. Pour quelques espèc-es strictement marines il est
nécessaire de séparer les organismes servant de nourriture de leur bouillon
eutrophié de culture. Comme nourriture pour plusieurs espèces de Bryo¬
zoaires Oxyrrhis marina (Dinoflagellata) et Cryptomonas sp. (Cryptomona-
dina) se sont montrés satisfaisants. Pour la propagation asexuelle d’espèces
incrustantes une méthode nouvelle et simple à été trouvée. On laisse les
Bryozoaires se répandre d’un couvre-objet à un autre. Les couvres-objet sont
fixés sur les lames par des pièces de PVC-tuyau.

Sous les conditions de culture Conopeum reticulum (L.) développe des
polypides dans des « espaces triangulaires, interopesiaux » agrandis ce qui
nous rend à mème de les identifiér comme hétérozooides (« reticulumzooides »).
Les parois latérales de zooides vieillissants de C. reticulum s’accroissent,
couche par couche, verticalement. Comparés avec les reticulumzooides de
Conopeum aussi les épines et tubercules du genre Membranipora Blainville
peuvent étre identifiés comme hétérozooides.

Zusammenfassung. — Eine Kulturmethode, modifiziert nach Grell,
Schneider, Kaissling und nach Hauenschild, eignet sich gut fiir Bryozoen
aus dem Brackwasser und aus dem Polyhalinikum. Fùr einige vollmarine
Arten ist eine Trennung des Futters von seinem eutrophierten Nàhrmedium
notwendig. Als Futter fiir etliche Bryozoen-Arten haben sich Oxyrrhis marina
(Dinoflagellata) und Cryptomonas sp. ( Cryptomonadina) bewàhrt. - Fiir die
ungeschlechtliche Vermehrung von flàchig' wachsenden Arten wurde eine
neue, einfac-he Methode entwickelt: Die Bryozoen werden auf Deckglàsern
wachsen gelassen, von einem Stiick auf ein anderes, wobei die Deckglàser
mit PVC-Schlauchstiicken auf Objekttràgern festgehalten werden.

Unter den Kulturbedingungen entwickeln sich bei Conopeum reticu¬
lum (L.) in vergrosserten « triangularen, interopesialen Raumen » Polypide,
wodurch diese Gebilde als Heterozooide erkannt werden (« Reticulumzooide »).
Die Lateralwande alter werdender Zooide wachsen bei C. reticulum schicht-
weise in die Hohe. - Durch Vergleich mit den Reticulumzooiden von Cono¬
peum konnen die Dornen und Tubercula der Gattung Membranipora Blain¬
ville ebenfalls als Heterozooide identifiziert werden.

A CULTIVATION METHOD FOR SALTWATER BRYOZOA ETC. 121

The first experimental researches on marine Bryozoa were
done by Marcus (1926) by simple rearing in naturai seawater.
Schneider (from 1955 on) and Kaissling (1963) undertook their
light-physioìogical experiments with Bugula using a cultivation
method, which was developed by Grell (1950, not published).
My cultivation method for saltwater Bryozoa is also based on
Greli/s methods G).

Oxyrrhis marina (a heterotroph Dinoflagellata), which were
fed by Dunaliella sp. (Phytomonadina), were used to feed thè
Bryozoans, as used by Grell, as were also Cryptomonas sp.
(Cryptomonadina), which is an organism recommended by Hauen-
schild as food for marine animals. Dunaliella and Cryptomo-
nas were cultivated in a nutrient solution, which is prepared ac-
cording to a combined method of Grell and Hauenschild. The
nutrient solution contains in 1000 cc seawater, 100 mg NaN03 ,
20 mg Na2HP04 • 12 H20, and 10-20 ccm soil extract, and should
be sterilized and filtered.

The seawater was obtained from thè Kieler Forde (about
13-17%0 S). By dilution with tapwater I get 10%o S. I produce
20-40%o S by adding some concentrated, artificial seawater (about
153%0 S), which is prepared by making a solution of thè 6 main
marine salts (p.a.) (after thè reeept for thè simple, artificial sea¬
water of Hauenschild, 1962).

The Bryozoa were reared, according to thè different experi¬
mental conditions, in glass or plexiglass vessels of various sizes,
usually at temperatures of 14-1 6°C, in dimlight, and aerated.
Every 3-4 days thè colonies were cleaned from faeces and bac-
teria by gentle brushing and provided with a new food suspension.

The admixtures of thè nutrient solution for thè autotrophic
protists eutrophized thè medium. This is tolerated by species from
brackish and polyhaline waters, but some typical marine species
do poorly in such an eutrophic medium. For these sensitive spe-

(9 I am endebted to Prof. Dr. K. Grell for his kindness in introducing
me to thè cultivation methods in thè protozoological laboratory of thè
Zoological Institute of thè University of Tùbingen, and for his providing
me with thè stock cultures of thè foodorganisms.

I also thank very much Dr. J. P. Woodring, Dept. of Zoology, Loui¬
siana State University, Baton Rouge, La, 70808, U.S.A., for his assistance
in translating this manuscript into English.

D. JEBRAM

1 99
1 lj Zj

cies thè food must be separated from thè nutrient medium and
placed in normal, sterilized seawater, before it could be fed to
thè Bryozoa. This separation may be a problem. The cells pass
through thè po-res of all paper filters and also through all fine
fritted glass filters. Membrane filters provide a good separation,
but are unpractical because they work too slowly. The cells may
be separated from thè medium by centrifugation. Because Bryo¬
zoa are very voracious, a large amount of food suspension is re-
quired, when one is rearing a larger number of Bryozoan colonies.
Normal centrifugation is unpractical, because it separates at one
time only a few ce. Therefore, a centrifuge is required that
utilizes several larger vessels (containing 500 ccm, or more), and
that has a high rotation speed. A continuai passage centrifuge
may better be used, in which in one tube thè protistan suspension
is led in, and out of an other tube thè almost celi free medium
Comes out. The foodorganism cells can be washed out as a sedi-
ment from a trap mechanism, after some litres of protistan sus¬
pension have been run through thè centrifuge (2). It should be
noted, that by centrifuge separation a larger number of cells is
lost.

The kind of food seems to be of great importance for thè
Bryozoa. Although several of thè laboratory treated species fed
well on both Oxyrrhis and Cryptomonas, and with both sorts of
food grew and matured well, everytime thè type of food was
changed, all active polypids were reduced and replaced by a new
one. The physiology of thè polypids seem to be regulated by
thè food. A change of thè kind of food requires a change in thè
physiology of digestion, which results in a change of thè poly¬
pids. Probably some of thè species, which grew poorly under my
conditions, did so because of this phenomenon. Surely there are
Bryozoan species, which require other kind of food than that
used by me (3).

(■) The continuai passage centrifuge model available to me was old
and intricate to handle, and so I used this method for only a few months.
The results, however, were satisfactory with some marine species.

(3) Some days ago I received some reprints from J. S. Bullivant, New
Zealand Oceanographic Institute, Department of Scientific and Industriai
Research, Wellington, who reported good results in feeding Zoobothryon
verticillatum and other Bryozoan species with Phaeodactylum tricornutum,
Monochrysis lutherì, and other food species.

A CULTIVATION METHOD FOR SALTWATER BRYOZOA ETC.

123

For laboratory rearing of Bryozoa thè tvpe of substrate is
important. Plates of glass have prooved in many regards to be
sufficient by many authors, for example for Hvdrozoa and fresh-
water Bryozoa. I have used glass slides as a substrate for several
saltwater Bryozoan species with good results. However, glass is
not accepted by all species. Some species, above all stolonial and
pseusostolonial forms, can not or only with difficulties adhere
to thè smooth surface. Moreover there are species, which seem
to need special Chemical conditions of thè surface of thè sub¬
strate. For example, penetrating Ctenostomata need lime or wood,
and Flustrellidra hispida and Membranipora membranacea seem
to need seaweeds such as Laminaria and Fucus. For such species
special cultivation methods must be developed.

JL □

0: S

Fig. 1. — Asexual multiplying of incrusting Bryozoa.

B = Bryozoan colony; c = coverslip; d = distai, m = middle, and
p = proximal part of thè growing colony; PVC = slit piece of poly-

vinyl tubing; s = glass slide.

Closely related to thè substrate problem is thè question of
thè asexual multiplication of incrusting colonies. Whilst bushv
and stolonial forms are easily propagated by cutting off bran-
ches of thè colonies, thè incrusting species grow strongly adher-
ing to thè substrate and can only be subcultivated by separating
a part of thè substrate with a part of thè adhering colony. I have
developed a new, simple, but practical method for this: I allow
thè colonies, which are to be multiplied, to grow not on thè slide

124

D. JEBRAM

itself but on coverslips, which are held fast on thè slides by slit
pieces of polyvinyl-tubing. The Bryozoa grow frcm one coverslip
to thè other. Afterwards, thè colonies can be cut through along
thè border of thè coverslips, and thè separate pieces used for
further subculturing (fig. 1). Since it is necessary for experi-
mental research to use clone material of thè animals to eliminate
individuai, genetic differences, this method is an important foun-
dation for such experiments.

The following species I am currently rearing (or have reared) under
thè above mentioned conditions (some for over 3 years): ( Tubulipora sp.),
Alcyonidium polyoum, A. hirsutum, *AlcyonicLium sp., *Bowerbankia gracilis,
( B . i rubricata ), * Favella repens, * Electra crustulenta, *E. monostachys, *E.
pilosa, (*E. posidoniae), *Conopeum seurati, *C. reticulum, *Biigula stolo¬
nifera (from thè stock of Grell), ( *Cribrilina panciata), ( Hippothoa hya-
lina), ( Escharella immersa), {Micropor ella ciliata), Cryptosula pallasiana.

= well growing species, which became mature in thè laboratory;

( ) = these species were reared only a short time, and/or grew poorly.

As an example for thè import ance of thè work with culti-
vati on methods, I will describe here thè development of Cono-
peum reticulum (L.) in thè laboratory. I have reared this species
now about one year. It grows well and becomes mature under mv
cultivation conditions. After thè colony was fed two months with
Cryptomonas , I made thè initial observation, which resulted in
thè determination of thè following process : In thè « triangular,
interopesial cavities » on thè proximal frontsides of thè cystids
of thè autozooids, small redbrown bodies were to be seen, of nearly
thè same colour, as thè gut of Cryptomonas fed autozooids. As
thè colony became older, some of thè « triangular cavities » en-
larged and were seen to contain polypids. Therefore, these struc-
tures are reai zooids, and thè name « reticulumzooid », used
by several authors, is correct.

According to my observations in thè laboratory thè ontogeny
of thè zooids of Conopeum reticulum is to be devided into dif-
ferent stages (fig. 2) :

Stage I (about 1-2 weeks old) includes thè growing border
area of thè colony (proceeding from thè outer edge towards thè
middle) : a) cystidbuds, containing young polypidbuds ; b) « fini-
shed » cystids, including partially developed polypidbuds ; in thè

A CULTIVATION METHOD FOR SALTWATER BRYOZOA ETC.

125

proximal corners of thè cryptocyst thè lateral walls of thè reti-
culumzooids start to grow, beginning under thè frontal mem¬
brane of thè autozooids ; c) autozooids with evaginating polypids ;
in thè meanwhile thè calcification of thè lateral walls of thè re-
ticulumzooids would be finished on thè distai side, and now these
walls reach over thè frontal membrane of thè autozooids ; d) brown
bodies appear in thè autozooids by reduction of thè first polypid
generation ; within thè more developed reticulumzooids thè first
« feeding bodies » (see next stage) begin to grow.

Fig. 2. — Developmental stages I-IF of Conopeum reticulum (L.) in
fontal view and sagittal section (schematic drawing). The dotted
lines in thè opesia of stage II' show thè wall building fold of thè
frontal membrane (see fmf in fig. 3 b) (not thè cryptocyst).

(Further explanation see text.).

Stage V (about 2 weeks to 3 months old): Within thè reti¬
culumzooids thè first generation of « feeding bodies » begins
to take up food, which can be recognized by thè red colorir of
Cryptomonas (some about thè beginning of thè 2.nd, most dur-
ing thè 6.th and thè following polypid generations in thè auto¬
zooids). The «feeding body» seems to consist of a very small
excavation in a tissue layer; tentacles and a reai gut are not to
be seen; but thè true nature of thè «feeding body» until now
is not certain. In thè meantime thè lateral walls of thè autozooids

D. JEBRAM

126

are growing upwards, and with each polypid generation an ad-
ditional layer is formed. Beginning in thè 3.rd month thè auto-
zooids may become mature.

Stage II (beginning about thè 4.th month): Some of thè re-
ticulumzooids have grown larger and contain a trae, minute po¬
lypid with tentacles and an U-shaped alimentary canal. The cy-
stidrooms of these reticulumzooids are enlarged, in that their
lateral walls in growing layer bv layer upwards have thereby also
partly laterally expanded. In this way thè cystids of thè reticulum¬
zooids take on a more or less conical form, whilst thè aperture
fields of thè autozooids are gradually restricted. In this stage
secondary reticulumzooids begin to grow. The autozooids in thè
meantime were or became mature. The lateral walls of thè auto¬
zooids also grow upwards in layers, being apparently built up by
cells under thè lateral parts of thè frontal membrane, a position
where a fold appears in thè older stages.

Stage II' (beginning about thè 5.th month): Whilst thè
cystids of some of thè reticulumzooids continue enlarging them-
selves and partly expanding more to thè sides, they build up ge-
nerations of increasing larger polypids. Some of thè polypids in
thè reticulumzooids attain thè size of thè polypids in thè auto¬
zooids. Some reticulumzooids become mature. In contrast thè
autozooids of this age are not very active and many of them
include for long periods of time a brown body ; however, some
also contain ovas.

In nature stage I and T are to be found. The « feeding bo-
dies » seem to have been overlooked in thè past, probably be-
cause they are so small. Until now thè development of polypids
in thè « triangular cavities » was not observed in specimens from
nature. Either thè colonies did not reach thè necessary age in na¬
ture, or unfavourable conditions in thè naturai habitats decisi-
vely reduced thè vitality and growth rate. So this species possesses
physiological potences for structure formations, which never or
only seldom may achieve under naturai conditions, but which can
be realized under cultivation conditions.

The development of thè reticulumzooids distinctly shows that
thè formation of a reai polypid depends on a sufficiently enlarged
volume of thè cystid. The reticulumzooids are at first so small,

A CULTIVATION METHOD FOR SALT WATER BRYOZOA ETC.

127

that polypids with tentacles and a gut have unsufficient space.
The formation of thè « feeding bodies » in thè first stage is an
interesting morphoìogical feature, which will later be described
in detail in a separate, histological in vesti gation.

The layer-type growth of thè lateral walls seems to be a no-
velty within thè C hello stornata. The first impressimi is that this
layered walls bear resemblances to those walls found in some
Cyclostomata, but it is not yet clear, wether both structures can
be directly compared.

The described observations allow a phylogenetic derivation of
thè spines of thè genus Membranipora Blain ville from zooids. A
comparison of thè first developmental stages shows without doubt,
that thè basis of thè spines of Membranipora membranacea (L.)

Fig. 3. — Schematic comparison of thè reticulumzooids of Cono-
peum and thè spines of Membranipora. a) starting stage, and b) old
stage (IP) of a reticulumzooid of Conopeum reticulum (L.); c) to-
werzooid, and d) spine of Membranipora membranacea (L.); e) spine
of thè Callopora- type (schematic drawing). af = aperture field;
bb = brown body; c = cystid (basai and lateral walls); cp =: commu-
nication pores and rosette plates; fm = frontal membrane (=af);
fmf = wall building fold of thè fm ; mp = parietal muscle ; o = oper-

culum; p — polypid.

128

D. JEBRAM

are homologous to thè cystidbuds of thè reticulumzooids of Cono-
peum reticulum (L.). The building of thè « towerzooids » from
Membranipora membranacea may serve as a model for thè spines.
The towerzooids arise in that thè front al membrane grows
like a tube upwards, after thè polypids within these autozooids
are reduced. In this case thè autozooids themselves seem to come
into a physiological condition that thè bases of thè spines have,
when they start to build up thè upper part of thè spines. This
upper part of thè spines is homologous to thè tube-like grown
frontal membrane of thè towerzooids. Thus, thè spines of Mem¬
branipora represent much reduced towerzooids. (The « large
spines » of Membranipora villosa Hincks illustrate an interme¬
diate form.) - Silén (1942) derived thè type of spines of Callo-
pora Gray from zooids. The spines and tubercula of Membrani¬
pora are likewise heterozooids, perhaps they have developed in
another phylogenetic way (analogous) (fig. 3).

REFERENCES

Bobin G. & Prenant M., 1962 - Les espèces frangaises du genre Conopeum
Gray (Bryozoaires Chilostomes) - Cahiers de Biologie marine, T. Ili,
pp. 375-389.

Bullivant J. S., 1968 - The rate of feeding of thè Bryozoan, Zoobothryon
verticillotum - New Zeald. J. Marine and Freshwater Res., Voi. 2,
No. 1, pp. 111-134.

Hauenschild C., 1962 - Die Zucht mariner Wirbelloser ini Laboratorium
(Methode und Anwendung) - Kieler Meeresforsch., Bd. 18, Sonderheft,
pp. 28-37, 3 Pls.

Kaissling K.-E., 1963 - Die phototropische Reaktion der Zoide von Bugula
avìcularia L. - Zeitsch. f. vergleic-h. Physiologie, Bd. 46, pp. 541-594.

Marcus E., 1926 - Beobachtungen und Versuc-he an lebenden Meeresbryozoen
- Zool. Jahrb., Abt. f. Syst., Bd. 52, pp. 1-102, Pls. 1-2.

Prenant M., & Bobin G., 1966 - Bryozoaires Deuxième Partie, Chilostomes
Anasca - In: Faune de France, T. 68, 647 pp.

Schneider D., 1959 - Der Aufbau der Bugula- Tierstocke und seine Beein-
flussung durch Aussenfaktoren - Biol. Zbl., Bd. 78/2, pp. 250-283.

Silén L., 1942 - Origin and Development of thè Cheilo-Ctenostomatous Stem
of Bryozoa - Zoolog. Bidrag f. Uppsala, Bd. 22, pp. 1-59.

Atti Soc. It. Se. Nat. e Museo Civ. St Nat. Milano - 108: 129-151, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

19. Group 3 : Ecology and Paleoecology.

John H. Bushnell (*)

ASPECTS OF ARCHITECTURE, ECOLOGY,

AND ZOOGEOGRAPHY OF FRESHWATER ECTOPROCTA

{Bryozoa)

Riassunto. — Vengono esaminate otto specie di Ectoprocta : Phimatella
repens, Plumatella fruticosa, Plumatella casmiana, Plumatella fungosa, Cri-
statella muceclo, Hyalinella punctata, trovate nella parte occidentale del¬
l’America del Nord, Fredericella sultana proveniente dallo Stato del Colo¬
rado, negli Stati Uniti, e Plumatella repens, Fredericella sultana, e Frederi¬
cella australiensis dagli Stati di Chihuahua e Durango, nel Messico.

Le informazioni di carattere limnologico indicano che P. fruticosa è
limitata agli ambienti aventi i più bassi valori e la più ristretta gamma
di ceneri, di sostanze organiche, di CO2 legato, e di pH, e che è la più
vivacemente colorata di tutte le specie indigene del Colorado. Questa specie
si trova soltanto nei laghi montani. P. repens cresce negli ambienti di più
alto livello eutrofico, e F. sultana prevale nelle zone di terreno aperto.
P. casmiana è l’unica specie incontrata in un ambiente prettamente alcalino
dei Grandi Altopiani centrali, e P. fungosa è stata trovata soltanto nei
laghi delle Montagne Rocciose occidentali. P. australiensis è stata notata
in tre diverse località dell’arido altopiano centrale messicano.

Nelle colonie di P. fruticosa trovate nel Colorado, le minuscole aree di
gemmazione si riscontrano di rado. Gli statoblasti di questa specie, in modo
particolare quelle provenienti dagli stagni formati dalle morene glaciali,
sono più grandi di quelle della maggior parte delle altre osservate. P. ca¬
smiana libera leptoblasti attraverso una cisti ialina e un poro vestibolare.
Vengono pure descritti lo sviluppo zoariale di P. fungosa, e la insolita archi¬
tettura zoariale di F. australiensis.

Si discute, inoltre, della classificazione di F. australiensis, e si fa notare
quanto siano rari gli ambienti nel mondo dove si riscontra questa specie.
Si accenna a certi aspetti della morfologia e dell’ecologia che possono costi-

(*) Department of Biology, University of Colorado - Boulder, Colo¬
rado, USA.

130

J. H. BUSHNELL

tuire argomenti validi contro la classificazione di F. australiensis e F. sul¬
tana sotto la medesima specie. Viene esaminata l’adattabilità di certe specie
di Ectoprocta.

Summary. — Eight species of Ectoprocta from western North America
are discussed: Plumatella repens, Plumatella fruticosa, Plumatella casmiana,
Plumatella fungosa, Cristatella muceclo, Hyalinella punctata, and F vederi-
cella sultana from thè State of Colorado, U.S.A. and Plumatella repens,
Fredericella sultana, and Fredericella australiensis from thè States of Chi¬
huahua, and Durango, Mexico.

Limnologica! information shows P. fruticosa restricted to habitats with
thè lowest values and narrowest range of ash, organic, bound C02 , and pH,
and thè highest color of any Colorado species. This species is found only
in montane lakes. P. repens is found in thè more eutrophic habitats, and
F. sultana has thè most euryzonal distribution. P. casmiana was thè only
species associated with an alkali habitat on thè centrai Great Plains, and
P. fungosa only from montane lakes in thè western Rocky Mountains.
F. australiensis occurs at three sites in thè high, arid centrai plateau of
Mexico.

The diminutive budding zone of P. fruticosa is infrequent on Colorado
colonies. Statoblats of this species, especially those from glacial moraine
ponds are wider than most others reported. P. casmiana releases leptoblasts
via a hyaline cyst and vestibular pore. Zoarial development is described for
P. fungosa. Unusual zoarial architecture is described for F. australiensis.

The species status of F. australiensis is considered, and attention is
directed to thè uniqueness of thè world habitats of this species. Certain
aspects of thè morphology and ecology argue against thè conspecificity of
F. australiensis and F. sultana. The adaptive success of certain ectoproct
species is considered.

Zusammenfassung. — Mann diskutiert acht Arten von Ectoprocta aus
den westlichen Nord-Amerika : Plumatella repens, Plumatella fruticosa, Plu¬
matella casmioma, Plumatella fungosa, Cristatella mucedo, Hyalinella punc¬
tata und Fredericella sultana aus Kolorado, Vereinigten Staaten, und Plu¬
matella repens, Fredericella sultana und Fredericella australiensis aus den
Staaten Chihuahua und Durango in Mexico.

Limnologische Informationen zeigen, dass P. fruticosa ist zu den Habi-
taten mit den niedrigsten Werten und den engsten Variationen der Asche,
□rganisches, C02 , pH, und hochster Farbe jeder Kolorado-Arten gehòrig.
Diese art ist nur in montanen Seen gefunden. P. repens ist in mehr eutro-
phischen Habitate gefunden, und F. sultana hat die meist allgemeine Ver-
breitung. P. casmiana ist die einzige Art, die mit einer Alkalischen Habitat
auf der zentralen Pràrie associiert ist, und P. fungosa kommt nur in den
montanen Seen der westlichen Felsengebirgen vor F. australiensis ist von
drei Lokalen der hohen, trockenen Zentral-Plateau Mexico bekannt.

Die winzige Knospenzone der P. fruticosa ist in Kolorado-Kolonien
ausserordentlich. Die Statoblasten dieser Art, speziell aus glazialer Moràn-

ASPECTS OF ARCHITECTURE, ECOLOGY, ETC.

131

Damme, sind breiter als von anderen Arten bekannt. P. casmicina lòst
Leptoblasten via eine hyaline Zyste und eine vestibulare Pore ab. Die zo-
ariale Auswicklung’ ist fiir P. fungosa beschrieben. Eine ausser-ordentliche
zoariale Struktur ist fiir F. australiensis beschrieben.

Die Art-Statur der F. australiensis is diskutiert, und Aufmerksamheit
ist zu den Einzelheiten der Welt-Habitat dieser Art gewidmet. Speziellen
Gesichtspunkte der Morphologie und der Oekologie sprechen wider jeder
Auffassung, dass F. australiensis und F. sultana conspezifisch sind. Die
adaptive Anpassung gewisser Ectoprocten ist diskutiert.

There are few studies or reports of Ectoprocta from western
North America. The occurrence, form, and ecology of thè fresh-
water Ectoprocta in thè west are of particular interest, because
thè geology, soils, vegetation, lakes and streams are different
from those in thè midwestern and eastern regions of thè conti-
nent. I shall, therefore, discuss certain aspects of my studies and
observations on ectoprocts of western North America, especially
as they relate to species of thè genus Plumatella and thè genus
Fredericella. The organisms to be discusseci are from thè State
of Colorado in thè western U.S.A. and from thè States of Chi¬
huahua and Durango in Mexico.

Colorado has thè highest mean elevation of any of thè Rocky
Mountain states, 2073 meters (Pennak, 1963), and there is con¬
siderale intraregional variability in thè geochemistry, topogra-
phy, and climate of thè Rocky Mountain region. There is great
variation, biologically, chemically, and physically, in thè lakes of
thè northern Colorado lake district, especially in thè montane
lakes (2500-3200 m.). Pennak (1945) divided montane lakes lim-
nologically into drainage and semi-drainage lakes. Most of thè
lakes fall into thè first category and are situated in valleys where
there is continuous inflow and outflow. Biologically, thè most
fertile lakes, supporting thè greatest numbers of invertebrates
and thè most luxuriant growths of rooted aquatic plants, are thè
semi-drainage lakes without regular inflow and outflow. Lakes
and ponds in thè montane region are often closely encircled by
spruce and pine, but on other occasions by willow and dwarf
birch. On thè western slopes of thè Rocky Mountains in northern
Colorado nearly pure stands of lodgepole pine surround some
lakes while aspen may surround others. Many of these lakes are

J. H. BUSHNELL

locateci on thè nearly level surface of mesas where arid or semi-
arid conditions prevali.

The alpine lakes are far less variable and less productive.
The exposed rocks of most of thè Rocky Mountains are largely
insoluble schists, gneisses, and granites low in nitrates, sulfates,
phosphates, carbonates, and fluorides (Pennak, 1963). There is
little organic matter being washed into thè majority of high lakes
as water filters through a very thin soil cover. Pennak has pointed
out that many high lakes have a total ash content of less than
15 mg/1, 6 to 12 mg of this total being Silicon compounds thereby
leaving only 3-9 mg for all other inorganic ions. After Silicon, cal-
cium and bicarbonate ions are deducted, all other inorganic ions
may contribute less than 1 mg/1 to thè total ash content of thè
water. The pH of thè waters of thè alpine and montane lakes in
generai are around neutrality or slightly below. Pennak (1963)
gives average figures of 28.52 and 10.41 mg/1 respectively of ash
and total organic matter in montane drainage lakes and 60.23
and 34.08 mg/1 of thè same in montane semidrainage lakes.
Average figures for ash and organic matter for alpine lakes are,
of course, lower. Calcium and phosphate-phosphorous are nearly
thè same for semidrainage and drainage montane lakes, while
nitrate^nitrogen is considerably higher in thè former, on thè
average 1.137 mg/1 to 0.168 mg/1. That this nitrogen accumulator
role of semidrainage lakes may be of fundamental importance in
thè biology of montane lakes has been strongly endorsed by
Pennak (1958).

There is a considerable increase in tota! residue in thè plains
lakes of Colorado as compared to thè true mountain lakes. Plains
lakes are those below 1700 meters in altitude. Considerable locai
variations in thè geochemistry contribute to great variation in
thè plains, and lakes become more alkali thè farther one travels
east from thè mountains. The greater distances thè rivers flow
out onto thè plains thè greater thè aceumulation of various Che¬
micals. The nonalkali plains lakes average 202.96 mg/1 ash and
24.96 mg/1 of organic material, while comparable figures for al¬
kali lakes are 1,729.78 and 237.20 mg/1 (Pennak, 1963). The only
large bodies of water in thè mountains of Colorado are thè res-
ervoirs, all formed in recent years. Of thè naturai lakes, mostly
glacial in origin, almost none are as large as one square mile in

ASPECTS OF ARCHITECTURE, ECOLOGY, ETC.

133

size or much over 5 meters in depth. Nearly all thè plains lakes
in thè Rocky Mountain region are artificial, formed by damming
one or more shores, and connected via a network of irrigation
canals. Some are flushed rather severely by regular inflow and
outflow, or by irrigation needs; others have a more stable water
leve!, thus encouraging thè development of more stable biological
communities.

In extremely thorough recent searches of Colorado plains,
montane and alpine lakes, (a total of 44) seven species of Ecto-
procta have been found in 31 lakes and 2 streams. All of thè lakes
in which ectoprocts were not found were either strongly alkali
plains lakes, 25-150 miles east of thè eastern foothills of thè Rocky
Mountains or certain of thè very high alpine lakes, e.g., Summit
Lake (3884 meters), at thè base of rock and gravel strewn cirques.
With respect to these two extremes of habitat, only one species,
FredeHcella sultana , has been found in Colorado in an alpine
lake and only one species, in a single locale, in a shallow, centrai
plains, alkali lake, Plumatella casmiana.

The two most common species in thè Rocky Mountain region
of western North America are Plumatella repens (12 sites) and
Plumatella fruticosa (10 sites). Certain limnological data for all
species are given in Table I. It is remarkable that P. fruticosa
was disco vered in ten of thè 31 lakes in which ectoprocts were
found. This equals thè number of times this species was found
in 123 ectoproct inhabited lakes in Michigan (Bushnell, l965a).
Prior to thè Michigan report thè species had been found in only
two locations in thè much more extensively explored eastern half
of North America. This suggests that thè species may be much
more common in thè western portions of thè continent.

All specimens of P. fruticosa were taken from montane lakes
and ponds both east and west of thè Rocky Mountain Continental
Divide. In thè east thè collections were taken largely from small
glacial moraine ponds with thè greatest abundance of colonies
being taken from locations on top of thè Arapahoe glacial mo¬
raine, a termino-lateral moraine. This moraine lies at thè base of
two valleys, both pointing into thè Continental Divide. The ponds
are all about 10,400' in altitude, surrounded very closely by lod-
gepole pine and englemann spruce. In some cases thè ponds are

134

J. H. BUSHNELL

surrounded by a wide trembling sedge border (Fig. 1) while other
ponds are overhung by dwarf birch and willows.

Collection sites to thè west were small lakes largely encircled
by lodgepole pine or aspen. All thè montane ponds were from
0.3-1. 5 meters in depth and frozen to thè bottoni in winter. In
most of thè ponds and lakes either Nuphar polysepalum, native
to thè Rocky Mountain region, or Sparganium sp. (or both) are
present.

The lakes in which P. repens was found were mostly on thè
western edge of thè Great Plains, adjacent to thè foothills zone.
Other collections were taken from montane, semidrainage lakes.
In all cases they were taken from lakes with rich growths of
rooted aquatics and floating algae, most commonlv potomogetons,
Myriophyllum, Elodea canadensis and Ceratophyllum demersum.
The biological and Chemical conditions most closely resembled
those prevailing in large numbers of eutrophic waters in thè lake
districts of midwestern U.S.A.

Plumatella fungosa was found in four montane lakes west of
thè Continental Divide, all within a few miles distance from each
of thè other collection sites. Two of thè locations are reservoirs ;
one a naturai lake in thè lodgepole pine surrounded by high
rocky bluffs and traversed by a gentle inflow and outflow stream.
The last location is a lake formed by beaver dams in a small dra-
inage stream. The two small reservoirs in which thè most lux-
uriant colonies appeared were partially surrounded by aspen, and
otherwise by gentle slopes covered by sagebrush and other arid
plateau vegetation. The thick encrustments of P. fungosa were
found in small bays shaded by dense aspen groves. Dense growths
of Polygonum and a remarkably rich plankton community were
present.

None of thè lakes in thè high plateau district (North Park
area) on thè western slopes of thè Rocky Mountains, where P.
fungosa was found, are severely flushed by rapid inflow streams
and snow melt in thè spring and earlv summer. Because of this
these lakes are not subject to thè severe seasonal turbidity and
loss of organic material, e.g., nitrates, characteristic of drainage
lakes located in steeper terrain on thè eastern slopes.

The two occurrences for Plumatella casmiana, previously
identified in thè western hemisphere only from material collected

ASPECTS OF ARCHITECTURE, ECOLOGY, ETC. 135

in Lake Erie or its environs, extends thè range of this species
considerably. The alkali reservoir from which it was collected in
thè treeless centrai Great Plains region of eastern Colorado has
a maximum size of approximately 3696 acres. In this habitat thè
zooecia were attached to twigs of shrubs in a 6 ft. wide irrigation
inlet and to a few pieces of deteriorated vegetation on a shallow
wind-blown shore. The second collection was taken from a small
grave! pit pond, 5 miles east of thè foothill zone of thè Rocky
Mountains, near Boulder, Colorado. The basin of this 1/4 acre
pond was a foraier gravel pit, one of several, in thè vicinity.
These gravel pits have been supplied almost entirely by ground
water seepage from nearby Boulder Creek. While most of thè
associated gravel pit ponds or lakes (Sawhill lakes) lacked vege¬
tation, thè one in which P. casmiana was found was thickly over-
grown from one shore to another by a rooted aquatic community
of which Cerai ophylliim clemersum and Elodea canadensis were

Fig. 1. — A moraine pond in thè Rocky Mountains of Colorado.
One of several montane ponds in which Plumatella fruticosa is

found.

136

J. H. BUSHNELL

codominants. The ectoproct was covering every substrate in late
June and early July of this year, i.e., logs, rocks, and densely ent-
wined about thè stems and leaves of thè dominant rooted aquatic
plants. By July 8 floating algal mats ( Rhizoclonium sp.) occupied
nearly all thè open water among thè rooted aquatic plants.

The single small colony of Hyalinella punctata was found in
a semidrainage montane lake on thè eastern slopes of thè Con¬
tinental Divide. A very thick and clear gelatinous zoarium had
developed a small colony. No statoblasts had been produced, but
thè statoblast from which thè colony had developed was present.
It was thè small type floatoblast, heretofore not reported for
Hyalinella punctata in thè western hemisphere.

The locations for Cristatella mucedo were Glacier Lake and
Muskee Lake, both montane lakes. Small colonies of no more than
40-50 individuai were found in thè early summer of 1967 and
again in 1968. The temperature of thè lake on July I, 1968, was
15 C. No large colonies were found in late summer and early
autumn but numbers of statoblasts could be found along thè rocky
lake shores. This species was not unexpected as it has a holoarctic
distribution in several colder north temperate lakes. The author
has taken thè species from two lakes 75 miles Southwest of Hudson
Bay in north centrai Canada.

The seven locations from which Fredericella sultana was
taken establish thè species as thè most euryzonal and euryokous
species in thè Colorado collections. It occurs from lakes on thè
western Great Plains up to lakes in thè alpine zone, in both
eutrophic and oligotrophic situations and in both lotic and lentie
water». This wide range of habitat, evident for F. sultana in thè
Rocky Mountains region only reinforces thè broad physical and
Chemical adaptability demonstrated and discussed for this species
in an earlier study (Bushnell 1966).

The altitudinal range and certain standard limnologica! va-
lues for ectoproct habitats in Colorado are summarized in Table I.
It is apparent that F. sultana inhabits waters with thè lowest,
or near thè lowest, figures for all limnological measurements
given. Plumatella repens shows somewhat higher figures for all
categorie». However, unpublished data for these same limnological
categories from Michigan and Pennsylvania are generally consis-
tent with Table I, except that F. sultana occurred in these states

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138

J. H. BUSHNELL

at sites with ash, organic, and pH readings nearly as high (in
two cases higher) as P. repens in Colorado. F. sultana has a
lower temperature tolerance, grows and begins development at
lower temperature®, and demonstrates greater physical and Che¬
mical tolerances than other species in its ability to develop on
wave washed shores, in rapid rivers and in locations near thè
bottom. There is increasing evidence that F. sultana will not
tolerate thè extreme high temperature®, (e. g., 35°C. and over)
endured by P. repens, or situations in which an extremely high
pH prevails. While thè low figures in Table I for Plumatella
fruticosa are in dose agreement with those for F. sultana, thè
ranges for this species are narrowest of all. This sup-ports thè
contention (Bushnell 1966) that this species is more narrowly
adapted to generally oligotrophic neutral or slightly acid, and
often highly colored waters. Similar habitats, and associations
with indicator organism of such habitats, Tabella pennsylvanica
and Batrachospermum ectocarpum have been discussed for Mi¬
chigan. The habitat data (Table I) for Plumatella fungosa, are
consistent with those for P. repens. The measurements for species
with fewer collection sites are important only as they may be
combined with future limnologica! information.

The tabular information is not given to suggest that one or
another factor is by itself restrictive or congenial for a particular
species, but only to indicate that generally different environ-
mental situations may be associated with different species. It
suggest® that other unmeasured factors, associated with these
generai limnologica! conditions, may govern thè occurrence of
freshwater ectoprocts.

A somewhat unexpected aspect of ectoproct distribution in
Colorado is that only fi ve co-occurrences of ectoprocts are recor-
ded for thè 33 extensively studied habitats in which these animals
have been found. In none of these five lakes were more than two
species found. Some of this is doubtless explained by thè small
size of thè naturai lakes in Colorado, from which a majority of
thè collections were made. The lakes of eastern North America,
from which several species have been reported (Bushnell 1965a),
have been much larger lakes. These larger lakes offer a consi-
derably greater variety of intralake habitats, viz., bays with

ASPECTS OF ARCHITECTURE, ECOLOGY, ETC. 139

considerable plant growth, extreme wave washed shores, several
different plant communities, and inlets where slowly moving
rivers deposit considerable river berne organic material and de-
tritus as they enter thè lake. The fact that so many of thè very
small Colorado lakes are frozen to thè bottoni during thè winter
and that so few have even a temporary thermocline, and thè
enriching effeets of a spring and autumn overturn, may be other
factors. Certain barriers to easy distribution, e. g., mountain
ranges, steep stream gradients, a vast semiarid region to thè east,
north and south (with predominantly strongly alkali ponds or
reservoirs) and a prevailing westerly wind, may help to explain
thè paucity of species in any given habitat.

The five co-occurrences involved F. sultana and P. fruticosa
on two occasions, in lakes no more than one mile distant and
connected by a creek, C. muceclo and P. repens, C. mucedo and
F. sultana, and P. repens and H. punctata. In no location were
these co-occurring species found in dose physical association.

Knowledge of thè freshwater Ectoprocta of Mexico is limited
essentially to a paper by Rioja (1940) in which P. fruticosa,
several phases of P. repens, H. punctata and F. sultana are all
reported from Lake Xochimilco near Mexico City. The author
has taken ectoproets from thè states of Durango and Chihuahua,
with most collections coming from reservoirs or shallow irri-
gation lakes on thè high plateau of centrai Mexico, in thè
Chihuahuan desert region of Chihuahua and northern Durango.
A single small colony of P. repens was taken from a roadside
pond (former excavation site) near thè southern boundary of
Chihuahua. The marshy habitat was largely overgrown with thè
tali Typha domingensis . A second collection was taken from a
small lake in Durango province. Numerous colonies of F. sultana
were found in a small stream high in thè Sierra Madre Occi¬
dentale mountain range of west centrai Durango.

The most extensive and ìuxuriant specimens of Ectoprocta ,
Fredericella australiensis , were obtained from shallow reservoirs,
or irrigation lakes, of thè arid, largely treeless, somewhat rolling
centrai plateau of Mexico (Fig. 2). The rare F. australiensis was
taken from three sites of this region, one in Chihuahua and two
in northern Durango. Rooted vegetation was not abundant in any

140

J. H. BUSHNELL

of thè lakes. One had patches of Scirpus sp. in thè vicinity of thè
ectoproct growths, and a second very shallow irrigation reser-
voir had heavy bottoni growths of Ludwigia palustris.

Colonies of F. australiensis were growing on almost all thè
plants and rocks sampled in these lakes. The near shore area of

Fig. 2. — Big Boquilla Reservoir (Lake) in southern Chihuahua
Desert, Mexico. Numerous colonies of F redericella australiensis were

taken here.

both lakes was covered with several inches of gyttja and thè
plants were often encrusted with a whitish detritus. Colonies
found in thè third lake were smaller. This lake was notably
barren, with a bottoni of large rocks and smaller rubble. All
three lakes were created by thè damming of small shallow desert
streams or by irrigation canals from temporary streams. None
of them was more than fifteen years old. All collections were
made during August and thè water temperature was 30°C-35°C
during thè day. A few insect larvae and oligochaetes were thè

ASPECTS OF ARCHITECTURE, ECOLOGY, ETC.

141

most obvious associateci animals. However, thè sponge Astero-
myenia piumosa was closely associateci with F. australiensis in
one of thè lakes.

Colony Form and Morphology.

Detailed measurements and descriptions of thè eight species
of Ectoprocta discussed in this paper will be contained in a sepa¬
rate publication now in preparation. However, certain aspects of
thè colony growth, measurements, and some speculative conside-
rations are appropriate to thè present discussion.

In generai, all specimens of P. repens, P. fruticosa , and
P. casmiana conform to previously published « tvpical » descrip¬
tions. Only one colony of P. repens, taken from a Colorado sands-
tone quarry, was somewhat unusual in that thè zooecia protruded
nearly vertically from thè substrate for distances of 2.1 to nearly
3.0 mm. Several orifice areas were somewhat serrated. In all
other characters these specimens and those from other locales
conformed, e. g., lack of encrustation, statoblast morphology and
measurements, tentacle number, shape of zooecia, amount of
septation, and colony forni, as summarized for this species by
Bushnell (1965b; Table I).

Colonies of P. fruticosa are largely consistent with Michigan
specimens (Bushnell, 1965c) in such characters as zooecial size,
transparency, keeling, septation, tentacle number and growth
pattern. Many colonies in thè moraine ponds were only loosely
attached to thè substrate, sometimes hanging down from thè
undersurface of sticks for 3-6 centimeters. The linear series of
small daughter zooecia produced by a mother zooecium were
found in colonies from only two of thè ten collection sites, in
both cases from moraine ponds. This unique budding zone of
P. fruticosa was found in colonies from only 4 of 10 collection
sites in Michigan (Bushnell 1965c). It had not been mentioned
previously for thè western hemisphere (Davenport, 1904, Lake
Erie; Rogick, 1935, Lake Erie; Rioja, 1940, Mexico; Marcus,
1942, Brazil). From thè papers of Jullien (1885), Wiebach
(1954), and Toriumi (1954) it is obvious that thè linear budding
zone of P. fruticosa frequently has a greater number of daughter
buds in a series, and is more often observed, on european and
eastern asiatic specimens, than on those from North America.

J. H. BUSHNELL

142

Statoblasts of P. fruticosa collected in western North Ame¬
rica are not so narrow as those from Michigan or from thè
eastern hemisphere. The length to width ratio for floatoblasts
from other collections is usually between 2.3 : 1 and 2.8 : 1 (e. g.,
Braem, 1890; Pateff, 1924; Toriumi, 1954; Bushnell, 1965c).
Ratios for sessoblasts have been similar to those for floatoblasts.
The length to width ratios of thè statoblasts in Michigan collec¬
tions is 2.45 : 1 for floatoblasts and 2.3 : 1 for sessoblasts. In thè
Colorado collections thè length to width ratio for all but one
collection site is 2.04 : 1 for floatoblasts and 2.31 : 1 for sessoblasts.
Collections from lakes on thè western slopes of thè Rocky Moun-
tains had thè narrowest statoblasts, 2.21 : 1 for floatoblasts and
2.25: 1 for sessoblasts. Brainard lake, a cold montane lake (10,000
ft. elev.) fed by two rushing streams emanating from tundra
glaciers, has colonies of P. fruticosa with statoblasts consistente
less elongate than most other reports (Fig. 3, 4). From measu-
rements of more than 200 statoblasts in thè past three years
floatoblasts from Brainard lake have a length to width ratio of
1.60:1 and sessoblasts a ratio of 1.64:1.

Other reports of unusually wide statoblasts have been made
for P. fruticosa (Annandale, 1911, India; Vorstman, 1928, Java;
Marcus, 1942, Brazil). Toriumi (1954) seriously questioned thè
validity of thè Vorstman and Annandale specimens, claiming, in
effect, that they did not overlap thè range of length to width
rations of P. fruticosa . Vorstman gives a ratio of 1. 6-2.0 : 1.
Marcus (1942) published thè last description of unusually wide

Fig. 3. — Wide floatoblast of Plumatella fruticosa from Brainard Lake,
Colorado.

Fig. 4. — Wide sessoblast of Plumatella fruticosa.

Fig. 5. — Portion of a colony of Plumatella fungosa from Ninegar Reser-
voir, Colorado.

Fig. 6. — Densely entwined colony of Fredericella australiensis on stem of
Ludwigia palustris from Big Boquilla Lake, State of Chihuahua,
Mexico.

Fig. 7. — Statoblast of Fredericella australiensis from Big Boquilla Lake,
State of Chihuahua, Mexico.

144

J. H. BUSHNELL

P. fu uticosa statoblasts from colonies f ound in thè southern por-
tion of thè State of Sào Paulo, Brazil. For these he gave an
average ratio of 1.76:1 in thè text, (1.66:1, in summary). This
is dose to thè same as thè figures for Brainard Lake, Colorado.
His drawing, figure 2, showing a floatoblast of P. fruticosa is
remarkably like figure 3, in this paper. Even though Marcus was
not completely satisfied with thè identification of P. fruticosa in
Brazil, and recent keys to thè freshwater Ectoprocta continue to
state that statoblasts of P. fruticosa are more than twice as long
as broad, there is no doubt from thè range of ratios for Colorado
specimens that there is a continuum as regards shape. Once again
thè extreme variability of criticai identification characters for
freshwater ectoprocts is highlighted. A ratio of 1.6:1 is one
extreme for statoblasts of P. fruticosa. The other extreme is a
ratio of more than 3 : 1 for thè commonly narrower european
specimens (Wiebach, 1954).

The lamella on thè sessoblasts of P. fruticosa is characte-
ristically wide and possesses thè sharply defined reticulations,
better developed by this speeies than by any other freshwater
ectoproct. The tuberculations at thè periphery of thè capsule are
not in generai as abundant or elongate on Colorado samples as
they are on so many of thè Michigan specimens.

Specimens of P. casmiana from thè western United States
are in excellent agreement with descriptions by Ora (1907),
Rogick (1941), Toriumi (1955a), Sebestyen (1961) and Wiebach
(1963). In fact, as one examines an increasing number of speci¬
mens of this speeies, there appears to be a refreshing consistency
with respect to thè architecture of thè colony, thè individuai
zooecia and polypides, and thè statoblasts. The keel, encrustation,
hyaline furrow, tentacle number (30-40 in Colorado specimens),
and growth pattern are in dose agreement for colonies collected
from numerous regions of thè world. There is a conformity with
respect to float coverage on thè pyknoblasts of all collections -
similar in size to P. repens , but intermediate with respect to
float coverage between P. emarginata and P. repens. The lepto-
blasts from many sites are likewise largely identical. Only
leptoblasts were being produced by thè hundreds of colonies
found in Sawhill pond near Boulder, Colorado in June and early
July, 1968. Most of thè colonies from thè alkaline Nee Noshe

ASPECTS OF ARCHITECTURE, ECOLOGY, ETC.

145

Reservoir (July 1967) in thè arid centrai Great Plains were pro-
ducing leptoblasts, but a few had pyknoblasts. Some colonies at
each location had developed from pyknoblasts, others from lepto¬
blasts, and sessoblasts. In recent collections from Sawhill pond
several leptoblasts were released through a vestibular pore. This
phenomenon was first noted for species of Stolella and for
Hyalinella carvalhoi by Marcus (1941, 1942). Wiebach (1952)
described thè release of floatoblasts from polypides of P. fruti¬
cosa through thè agency of a protrusive hyaline cyst. A similar
cyst was observed as thè mechanism of release of leptoblasts in
P. casmiana.

The author has continuing reservations about thè species
status of Plumatella fungosa. Certainly no characteristic argues
more strongly for thè species status of this form than thè mas¬
sive and physically tough zoarium produced by thè vertical
growth of parallel series of zooecia and by thè unusually perma-
nent adherence of all zooecia. A degree of zooecial adherence is
known for other species, e. g., P. emarginata, but nowhere is it
so important for colonial form as in P. fungosa. The zooecia will
tear at any location before they will break at points of contact
with other zooecia.

Certainly, as Wesenberg-Lund (1896) claimed, massive co¬
lonies of P. fungosa are formed by thè simultaneous germination
of numerous statoblasts on a substrate. Fungoid colonies of P. re-
pens have been formed on a substrate over successive years
(Bushnell 1965b), but thè important colonial aspect (as stressed
before) that must distinguish P. fungosa from other fungoid-tvpe
colonies is thè vertical nature of thè zooecia, and thè denseness
of thè zoarium resulting from thè total adherence of all zooecia.
There is some question as to whether such a distinction is always
made by biologists reporting fungoid masses as P. fungosa. Those
colonies from Sardinia, pictured by Carrada (1964), described
by Lacourt (1949, reports P. fungosa as most common species in
thè Netherlands) may not be, in each case, thè exact form port-
rayed by Allman (1856).

The colonies in Colorado develop first as small intertwining
colonies, germinated from sessoblasts in numerous parallel series
on thè substrate, and from large numbers of floatoblasts caught
in detritus of thè substrate. The remarkable stickiness of thè

J. H. BUSHNELL

146

newly germinateci ancestrulae and subsequent zooecia insures that
not only zooecia will adhere, but also ancestrulae will attach to
any piece of sand or wood or detritus. This means that several
zooecia, originally not contiguous, will eventually (with growth)
be brought into physical contact bv their strong adherence to
small chunks of matter on which other zooecia are also adherent.
Borg (1941) refers to thè P. repens- type young colonies of P. fun¬
gosa. Small colonies in thè early stages of growth are frequently
encrusted. The base of a large zoarium is composed largely of
horizontal zooecia richly intertwined. Later thè zooecia of thè
total compound colonial mass is directed vertically (Fig. 5).

The statoblasts of P. fungosa in Colorado resemble those of
P. repens, but they are larger (average 0,475 X 0,305 min). Ave-
rages for Michigan floatoblasts for P. repens (Bushnell 1965b)
were 0.35 X 0.26 mm. (Colorado floatoblast sizes are comparable).
The largeness of thè P. fungosa statoblasts is mentioned by Abri-
kosov (1927a), Borg (1941), and Lacourt (1949). The latter
describes a small and a large statoblast for colonies of P. fun¬
gosa , thè large one not quite as large as thè average for Colo¬
rado specimens.

The single small colony of H. punctata in a Colorado mon¬
tane lake was colorless, linear, and with a zooecial diameter of
more than 0.95 mm. There were no protruding zooecial tips, only
a fiat zoarial surface from which poìypides could be extended.
There were no statoblasts except thè one from which thè colony
had originated. This floatoblast was a small floatoblast, only
slightly larger than those described by Lacourt (1949). Krae-
pelin (1887) and Toriumi (1955b) also refer to thè small stato¬
blasts sometimes associated with H. punctata.

The colonies of F. australiensis from Mexico were largely
repent, not showing thè long raised tips portrayed by Rogick
(1945) for Wyoming specimens. A keel was moderately developed
on thè repent portions, but largely absent on thè somewhat raised
tips. It was not nearly so well defined as on thè repent zooecia
of F. sultana. While thè colonies were usually loosely encrusted
thè luxuriant colonies were different from previous descriptions
in their growth form. They tended to intertwine forming compact
nodular masses on thè stems of plants (Fig. 6).

ASPECTS OF ARCHITECTURE, ECOLOGY, ETC.

147

The colonies agree more closely in measurements, tentacle
number, zooecial diameter, and zooecial shape (elliptical in cross
section) with Rogick’s (1945) var. broivni than with var. trans¬
caucasica (Abrikosov, 1927b) or australiensis (Goddard, 1909).
The statoblasts of thè Mexican collections average 0.376 mm. bv
0.292 mm. The zooecia while being as narrow as 0.235 mm., ave¬
rage 0.40 mm. (Fig. 7). There were often 3 to 4 statoblasts in
each zooecium.

The species status of F. australiensis is in doubt. Borg’s
(1936) specimens from thè centrai Sahara, as Rogick (1945) sug-
gested, appear to be F. australiensis rather than F. sultana. Mar¬
cus (1946) described a variety from Brazil as F. sultana crenu-
lata , seemingly intermediate between F. sultana and F. austra¬
liensis. Marcus (1953) described F. australiensis for Lake Ti-
ticaca, Abrikosov (1961) split Fredericella into several species,
subspecies and varieties, feeling that differences in statoblast
design and dimension are sufficient for increasing all subgeneric
categories. Then Bonetto and Cordiviola (1965), perhaps more
reasonably, suggested that probably only one species of Frederi¬
cella should be recognized, F. sultana. They suggested this on
thè basis of collections in Argentina where statoblasts from a
single locale show a continuum in shape, ranging from F . sultana
through var. crenidata to F. australiensis. They also claim a
direct relationship between narrowness and speed of water. Se¬
vera! freshwater ectoproctologists have doubtless considered that
thinner zooecia, and a more pronounced keel (physical reinfor-
cement), are likely to be associated with lotic situations. Indeed,
it appears that this may be true for Plumatella emarginata which
occurs more frequently in streams than does P. repens. Even
though thè author would like to accept thè single species concept
for Fredericella on thè basis of such a contention, experience
with United States collections of F. sultana will not support this.
Numerous collections of extremely narrow* statoblasts and narrow
zooecia have come from lentie habitats. Nevertheless, if it is as-
sumed that F. australiensis is, in faci, conspecific wTith F. sultana ,
then, presumably, environmental influences are of some impor-
tance in dictating thè intraspecies differences betw*een these two
forms. All thè major differences suggest this possibility. F. aus¬
traliensis is consistently huskier than F. sultana, i.e., greater

J. H. BUSHNELL

148

number of tentacles, noticeably wider zooecia, larger sessoblasts
and a generally somewhat larger number of sessoblasts. If these
are intraspecific differences, then it might be assumed further
that thè differences described are attributable to a more favo-
rable environment, e.g., nutritional. It is generally true for ani-
mais that differences of magnitude of various body dimensions
and number of parts, as a mark of intraspecies variation, is cau-
sally associatori. with nutrition or a generally more optimal en¬
vironment. This suggests that thè generally more robust austra -
liensis forni of F. sultana is found in thè most favorable habitats.
There is, unfortunately, no concrete evidence to support this. What
scattered evidence does exist suggests, if anything, thè opposite.
The Mexican bodies of water are all new within thè past 10-15
years. Except at Big Boquilla there was very little organic matter
and no abundance of other organisms. The irrigation reservoir
in Durango province was shallow. The water had a greyish tur-
bidity following wind agitation of thè water. The abundance of
F. anstraliensis was greater here than at either of thè other two
Mexican sites.

Something besides nutrition may be assumed to be dictating
intraspecies differences, but it can stili be argued that if this
is so thè more robust anstraliensis must nevertheless enjoy thè
more optimal habitats. But then it is difficult to believe that
there are so few optimal habitats for F. sultana , when thè species
is so much more common and cosmopolita!! and frequently so
luxuriant in its growth. It is possible that F. anstraliensis is an
intraspecies variant with a peculiar genotype, for some reason
especiallv successful at certain sites. Attention should be directed
to thè kinds of habitats in which F. australiensis has been found.
Regrettably there is little quantitative limnological information
on these locales, but there is a certain uniqueness about them.
F. australiensis has never been found in any of thè great tempe¬
rate zone lake districts of thè world where most of thè collecting
has taken place. In these regions, whether from lakes, ponds, or
streams, only thè typical F. sultana occurs. Instead, except for
thè intergraaing statoblasts of thè Argentine collections, reports
of F. australiensis come from semiarid or arid desert regions, viz.,
inland New South Wales, thè arid east Georgian region around
Tiflis between thè Caspian Sea and thè Black Sea, a stream in

ASPECTS OF ARCHITECTURE, ECOLOGY, ETC.

141)

thè centrai Sahara, Lake Titicaca, an alkali pond in southwestern
Wyoming, and from thè arid Chihuahuan Desert and centrai pla¬
teau of Mexico. The range of soils found in such areas (Bunting,
1965), e.g., chernozems, serozems, alkaline-calcareous rich in silt,
grey-brcwn alluvium rich in calcium and magnesium carbonates,
red calc-loams, gypseous clay, sand, will help dictate thè water
chemistry for such habitats. The mean water temperature at
these locations may affect thè aquatic life, as will thè qualitatively
and quantitatively different allochthonous material which is blown
or leaches into thè lakes and streams.

We are left with thè somewhat tenuous supposition that
these two forms, F. sultana and F. australiensis, are separate
species and that any overlap in characteristics, reflects, again,
thè potentiaì phenotypic plasticity of members of thè Phylacto-
laemata. In this case thè unique habitats frequented by F. aus¬
traliensis suggest two species with a different ecology, with F.
sultana being thè more successful and euryokous form.

Acknowledgements.

Appreciation is extended to: Dr. Scott Herrmann, for certain limnolo-
g'ical data which were combined with those of thè author in producing
Table I; Dr. Doris Love, for her German summary; Mrs. C. Julia Amari,
for her Italian summary.

REFERE N CES

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Rend. Ac-ad. Sci. URSS, 19(A), pp. 307-312.

Abrikosov G., 1927b - To thè knowledge of thè fauna of thè Caucasus -
Russ. Hydrobiol. Zeitschr., Saratov, USSR, 6, pp. 84-92.

Abrikosov G., 1961 - Sistematika i geograficheskoe rasporstraneniye roda
Fredericella (Bryozoa, Phylactolaemata) - Zool. Zhur., 40 (3), pp. 334-
339.

Allman G. J., 1856 - A monograph of fresh-water Polyzoa - Ray Soc.,
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Annandale N., 1911 - The Fauna of British India. Freshwater Sponges,
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240, 245-247.

150

J. H. BUSHNELL

Bonetto A. A. & Cordiviola E., 1965 - Notas sobre Briozoos ( Endoprocta
y Ectoprocta ) del Rio Parana. III. Fredericella sultana (Blumenbach)
en el Parana medio - Physis, 25, pp. 255-262.

Borg F., 1936 - Sur quelques Bryozoaires d’eau douce Nord-Africains - Bull.

Soc. Hist. Natur. Afrique du Nord, 27, pp. 271-283.

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Bunting B. T., 1965 - The Geography of Soils - Aldine Pubi. Co., Chicago,
pp. 213.

Bushnell J. H., 1965a - On thè taxonomy of freshwater Ectoprocta in
Michigan - I. Trans. Amer. Micros. Soc., 84 (2), pp. 231-244.
Bushnell J. H., 1965b - On thè Taxonomy of freshwater Ectoprocta in
Michigan - II. Trans. Amer. Micros. Soc., 84 (3), pp. 339-358.
Bushnell J. H., 1965c - On thè Taxonomy of freshwater Ectoprocta in
Michigan - III. Trans. Amer. Micros. Soc., 84 (4), pp. 529-548.
Bushnell J. H., 1966 - Environmental relations of Michigan Ectoprocta,
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Carrada G. C., 1964 - Plumatella fungosa (Pallas) e Paludicella articulata
(Ehrenberg) ( Bryozoa ) nello stagno di Cabras (Sardegna occ.) -
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Davenport C. B., 1904 - Report on thè fresh-water Bryozoa of thè United
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Goddard E. J., 1909 - Australian fresh-water Polyzoa - Proc. Linn. Soc. N.S.
Wales, 34, pp. 487-496.

Jullien J., 1885 - Monographie des Bryozoaires d’eau douce - Bull. Soc.
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Kraepelin K., 1887 - Die Deutschen Susswasser-Bryozoen - Abh. Naturw.
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pp. 289-321.

Marcus E., 1941 - Sobre Bryozoa do Brasil - Boi. Fac. Fil. Cien. Letr. Univ.
Sào Paulo, Brazil, 5, pp. 3-208.

Marcus E., 1942 - Sobre Bryozoa do Brasil II - Boi. Fac. Fil. Cien. Letr.

Univ. Sào Paulo, XXV, Zool. 6, pp. 62-87.

Marcus E., 1946 - New Brazilian forni of Fredericella sultana - Comm.

Zool. Mus. Hist. Natur. Montevideo, 2 (31), pp. 1-10.

Marcus Evel., 1953 - Bryozoa from lake Titicaca - Boi. Fac. Cien. Letr.,
Sào Paulo, Zool., 18, pp. 149-163.

Oka A., 1907 - Zur Kenntnis der Sùsswasser - Bryozoen Fauna von Japan -
Annot. Zool. Japan, VI, pp. 117-123.

Pateff P., 1924 - Mitteilungen iiber die Sùsswasser - Bryozoen Bulgariens -
Trav. Soc. Bulg. Sci. Nat., 11, pp. 119-121.

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Pennak R. W., 1945 - Some aspects of thè regional limnology of northern
Colorado - Univ. Colo. Studies, D, 2, pp. 263-293.

Pennak R. W., 1958 - Regional lake typology in northern Colorado, U.S.A. -
Verh. intera. Ver. Limnol., 13, pp. 264-283.

Pennak R. W., 1963 - Roc-ky Mountain States (from Limnology in North
America) - Univ. Wisc. Press, pp. 349-368.

Rioja E., 1940 - Contribucion al conocimiento de los Briozoarios del Lago
de Xochimilco - Ann. Inst. Biol. Mex., XI, pp. 585-592.

Rogick M. D., 1935 - Studies on fresh-water Bryozoa. IL Bryozoa of Lake
Erie - Trans. Amer. Micros. Soc., 54, pp. 245-263.

Rogick M. D., 1941 - Studies on fresh-water Bryozoa. X. Occurrence of
Plumatella casmiana in North America - Trans. Amer. Micros. Soc.,
60, pp. 211-220.

Rogick M. D., 1945 - Studies on fresh-water Bryozoa, XVI. Freclericella
australiensis var. browni - N. Var. -Biol. Bull., 89, pp. 215-228.

Sebestyen 0., 1961 - Occurrence of Plumatella casmiana Oka (Bryozoa) in
Lake Balaton - Annal. Biol. Tihany, 28, pp. 125-133.

Toriumi M., 1954 - Taxonomical study on fresh-water Bryozoa. Vili. Plu¬
matella fruticosa Allman - Sci. Rep. Tohoku Univ., 20 (4), pp. 293-302.

Toriumi M., 1955a - Taxonomical study on fresh-water Bryozoa. X. Pluma¬
tella casmiana Oka - Sci. Rep. Tohoku Univ., 21 (1), pp. 67-77.

Toriumi M., 1955b - Taxonomical study on fresh-water Bryozoa. XIII.
Hyalinella punctata (Hancock) - Sci. Rep. Tohoku Univ. 21 (4),

pp. 241-247.

Vorstman A. G., 1928 - Some Fresh-water Bryozoa of West Java - Treubia,
10, pp. 1-14.

Wesenberg-Lund C., 1896 - Biologiske Studier over Ferskvands-bryozoen
- Vidensk. Meddel. Dansk. Naturhistor. Foren, 8 (5), pp. 252-363.

Wiebach F., 1952 - Uber den Ausstoss von Flottoblasten bei Plumatella
fruticosa (Allman) - Zool. Anz., 149, pp. 181-185.

Wiebach F., 1954 - Uber Plumatella fruticosa - Arch. Hydrobiol. 49,
pp. 258-272.

Wiebach F., 1963 - Studien uber Plumatella casmiana Oka (Bryozoa) -
Vie et Milieu, XIV (3), pp. 579-596.

Atti Soc. It. Se. Nat. e Museo Civ. St Nat. Milano - 108: 152-154. 31-XII-1968

lst I.B.A. International Conferente on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

20. Group 3: Ecolegy and Paleoecology.

Thomas J. M. Schopf (*)

GENERALIZATIONS REGARDING THE PHYLUM
ECTOPROCTA IN THE DEEP-SEA (200-6000 m)

Riassunto. — 1) La campionatura degli Ectoprocta di mare profondo
proviene da collezioni dell’Atlantico settentrionale e da profondità di 200-
1000 m. La natura della fauna è tale che 2) il numero delle specie decresce
con la profondità; 3) le specie sono zonate secondo la profondità; 4) i primi
colonizzatori appartengono a forme erette foliacee; 5) diverse stirpi (più di
5 famiglie) costituiscono la fauna così da suggerire più di un tempo di
colonizzazione; 6) il contenuto dell’intestino (e quindi della dieta) include
detriti; 7) gli avicularia e le ovicelle sono infine egualmente comuni sia
nella fauna di mare profondo che in quella della piattaforma continentale.

Summary. — 1) Sampling’ of deep-sea ectoprocts is very biased towards
collection from thè North Atlantic and from depths of 200-1000 m. The nature
of thè fauna is suc-h that 2) thè number of species decreases with depth ;
3) species are depth zoned; 4) thè prime colonizers are erect, foliacous forms;
5) several lineages (more than 5 families) comprise thè fauna thus suggesting
more than one time of colonization ; 6) thè gut contents (and hence diet)
includes detrit.us; 7) avicularia and ovicells are at least equally common in
deep-sea forms as in Continental shelf forms.

Samples . Conclusions from any type of biogeographic study
are only as relevant as thè distribution of data permit. Accor-
dingly I have first been concerned with thè restrictions imposed
by thè geographic and depth distribution of sampling programs.

("') Lehigh University, Department of Geological Sciences and Marine
Science Center - Bethlehem, Pennsylvania, USA.

GENERALIZATION REGARDING THE PHYLUM ECTOPROCTA ETC. 153

Fifty-five percent of thè deep-sea stations with ectoprocts
are in thè North Atlantic, which has less than 20 percent of
thè World Ocean. Additionally, many stations of major expedi-
tions in other oceans are associated with islands and their
adjaeent ridges. Institutions of thè western coast of Europe and
eastern coast of thè United States have been responsible for a
disproportionatelv large number of marine biological expeditions.
Also, when away from port, ships use islands as home bases and
tend to do a huge amount of their work near them. Reading
thè narrative of thè Challenger expedition, for example, reveals
how much more intensively thè areas near islands were sampled
compared with open ocean regions.

In terms of depth distribution, shallow areas are over
represented in ectoprocts relative to deep areas. Of thè 658
stations that have yielded deep-sea ectoprocts, 500 of them
(75 percent) are from depths between 200 and 1000 meters.
However, a consistent 20-30 percent of thè stations in thè depth
intervals of 200-1000 m, 1000-2000 m, 2000-3000 m, 3000-4000 m,
4000-5000 m, and 5000-6000 m for thè Challenger and Siboga
expeditions, and Woods Hole Oceanographic Institution benthic
ecology program, yielded ectoprocts. Thus thè relatively small
numbers of ectoproct collection in deep water is a sampling
artifact.

Nature of thè fauna. The following generalizations are
offered regarding thè nature of thè deep-sea ectoproct fauna.

1) The number of speeies per station decreases with depth.
Characteristically a maximum of 30-100 speeies exists per station
on thè Continental shelf (0-200 m) and upper Continental slope
(200-600 m). This maximum number decreases to about 10 by
1000 m and to 5 by 2000 m and deeper. This decrease may be
observed within specific expeditions and in a plot of speeies per
station from all expeditions.

2) Speeies are depth zoned on transeets from thè Conti¬
nental shelf, over thè Continental slope and Continental rise, and
onto thè abyssal plain. Currents run parallel to thè contours and
thus larvae are distributed along lines of approximately equal
depth. A few exceptions to this generai pattern are known but
are not understood. These may represent sibling speeies.

154

T. J. M. SCHOPF

3) The absence of hard substrates over most of thè
deep-sea insures that thè prime colonizers are thè erect forms
that are capable of attaching to Foraminifera and to other soli-
tary particles in thè silt or elay matrix. Secondary colonizers are
those that require a stable, fiat surface and may exist on small
pieces of shell, other ectoprocts, or hvdroids that exist in thè
deep-sea.

4) Just as on thè Continental shelf, cheilostomes far out-
number cyclostomes and ctenostomes in deep-water. Several linea-
ges, including both Anascans and Ascoporans, have invaded thè
deep-sea. The cheilostome families Farciminaridae, Scrupocella-
ridae, Bicellarìellidae, Cellaridae and Bifaxaridae are commonly
represe nted.

5) A shift in habitat off thè Continental shelf has meant
a change in diet. Shelf ectoprocts flourish on filtering diatoms
and coloured flagellates, neither of which occurs in abundance
below thè photic zone (about 100 m). The gut contents of thè
few specimens so far examined has revealed no recognizable
organism. Only «detritus», including CaC03, could be recognized.

6) Lastly I would mention a fewT more aspects of mor-
phology. Avicularia and ovicells are at least as common in deep-
sea forms as in Continental shelf forms. Thus thè same selection
pressures that cause these to evolve in shallow water exist in
deep water, where thè environment is nearly Constant. Deep-sea
soft-bottom species are typically not well calcified, but in this
respect are not different from erect, bush-like forms of thè Con¬
tinental shelf.

Acknowleclgements.

Work leading to thè conclusions presented here was carried out at thè
Marine Biological Laboratory, Woods Hole Massachusetts. The extensive
data supporting some of these conclusions are presented in a paper submitted
elswhere. The Rogick collection of books and reprints on bryozoa of thè
MBL library greatly aided thè work. I am indebted to H. L. Sanders and
R. R. Hessler, Woods Hole Oceanographic Institution, who provided me with
bryozoan collections of thè WHOI benthic ecology program. K. W. Kauf-
mann, Jr., Lehigh University, assisted in preparati on of slides. The research
was supported by National Science Foundation Grant GB-7325. Contribution
No. 60 from thè Marine Science Center, Lehigh University.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 155-160, 31-XI1-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12tn-16th, 1968

21. Group 3: Eeology and Paleoecology.

Patricia Lynette Cook (*)

OBSERVÀTIONS ON LIVING BRYOZOA

Riassunto. — Vengono fatte le seguenti osservazioni su due specie vi¬
venti provenienti dal Ghana :

1. SteganoporeUa buskii - La parziale profusione degli embrioni che
si sviluppano dalLorific-io della membrana sub-opercolare e la crescita dei
primi zooidi nelle giovani colonie.

2. Hippoporidra senegambiensis - La forma dei polipidi negli auto-
zooidi e negli zooidi corticali e 1 insediamento larvale sulle conchiglie di
Turritella abitate da paguri.

Summary. — The following observations were made on 2 living species
from Ghana:

1. SteganoporeUa buskii. The partial protrusion of developing embryos
from thè orifice of thè sub-opercular membrane, and thè growth of thè first
zooids in young colonies.

2. Hippoporidra senegambiensis. The forni of thè polypides in thè auto-
zooids and thè cortical zooids, and thè larvai settlement on Turritella shells
inhabited by pagurid crabs.

Résumé. — Les observations suivantes ont fait sur deux espèces vivantes
de Ghana:

1. SteganoporeUa buskii. La saillie partiale des embryons develop-
pantes par l’orifice de la membrane suboperc-ulaire, et l’accroissement des

zooides primaires des colonies jeunes.

2. Hippoporidra senegambiensis. La forme des polypides des auto-
zooides corticales, et la fixation des larves sur les coquilles de Turritella ha-
bitées par les écrevisses pagurides.

(*) British Museum (Naturai History), Department of Zoology - Lon¬
don, U. K.

156

P. L. COOK

Zusammenfassung. — An zwei lebenden Arten aus Ghana wurden fol-
gende Beobachtungen gemac-ht :

1. Steganoporella buskìi. Die teilweise Ausstiilpung von sich ent-
wickelnden Embryonen aus der Mundoffnung der suboperkularen Membran
und das Wachstum der ersten Einzeltiere (Zooiden) in jungen Kolonien.

2. Hippoporidra senegeambiensis. Die Gestalt der Polypiden der Auto-
zooiden, die Zooiden der « kortikalen » Zone und die Ansammlung von Larven
^n von Einsiedlerkrebsen bewohnten Turritella - Gehàusen

Observations were made recently on more than 70 species
of living Bryozoa from thè coast of Ghana. Notes on 2 species are
given here.

1. Steganoporella buskìi Harmer. Large, encrusting and erect
colonies were found from thè littoral region, and from off-shore
reefs (in 20 m) and thè Continental shelf (in 55 m).

Fig. 1. — Steganojjorella buskìi. a. Frontal view of zooid with oper-
culum open. b. Lateral view with embryo partially protruded. Oper-
culum ( op .), sub-opercular membrane (sm), embryo (e), degenerated
cryptocyst (c). The broken line in b. indicates thè position of thè
cryptocyst before degeneration. Scale = 0,5 mm.

OBSERVATIONS ON LIVING BRYOZOA

157

Many zooids contained embryos, which are orange at first,
becoming pink as thè ciba become active. The polypide and cryp-
tocyst degenerate as thè embryo develops (see Cook, 1964 a: 50).
The opercula of zooids with embryos open fully, exposing thè sub-
opercular membrane, which has a transverse, slit-like orifice. Dev-
eloping embryos are partially protruded through this orifice, and
remain in this position from 3-10 minutes. The operculum then
closes. When their cilia are fully developed, thè embryos are no
longer protruded, and rotate within thè distai part of thè zooidal

cavity for 2-5 days before release.

Coilostega with similar brooding arrangements, such as Smit-
tivora levinseni (Canu & Bassler) and Onychocella alida Hastings,
where thè ovicells are vestigial and thè large embryos are brooded
in thè distai part of thè zooid, bave not been seen to protrude

Fig. 2. — S. buskii. a. Primary sac. b. First zooid differentiated.
c. Lateral view. d. Second zooid differentiated. Scale — 0,5 nini.

158

P. L. COOK

embryos. In these species thè polypide is active during develop-
ment of thè embryo.

If thè polypide is involved in thè supply of oxygen to thè
embryo in species with internai brooding, it seems possible that
thè protrusion in S. buskii is necessitateci by thè absence of a
polypide.

Larvae of S. buskii settled 33-48 hours after release. The pri-
mary individuai on metamorphosis consists of a large, shield-
shaped sac. The first zooid is differentiated from thè centrai part
of thè sac, and is followed by 2 secondary zooids which are there-
fore not in fact budded from thè primary zooid. Further obser-
vations must be made to see if this type of development is generai
in thè Coilostega.

2. Hippoporidra senegambiensis (Carter). Specimens were
found in large numbers on muddy sea-bottoms from 30-40 m. The
genus is exclusively associate d with pagurid crabs inhabiting gas-
tropod shells (see Cook, 1964 b: 22).

Two forms of zooid are known in Hippoporidra. The aut-
ozooid in H. senegambiensis has a polypide with 10-12 tentacles,
thè proximal 2 pairs are very short. Extrusion and retraction is
rapid and frequent, and feeding occurs while thè pagurid is mov-
ing. The cortical zooids are large and form thè bases and centres
of thè protuberances and branches of thè zoarium. They show no
evidence of polypides in preserved material, and are filled with
a yellow, granular substance. Living, young cortical zooids do pos-
sess a polypide. It has only 6 tentacles, which are without cilia.
The distai pair is very long, thè remaining pairs are reduced. Fre¬
quenta thè distai pair only is slowly extruded, and remains with¬
out movement for 2-3 minutes. The whole tentacular crown is then
extended, but thè tentacles are not expanded ; they remain closely
apposed, diverging slightly at thè distai ends. The crown then
makes 2-4 rapid lateral movements for from 3-6 seeonds, is then
retracted, and not extended again for from 10-30 minutes. The
behaviour of these polypides is similar to that noted by Silén
(1966), in zooids producing spermatozoa. Cortical zooids may thus
have a dual function, but no spermatozoa have been seen in living
or preserved specimens.

OBSERVATIONS ON LIVING BRYOZOA

159

Fig. 3. — Hìppoporidra senegambiensis. Autozooid (left) and cor-
tical zooid (right), with tentacles extruded. Arrows indicate direc¬
tion of lateral movements of tentacular crown of cortical zooid.

Scale = 0,5 mm.

160

P. L. COOK

Breeding colonies were kept in dishes with different substrata
provided for settlement of larvae. 10 ancestrulae were found on
Turritella shells inhabited by pagurids. 8 were near thè mouth of
2 shells, 2 half-way toward thè apex of 2 other shells. No ances¬
trulae were found on shells inhabited by thè gastropod, or colonised
by other Bryozoa, nor on lamellibranch shells, shell fragments, or
dead Bryozoa,

The indications are that most larvae settle near thè mouth of
Turritella shells inhabited by pagurids, and that thè resulting
colony is thè most successful. Ancestrulae on other parts of shells
are more liable to damage, but occasionally colonies develop in
this way. Shells inhabited by thè gastropod are unsuitable, prob-
ably due to thè presence of thè periostracum, and other substrata
would normally be covered by mud in thè areas where H. sene-
gambiensis occurs.

REFERENCES

Cook P. L., 1964 a - Polyzoa from west Africa. 1. Notes on thè Steganopo-
rellidae, Thalamoporellidae and Onychocellidae - Ann. Inst. Oceanogr.
(Calypso VI), 41, pp. 43-78, figs. 1-3, pi. 1.

Cook P. L., 1964 b - Notes on thè genera Hippoporma Neviani, Hippoporella
Canu, Cleidochasma Harraer and H ippoporidra Canu & Bassler - Bull.
Br. Mus. nat. Hist. (Zool.), 12, 1, pp. 1-35, figs. 1-8, pls. 1-3.

Silén L., 1966 - On thè fertilization problem in thè gymnolaematous Bryozoa
- Ophelia, 3, pp. 113-140, figs. 1-15.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 161 -1(54. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

22. Group 3: Ecology and Paleoecology.

Ferdinand D. Flor (*)

THE VARIATION OF

SPIROPORA VERTICILLATA Goldfuss, 1827
FROM UPPER CRETACEOUS DEPOSITS

( Bryozoa )

Riassunto. — Viene esaminata la specie Spiropora verticillata Goldfuss,
1827 proveniente da depositi supra-cretacici dell’Europa settentrionale (San-
toniano - Campaniano - Maastrichtiano e Daniano). Vi è una relazione tra
le forme zoariali di crescita e la distanza dalla costa ( ? profondità, movi¬
mento dell’acqua). Questa specie può essere quindi usata come indicatore pa¬
leoecologico.

Summary. — It was investigated thè species Spiropora verticillata Gold¬
fuss, 1827 from Upper Cretaceous deposits (Santonian, Campanian, Maa-
strichtian, Danian) in Northern Europe. There is an interrelationship bet-
ween thè growth-form and Coastal distance ( ? depth, water-movement). Thus
this species can be used as paleoecological indicator.

Zusammenfassung. — Mit Hilfe variationsstatistischer Methoden wurde
die Spezies Spiropora verticillata Goldfuss, 1827 aus dem Santonien, Cam-
panien, Maastrichtien und Danien nordeuropàischer Fundorte bearbeitet.
Dabei ergaben sich eindeutige Varianten der kiistennahen und kiistenfernen
Fazies, die als bathymetrische Indikatoren verwendet werden kònnen.

The fossil Bryozoa have proved to be important not only for
stratigraphical but also for paleoecological research. Until now
in literature synecological methods have been preferred to aut-
ecological methods. This report is based upon paleoautecological
investigations of thè species Spiropora verticillata Goldf. 1827 of
different Upper Cretaceous deposits of Northern Europe. The go-
nozooecia of this species are characterized by a long and relatively

(*) Geologisches Staatsinstitut, Von-Melle-Park 11 - Hamburg 13, Ger-
many (W.).

162

F. D. FLOR

thin tube. It begins between two zooecia in longitudinal-distal
direction, continues transversally being closely attached to thè fol-
ìowing aperture-ring on thè distai side. Then there follows again
a longitudinal-distal part etc. This mode of growth may appear
severa! times in a row.

The material used was taken from Santonian, Campanian,
Maastrichtian and Danian and variation of this species in Coastal
areas were compared to off-coastal ones. A comparison of thè
tota! Bryozoa- fauna of these different biotopes already shows
distinct differences. The free-growing forms of thè Santonian
coasta! region in Northern Germany (Harzvorland) are normally
larger and coarser than thè corresponding Bryozoa in thè off-
coastal facies in Northern Germany and Denmark. The Bryozoa
Cyclostomata are thè most common ones there. Their character-
istical structure is as follows : many lamina, bulbous, thick stems
and thick lamina. But there are also some thin growth-forms,
which had probably settled in thè paleoecological caves of that
region with strong water-movement. Comparable growth-forms of
thè Coastal region have been found 500 km north of that region
in thè Campanian Cliff-facies of Sweden (Schonen).

In contrast to this biofacies thè Campanian Chalk of Den¬
mark and Northern Germany is characterized by Bryozoa of small
and delicate growth-forms. In this off-coastal facies we don’t find
any specimens of thè thick type.

The material used for research was made available by Prof.
Dr. Dr. h. c. E. Voigt, Geologisches Staatsinstitut, Hamburg, who
kindly offered his private collection of Bryozoa for this purpose.
I am very grateful to him.

Measurements : For variation-statistical comparison I me-
asured thè following criteria of thè zoaria. 1. The diameter of thè
Bryozoa-stems (B in fig. 1 and table). It was measured in thè
middle section between two aperture-rings. That was done without
specific orientation on unramified specimes. In a ramified section
I measured vertically to thè leve! of ramifying. 2. The height bet¬
ween thè aperture-rings (H in fig. 1 and thè table). In most
cases thè height was measured in longitudinal direction from thè
distai aperture-rim to distai rim of thè following aperture-ring.

Localities: Nr. 1 : Voldum, Jutland (Denmark), Danian. Nr. 2:
Bastad, Schonen (Sweden), Campanian. Nr. 3: Hemmingslycke,
Schonen (Sweden), Campanian. Nr. 4: Rtigen (Eastern Germany),

THE VARIATION OF SPIROPORA VERTICILLATA ETC.

163

Lower Maastrichtian. Nr. 5 : Faxe, Seeland (Denmark), Danian.
Nr. 6 : Làgerdorf near Hamburg (Western Germany), Lower Cam-
panian. Nr. 7 : Hemmoor near Bremen (Western Germany), Upper
Maastrichtian. Nr. 8: Sudmerberg near Goslar (Western Ger¬
many), Santonian.

One of thè results of thè investigations in Bryozoa from 50
localities in Northern, Middle and Southern Europe is, that we
find no change of thè range in Sjnropora verticillata between
Santonian and Danian. Thus it is possible to compare thè material
with different stratigraphical vaine, too.

The range in mm (variation-statistical mean) :

Quantity of
Measurements

Nr.

1 Voldum, Danian

0,8-1, 8 (1,35)

1, 2-2,0 (1,57)

2 Bastad, Campanian

1,3-2, 3 (1,49)

0,6-1, 9 (0,88)

3 Hemming’slycke, Camp.

1,0-2, 7 (1,66)

0,7-1, 7 (1,02)

177

4 Riigen, L. Maastr.

0,4-1, 4 (0,63)

1,0-2, 8 (1,61)

239

5 Faxe, Danian

0, 4-1,0 (0,68)

1, 1-2,1 (1,55)

231

6 Làgerdorf, L. Camp.

0,5-0, 7 (0,60)

1,0-1, 8 (1,28)

7 Hemmoor, U. Maastr.

0,6-1, 4 (0,93)

1, 0-2,1 (1,42)

8 Goslar, Santonian

0,7-1, 6 (1,05)

0,4-1, 2 (0,93)

It was shown by thè measurements and thè variation-stat¬
istical mean (M in mm), that thè big variants are limited to thè
Coastal deposits and thè « dwarfed » variants are mostly found
in off-coastal deposits. The comparison of thè distance between thè

164

F. D. FLOR

aperture-rings shows a contrary relation. The smallest distance
between thè aperture-rings is found at specimens from Coastal
facies. Specimens of Spiropora verticillata with thè greatest
distance we found in thè facies of deeper water.

Fig. 2 (left). — Mean of thè stem-diameter.

Fig. 3 (right). — Mean of thè distance between thè aperture-rings.
The numerals indicate thè localities. Paleogeographieal (Upper Creta-
ceous) sketch: pointed =z terrestric facies, unpointed = aquatic facies.

As a conclusion we can say, that thè variants of thè Coastal
facies are characterized by large diameter of thè stems and re-
latively small distance between thè aperture-rings ; thè specimens
of thè off-coastal regions are thin and have a relatively great
distance between thè aperture-rings. These relation may also be
interpreted in a statical senso. There seems to be an interrelation-
ship between growth-form and water-movement. Thus thè Bryo-
zoa of this species correspond in habitus to thè total Bryozoa-
fauna, as described in thè beginning. So thè species Spiropora ver¬
ticillata can be used as bathymetrical indicator in Santonian, Cam-
panian, Maastrichtian and Danian deposits of at least Northern
Europe. A variation of thè zooecia-diameter was not found in
this geological period. Investigations about thè thickness of thè
zooecia-wall are intended.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 165-173. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

23 Group 3 : Ecology and Paleoecology.

VlRGIL GHIURCA

LE BIOTOPE RÉCIFAL À BRYOZOAIRES
DU MIOCÈNE DE LA ROUMANIE

Riassunto. — Nell’evoluzione del biotopo scopulare miocenico a Briozoi
della Romania, vengono distinti due stadi principali, condizionati dalla va¬
riazione nella salinità delle acque:

1) Stadio stenoalino tortoniano, in cui si è sviluppata una ricca as¬
sociazione scopulare a Briozoi.

2) Stadio salmastro sarmaziano, in cui la bassa salinità ha agito come
un fattore selettivo sull’associazione scopulare a Briozoi, tale associazione
risultando povera in generi e specie ma molto ricca in individui di grande
taglia.

Summary. — In thè development of thè Miocene reefal biotope witn Bryo¬
zoa from Roumania, two main stages are distinguished, particularly condi-
tioned by thè variation of thè salinity, namely:

1) The Tortonian stenohalin stage in which there a rich reefal Bryozoa
association developed.

2) The Sarmatian brackish water stage in which thè low salinity acted
as a selective factor upon thè reefal Bryozoa association, resulting from these
some associations poor in genera and species but very rich in individuals of
high sizes.

En Roti manie a été signalée une faune riche en Bryozoaires
dans le Triasique de Brasov (15), le Jurasique récifal de Dobrou-
dja, l’Eocène supérieur du bassin de la Transylvanie (8, 14, 19, 21)
et surtout dans la partie supérieure du Miocène qui affleure de
nos jours presque dans toutes les régions du pays. (*)

(*) Universitatea « Babes Bolyai », Catedra de Geologie Str. Kogilni-
ceanu - Cluj, Roumania.

166

V. GHIURCA

Les faunes miocènnes a Bryozoaires ont attiré depuis long-
temps l’attention des spécialistes comme A. E. Reuss (18), A.
Manzoni (16, 17), qui ont décrit dans leurs ouvrages 54 espèces de
Bryozoaires récoltées à Buituri et Lapugiul de Sus en Transylva-
nie. Parmi les formes décrites et decouvertes chez nous, 15 nouvel-
les espèces pour la littérature mondiale ont les holotypes décrits
d’après les formes trouvées dans le deux localités.

La plupart des formes des Bryozoaires tortoniens décrites et
trouvées à Lapugi et Buituri (7, 14), à Costei (11), Talmacel et Cis-
nadioara (18), en Transylvanie et les autres de Delinesti et Zor-
lentul Mare en Banat (12), ont été collectées des facies de plage
formés de sable riche en coquilles de mollusques quelquefois rou-
lées, semblable comme présentation au facies Pontilevien de l’Hel-
vétien de France.

Une petite partie des formes signalées dans le Tortonien
de Lapugi, Buituri et Costei provient des facies argileux plus
profonds semblable au type des argiles de Baden en Autriche.

Dernièrement ont été mises en évidence des faunes riches en
Bryozoaires récoltées des facies récifaux du Tortonien et du Sar-
matien du bassins Baia-Mare (6), Simleu (9) et des autres points
de la Transylvanie (10, 11, 13). Le facies récifal de la Roumanie
a quelques affinités avec le facies sous-littoral Savignéen signalé
par M. M. E. Buge et P. Calas de France (3). Leur caractère
récifal chez nous est plus clair et mieux individualisé.

Le biotope récifal, le processus récifogénétique et Tétude com-
plexe des récifs géologiques formés des biocénoses des Bryozoaires
sont des domaines très interessants mais très peu étudiés.

Les formations récifales à Bryozoaires du Miocène supérieur
de la Roumanie sont bien développées et c’est facile d’étudier en
détail le biotope et leurs biocénoses. En peu des pages j’essayerai
de tracer les principaux caractères du biotope récifal à Bryozoaires
et d’établir surtout le composant et les traces essentielles des bio¬
cénoses récifaux, d’après mes propres recherches et utilisant les
découvertes des autres chercheurs dans ce domaine.

Les récifs à Bryozoaires sont bien développés en Roumanie
dans le cadre des dépòts tortoniens et sarmatiens, aussi dans les
pays voisins (Autriche, Hongrie, Jugoslavie et TUnion Soviétique),
pays appartenant à l’aire du bassin de la mer Paratethys.

LE BIOTOPE RÉCIFAL À BRYOZOAIRES ETC.

167

Entre les deux types de dépòts récifaux à Bryozoaires d’àge
tortonien et sarmatien il y a des différences essentielles, surtout
en ce qui concerne le composant des biocénoses, différences con-
ditionnées par la variation des facteurs physiques, chimiques et
biologiques du biotope pendant les deux étapes données.

En Roumanie on peut très bien suivre l’évolution des faunes
de Bryozoaires récifaux, depuis les associations stenohalines du
Tortonien supérieur jusqu’à celles polihalines du Buglovien et
puis chez les brahihalines du Sarmatien inférieur (Volhynien).
On peut poursuivre plus loin l’évolution des faunes récifaux à
Bryozoaires dans le Sarmatien moyen (Bessarabien) sur les aires
de plat-formes Russe olì elles se dedevéloppent puis dans les con-
ditions dTm milieu mesohalin, afin que, pendant le Sarmatien su¬
périeur (Kersonien) radaptation au milieu oligohalin soit accom-
plie. Les formations récifales tortoniennes et sarmatiennes à
Bryozoaires de FUnion Soviétique sont citées dans la littérature de
spécialité sous les dénominations de Toltrys, Miodobores et On-
co'ides.

I - Ainsi pendant l’étape tortonienne, dans le cadre d’une mer
douée d’une salinité normale le biotope récifal à Bryzoaires de la
mer de Paratethys avait les suivantes caractéristique essentielles :
la salinité autour de 35 %c, la température entre 22°-28°C., une pro-
fondeur de 10 à 80 m., et maximum 150 m., le souslitée solide, ro-
cheuse ou sabloneuse, pH 8, 6-8,9, des eaux oxygénées, bien aérées
dotées d’une nourriture abondante, des eaux sans une trop grande
turbulence, la zone euphotyque bien éclairée étant la plus favorable.

Parm les biocénoses récifales développées dans de telles con-
ditions on peut distinguer tout spécialement deux composants prin-
cipaux entremèlés biologiquement l’un à l’autre de la manière sui-
vante: des phytocenoses du type des prés sous-marins aux mélo-
besioidées, les plus abondantes étant les plantes du genre Litotham-
ninm, Archaeolitothamnium, Litophyllum, Mesophyllum, Jania,
Melobesia et les zoocénoses parmi lesquelles on trouve en prédo-
minance les formes de Bryozoaires.

Parmi les faunes à Bryozoaires de type récifal ont été signa-
lées en Roumanie (6, 9, 10, 11, 12) plus de 120 espèces. Les plus
fréquentes et les plus importantes dans le processus récifogénetique
ont été: Sertella rubeschii Rss., S. cellulosa Linné, Cellaria fistu-

168

V. GHIURCA

Iosa Auct., Crisia hornesi Rss., Porella cervicornis Pallas, Tubn-
cellaria ceroicles Eli. et Sol., S crup o cellaria elliptica Rss., Ceriopora
globidus Rss., Lichenopora deformis Rss., Calpensia cuculiata Rss.,
Idmidronea atlantica Johnst., Cribrilaria radiata Moli, Ybselosoe-
cia typica Manz., Cellaria farciminoides Johnst., Pleuronea per-
tusa Rss., Adeonella polystomella Rss., Hippopleurif era megaiota
Rss., Myriozoum truncatum Pallas, Hornera verrucosa Rss., Ter-
via vibicata Manz., Ceriopora cylindrica Rss. et Diaperoecia ru-
gidosa Manz.

Si nous analysons statistiquement la fréquence des epèces dans
le cadre de l’association totale le résulat est le suivant: 64% d’espè-
ces de Cheilostomes et 36% d’espèces de Cyclostomes. La fré¬
quence statistique des individus dans le cadre de rassociation ré-
cifale globale nous donne une proportion égale 50% Cheilostoma-
tes et 50% Cyclostomates.

Auprès de Bryozoaires et de Mélobesioidées il y a constament
dans cette association récifale d’autres formes organiquement liées
aux précédentes par exemple, parmi les Vers les genres Serpula
et Ditrupa, les Brachiopodes avec les genres Terebratida, Argiope
et Miihlf elditia, les Lamelibranchiates avec Pecten, Pectuncidus,
Pycnodonta, Lithodomus et puis les Echinides appartenant aux
genres Arbacina, Cidaris, Echinometra, Scutella, Echinolampas,
les Artropodes aussi représentès par des formes de Decapodes et
les Foraminifères assez abondants surtout, les genres Amphiste-
gina et Heterostegina.

Il semble que le róle d’organisateur principal, dans le cadre
des associations de ce type, revient aux àlgues calcaires, qui par
le développement de leur thalles ont crée un milieu et une sous-
litée favorables pour le fixement et le développement des Bryo¬
zoaires et d’autres organismes bentonique, chose très bien rema-
rarquée par M. M. E. Buge et P. Calàs (3) situation à laquelle
s’ajoute bien etendu la constance durable des facteurs physiques
et chimiques du biotope.

Par l’activité construtive commune de ces formes d’animaux
ont pris naissance des formations récifales du type des biohermes
et des biostromes classiquement développées dans le Tortonien du
bassin Baia-Mare et dans le Buglovien de la piate-forme moldave.
De telles formations sont également bien développées dans les bas-
sins Simleu, Beius, Zarand, et Mures de la Transyìvanie et Bahna-

LE BIOTOPE RÉCIFAL À BRYOZOAIRES ETC.

1 69

Orsova de Banat et quelquefois dans les zones sous-carpathique
où les apports terrigènes étaient plus actifs. Une bonne partie de
ces calcaires récifaux ont été décrits dans la littérature sous le
nom de calcaires de Leitha.

Autour des biohermes se sont développés des facies réfciogéné-
tiques composés de calcaires bioclastique et latéralement de calcai¬
res oolitiques, de sables et limons calcaires qui s’encadrent dans
la catégorie des roches sous-récifales. Les calcaires tortoniens sont
en général campacts, blancs et composés de 30% Bryozoaires 30%
Algues calcaires, 30% Foraminifères et 10% d’autre organismes
de facies récifal. Dans la formations de ces calcaires on ne peut
pas exclure quelques processus de précipitation directe du car¬
bonate de calcium. Il faut souligner le fait que dans les associa-
tions composées de hexacoraillers les Bryozoaires et les algues
sont absents en général.

II - Pendant l’étape sarmatienne après le changement des
conditions paléogéographique qui a eu lieu sur la limite entre Tor-
tonien et Sarmatien, la mer Paratethys perd son lien d’alimen-
tation avec Tethys et se transforme dans un mer interne qui peu
à peu s’adoucit et par fragmentation cette mer devient une sèrie
des bassins secondaires.

La salinité, l’un des facteurs esentiels du biotope est plus
faible pendant le Buglovien 30%, et puis de 30% à 18% dans le
Sarmatien inférieur, de 18% à 8% dans le Sarmatien moyen et
de 8% à 0,5% durant le Sarmatien supérieur. Dans de tells con¬
ditions de milieu la formation et la composition des biocénoses ré¬
cifaux à Bryozoaires sont déterminées évidement par la salinité
qui a un ròle sélecteur en favorisant le développement de quelques
espéces ou la disparition des autres. Les autres facteurs du bio¬
tope, la température, la profondeur, la souslitée, l’aération, la
transparence le pH, restent en général les mèmes comme dans le
Tortonien. Les phytocénoses d’algues marines sont elles aussi rem-
placées par de nouveaux types adaptés aux nouvelles conditions.

Dans les conditions du milieu brahihalin et puis mesohalin
il ne reste plus de riches faunes de Bryozoaires tortoniens que
peu d’espèces capables de s’adapter aux nouvelles conditions, en
échange la taille des formes adaptées aux nouvelles conditions

170

V. GHIURCA

s’accroìt et surtout la fréquence ahurissante du nombre d’ indi-
vidus dans le cadre de quelques espèces. La grande fréquence des
individus et leur taille sont une sorte de compensation vis-à-vis de
la pauvreté des genres et des espèces. Un cas presque similaire
a été signalé par M. M. P. Cotillon et B. Walter (4) dans le
Crétacé inférieur des Basses Alpes et du Var.

Parmi les espèces de Bryozoaires tortoniens adaptées aux
nouvelles conditions saumàtre et decouvertes en Roumanie il faut
remarquer les espèces suivantes : Schizoporella unicornis Johnst.,
S. tetragona Rss., Berenicea congesta Rss., Diastopora corrugata
Rss. et Lepralia montifera Ulr. et Bassler.

Dans les facies sarmatiens récifaux à Bryozoaires de la Rou¬
manie, de l’Autriche (2) et de l’Union Soviétique (5,20) ont été
signalées une serie de nouvelles espèces qui dérivent elles aussi
par la sélection et l’adpatation des formes tortoniennes. Toute la
faune récifale se compose des ces quelques forme citées et les
suivantes : Cryptosula terebrata Sinz., Schizoporella bessarabica
Nic., S. semilunaris Saulea Bocec, S. tuberculata S. Bocec, S. va-
riabilis Rss., S. terres Eich., S. spongitiformis S. Bocec, S. rhom-
boicles S. Bocec, S. eichwaldi Feof., S. mariae Feof., S. biglobularis
Feof., S. longiavis Feof., S. austriaca Bobies, Nitscheina lapidosa
Pallas, N. leo Feof., N. kischenewensis Feof., Pyripora sarmatica
Bobies, E noplo stornella wolfpassiegensis Bobies.

Dans le Sarmatien inférieur (Volhynien) les associations sont
prédominées presque exclusivement par les formes de Cryptosula
terrebrata Sinzov, Tubulipora cumidus Sinzov, Crisiella carnun-
tina Bobies, et les quelques formes tortoniennes peu nombreuses
adaptées aux nouvelles conditions déjà citées plus haut.

Durant le Sarmatien moyen (Bessarabien) de l’Union Sovié¬
tique la faune est plus reduite, on trouve en prédominance
presque exclusive seulement les formes de Nitscheina lapidosa
Pallas et N. leo Feof anova. Dans les biocénoses à Bryozoaires
récifaux sarmatiens le pourcentage des formes Cheilostomates
depasse 80% et celui de Cyclostomates baisse sous 20%. Dans les
associations récifales il y a pas seulement des Bryozoaires, mais
assez fréquemment des algues calcaires aussi, beaucoup de vers
du genre Serpida et Spirorbis , panni les Lamellibranchiates on

LE BIOTOPE RÉCIFAL À BRYOZOAIRES ETC.

171

trouve en prédomonance le genre Cardium et parmi les Fora-
minifères le genre Nubecularia.

En Ronmanie les formations d’àge sarmatien inférieur et
en partie moyen on les retrouve sous les mémes formes de bio-
hermes et biostromes dans le bassin de Baia-Mare, Simleu, Beius
et Zarand et on cite de manière sporadique des facies à Serpula
aussi dans la zone souscarpathique de la Muntenie et de l’Oltenie.

Il y a des cas, surtout dans le Sarmatien inférieur, qu’on
trouve des récifs composés prèsque exclusivement des formes de
Cryptosula terebrata Sinzov, par exemple le caz des formations
récifaux du bassin de Baia-Mare et Simleu et surtout les restes
d’un bioherme qui se trouve seulement sous forme de blocs à
Berca dans les souscarpathes de la Muntenie. Les calcaires réci¬
faux formés ont l’aspect des calcaires cavernaux mols, ou bien
Taspect des calcaires compacts, durs aux cavitées remplies de
calcite, de calcédonie ou de quartz recristalisé.

Dans les régions de Podolie et de Moldavie en Union Sovié-
tique les biohermes à Bryozoaires à Serpula et à Nubecularia
sont très bien développés et forment trois alignement de récifs
barrière. Des formations similaires sont signalées sur des aires
moins restreintes en Autriche, Hongrie et Jugoslavie.

En conclusion, dans le développement du biotope récifal
miocène à Bryozoaires de Roumanie et les pays limitrophes on
distingue deux étapes principales conditionnées spécialement par
les variations de la salinité, a savoir :

1) L’étape marine tortonienne caractérisée par une sali¬
nité normale, dans le cadre de laquelle s’est développée une riche
association de Bryozoaires récifaux (plus de 120 espèces).

2) L’étape saumàtre sarmatienne pendant laquelle la sali¬
nité plus faible a actionné comme un facteur sélectif sur les
associations de Bryozoaires récifaux en résultant des associations
pauvres en genres et espèces, mais très riches en invidus qui
sont de grandes tailles (25 espèces).

Les biohermes et les biostromes formés par l’activité cons-
tructrice des ces associations sont bien développés dans le Tor-
tonien et dans le Sarmatien inférieur de Roumanie et pendant
le Sarmatien moyen et supérier de l’Union Soviétique. En conse-

172

V. GHIURCA

quence sur ces aires on peut c’est à dire poursuivre l’évolution
et Tadaptation par degrés des quelques faunes stenohalines à
Bryozoaires de type récifal en passant d’un milieu marin à
d’autre milieux polihalins, brahihalins, mesohalins et mème
oligohalins.

BIBLIOGRAPHIE

(1) Alloiteau J., 1959 - Introduction à la séance spécialisée sur les milieux

récifaux - Bull, de la Soc. Géol. de France, Paris, 7-sér., 1-4.

(2) Bobies A. C., 1957 - Bryozoenstudien. II, Die Bryozoen des òsterrei-

chischen Sarmat - Jarhb. d. Geol. Bunden. Wien, 100 Bd., H. 1.

(3) Buge E. & Calas P., 1959 - Biohermes et biostromes à Bryozoaires du

Miocène d’Europe - Bull, de la Soc. Géol. de France, Paris, 1-4.

(4) Cotillon P. & Walter B., 1965 - Essai pétrogénétique et paléoecologi-

que sur un niveau de calcaires bioclastiques dans le Crétacé inferieur
des Bassis Alpes et du Var - Étude systématique de ses Bryozoaires.
Bull, de la Soc. Géol. de France, Paris, 7-sér., VII.

(5) Feofanova Iu. M., 1953 - K izuceniu verhnetreticnih msanok Moldavii

i Krìma - Biul. M. O-va. Isp. Prirod-Otd. Geologii, Moskwa, XXVIII, 3.

(6) Ghiurca V., 1961 - Contribuii la cunoasterea faunei de Bryozoare tor¬

tomene din Tara Chioarului. (Bazinul Baia-Mare) I - Stud si Cercet.
de Geol., Bucuresti, VI-4.

(7) Ghiurca V., 1961 - Contribuii la cunosterea faunei de Bryozoare din

Transilvania. II - revizuirea taxonomica a Bryozoarelor de la Lapugi
si Buituri publicate de A. Koch. Stud. Univ. Babes-Bolyai. Geol. Geogr.
Cluj. - II - f. 1.

(8) Ghiurca V., 1962 - Idem. Ili - Revizuirea taxonomica a Bryozoarelor

Eocen superioare din NW Transilvaniei publicate pina in prezent
Stud. Univ. Babes-Bolyai. Geol. Geogr. Cluj f. 2.

(9) Ghiurca V. si Nicorici E., 1963 - Idem. IV - Bryozoarele Tortomene

de la Preuteasa Tusa. (Bazinul Salaj) - Stud. Univ. Babes-Bolyai
Geol. Geogr. Cluj. f. 1.

(10) Ghiurca V., 1964 - Idem. V - Bryozoarele Tortomene de la Lopadea

Veche. (Raionul Aiud) - Stud. Univ. Babes-Bolyai. Geol. Geogr. f. 1.
Cluj.

(11) Ghiurca V., Dusa A., 1966 - Idem. Bryozoarele Tortomene de la Cos¬

terni de Sus. VI - Anal. Univ. Bucuresti. Geol. Geogr., Bucuresti,
XV-2.

(12) Ghiurca V., Florei N., 1966 - Idem. VII - Bryozoarele Tortomene de la

Delinesti si Zorlentul Mare. (Banat) - Stud. si Cercet. de Geol. Geofiz.
Geogr. ser. Geol., Bucuresti, XI-1.

(13) Ghiurca V., 1966 - Idem. Vili - Bryozoarele Tortomene de la Talmacel

sì Cisnadioara - Stud. Univ. Babes-Bolyai. Geol. Geogr. Cluj f. 1.

LE BIOTOPE RÉCIFAL À BRYOZOAIRES ETC. 173

(14) Hejjas I., 1894 - Beitràge zur Kenntnis der tertiàren Bryozoenfauna

Siebenbiirgens. - Orv. Term Tud. Ért. Kolosvar. XVI.

(15) KÙHN O., 1935 - Die Anthozoen, Hydrozoen, Tabulateli und Bryozoen

der Trias von Brasov - A. Inst. Geol. Rom., XVII, Bucuresti.

(16) Manzoni A., 1877 - Briozoi fossili del Miocene d’Austria ed Ungheria,

II - Denkschr. d. k. k. Akad d. Wissensch., XXXVII, Wien.

(17) Manzoni A., 1878 - Idem. Ili - Denkschr. d. k. k. Akad. d. Wissensch.,

XXXVIII, Wien.

(18) Reuss A. E., 1874 - Die fossilen Bryozoen des òsterreischisch-ungari-

schen Miozaens, I - Denkschr. d. k. k. Akad. d. Wissensch., XXXIII,
Wien.

(19) Saulea Bocec E., 1943 - Les Bryozoaires de la zone récifale du Sar-

matien Moyen des départements d’Orhei et de Lapusna - An. inst.
Geol. al Rom., XXII, Bucuresti.

(20) Suraru M., 1951 - Revizuirea Bryozoarelor Cheilostomate eocene din

materialul adunat de Héjjas I - Stud. si Cercet. Stiint. - II - 3, 4, Cluj

(21) Pergens Ed., 1877 - Note préliminaire sur les Bryozoaires fossiles des

environs de Kolozsvàr - Bull, de Séances Soc. Roy. Malac. de Belgique,
XXIII, Bruxelles.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 174-177, 31-XII-1968

lst I.B.A. International Conferente on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

24. Group 3: Ecology and Paleoecology.

Reginald J. Scolaro (*)

PALEOECOLOGIC INTERPRETATION
OF SOME FLORIDA MIOCENE BRYOZOA

(Preliminary Report)

Riassunto. — La Formazione « Chipola » è nota per la sua ricca fauna
tropicale: 52 specie di Bryozoa (24 delle quali si ritrovano nei mari attuali)
sono state finora riconosciute. Delle specie tuttora viventi, il 42% ha distri¬
buzione tropicale, il 46% è di acque temperate e il 12% è euritermo. Da ciò
si può dedurre che i mari della Form. « Chipola » erano caldi con una sa¬
linità vicina al 3 5%0. Inoltre, persino nella relativamente piccola area in cui
essa è esposta, la formazione può essere divisa in tre biofacies, ognuna delle
quali è caratterizzata da una differente associazione briofaunistica. Queste
differenze faunistiche includono un piccolo numero di specie guida, diffe¬
renze nel numero delle specie e differenze morfologiche nell’ambito della
specie. Esse sono in relazione principalmente con la diversità dei substrati.

Summary. — The Chipola Formation has long been known to contain a
rich marine tropical fauna: fifty-two bryozoan species — twenty-four of
which occur in Recent seas — have been found in it. Of thè extant species,
forty-two per cent are entirely tropical in distribution, forty-six per cent are
warm temperate and twelve per cent are eurythermal, suggesting that thè
Chipola seas were warm, tropical waters with a salinity dose to 35%c. Fur-
ther, even in thè relatively small area in which it is exposed, thè formation
can be divided into three biofacies, each characterized by a distinctive as-
semblage of bryozoans. These faunal differences include a few restrictive
species, differences in species abundance and differences in morphology within
species. They are related primarily to differences in substrate.

(*) The University of Georgia, Department of Geology - Athens, Geor¬
gia USA.

PALEOECOLOGIC INTERPRETATION OF SOME FLORIDA ETC.

175

The Chipola Formation has long been known to contain a
rich marine tropical fauna. Yet Canu and Bassler in 1923 re-
ported only five species of Bryozoci from thè formation at thè
type locality on thè Chipola River. Additional collecting from ex-
posures in thè vicinity of thè type locality near Clarksville in
northwestern Florida has yielded at least fifty-two bryozoan spe¬
cies, twenty-four of which occur in Recent seas. Of thè extant
species, forty-two percent are entirely tropical in distribution,
forty-six percent are warm temperate, and twelve percent are
eurythermal, suggesting that thè Chipola seas were warm, tro¬
pical waters with a salinity dose to 35%c. Further, even in thè
relatively small area in which it is exposed, thè formation can
be divided into three biofacies, each characterized by a distinc-
tive assemblage of bryozoans. These faunal differences include
a few restrictive species, differences in species abundance, and
differences in morphology within species. They are related pri-
marily to differences in substrate.

The Chipola Formation, middle Miocene in age, consiste of
blue-gray to yellow-brown, richly fossiliferous marls, generally
hearing considerable amounts of quartz sands. Exposures of thè
formation are confined to thè banks of Tenmile Creek, thè Chi¬
pola River, and Farley Creek. Tenmile Creek flows from thè
west and Farley Creek from thè east into thè south flowing Chi¬
pola River. Elsewhere in thè area, thè formation is subsurface.
As thè geographic relief throughout Florida is small, thè distri¬
bution of Chipola sediments is particularly fortuitous. The strike
of thè formation is approximately east-west and parallels thè
direction of Tenmile Creek and Farley Creek. The dip is south-
ward and nearly parallels thè direction of thè Chipola River.
Thus, as thè slope of thè river is less than thè dip of thè for¬
mation, thè entire section can be collected by proceeding down-
stream. Although Tenmile Creek parallels thè strike of thè for¬
mation, a nearly complete section is represented here at one
locality.

The incidence of three biofacies within thè formation in thè
vicinity of thè type locality near Clarksville, Florida is coinci-
dent with thè geographic distribution of three lithofacies along
Tenmile Creek, thè Chipola River, and Farley Creek.

176

R. J. SCOLARO

The dominant sedimentary type in thè paleoenvironment ex-
posed along Tenmile Creek probably was a mud with silt-sized
clay particles and a low calcium carbonate content. The Recent
records of Membranipora tennis Desor, Crassimarg inai ella lem
cocypha Marcus, and living relatives of thè fossil species Metra-
rabclotos chipolanum Cheetham indicate that thè depth of water
during Chipola time was generally greater than 18, but less than
31, meters. The greater abundance of these species in thè Tenmile
Creek biofacies than in thè others is considered evidence of shal-
lower water depth in thè Tenmile Creek paleoenvironment. Ex-
tensive distribution of both thè low and high salinity morphologic
forms of Hippoporella gorgonensis Hastings supports thè hypo-
thesis of salinity variation and fluctuations down to 30 % are
thought to have occurred. Crosshatch impressions on thè basai
surface of Diaperoecia sp. and thè occurrence of Rhynchozoon
edax (Canu and Bassler), Lichenopora sp., and Diaperoecia sp.
only as loose fragmente in thè sieve fractions indicates a soft,
readily decomposable substrate, possibly fleshy algae or marine
spermatophytes.

Specimens of these species were more common in thè Tenmile
Creek biofacies than in thè other two, suggesting that plant or-
ganism were more common here. The large molluscan community
is predominantly infaunal in habit. As minimal disruption of thè
originai biotope has occurred, thè mollusks probably did not
provide a significant amount of substrate. Competition among
sessile organism evidently was considerale and thè number of
brvozoan genera is smallest in thè Tenmile Creek biofacies.

Marls of high calcium carbonate content with some quartz
sands characterize thè paleoenvironment exposed along thè Chi¬
pola River. The brvozoan subassemblage is typified by substantial
increases in thè number of membraniporiform genera and by
moderate increases in thè number of cellariiform and vincula-
riiform genera. In addition, many species of all growth forms
show significante large increases in thè frequency of occurrence,
and some only noticeable increases, over those occurring in thè
Tenmile Creek paleoenvironment. An increase in thè substrate
availability in thè form of a large epifaunal invertebrate assem-
blage of mollusks and coelenterates is a major cause for this
change.

PALEOECOLOGIC INTERPRETATION OF SOME FLORIDA ETC.

177

Sandy marls of high calcium carbonate content are typical
in thè paleoenvironment exposed along Farley Creek. All growth
forms have their greatest representation in this biofacies both
in thè number of species and in thè numerical abundance of
each species. T riportila stellata (Smitt), Hippaliosina rostrìgera
(Smitt), Celleporaria magnifica (Osburn), and Vibraculina sp.
are especially common. Particles of C. magnifica are so abundant
that they constitute a small but significant part of thè total
bioclastic material. Maximum development of thè bryozoan fauna
is in part a response to substantial increases over thè Chipola
River biofacies in thè substrate availability.

REFERENCE

Canu F. & Bassler R. S., 1923 - North American Later Tertiary and Qua-
ternary Bryozoa - U.. S. Nati. Mus., Bull. 125, pp. 1-302, pls. 1-47,
text-figs. 1-38.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 179-184. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
25. Group 4: Evolutionary Patterns and Systematics.

Richard S. Boardman (*)

COLONY DEVELOPMENT

AND CONVERGENT EVOLUTION OF BUDDING PATTERN

IN « RHOMBOTRYPID » BRYOZOA

Riassunto. — Studi tridimensionali dettagliati sui bizzarri tipi di gemma¬
zione dei Bryozoa « rhombotrypidi » hanno dimostrato che questi tipi sono
identici in tre generi largamente diffusi nel tempo e attualmente conside¬
rati come appartenenti a tre diverse famiglie. I tipi di gemmazione sono
quindi considerati come un esempio di evoluzione convergente.

Summary. — Detailed three-dimensional studies of thè bizarre budding
pattern of « rhombotrypid » Bryozoa i indicate that this pattern is identical
in three genera widely spaced in time and presently considered to be in
different family groupings. The budding pattern is therefore inferred to be
an example of convergent evolution.

The post larvai growth of a bryozoan colony has at least
two major stages distinguished on morphology, budding habit,
and position of zooids in thè colony. The first stage, termed thè
stage of astogenetic change, is expressed by thè colony founders
which are restricted to thè most proximal region of thè colony,
termed thè zone of astogenetic change. Variation in morphology
and budding pattern characterize these zooids.

As colony growth proceeds distally from thè founder indi¬
viduai, morphologically comparable zooids appear in one or more
endlessly repeatable patterns of budding beginning thè second
major episode of colony growth, here termed thè stage of asto-

(*) Smithsonian Institution, U. S. National Museum, Division of In¬
vertebrate Paleontology - Washington D. C., USA.

ISO

R. S. BOARDMAN

genetic repetition. This zone can contain considerable complexity
producing more than one growth habit simultaneously, or cyclic
developments of zooids of different morphologies and function
along thè same growth axis. Budding patterns, however, have
thè property of endless repetition of one to several kinds of
zooids in characteristic arrangements.

In Paleozoic Bryozoa, thè most detailed work to date on
thè earliest growth stages of bryozoan colonies was done by
E. R. Cumings (1904, 1905, 1912). The stage of astogenetic
change as here defined includes thè phylastic and nepiastic
stages of his earlier work (1904, p. 56). Cumings’ nepiastic stage
ends with «... thè establishment of thè definite budding habit
of thè colony ». The stage of astogenetic repetition corresponds
to his neanastic, ephebastic, and gerontastic stages (Cumings,
1904, p. 59 ).. « The neanastic stage begins with thè assumption
of thè habit of budding that is to characterize thè adult colony ».
and, «... termi nates with thè development of an adult colony.
The ephebastic and gerontastic stages refer, as in other orga-
nism, to f ully adult and senile growths ».

Cumings was influenced by thè theory of Recapitulation and
his studies emphasized thè first growth stages in bryozoan colo¬
nies. Further, he was impressed by morphologic irregularities
caused by environmental factors in later growth of colonies.
These influences led him to propose a challenging approach to
bryozoan classification in which only thè early nepiastic stage
had phylogenetic significance or classificatory value above thè
generic level (Cumings, 1904, p. 76).

The present day philosophy of systematics contends that
morphologic variation that is largely controlled genetically re-
flects phylogenetic relationships and potentialìy can have classi¬
ficatory value at any hierarchial level. Obviously then, thè ap¬
proach to a phylogenetic classification is to distinguish genetic
from extra-genetic variation in thè bryozoan colony.

On thè assumption that individuala in a colony are asexually
produced and thè same genetic makeup exists throughout a co¬
lony, morphologic variation within thè colony can be considered
extra-genetic in origin. Recognition of genetic variation within
a single population and in populations distributed in time and
space is then possible through comparison of zooids in similar

COLONY DEVELOPMENT AND CONVERGENT EVOLUTION ETC. 181

extra-genetic circumstances of ontogeny, astogeny, polymorphism,
and closely as determinable, microenvironment. Since Cumings’
work, thè taxonomv of Paleozoic Bryozoa at all categorical levels
has been obtained almost entirely from characters in thè zone
of repetition. Certainly from this experience it has been demons-
trated and is to be expected that features reflecting genetically
controlled variation occur throughout a colony and that they are
not modified beyond recognition by thè environment. These gene¬
tically controlled variations then should be suitable for evaluation
throughout thè taxonomic hierarchy of thè phylum.

Little has been published on thè three dimensionai morpho-
logy of zooecia and budding patterns of thè zone of astogenetic
repetition that compares with Cumings’ work on thè zone of
astogenetic change. Budding patterns of hemispherical and dis-
coidal zoaria of Ordovician age were discussed by Mannil, 1961 ;
fenestellate zoaria by Taverner-Smith, 1965, and bifoliate and
incrusting zoaria by Boardman and Utgaard, 1966. These papers
serve to emphasize how little is known about zooecial form and
budding and something of thè potential for increased biological
understanding and taxonomic use.

In most ramose Bryozoa lack of obvious pattern as seen in
two-dimensional sections has made a three-dimensional unders¬
tanding of zooecial shape and budding pattern appear difficult.
In thè Upper Ordovician genus Rhombotrypa Ulrich and Bas-
SLER, 1904, p. 44, thè exceptional regularity of thè quadrate
zooecia in thè endozone and strong cyclic patterns in longitu-
dinal section suggested that thè genus might be a convenient
starting point in thè understanding of budding patterns in thè
ramose growth habit. The appearance of apparently similar
quadrate zooecia and budding pattern in endozones in Middle
Silurian ( Acanthotrypina VlNASSA de Regny, 1920, p. 221) and
Upper Paleozoic ( Rhombotry polla Nikiforova, 1933, p. 9) genera
of quite different morphologic characters in exozones further
suggested thè need for a detailed morphologic study before phv-
logenetic inferences could be made with any degree cf reliability.

Each branch of a colony of Rhombotrypa is divided trans-
versely into short segments defined by (1) zooecial orientation
and (2) thè appearance of new zooecia between those alreadv
established. Each segment can be thought of as a generation of

182

R. S. BOARDMAN

growth. Boundaries between generations arch convexly in a distai
direction across thè endozone. Approximately half of thè zooecia
of a generation are terminated by curving outward to thè exo-
zone in a band around thè branch, thè inner half of thè zooecia
continue distally within thè branch into later generations.

Within thè endozone, aboral ends of new zooecia budded
from all zooecial corners of thè preceding zooecia to start thè
new generation. The new buds, quadrate like thè older zooecia,
are rotated 45° relative to zooecia in thè preceding generation
so that thè buds grew by keeping their corners migrating along
thè sides of thè earlier zooecia. Corners of thè new zooecia carne
together at thè midpoints of thè earlier zooecial walls causing
thè earlier zooecia to be turned 45° with them and distributing
thè old and new zooecia in a checkerboard pattern.

The 45 degree rotation of zooecia and thè initiation of bud-
ding from all zooecial corners of thè preceding generation pro-
duced new zooecia with sides approximately 0.7 thè length of
sides of preceding zooecia at thè generation boundary. In order
for thè budding pattern to be capable of endless repetition of
comparable zooecia, an increase in cross sectional area was neces-
sary for all zooecial tubes within any one generation of growth.
A new generation began each time thè zooecia attained thè maxi¬
mum cross sectional area established for that colony. Thus,
zooecial cross sections remained comparable with each generation
rather than getting progressively smaller.

No zooecia are terminated within thè endozone. The equal
expansion of zooecia within a generation was in effect growth
from within thè branch which forced all zooecia to curve out¬
ward to thè exozone where they terminated. Approximately half
of all zooecia in a generation terminate within thè generation in
a band around thè branch, half of these were from earlier gene¬
rations and half from thè new generation in thè checkerboard
arrangement. The half of thè generation remaining in thè endo¬
zone continued on to later generations keeping thè number of
zooecia essentially Constant along a branch enabling branch dia-
meters to remain comparable.

Finally, thè square zooecia were able to forni a circular
branch by virtue of zooecial expansion from within thè branch
forcing zooecia to curve outward unti! ultimately they intersected

COLON Y DEYELOPMENT AND CONVERGENT EVOLUTION ETC. 183

thè zoarial surface at nearly right angles. The relatively dose
spadng of many small zooecia and progressive redudions in
zooedal length as rows of zooecia approached thè zoarial surface
then combined to produce a smoothly curved zoarial exterior.

Detailed study of thè three genera of different geologie ages
indicates that their remarkable endozonal budding patterns are
similar in all observable characters. Considering thè taxonomic
characters as they are now understood in thè zone of astogenetic
repetition, however, thè exozones of thè three genera are quite
different and would be placed in different families by most
workers.

Rhomb otrypa, thè Ordovician genus, has sharp zooecial
boundaries, generally integrate walls, closely spaced planar and
cystoidal diaphragms, and no acanthopores. Acanthotrypina, thè
Silurian genus, has poorly defined or no zooecial boundaries,
amalgamate walls, few diaphragms in zooecia, pierced diaph¬
ragms in mesopores similar to those of Trematopora, and abun-
dant large acanthopores. Rhomb otrypella, thè Upper Paleozoic
genus, is a typical stenoporid with some development of moni-
liform zooecial walls, few perforated diaphragms in zooecia, and
two sizes of acanthopores.

It is conceivable certainly that thè Silurian and Upper Paleo¬
zoic genera are related. Intervening faunas are so poorly known,
however, that no evidence is presently available. Using thè cha¬
racters of thè entire zone of astogenetic repetition, thè diffe-
rences found in thè exozone are inferred to piace thè genera
in different families, and thè budding pattern of thè endozones,
bizarre as it may be, apparently evolved independently and cons-
titutes, an example of convergent evolution.

REFERENCES

Boardman R. S. & Utgaard J., 1966 - A revision of thè Ordovician bryozoan
genera Monticulipora, Pcroìiopora, Heter otrypa and Dekayia - Journal
of Paleontology, voi. 40, no. 5, pp. 1082-1108, 9 fig’s., 10 pls.

Cumings E. R., 1904 - Development of some Paleozoic Bryozoa - The Ame¬
rican Journal of Science, voi. 17, no. 97, pp. 49-78, 83 figs.

Cumings E. R., 1905 - Development of Fenestella - The American Journal
of Science, voi. 20, no. 117, pp. 169-177, pls. V-VII.

184

R. S. BOARDMAN

Cumings E. R., 1912 - Development and systematic position of thè monticu-
liporoids - Bulletin of thè Geological Society of America, voi. 23, pp.
357-370, pls. 19-22.

Mannil R., 1961 - On thè morphology of thè hemispheric zoaria of Trepo-
stomata (Bryozoa) - Trudy Instituta Geologii Akademii Nauk Est.
SSR., no. 6, pp. 113-140, 8 pls.

Nikiforova A., 1933 - Middle Carboniferous Bryozoa of thè Donetz Basin -
Transactions of thè United Geological and Prospecting Service of
USSR, Fascicle 237, pp. 4-46, 7 pls.

Tavener-Smith R., 1965 - A new fenestrate bryozoan from thè lower Car¬
boniferous of County Fermanagh - Paleontology, voi. 8, pt. 3, pp. 478-
491, pi. 66, 7 text-figs.

Ulrich E. 0. & Bassler R. S., 1904 - A revision of thè Paleozoic Bryozoa
part II. Trepostomata - Smithsonian Miscellaneous Collections, voi. 47,
no. 1470, pp. 15-55, 14 pls.

Vinassa de Regny P., 1920 - Sulla Classificazione dei Treptostomidi - Estratto
dagli Atti della Società Italiana di Scienze Naturali - Voi. 59, pp. 212-
231.

Atti Soc. It. Se. Nat. e Museo Civ. SI. Nat. Milano - 108: 185-194. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
26. Group 4: Evolutionary Patterns and Systematics.

Alan H. Cheetham (*)

EVOLUTION OF ZOOECIAL ASYMMETRY AND ORIGIN
OF PORICELLARIID CHEILOSTOMES

( Bryozoa )

Riassunto. — L’asimmetria zoeeiale aumenta nelle popolazioni dei Cheilo -
stornata « poricelariiformi » che si succedono dal Cretacico superiore al¬
l’Attuale.

La tendenza evolutiva è allometrica rispetto alle serie zoariali e produce
un distinto dimorfismo zoeeiale a partire dal Terziario medio. Quest’aumento
della asimmetria è accompagnato dalla scomparsa delle ovicelle. Allo stesso
tempo gli avicularia assumono un’orientazione asimmetrica e il tipo di gem¬
mazione della colonia diventa più regolare.

Finora il genere Nellia è stato considerato come rappresentante di un
altro gruppo, molto lontano dai Poricellariidae, ma l’estrapolazione di questa
tendenza ci fa pensare che il genere Nellia sia in effetti il progenitore di
quest’ultimo gruppo.

Nellia ha dato origine ad altri generi, compresi Vincularia e Rimosocella
che sono convergenti con i Poricellariidae in uno o più caratteri della mor¬
fologia zoeeiale o del tipo di gemmazione della colonia.

Summary. — Zooecial asymmetry increased in successive populations of
poricellariid cheilostomes ranging from Late Cretaceous to Recent. The trend
was allometric with respect to zoarial series and produced distinct zooecial
dimorphism by mid-Tertiary time. Concomitantly with inereasing asymmetry,
ovicells were lost, avicularia assumed asymmetrical orientation, and thè bud-
ding pattern of thè colony became more regular.

Extrapoi ation of these trends suggests thè genus Nellia, heretofore re-
garded as far removed from this group, to be ancestral to thè poricellariids.
Nellia appears also to have given rise to other genera, including Vincularia
and Rimosocella, convergent with poricellariids in one or more features of
zooecial morphology or budding pattern of thè colony.

(*) Smithsonian Institution, U. S. National Museum - Washington
D. C., USA.

186

A. H. CHEETHAM

Résumé. L’asymétrie zoéciale s’est accrut dans les populations successives
des Cheilostomes poricellariides depuis le Crétacé supérieur jusqu’à l’Actuel.
Cette tendance évolutionnaire était allométrique à l’égard des séries zoariales
et a produit avant le Tertiaire moyen un dimorphisme zoécial distinct. Cette
augmentation de l’asymétrie est accompagné par la disparition des ovicelles.
Au mème temps les aviculaires ont assumé une orientation asymétrique, et
la modèle du bourgeonnement des colonies est devenu plus réglé.

Jusqu’ ici le genre Nellia a été consideré comme le representatif d’un
autre groupe, très eloigne des Poricellariides, mais la extrapolation de ces
tendances suggère que le genre Nellia est en effet l’ancétre de ce groupe.
Aussi Nellia a probablement donné naissance a d’autres genres, y compris
Vincularia et Rimosocella, qui sont convergents avec les Poricellariides dans
un ou plusieurs des traits de la morphologie zoéciale ou du modèle du bour¬
geonnement des colonies.

Introduction.

Zooecia in cheilostome Bryozoa normally are bilaterally sym-
metrical and — in thè absence of brood chambers, mandibles, or
setae — monomorphic. Groups in which asymmetrical, polymor-
phic zooecia occur in regular positions in thè budding pattern of
a colony generally have been regarded as markedly divergent and
taxonomically distinct from « normal » cheilostomes.

Poricellariids, which are widely distributed in sediments of
Paleocene to Recent age (Lagaaij, 1968, fig. 4), are perhaps thè
most conspicuous and abundant of these groups. New occurrences
in thè Upper Cretaceous and Tertiary of thè Gulf of Mexico-Ca-
ribbean region extend thè known range and distribution of thè
group, and comparison of these populations with previously de-
scribed poricellariids permits delineation of evolutionary trends in
thè morphology of their zooecia and thè budding pattern of their
colonies. Phylogenetic relationships of poricellariids to other chei¬
lostomes may be inferred by extrapolation of these trends.

Zooecial morphology.

Zooecial asymmetry is deviation in shape and structure from
thè basic bilateral symmetry of cheilostome zooecia. As such, it
is a tundamental property of thè zooids of which thè zooecia are
part and, in this respect, is different from superficial asymmetry.
The latter includes adventive asymmetry, i.e., asymmetrical distri¬
bution or orientation of spines, avicularia, and thè like, and for-

EVOLUTION OF ZOOECIAL ASYMMETRY AND ORIGIN ETC.

187

tuitous asymmetry, such as results from crowding of zooids or
bifurcation of series of zooids.

Zoo ecidi polymorphism is discontinuous variation of thè ordi-
nary zooecia in a colony. Variation in thè forni of zooecia in thè
proximal zone of thè zoarium, producing thè record of astogenetic*
change, is a typical feature of cheilostome morphology and does
not constitute polymorphism. Possession or lack of an ovicell or
other brooding apparatus, constituting reproductive polymorphism,
also is excluded here from zooecial polymorphism.

Poricellariid zooecia are segregated in distinct series in thè
zoarium on thè basis of thè direction of their asymmetry. All of
thè principal zooecial openings (opesiae) curve toward thè midiine
of one side (frontal) of thè zoarium and are completely hidden in
thè opposite view (dorsal). They are arranged in two sets of two
series each, left and right frontal series lying in a frontal posi-
tion, and left and right lateral series lying in a dorso-lateral po-
sition. The zooecia in thè two series of a set, i.e., left and right
frontals or left and right laterals, are mirror images. The amount
of asymmetry of zooecia belonging to series of different sets may
be thè sanie or different. If different, thè zooecia are dimorphic.

Zooecial asymmetry in poricellariids is expressed by zooecial
shape and, structurally, by thè unilateral opening (opesiule) in thè
cryptocyst for thè parietal muscles, invariably lying toward thè
frontal side of thè zoarium. In advanced poricellariids, adventive
asymmetry, produced by thè position and orientation of thè avicu-
larium lying on thè proximal gymnocyst, is superimposed on and

accentuates zooecial asymmetry.

In this study zooecial shape has been measured by three va-
riates, zooecial length, zooecial width, and thè angle (6) between
thè zooecial axis and thè bisectrix of thè opesia. Avicularian orien¬
tation (thè angle a between thè avicularian axis and thè zooecial
axis) and avicularian length were used to measure adventive
asymmetry. The asymmetrical distribution of thè opesiule is inva¬
riate in thè populations studied.

Evolutionary trends were determined from estimates of cen¬
trai values of thè five variates in four successive poricellariid
samples. Identification of trends in estimates is affected by varia¬
tion, specifically by thè relation between thè amount of variation
within a colony and thè total variation in thè colonies of a sample

188

A. H. CHEETHAM

of a taxonomic population. All five measures are variable within
and among colonies.

In three of thè four samples analyzed, among-colony variation
is not significantly different, on thè average, from within-colony
variation. For zooecial length and width, coefficients of variation
range from 9 to 16 for samples and from 6 to 21 for specimens ;
17 per cent or fewer of thè specimens show significantly less va¬
riation (as determined by F-tests on variances) than thè sample
of which they are parts.

On thè other hand, thè fourth sample (Eocene) is heteroge-
neous with respect to zooecial width, as indicated by its high
among-colony variation (21) compared to within-colony variation
(8-12). A majority (62 per cent) of thè included specimens display
signiticantly less variation than thè sample total. Division into
two subsamples reduces thè variation in each to a level (10 and 14)
commensurate with specimen variation and with thè variation
shown by other samples. This sample, therefore, has been inter-
preted, in thè following description of evolutionary trends, as
representing two populations.

The variation within a poricellariid specimen thus serves to
calibrate population variation and, for thè majority of specimens,
is not significantly different from that in a population sample.
Theretore, relatively few specimens are needed to estimate popu¬
lation parameters, at least in thè poricellariids studied.

Discontinuous variation in poricellariid characters, i.e., zoo¬
ecial dimorphism, is indicated by a significant decrease, to a
level below specimen variation, resulting from separation of thè
trontal and lateral sets of zooecia. Such decreases occur in zoo¬
ecial width and thè angle 0 in Oligocene and Recent populations,
and a decrease in thè frontal series of one Eocene population
suggests incomplete dimorphism in zooecial width. Zooecial length
and avicularian characters appear not to be involved in di¬
morphism.

In generai, thè dimensionai variates (zooecial length, zooecial
width, and avicularian length) show no significant time-related
changes in thè amount of population variation. In accordance
with previous studies, avicularian length has about twice thè va¬
riation of zooecial dimensions. The orientational variates (thè
angles 0 and oc), on thè other hand, trend distinctly from higher to
lower values in younger populations.

EVOLUTION OF ZOOECIAL ASYMMETRY AND ORIGIN ETC.

189

Evolutionary trends in zooecial morphology of poricellariids
may be characterized as follows.

1. Asymmetry increased gradually from Late Cretaceous to
Recent, affecting both zooecial width and thè angle 6, which be-
came less variable as stable orientations were achieved. The
amount of asymmetry in Recent populations (mean zooecial width,
24 dekamicrons ; mean 6, 50°) is more than 50 per cent greater
than that in Cretaceous populations (mean zooecial width, 14 de¬
kamicrons; mean 6, 32°).

2. Lateral zooecia became more asymmetrical more rapidly
than frontal ones. This allometric trend produced distinct zooecial
dimorphism by Oligocene time, and in Recent populations, thè la¬
teral zooecia are about 50 per cent more asymmetrical in both
zooecial width (26 dekamicrons) and thè angle 6 (64°) than frontal
ones (21 dekamicrons; 36°). In Eocene time, some species diversi-
fication resulted from accelerated increase in zooecial width in at
least one population.

3. Probably as a result of thè rapidly increasing asymmetry
of lateral zooecia, ovicells, which occur on lateral zooecia in Cre¬
taceous poricellariids, were lost by Tertiary time. In Recent pori¬
cellariids, embryos develop within thè zooecal cavities (Waters,
1913, p. 492).

4. Through modification of distribution and orientation of
avicularia, adventive asymmetry was superimposed on and accen-
tuated zooecial asymmetry. In thè Cretaceous, avicularia were
generally paired and, with a great deal of variation (coefficient ot
variation, 81), directed proximally (mean angle a, 15°). By Eocene
time, one avicularium had been lost, and thè remaining one has
rotated laterally to a nearly transverse position (mean angle a,
59°) in Recent poricellariids. Variation in orientation decreased
(to a coefficient of 25-31) as a more stable position was reached.
Concomitantly, avicularian length increased (from a mean of six
dekamicrons in thè Cretaceous to eight in Recent populations).
Most of thè change in avicularia took place between Eocene and
Oligocene populations.

Avicularian evolution was more rapid in thè lateral series,
but, because of thè inherently greater variation in avicularian
characters, did not contribute significantly to dimorphism.

190

A. H. CHEETHAM

Budding pattern of thè colony.

Evolutionary trends in zooecial form of poricellariids are cor-
related with a change in thè budding pattern of thè colony.

The colonies of living poricellariids are jointed, thè calcified
segments connected by uncalcified tubes in such a way that bran-
ching occurs at each joint. Most specimens, including all known
fossils, consist of disarticulated segments whose connections are
indicated by openings in both ends, three proximally and two
groups of three each distally, in all material examined.

The arrangement of zooecia in a colony is regular not only
in consisting of two frontal and two lateral series in each seg-
ment but also in having thè budding alternate from series to
series in a definite sequence. Each segment originates with three
zooids, thè proximal parts of which lie in thè distai end of thè
next proximal segment and to which they are connected by one
larger and two smaller tubes. Each of thè three proximal zooids
originates a series. Zooid 4, which begins thè fourth series, arises
by bifurcation from zooid 1 and does not participate in thè joint.
Zooids 1 to 4 increase progressively in length, width, and struc-
tural complexity and can be identified at thè proximal end of
each segment as a primoserial zone of change . (In modern pori¬
cellariids, a similar progression of zooecial changes occurs over
thè first few proximal segments of thè colony, which thus form
a zone of astogenetic change; Waters, 1913, p. 490; Harmer, 1926,
p. 315.) Beginning with zooid 4, zooecial morphology is approxi-
mately Constant within each series. This portion of thè segment,
distai to thè fourth zooid, is thè zone of repetitive budding (and
measurement of zooecial variates was restricted to this zone). The
two sets ot openings at thè distai end of this zone correspond to
thè proximal ends of thè first three zooids of thè next segments.
The larger opening of each group, representing zooid 1 of thè
next segment, develops by lineai addition to its series, whereas
thè two smaller ones, representing zooids 2 and 3, originate by
bifurcation.

The first zooid of a segment may belong to any series. Seg¬
ments originating with each of thè four series (left and right la¬
teral, left and right frontal) occur in about equal numbers in all

EYOLUTION OF ZOOECIAL ASYMMETRY AND ORIGIN ETC.

191

of thè samples studied. The sequence in which zooids belonging
to thè tour series appear in thè primoserial zone then serves as
thè template for budding and bifurcation in thè zone of repetition.
Two such templates occur in thè poricellariids.

1. In all modern poricellariids zooid 4 of each segment be-
longs to thè same set (frontal or lateral) as zooid 1. Zooids 2 and 3
belong to thè two series of thè other set. After a given number
of zooids have budded, each series bifurcates in turn, in thè same
order in which its primoserial zooid appeared. The first and se-
cond bifurcate at thè distai end of thè segment, whereas thè third
and fourth bifurcate at thè proximal ends (primoserial zones) of
thè next segments. Therefore, thè first and second series have
one more zooid each than thè third and fourth. Moreover, thè
first zooids of thè distai segments necessarily belong to diffe-
rent series than thè first zooid of thè proximal segment does.
The whole budding pattern in thè part of thè colony distai to thè
zone of astogenetic change is thus deducible from a single seg¬
ment. This strictly regular pattern occurs only in poricellariids
having highly asymmetrical, distinctly dimorphic zooecia. It re-
sults from thè lineai descent of zooids having thè same relative
positions in each segment, laterals giving rise to laterals and fron-
tals to frontals throughout thè distai part of thè colony.

2. Cretaceous and early Tertiary poricellariids have a
slightly less regular budding pattern in which lateral and frontal
series apparently are not in continuous lineai arrangement throu¬
ghout thè distai part of thè zoarium. The order in which thè series
bifurcate is thè reverse of that in which they appear in thè pri¬
moserial zone, and, as a consequence, each series has thè sanie
number of zooecia within a segment. The zooecial couplets 1-4
and 2-3 may each belong to thè same set of series, frontal or la¬
teral, as they do in advanced poricellariids, or they may belong
to different sets. This pattern occurs only in those poricellariids
having less asymmetrical, not distinctly dimorphic zooecia.

Evolution of thè more regular budding pattern of modern
poricellariids is thus a consequence of thè development of dimor¬
phic zooecia which in turn resulted from thè allometric increase
in zooecial asymmetry.

192

A. H. CHEETHAM

Inferred phylogenetic relationships.

The following inferences can be made about thè ancestor of
poricellariids by extrapolating these trends in thè morphology of
zooecia and thè budding pattern of thè colony: (1) The zooecia
were monomorphic and probably symmetrical. (2) Ovicells of pori-
cellariid structure (entozooecial) occurred on zooecia probably ir-
respective of zoarial series. (3) Avicularia of thè same position
and form as in poricellariids (adventive, gymnocystal ; with
pointed rostrum and pivotal bar) were paired and directed more
or less proximally. (4) The budding pattern of thè colony was like
that of primitive poricellariids or slightly less regular.

The genus Nellia, regarded as far removed from poricella¬
riids by Harmer (1926, p. 240), Bassler (1953, p. 179), and Chee-
tham (1966, p. 48), fulfills these qualifications but differs conspi-
cuously from poricellariids in having much less nearly complete
cryptocysts. The budding of Nellia tenella follows thè pattern of
primitive poricellariids (Harmer, 1926, p. 243-244), though, be-
cause of its symmetrical zooecia, frontal and lateral series cannot
be identified. Other species of Nellia have a simpler pattern
(Harmer, 1926, p. 245; Cheetham, 1966, p. 52), in which only
two proximal zooids participate in thè joint, subequally. This
pattern has also been described in thè genus Rimosocella which
has symmetrical zooecia and complete cryptocysts (Cheetham,
1960). The occurrence of Nellia having both types of budding
together with primitive poricellariids in thè Caribbean Upper
Cretaceous, thè oldest occurrence of both groups, makes their
phylogenetic relationship more likely.

Through Nellia, thè poricellariids are probably also related
to thè genus Vincularia in which thè budding pattern is highly
regular, but of a different form from that of thè advanced pori¬
cellariids (Cheetham, 1966, p. 56-57). The zooecia are dimorphic,
those identifiable as lateral series being slightly asymmetrical.
The joints are tripartite, zooids 1 and 3 invariably belonging to
thè lateral series. The number of zooids is thè same in each series,
rather than binary as in advanced poricellariids. In some species
of Vincularia, ovicells occur on lateral zooecia. Avicularia, where
present, are single, but directed frontally, rather than laterally
as in advanced poricellariids. Unlike poricellariids, Vincularia
never developed extensive cryptocysts.

EVOLUTION OF ZOOECIAL ASYMMETRY AND ORIGIN ETC.

193

A great diversity of budding patterns has been described in
thè major cheilostome group generally called cellularines (Harmer,
1923). Many of thè genera have jointed, biserial zoaria, and,
though their zooecia are basically symmetrical, adventive asym-
metry is common in thè group. Of thè budding types described
by Harmer, type 8 appears first in thè fossil record and may be
regarded as thè basic pattern in biserial forms. Though it is im-
possible to establish thè homology of thè two series of zooecia on
morphological grounds, it is possible that thè other two have
been reduced to form thè dorsal vibracula. Cellularines have
gymnocystal spines, very little developed cryptocysts, and ovi-
cells of a different structural type (hyperstomial) from Nellia,
Vincularia, Rimosocella, and primitive poricellariids.

In summary, thè following phylogenetic relationships are
suggested on thè basis of thè stratigraphic distribution of these
genera :

1. Poricellariids evolved from Nellia in Late Cretaceous
time through inception of zooecial asymmetry, completion of thè
cryptocyst, and restriction of ovicells to lateral zooecia.

2. Vincularia evolved from Nellia in Paleocene time con¬
vergente with poricellariids through development of zooecial
asymmetry and dimorphism, appearance of adventive avicularian
asymmetry, restriction of ovicells to lateral zooecia, and modifi-
cation of thè budding pattern to greater regularity.

3. Rimosocella evolved from Nellia in Eocene time conver¬
gente with poricellariids through completion of thè cryptocyst.

The cellularine cheilostomes also may have developed from
Nellia in one or more lineages, going back to Eocene time, through
structural changes in thè ovicell and other features and thus may
be related to thè poricellariids.

If Nellia , Vincularia, Rimosocella, and thè poricellariids are
as closely related as thè trends in their budding patterns and
zooecial morphology suggest, their family assignments (Harmer,
1926; Bassler, 1953; Cheetham, 1960, 1966) require revision.
Whether they should be included with thè cellularines in thè
superfamily Scrupocellariacea cannot be decided at this time.

194

A. H. CHEETHAM

Samples studied.

Upper Maestrichtian, Westmoreland Parish, Jamaica.

Jerusalem Mountain Inlier ; yellow calcareous shale between
limestones with Lopka arizpensis jamaicensis (Trechman),
about 70 feet below top of Cretaceous. Coll. J. E. Hazel.

Lutetian, Gourbesville (Manche), France.

Sables de Fresville. Coll. D. Curry.

Rupelian, St. Stephens, Clarke County, Alabama. Chickasawhay
Formation; Lone Star Cement Company quarry; buff cal¬
careous sand with Lepido cy dina undosa Cushman. Coll.
A. H. Cheetham.

Recent, Bombay, India. Beach sand, Juhu Beach, Salsette Island.
Coll. Y. Nagappa.

Recent, Seria, Brunei. Beach sand, Panaga Beach. Coll. A. J. Key.

REFERENCES

Bassler R. S., 1953 - Bryozoa - In R. C. Moore, editor, Treatise on Inverte¬
brate Paleontology, Pt. G, 253 pp., 175 figs., Lawrence, Kansas.

Cheetham A. H., 1960 - Rimosocella, New Genus of Cheilostome Bryozoa -
Micropaleontology, voi. 6, pp. 287-289, 5 figs.

Cheetham A. H., 1966 - Cheilostomatous Polyzoa from thè Upper Brackle-
sham Beds (Eocene) of Sussex - British Museum (Naturai History),
Bulletin, Geology, voi. 13, no. 1, pp. 1-115, 81 figs.

Harmer S. F., 1923 - On Cellularine and Other Polyzoa - Journal Linnaean
Society of London (Zoology), voi. 35, pp. 293-361, pls. 16-19.

Harmer S. F., 1926 - The Polyzoa of thè Siboga Expedition, Part. II, Chei-
lostomata Anasca - Siboga Expedition Reports, voi. 28, pp. 181-501,
pls. 13-34.

Lagaaij R., 1968 - Fossil Bryozoa Reveal Long-Distance Sand Transport
Along thè Dutch Coast - Koninkl. Nederland. Akademie van We-
tenschappen, Amsterdam, Proceedings, Ser. B, voi. 71, pp. 31-50, pi. 1,
6. figs.

Waters A. W., 1913 - The Marine Fauna of British East Africa and Zan¬
zibar from Collections Made by Cyril Crossland in thè Years 1901-
1902, Bryozoa-Cheilostomata - Zoological Society London, Proceedings,
1913, pp. 458-537, pls. 64-73.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 195-211, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
27. Group 4: Evolutionary Patterns and Systematics.

Hugo Ivan Moyano G. (*)

POSICIÓN SISTEMATICA DE LOS GENEROS
ROMANCHEINA, ESCHAROIDES, CELLARINELLA

Y SYSTENOPORA

( Bryozoa , C hello stornata, Ascophora)

Riassunto. — E’ stata studiata l’anatomia di Romancheina martiali
Jullien, 1888; Escharoides bubeccata Rogick, 1955; Escharoides tridens
(Calvet, 1909); Cellarinella rossi Rogick, 1956; Cellarinella njegovannae
Rogick, 1956 e Systenopora contrada Waters, 1904, appartenenti alle fa¬
miglie Exochellidae e Sclerodomidae.

Il loro studio ha permesso di ottenere i seguenti risultati :

1. - Sotto la parete frontale calcarea vi è una grande cavità aperta
distalmente.

2. - Il fondo di questa cavità è dato dalla membrana frontale in¬
terna che ha dei fascicoli muscolari nella parte inferiore dei suoi bordi la¬
terali. Per conseguenza questa membrana è omologa di quella dei Briozoi
Anasca Malacostega.

3. - Questa membrana ha una fessura distale, il cui bordo prossi¬
male è un po’ indurito e corrisponde agli opercoli dei generi Bugula o Mem-
branipora.

4. - L’ancestrula di Romancheina martiali ha una parete frontale
esterna molto calcificata che si sviluppa come una pericisti.

Di conseguenza si può dire che le specie studiate non appartengono agli
Ascophora vera ma agli Ascophora imperfecta e si possono dunque ascri¬
vere alle famiglie Exochellidae e Sclerodomidae nell’ultimo gruppo insieme
alle famiglie Umbonulidae, Celleporariidae, Chlidionopsidae, Petraliidae, Pe-
traliellidae, E xechonellidae e Metrarabdotosidae.

(*) Universidad de Concepción, Instituto Central de Biologia - Con-
cepción, Chile.

196

H. I. MOYANO G.

Summary. — It has been made here an anatomical study of thè following
species: Romancheina martiali Jullien, 1888; Escharoides tridens (Calvet,
1909); Escharoides hubeccata Rogick, 1955; CeUarinella rossi Rogick, 1956;
Cellarinella njegovannae Rogick, 1956 and Systenopora contrada Waters,
1904, which belong respectively to thè families Exochellidae and Sclero-
domidae.

Beneath thè frontal calcareous external wall, there is a great cavity
widely and distally open through thè zoecial aperture. The floor of this sub-

frontal cavity is formed by thè frontal internai membranous wall provided
with lateral depressor muscles, and therefore it is homologous to thè frontal
wall of thè Bryozoa Cheilostomata Anasca Malacostega. This membranous
wall has a distally-plaeed slit to thè outlet of thè polipidian lophophore.
The proximal rim of thè slit is little hardened and correspond to thè oper-
cula such as those of thè genera Bugula or Membranipora.

The ancestrula of Romancheina martiali has a very calcified frontal
wall that is a pericyst according to its way of development.

Owing to thè characteristics indicated above, these species do not
belong to thè Ascophora Vera but to thè Ascophora Imperfetta, therefore
thè families Sclerodomidae and Exochellidae might be included in thè latter
group with Umbonulidae, Celleporariidae, Chlidionopsidae, Petraliidae, Pe-
traliellidae, Exechonellidae and Metrarabdotosidae.

Résumé. — On a étudié anatomiquement les espèces suivantes : Ro¬
mancheina martiali Jullien, 1888; Escharoides bubeccata Rogick, 1955;
Escharoides tridens (Calvet, 1990); Cellarinella rossi Rogick, 1956; Cella¬
rinella njegovannae Rogick, 1956 et Systenopora contrada Waters, 1904.
Ces espèces appartiennent aux families Exochellidae et Sclerodomidae.

Leur étude a permis d’obtenir les résultats suivants :

1. - Sous la parois frontale calcaire il y a une grande cavité ouverte
distalement.

2. - Le sol de cette cavité est la membrane frontale interne laquelle
a des fascicules musculaires dans la partie inférieure de ses bords lateraux.
Et par conséquent cette membrane est homologue à celle des Bryozoa
Anasca Malacostega.

3. - Cette membrane a une fente distale, dont le bord proximale est
peu endurci, et celui-ci correspond aux opereules comme ceux des genres
Bugula ou Membranipora.

4. - L’ancestrule de Romancheina martiali a une parois frontale ex¬
terne très calcifiée qui se developpe comme un péricyste.

Par conséquent on peut dire :

Les espèces étudiées n’appartiennient pas aux Ascophora Vera sinon
aux Ascophora Imperfeda, on peut donc piacer les families Exochellidae
et Sclerodomidae dans le dernier groupe avec les families Umbonulidae,
Celleporariidae, Chlidioìiopsidae, Petraliidae, Petraliellidae, Exechonellidae
et Metrarabdotosidae.

POSICIÓN SISTEMATICA DE LOS GENEROS ETC.

197

Introducción.

* Tradicionalmente los Cheilostomata han sido divididos en
los subórdenes Anasca y Ascophora, tornando en cuenta la au-
sencia o presencia de un saco de compensación respectivamente.
En los Anasca se retiene la membrana frontal primitiva y, en
generai, el opérculo està poco diferenciado de ella, mientras que
en la mayoria de los Ascophora existe un opérculo altamente
diferenciado colocado sobre una abertura zoecial encuadrada en
un marco calcàreo, ya que la pared frontal està fuertemente
calcificada.

Sin embargo, al observar la gran variedad de géneros descri-
tos dentro del orden Cheilostomata se puede fàcilmente advertir
que no existe una separación neta entre los dos subórdenes. Tipi¬
camente existe un grupo de transición entre ambos, los Cribri-
morpha , en los que sobre la pared frontal primitiva se encuentra
una capa calcàrea o pericisto, formada por espinas soldadas entre
si. Pero aparte de este grupo se advierte en muchos generos de
Anasca la tendencia a formar un escudo protector sobre la pared
frontal. Este es el caso, por e j empio, de los géneros Scrupocel-
laria, Aspidelectra , Tremopora, Arachnopusia, etc. Este escudo
està constituido por una espina que se modifica (, S crup o cellaria ),
por espinas modificadas y extendidas sobre la membrana frontal
o por varias espinas modificadas que coalescen entre si ( Tremo¬
pora y Arachyiopnsia respectivamente). La presencia de estas
espinas modificadas determina la aparición de una cavidad entre
el escudo y la membrana frontal subyacente. Y està cavidad
viene a representar una especie de saco de compensación o asco,
que no es homólogo al de los Ascophora, en los que el saco se
origina de un grupo de células por detràs del opérculo (Harmer,
1957: 645).

La observación de que no exista un opérculo diferenciado o
que sea dificilmente visible en algunos géneros colocados habi-
tualmente en el suborden Ascophora, nos ha llevado pensar sobre
su verdadera posición dentro del orden Cheilostomata. Esto es
particularmente darò en el caso de los géneros Cellarinella y
Systenopora ,- en los que la diagnosis genèrica alude a la inexis-
tencia de opérculo). Por otra parte en descripciones de especies

198

H. I. MOYANO G.

del gènero E scharoides , corno per e j empio de E. tridens (Calvet),
1909, E. bcLìdca Rogick, 1955 y de otras, no se habla de opérculo
o se dice que es muy tenue y dificil de ver (Rogick, 1955 : 447)
Y finalmente en la diagnosis de Romancheina martìali Jullien,
1888, tampoco se hace alusión al opérculo.

Todas estas consideraciones nos han llevado a la realización
de este trabajo con el fin de poner darò aunque sea someramente,
la posición sistemàtica de estos cuatro géneros.

Materiales y metodos.

Los ejemplares de las especies en que se hace este estudio
provienen del sur de Chile y de sus territorios antàrticos. La
procedencia exacta de ellos se indica en la Tabla I.

Las muestras fueron obtenidas principalmente por medio de
rastra triangular, a excepción de las de Romancheina martìali
que se obtuvieron con Draga Petersen de 0,1 m2. Una vez obte¬
nidas se fijaron en formol al 10% y luego fueron transferidas a
alcohol de 70°.

Tabla I.

Areas de recolección de las especies estudiadas.

Localidades

Posición

Geogràfica

Expedición

Colectores

Fechas

Especies

Estrecho de
Bransfield

63° 12' S

58° 35' W

XIX Exp. Ant.
Chilena

H. Moyano

30-XII-64

Cellarinella
rossi y C.
njegovannae

Bahia Chile

62° 28' S

59° 36' W

XXII Exp. Ant.
Chilena

A. Gallardo

13-1-68

Escharoides

bubeccata

Bahia Chile

62° 29' S

59° 39' W

N. Gonzàlez

-XI-51

Escharoides

tridens

Bahia Margarita

67° 50' S

68° 45' W

XIX Exp. Ant.
Chilena

H. Moyano

13-11-65

Systenopora

contrada

Bahia Inutil

53° 30' S

70° 11' W

Expedición

Centolla

A. Gallardo

3-V-62

Romancheina

martiali

POSICIÓN SISTEMATICA DE LOS GENEROS ETC.

199

Para el estudio propiamente tal, se dibujaron vistas fron-
tales y cortes longitudinales de las diferentes especies mediante
càmara clara. Los cortes se obtuvieron puliendo un trozo zoarial
sobre una piedra de asentar, luego se lavaron con agua corriente
y por ùltimo se montar on bajo alcohol. Los dibujos de las partes
blandas se cbtuvieron de ejemplares que habian sido descalcifi-
cados con HC1 diluido, después lavados y en ùltimo tèrmine mon-
tados en glicerina o gelatina-glicerina.

Sistemàtica.

El estudio se ha hecho sobre la base de tres especies de la
familia Exochellidae y tres de la familia Scleroclomidae de
acuerdo al sistema de Bassler (1953). Elias son respectiva-
mente: Romancheina martiali, Escharoides tridens , E. bubeccata,
Cellarinella rossi, C. njegovannae y Systenopora contrada.

POSICIÓN SISTEMATICA DE LAS ESPECIES ESTUDIADAS.

Phylum Ectoprocta
Clase Gymnolaemata
Orden Cheilostoniata Busk, 1852
Suborden Ascophora Levinsen, 1909

Familia Exochellidae Bassler, 1935

Gènero Romancheina Jullien, 1888

R. martiali Jullien, 1888

Gènero Escharoides Milne-Edwards, 1836
E. tridens (Calvet), 1909
E. bubeccata Rogick, 1955

Familia Sclerodomidae Levinsen, 1909

Gènero Cellarinella Waters, 1904

C. njegovannae Rogick, 1956
C. rossi Rogick, 1956
Gènero Systenopora Waters, 1904

S. contrada Waters, 1904.

200

H. I. MOYANO G.

Observaciones anatomicas.

Romancheina martiali Jullien, 1888

Figs. 1-13.

Se observaron seis colonias nuevas en las que pudo verse la
ancéstrula. Lo mas caractenstico de ella es la presencia de 5 a 7
espinas gruesas que se originari lateral y proximalmente desde
la parte media de la ancéstrula hasta el lado proximal vecino a
su abertura. Las tres espinas proximales se juntan por sus
extremos romos y dejan entre si orificios paralelos a sus longi-
tudes. Las dos espinas laterale® que esiguen a las anteriores tam-
bién se sueldan a ellas pero quedan un poco aparte en sus
extremos que se prolongan hacia adelante, de tal manera que
queda un espacio entre los extremos de las espinas precedentes
y los de éstas.

A medida que la colonia agranda por yemación de nuevas
zoecias, se van depositando sales calcàreas sobre el frente ancé-
strular, determinando la aparición de un àrea frontal distai con
cavidades. Està àrea se va cerrando progresivamente con la cal-
cificación al igual que los orificios que quedaron entre las espinas
proximales. En un estado màs avanzado el àrea se cierra total¬
mente y la pared asi formada, que equivale a un pericisto, se
asemeja en cierto modo a la que se balla en las zoecias adultas.
Lo que queda de este pericisto inicial en las ancéstrulas viejas es
la presencia de orificios màs o menos ocluidos entre las tres
espinas proximales. Las dos espinas màs distales nunca se fu-
sionan a las cinco precedentes, quedan libres y se proyectan un
poco lateralmente hacia adelante y arriba.

En las zoecias adultas (derivadas de la ancéstrula) no se
observan estas espinas y, en cambio, la pared frontal aparece
corno un tremocisto en el que se destacan grandes poros perisfé-
ricos que delimitan costillas leves sobre el frontal. La parte
anterior del frente zoecial se prolonga. en dos puntas, a veces
bastante largas, huecas y semejantes a las dos distolaterales de
la ancéstrula. Las dos espinas màs distales de la ancéstrula no
aparecen en las zoecias postancestrulares, pero en cambio, en el
lugar donde debieran aparecer se desarrollan las dos avicularias
làteroorales.

POSICIÓN SISTEMATICA DE LOS GENEROS ETC.

201

Al hacer un corte longitudinal de las zoecias, se puede
observar la existencia de una membrana frontal subyacente de
color café, que lateralmente presenta varios manojos espaciados
de fibras musculares. Està membrana deja una henditura trans¬
versai en su extremidad distai para la salida del polipido; sus
bordes estàn apenas engrosados, y asi, podriamos considerarla
corno el opérculo que està apenas diferenciado de la pared frontal.
Muy por encima de està membrana se halla la pared frontal
calcàrea externa, lo que hace que entre ambas exista una gran
cavidad ampliamente abierta al exterior a través de la abertura
zoecial. A ambos lados de la abertura zoecial externa se encuentra
una avicularia, cuya función, a nuestro modo de ver, es impedir
que otros seres vivos penetren a la cavidad subfrontal ; sin em¬
bargo hemos podido constatar que en una zoecia se habia fijado
una ancéstrula de otra especie sobre el techo de esa cavidad.

La ovicela hiperestomial no es muy grande y està finamente
perforada por poros bastante pequenos, escasos y ampliamente
esparcidos.

Escharoides tridens (Calvet, 1909)

Figs. 14-16.

Està especie que forma incrustaciones unilaminares sobre
piedras, conchas, etc. presenta una pared frontal con areolas late¬
rales que determinan la existencia, entre ellas, de costillas de
poco desarrollo. La parte proximal de la abertura externa, corno
es comun en todas las especies de este gènero, se levanta de tal
manera que el plano apertura! queda casi perpendicular al plano
de la pared frontal. Y corno en Roìyi ancheina, bajo ella existe una
cavidad ampliamente abierta en sentido distai.

Lateralmente cada zoecia puede presentar dos avicularias de
mandibula redondeada. Por la posición que ocupan, hacia la parte
media de los bordes zoeciales laterales, muchas veces enfrentan
a la abertura de las zoecias vecinas. Sin embargo, de ninguna
manera esto es totalmente regular, y por otra parte, su papel
protector es menor que el que tenian en Romancheina.

Al destruir la pared frontal externa por descalcificación,
aparece bajo ella una pared membranosa con musculos laterales

202

H. I. MOYANO G.

que la deprimen al igual que en los Malacostega. La parte an-
terior de ella lleva una henditura mas o menos semicircular que
representa al opérculo apenas diferenciado. A ambos lados y por
debajo de està formación opercular aparecen dos manojos mus-
culares mas fuertes que corresponderian a los depresores del
opérculo.

Las ovicelas son hiperestomiales y no perforadas, pero si,
rodeadas de areolas al igual que la pared frontal. En las mues-
tras, desgraciadamente, no existian ancéstrulas que pudieran
haberse estudiado.

Escharoides Imbeccata Rogick, 1965

Figs. 17-18.

Los zoarios de està especie se presentan corno tallos mas o
menos aplastados que dan dos o mas ramas al mismo tiempo por
su extremidad distai. Al mismo tiempo los bordes zoariales son
aserrados debido a la existencia de gigantescas avicularias fron-
tales, y a que la parte distai de la pared frontal se eleva consi-
derablemente.

Bajo la pared frontal calcàrea existe otra pared membra¬
nosa que al igual que en E. tridens puede ser deprimida por los
miisculos laterales. En su parte anterior se abre dando lugar a
un opérculo apenas insinuado. E1 àrea libre de està membrana
es mucho menor que en E. tridens, equivalendo, màs o menos,
a un tercio de la longitud zoecial. A los lados de la abertura
zoecial externa aparecen comunmente dos avicularias pequenas
cuya función seria la de proteger la entrada a la cavidad sub-
frontal. Ademàs de éstas aparece, por lo generai en las zoecias
de los bordes, una gran avicularia implantada sobre la parte
distai del frontal ya sea en posición mediana o lateral. Està
avicularia seguramente contribuye a la labor de las otras dos.

La ovicela es semejante a la de E. tridens, es decir, no per-
forada, con areolas e hiperestomial.

No existen ancéstrulas en nuestras muestras, pero sin em¬
bargo podemos hacer referencia a ellas a través de lo que senaló
Rogick al describir la especie. Su ancéstrula (Rogick, 1955: 443
y 446), al igual que la de R. martiali presenta 7 espinas, que se

POSICIÓN SISTEMATICA DE LOS GENEROS ETC.

203

curvan hacia el centro de la pared frontal pero sin soldarse
entre si. De éstas las dos mas distales son mas gruesas y pueden
ensancharse semejando a cuernos de alce. La diferencia con la
de Romancheina estriba en que las espinas no se sueldan entre
si y ademàs la parte proximal de la ancéstrula de E. bubeccata
no presenta el àrea acorozonada, rugosa y perforada que caracte-
riza a R. martidli, y en que las espinas que alcanzan mayor
desarrollo son las dos mas distales y no las immediatamente mas
anteriores corno sucede en Romanckema.

Cellarinella rossi Rogick, 1956
Figs. 19-22.

Los zoarios que son muy calcificados, estrechos, ramificados
y fijos al sustrato por rizoides quitinosos, presentan un aspecto
erizado debido a los grandes umbos suborales. Externamente no
se notan bordes zoeciales sino que sólo las aberturas de los
zooides que en su parte distai presentan una saliente peristomial
y en la proximal, una avicularia y un limbo puntiagudo. Entre
todas esas estructuras no hay sino que poros infundibulares de
distintos tamanos (tremóporos).

Al exterior no se hace presente la ovicela ni ningun otro
accidente, pero al hacer un corte zoecial en sentido longitudinal
se advierte un gran espacio entre el frontal tremocistico y la
pared zoecial membranosa subyacente. Està pared deja en su
parte distai una abertura mas o menos eliptica que està limitada
por un labio proximal y otro distai, de tal manera que no se
puede hablar de opérculo. Està abertura se continua en un tubo
membranoso que rodea al lofóforo polipidiano. La pared mem¬
branosa posee ademàs, musculos que la deprimen, siendo mayores
los làterodistales.

Por dentro de la abertura externa existe otra avicularia, que
desde fuera no se ve. Està tendria por objeto proteger a las
estructuras internas de cualquier animai que pudiera introducirse
al espacio subtremocistico ; su papel seria entonces corno el de
las avicularias orales de Romanchema. En suma, la presencia
de la avicularia externa, de la interna v de la barra calcàrea
orai en el lado proximal de la abertura concurririan a la pro-
tección del espacio interno.

204

H. I. MOYANO G.

Cellarinella njegovannae Rogick, 1956

Figs. 23-24.

De aspecto semejante al de la especie anterior, pero con tallos
mas anchos y superficie zoarial lisa por la ausencia de umbos
frontales. Externamente sólo se notan las aberturas cuyo borde
distai crece hacia abajo, y una avicularia pequena a cada lado
de ellas.

Bajo la pared frontal tremocistica, aparece la interna mem¬
branosa y semejante a la de las especies precedentes. Aqui tam¬
poco podemos hablar de opérculo y también podemos senalar que
la cavidad subtremocistica està ampliamento abierta por su parte
distai. La protección de esa cavidad se logra por el estrecha-
miento de la abertura zoecial externa, por la presencia de las
dos avicularias orales y por la existencia de la barra orai, tal
corno la que se seiìaló para C. rossi.

La estructura zoecial generai y en especial lo que se refiere
a la pared frontal interna provista de musculos depresores y
enmascarada por la presencia de un tremocisto arqueado sobre
ella, se mantiene para està especie y para las otras del gènero.

Systenopora contrada Waters, 1904

Figs. 25-26.

El zoario en aspecto y constitución externa es semejante al
de las dos especies precedentes. La diferencia mas notable se
refiere a la abertura zoecial externa que aparece corno una hen-
didura longitudinal bordeada por varias avicularias. La pared
frontal externa siempre es un tremocisto con poros infundibu-
lares irregulares.

En un corte longitudinal se puede apreciar la misma cavidad
interna que en las especies precedentes y la membrana frontal
subyacente que presenta paquetes musculares laterales que la
deprimen.

Por dentro de la abertura externa y lateralmente existe una
avicularia interna proporcionalmente mayor que la que se halla
en las especies de Cellarinella y su papel indudablemente sera el
de proteger la cavidad subfrontal.

POSICIÓN SISTEMATICA DE LOS GENEROS ETC.

205

Resumen y conclusiones.

De acuerdo al estudio realizado y vertido en las pàginas an-
teriores podemos senalar:

A. - Las especies estudiadas de los géneros Romancheina,
Escharoides, Cellarinella y Systenopora, presentali una pared
externa calcàrea que es un tremocisto o pleurocisto.

B. - Bajo la pared frontal externa existe una gran cavidad
ampliamente abierta al exterior, a através de la abertura zoecial
externa.

C. - Para impedir la entrada de particulas extranas, lar-
vas o paràsitos a la cavidad subfrontal, existen avicularias ex-
ternas cerca de la abertura zoecial (en todos los géneros estu-
diados), avicularias internas y barras orales por dentro de la
abertura externa ( Cellarinella y Systenopora).

D. - E1 piso de està cavidad està formado por la pared
membranosa frontal interna provista de musculos laterales de-
presores, y por lo tanto homóloga a la pared frontal de los
Bvyozoa Cheilostomata Anasca Malacostega.

E. - La pared membranosa presenta una hendidura de si-
tuación distai para la salida del polipido. E1 borde proximal de
està hendidura està poco endurecido y corresponde a opérculos
tales corno los de los géneros Bugula o Membranipora.

F. - La ancéstrula de Romancheina martiali tiene una
pared frontal muy calcificada cuando se halla totalmente de-
sarrollada. Està pared se origina en su parte distai por la unión
de cinco espinas lateromarginales, que dejan entre si hendiduras
o fenestras que pueden llegar a cerrarse con la progresiva cal-
cificación. De acuerdo al modo de desarrollo, està pared es un
pericisto.

Tornando en cuenta estas observaciones concluimos que:

1. - Los géneros estudiados no pertenecen a los Ascophora
Vera sino que a los Ascophora Imperfecta (Harmer, 1957). Por
lo tanto las familias Sclerodomidae y E xochellidae pueden ser

H. I. MOYANO G.

incluidas en el ùltimo grupo con Umbonulidae, Celleporariidae,
Chlidoniopsidae, Petraliidae, Petraliellìdae, Exechonellidae y Me-
trarabdotosidae.

2. - La pared frontal de la ancéstrula de Romancheina
martiali Jullien, 1888, es un pericisto.

3. - Suponiendo que la estructura ancestrular tenga si-
gnificado filogenètico, la presencia de un pericisto en la ancé¬
strula de Romancheina indicarla que este gènero se ha originado
de un C hello stoìnata Anasca.

BIBLIOGRAFIA

Bassler R. S., 1953 - Bryozoa. In Treatise on Invertebrate Paleontology.
Geological Society of America, Directed by R. C. Moore, Pari. G,
pàgs. i-xiii, G1-G253, Figs. 1-175.

Calvet L., 1909 - Bryozoaires. Expédition Antarctique Frangaise (1903-
1905) commandée par le Dr. Jean Charcot. Sciences Naturelles. Do-
cuments Scientifiques. 50 pàgs, làms. 1-3.

Cheetham A. H., 1968 - Morphology and Systematics of thè Bryozoan Ge-
nus Metrarabdotos - Smithsonian Miscellaneous Collections, 153 (1):
i-viii, 1-121, figs. 1-24, làms. 1-18.

Cook P. L., 1967a - Polyzoa (Bryozoa) from West Africa. The Pseudostega,
The Cribrimorpha and Some Ascophora Imperfecta - Bull. Brit. Mus.
(N. H.) Zool. 15 (7): 323-351, figs. 1-14, làms. 1-2.

Cook P. L., 1967b - Notes on Tremogasterina Canu and T remo gaster ina
robusta (Hincks) (Polyzoa, Ascophora) - Cahiers de Biologie Ma¬
rine, 8: 7-20, figs. 1-4, làms. 1.

Harmer S. F., 1957 - The Polyzoa of thè Siboga Expédition. Part 4. Cheilo-
stomata Ascophora - Rep. Siboga Exped. 28d: 641-1147. 70 figs. 33
làms.

Jullien J., 1888 - Bryozoaires. Miss, du Cap Horn, 6 (3): 1-92, làms. 1-14.
Moyano G. H. I., 1965 - Bryozoa colectados durante la Expedición Antàr¬
tica Chilena 1964-65, I. Familia Sclerodomidae - Pubi. Inst. Antàr¬
tico Chileno (5): 1-30, làms. 1-6.

Moyano G. H. I., 1968 - Distribución y profundidades de las especies ex-
clusivamente antàrticas de Bryozoa Cheilostomata recolectadas por
la Décimonovena Expedición Antàrtica Chilena, 1964-1965 - Boi. Soc.
Biol. Concepción. 40: 113-123.

Rogick M. D., 1955 - Studies on Marine Bryozoa. VI. Antarctic Escharoi-
des - Biol. Bull., 109 (3): 437-452, làms. 1-5.

Rogick M. D., 1956a - Studies on Marine Bryozoa. Vili. Exochella longi-
rostris Jullien, 1888 - Biol. Bull. Ili (1): 123-128, figs. 1.

POSICIÓN SISTEMATICA DE LOS GENEROS ETC.

207

Rogick M. D., 1956b - Bryozoa of thè United States Navy’s 1947-1948 An-
tarctic Expedition, I-IV - Proc. U. S. Nat. Mus. 105 (3358): 221-317,
làms. 1-35.

ROGICK M. D., 1965 - Bryozoa of thè Antarctic. In Biogeography and Eco-
logy in Antarctica - Monographiae Biologicae, 15 : 401-413.

VlGELAND I., 1952 - Antarctic Bryozoa. Det Norske Vid.-Akad. Oslo. Sci.
Results Norweg. Antarctic Exped. 1927-1928 (34): 1-16, 1 mapa,

làms. 1-3.

Waters A. W., 1904 - Bryozoa. Expéd. Antarctique Belge. Résul. Voy. S. Y.

- Belgica 1897-1899 . De Gomery, Rapp. Sci. Zool. pàgs. 1-114,

làms. 1-9.

EXPLICACION DE LAS FIGURAS

Romancheina martìali Jullien, 1888

1. _ Ancéstrula que muestra las tres espinas proximales y las dos próxi-

molaterales, unidas por su extremidad sobre la linea media del frente an-
cestrular. Màs allà de ellas se aprecia distalmente y al lado deiecho una
de las espinas anteriores que quedan libres.

2, 3, 4 y 5. — Ancéstrulas en las que se puede advertir el mayor crecimiento
y ensanchamiento de las dos espinas laterodistales, que van formando un
àrea distai que se proyecta por (telante y arriba de la abertura ancestrular.

6., — En està ancéstrula, la calcificación del àrea distai se ha completado
habiendo desaparecido casi completamente las aberturas entre las espinas
del pericisto. Las dos espinas distales libres sobresalen bastante màs que
los dos cueraos del àrea distai del pericisto.

7. — Colonia poco desarrollada en la que se nota la ancéstrula, cuya àrea
distai no està totalmente calcificada. En cada zoecia aparecen areolas fron-
tales que limitan costillas muy leves.

8. — Corte longitudinal de una zoecia adulta no ovicelada. La membrana
frontal subyacente ( Mfc ) aparece cortada a lo largo por su linea media.
Lateralmente y en el fondo se aprecian los musculos depresores de la mem¬
brana ( Md ). Entre la pared frontal externa ( Pfex ) y la membrana interna
hay una gran cavidad ( Cav ) abierta ampliamente en sentido distai, y su
salida està protegida por una avicularia lateral a cada lado (Av).

9. — Zoecia descalcificada con HC1. El lofóforo (Lf) es visible através de
la pared frontal membranosa. En la parte distai de la membrana se halla
la abertura para la salida del polipido ( Abi ) cuyos bordes apenas estàn di-
ferenciados de la membrana frontal. El espacio ovicelar aparece en el ex-
tremo distai ( Ov ).

208

H. I. MOYANO G.

10. — Vista orai de tres zoecies. Las avicularias (Av) presentai! un àrea
cribada lateral ( Acr ). Por encima del àrea cribada se hallan las prolonga-
ciones de la pared frontal calcàrea ( Pra ). En la parte inferior de la aber-
tura se ve el extremo distai de la membrana frontal ( Eamf ) y sobre ella
la cavidad interna subfrontal (Ci). La ovicela ( Ov ) se abre hacia la abertura.

11. — Vista orai de una zoecia en que faltan las partes blandas. La ovicela
(Ov), està perforada por pocos poros pequenos y ampliamente esparcidos.
Entre estos poros hay tubérculos calcàreos romos.

12. — Corte longitudinal de zoecias. La pared frontal externa se alza por
su parte distai (Exaf). Por sobre la ovicela hiperestomial (Ov), se halla la
avicularia (Av). En la parte inferior de la pared lateral se pueden ver sep-
tulas multiporas (Sep) y en la parte superior de la misma las aberturas in-
ternas correspondientes a las areolas externas.

13. — Abertura zoecial mirada oblic-uamente desde el lado distai. La ovicela
en formación (Ovf) se demuestra corno un repliegue ampliamente abierto
que se va cerrando hacia arriba.

Escharoides tridens (Calvet, 1909)

14. — Varias zoecias en vista frontal. La abertura zoecial (Abe) ancha y
ampliamente abierta lleva una espina a cada lado (Op). Entre las areolas
del pleurocisto (PI) hay algunas avicularias (Av), que a veces estàn apun¬
tando hacia las aberturas zoeciales. La ovicela no perforada (Ov) se halla
rodeada por areolas.

15. — Zoecia descalcificada mirada desde el lado frontal. La membrana
frontal (Mf), està rodeada lateralmente y por su lado interno por manojos
musculares (Md) que la deprimen. El polipido (P), cuyo lofóforo se aprecia
por transparencia, puede salir al exterior a través de la abertura zoecial
interna (Ahi) cuyo borde proximal (opérculo) apenas està diferenciado de
la membrana. En posición distai y en el lugar correspondiente a la ovicela
se halla una gran célula huevo (Ovul).

16. — La misma zoecia anterior mirada desde el lado basai. En ella es
posible apreciar en mejor forma el polipido y los musculos.

210

H. I. MOYANO G.

Escharoides bubeccata Rogick, 1955

17. — Vista frontal de varias zoecias. La pared frontal pleurocistic-a se
eleva en dirección distai justo por delante de la abertura externa (Abe). En
las zoecias marginales existe una gran avicularia frontal mediana o lateral
( Avf ). Y en la mayoria de las zoecias existe una pequena avicularia a cada
lado de la abertura (Avo).

18. — Corte longitudinal de una zoecia. Bajo la pared frontal (PI) se halla
la membrana frontal primitiva (Mf) y entre ambas una gran cavidad am-
pliamente abierta hacia adelante entre la abertura zoec-ial externa (Abe) y
la abertura interna por la que sale el polipido (Abi). En la parte inferior
de las paredes laterales se hallan varias séptulas multiporas (Sep).

CeUarineUa rossi Rogick, 1956

19. — Zoecia descalc-ificada mirada lateralmente. La membrana frontal
(Mf) deja una abertura en su parte distai (Abi), que aparec-e corno una
estructura casi bilabiada. El polipido (P) y los musculos depresores (Md)
pueden verse lateralmente.

20. — Vista frontal de varias zoecias. La abertura externa (Abe) presenta
por dentro de su lado proximal una elevación calcàrea o barra orai (Bo).
Bajo la parte proximal de la abertura existe una avicularia externa de man-
dibula triangular (Ave) y junto a ella un umbo mas o menos agudo (U).
La ovicella hiperestomial no sobresale al exterior, pero, en cambio, los gran-
des orificios del tremocisto zoarial se disponen mas o menos radialmente en
la zona en que ella se desarrolla (Zo).

21. — Corte longitudinal de dos zoecias. Como ya se vio en las especies an-
teriores bajo el grueso frontal calcàreo se halla la membrana frontal pri¬
mitiva (Mf), con opérc-ulo pràc-ticamente indiferenciado. La ovicela hiperes¬
tomial (Oh) se abre un poco por encima de la abertura externa hay un
umbo (U), y en la parte anterior de la cavidad sufbrontal se halla la' avi¬
cularia interna (Avi).

22. — Vista frontal de la misma zoecia de la figura 19.

Celiar ine Ila njegovannae Rogick, 1956

23. — Vista frontal de varias zoecias. La màs caracteristico de està especie
es el crecimiento en sentido proximal del borde distai de la abertura ex¬
terna. Por dentro de ella se halla la barra orai (Bo) y a cada lado una avi¬
cularia pequena (Ave) El tremocisto zoarial es caracteristico por sus pe-
quehos poros.

24. — Corte longitudinal de dos zoecias. La pared frontal tremoclstica està
atravezada por canales c-orrespondientes a los poros externos. Estos con-
fluyen lateralmente abriéndose en el interior a los lados de la membrana
frontal (Mf). La abertura interna (Abi) también tiene un aspecto bila-
biado y està mucho màs abajo que la abertura externa (Abe). La ovicela
(On) es semejante a la de la especie precedente.

Systenopora contrada Waters, 1904

25. - Vista frontal de seis zoecias. La abertura externa a diferenc-ia de
CeUarineUa es màs largas que ancha. Junto a ellas hay una o varias avi-
cularias externas pequenas (Ave). Por dentro de la abertura by lateral¬
mente hay una avicularia interna (Avi). La ovicela, aunque profundamente
inmersa, se advierte al exterior.

26. — Corte longitudinal de una zoecia. Bajo el gruesto tremocisto frontal
(TV) hay una cavidad amplia cuyo piso es la membrana frontal (Mf). Està
membrana presenta una abertura apenas notoria en su parte anterior (Abi).
Entre y por detràs de las aberturas externa e interna se abre ampliamente
la cavidad ovicelar (Ov). La presencia de la avicularia interna (Avi) pro-
tege la cavidad interna de la entrada de seres extranos.

Avo.

' * ,\ / V »«<

300 y^

:>^V«V*V'/Ì,V

I V* ^

'* a» .

] | *lt % *

500 >o

>10/

000 yU,

30ùyu\ \

® * • ' **,°.'» ' » * • _ ^ * «

:*V-": * *.•* ’. ;. * • <$. •

\< »6 . , J *

Xv ;.**;-^A ***' *

• • % » e

2? 500

4òe 4ò/ Ou

26 Abi

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 212-218, 31-XII-1968

lst I.B.A. International Conferenee on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
28. Group 4: Evolutionary Patterns and. Systematics.

Janine Prud’Homme (*)

RÉVISION DE QUELQUES TYPES
DE LA COLLECTION D’ORBIGNY (CRÉTACÉ)
CONSERVÉE AU MUSÉUM D’HISTORIE NATURELLE

DE PARIS

( Bryozoa )

Riassunto. — Lo studio sistematico di varie specie di Eschara Lamou-
roux, 1801, descritte da d’Orbigny in Paléontologie Frangaise, Ter-
rains Crétacés, Tm. V, 1850-1851, permette di mettere in evidenza ca¬
ratteri morfologici importanti quali la forma e la posizione deH’opesium, la
natura delle ovicelle, la forma degli avicularia.

E’ stata stabilita la posizione generica di ciascuna di tali specie ed è
stato riportato un certo numero di sinonimi.

Summary. — Systematic studies of various species of thè genus Eschara
Lamouroux, 1801 described in d’Orbigny’s Paléontologie Frangaise, Terrains
crétacés, Tome V, 1850-1851, have permitted us to point out important mor-
phological characters such as shape and position of thè opesia, nature of
thè ovicells, shape of thè avicularia. Their generic position has been estab-
lished and some synonyms were noted.

Résumé. — L’etude systématique des différentes espèces du genre
Eschara Lamouroux, 1801, décrites par d’Orbigny dans la Paléontologie
Frangaise, Terrains Crétacés, Tome V, 1850-1851, nous ont permis de mettre
en évidence les caractères morphologiques importants tels que la forme et
la place de Topésie, la nature des ovicelles, la forme des aviculaires. La
position générique de chacune a été établie, et un certain nombre de syno-
nymies ont été notées.

(*) Université de Bordeaux, Laboratoire de Geologie - Talence, France.

RÉVISION DE QUELQUES TYPES ETC. 213

Le genre Eschara Lamouroux, 1801 est représenté dans la
collection d’Orbigny par une quantité considérable d’ individus
appartenant à de nombreuses espèces provenant surtout d’af-
fleurements du Crétacé supérieur des Charentes, du Bassin de
Paris et du Cotentin. L’examen de ces échantillons permet d’étab-
lir qu’ils correspondent en fait à de nombreux genres souvent dif-
ficiles à déterminer d’après les descriptions et les figures don-
nées par l’auteur. A cause du mélange très important existant
parali les spécimens et aussi à cause de la perte de certaines
étiquettes indiquant la provenance du matériel, nous n’avons tenu
compte dans ce travail que des types effectivement figurés par
d’Orbigny.

En 1881 Jullien, travaillant sur cette collection, définit la
famille des Onychocellidae et décrit les genres Onychocella, Ogiva,
Ogivalia, Dictuonia, Coltura, Floridina et Smittipora. Il prend
comme critère générique la forme des opésies et celle des zoécies
et il indique pour chaque nouveau genre les espèces qui le com-
posent. En 1900 Canu reconnait déjà 1’ incohérence qui règne
dans la collection et, reprennant les descriptions données par Jul¬
lien les discute, parfois les complète et y redistribue les diffé-
retes espèces. Dans aucune de ces publication n’est mentionnée
la présence ni la nature des ovicelles qui sont actuellement con-
sidérés comme caractéristiques des genres et des familles. Aucun
aiitre travail de synthèse n’a été fait depuis, et seules quelques
espèces se retrouvent dans certaines publications de E. VoiGT sur
le Crétacé supérieur d’ Europe septent rionale. Notre but ici n’est
pas de redonner une description complète de toutes les espèces
d 'Eschara non plus que de les figurer mais simplement en nous
basant sur les principaux caractères morphologiques, de les in-
tégrer dans les divers genres connus. Nous suivrons pour cela la
classification donnée par R. S. Bassler en 1953.

Famille des Onychocellidae Jullien, 1881.

— Genre Onychocella Jullien, 1881 : un très petit nombre d’espè-
ces peuvent ètre rattachées à ce genre avec certitude. Eschara
dito (pi. 1, fig. 1) et Eschara edusa en présentent tous les
caractères ; par contre Eschara nerei a une opésie avec des in-

214

J. prud’homme

dentations peu marquées, une dent proximale, et son attribution
semble plus douteuse.

— Genre Collura Jullien, 1881: Le générotype, Eschara athulia

(pi. 1, fig. 3) est représenté par un fragment de colonie sur

lequel la forme particulière des cellules semble due à une al-
tération identique à celle qui affecte souvent les colonies
d 'Eschara royana entre autres. La valeur de ce genre ainsi
défini nous semble ètre douteuse.

— Genre Ogiva Jullien, 1881: Le générotype, Eschara actaea

(pi. 1, fig. 4) est assez bien figure par d’Orbigny en ce qui

concerne radure des zoécies et des onychocellaires, mais les
opésies sont en réalité beaucoup plus importantes. En général,
les onychocellaires ont un rostre droit, saillant au-dessus du
pian zoarial. On peut y ranger : Eschara acasta, Eschara are-
thusa, Eschara cynthia.

Trois autres espèces ont les caractéres essentiels identiques
mais le rostre de l’onychocellaire est incurvé comme chez les
Onychocella. Ce sont Eschara cypraea et Eschara santonensis
que nous considérons comme synonvmes, et Eschara drya.

— Genre Ogivalia Jullien, 1881: La seule différence existant avec
le genre précédent réside dans la forme semi-circulaire de
l’opésie. On peut y classer les espèces suivantes : Eschara ar-
cJiosia (pi. 1, fig. 8), Eschara didymia et Eschara echo dont
la particularité est de posséder d’énormes aviculaires fuselés
situés sur le marges des colonies.

- — Genre Ony choc diaria Voigt, 1957 : Il est représenté par les
espèces Eschara arsinoe, Eschara calypso et Eschara camilla.

— Genre Rhebasia Jullien, 1881 : Dans le traité de R. S. Bassler
il semble y avoir eu confusimi entre le générotype cité:
Eschara dorilas (pi. 1, fig. 5) et Eschara doris (pi. 1, fig. 2)
qui paraìt avoir été représenté à sa place. Les grands avicu¬
laires à partie antérieure arrondie que Fon trouve chez Es-
chara dorilas feraient plutòt classer cette espèce parmi les
Thyracella Voigt, 1930. Il semble qu’il soit difficile de conser¬
ver ce genre basé uniquement sur l’épaississement du bourrelet
interzoécial.

RÉVISION DE QUELQUES TYPES ETC.

215

Genre Smittipora Jullien, 1881 : La description originale com-
plétée par Canu qui signale comme caractère commun à toutes
les espèces crétacées «... une facette plongeante qui se déve-
loppe dans la partie supérieure de l’opésie . . . , (et) porte rovi-
celle quand il existe ...» semble avoir été ignorée par R. S.
BASSLER. Nous considérons ce genre dans le sens donné par
Canu. Il renferme, en plus de nombreuses formes de « Vin-
cularia », Eschara calliope (pi. 1, fig. 6) et Eschara cornelia.
Il se pourrait qu’une partie des spécimens décrits sous le nom
d’Eschara claudia (pi. 2, fig. 1) appartiennent à ce genre: ce
sont ceux qui sont représentés sur la planche 675 du traité
de d’Orbigny. Le type figuré sur la planche 671 n’a pas été
retrouvé.

Famille des Microporidae Hincks, 1880.

Genre Aechmella Canu et Bassler, 1917 : Une seule espèce,
Eschara crithea peut y ètre classée.

Famille des Aspidostomatidae Jullien, 1888.

Genre Euritina Canu, 1900 : En plus du générotype, Eschara
eurita (pi. 2, fig. 2) et de YEsckara delia que Canu avait lui-
mème attribués à ce genre, on peut y ranger Eschara clytia
et peut-étre aussi Eschara egaea bien que le seul spécimen de
cette dernière soit en assez mauvais état.

Genre Rhagasostoma Koschinsky, 1885 : Ce genre d’un aspect
très voisin de ceux de la famille des OnychoceUidae s’en dif-
férencie essentiellement par des ovicelles hyperstomiaux et
non endozoéciaux. De nombreuses espèces correspondent à sa
description, mais parmi elles se trouvent beaucoup de synony-
mes. Ce sont : Eschara acmon (pi. 2, fig. 3), Eschara aglaia et
charonia, la seconde n’étant qu’un fragment grèle de la pre¬
mière, Eschara bellona et lamarcki qui n’a rien de commun
avec celle de VON Hagenow, Eschara cassiope et chloris, Es¬
chara cepha, cressida, creona, cyane, et enfin Eschara cy-
therea.

Trois autres espèces forment un groupe à part ; ce sont : Es¬
chara aegle, Eschara aegon (pi. 2, fig. 4) et Eschara antiopa.

J. prud’homme

216

Elles ont toutes des ovicelles hyperstomiaux, des opésies pour-
vues d’ indentations opésiulaires nettes, des onychocellaires
droits, longs. Leurs cellules sont nettement séparées les unes
des autres, mais l’arrangement cellulaire donne cependant des
lignées longitudmales. Ce mème caractère se rencontre aussi
chez Eschara atalanta et Eschara cybele (pi. 2, fig. 5), mais
dont les aviculaires nombreux sont petits, droits avec un bec
court, Eschara andromeda a les mèmes caractéristiques cel-
lulaires et coloniales (pi. 2, fig. 6), mais possède des aviculai¬
res droits à large bec spatulé. Il est possible que Fon soit
amené à créer pour ce dernier groupe un genre différent.

Famille des Cellariidae Hincks, 1880.

— - Genre Dimorpho cellaria Voigt, 1930: Les trois espèces appar-
tenant à ce genre : Eschara amynthas, Eschara caecilia et Es¬
chara callirhoe (pi. 1, fig. 7) doivent ètre mises en synonymie.

Famille des Membranicellariidae Levinsen, 1909.

— Genre Dictuonia Jullien, 1881 : Le générotype, Eschara aceste
n’existant plus dans la collection, nous pensons pouvoir le rem-
placer par Eschara danae (pi. 2, fig. 7) qui semble identique.
La seule différence par rapport à la figure donnée par
R. S. Bassler est la taille plus importante de Fopésie. Nous
y rangerons aussi Eschara aegea, Eschara amata, Eschara
elea, Eschara cleon et son synonyme Eschara echinata, Es¬
chara cymodoce qui n’est autre qu 'Eschara danae, et Eschara
parisiensis.

Deux espèces pourraient aussi étre rapprochées de ce groupe :
pour Fune d’elles, Eschara achates, (pi. 2, fig. 8) d’Orbigny avait
créé le genre Lateschara, caractérisé par l’arrangement des zoé-
cies qui, jointives latéralement, foment des lignées transverses
et non longitudinales. Cette définition a été dernièrement reprise
par E. Voigt en 1967 pour des spécimens d’URSS, d’Allemagne,
du Danemark et d’Angleterre. Si ce genre Lateschara est con¬
servò, sa place semble ètre proche de Dictuonia.

REVISION DE QUELQUES TYPES ETC.

217

Famille des Coscinopfeuridae Canu, 1913.

— Genre Acoscinopleura Voigt, 1956 : Trois espèces y correspon-
dent: Eschara artemis, Eschara aspasia et Eschara elio.

— Genre Escharifora d’Orbigny, 1852 : Eschara argyrias et Es¬
chara bixa en font partie.

En dehors de ces espèces qui appartiennent aux principales
familles rencontrées lors d’une étude de la faune du Crétacé su-
périeur de France, un certain nombre d’autres, souvent existant
dans la collection à l’état très fragmentaires, peuvent avoir aussi
une attribution générique à peu près sùre. Ce sont Eschara arpia :
Punctur iella-, Eschara bonasia : Beis seiina ; Eschara diana : Tae-
nioporina ; Eschara clymene : Sy steno stoma-, alors que Eschara
dejanira pourrait peut ètre, avec son aviculaire spatulé et son
opésie denticulée, ètre une Labioporella.

Par ailleurs, les types d’ Eschara alimena, Eschara arcas,
Eschara bolina, Eschara camaena, Eschara cydippe et Eschara
electra ayant disparii, ces dernières n’ont pas été redéterminées.

BIBLIOGRAPHIE SOMMAIRE

Bassler R.. S., 1953 - In R. C. Moore, Treatise on Invertebrate Paleontology,
part G. 253 pp., 175 figs. - Geological Society of America and Univer¬
sity of Kansas Press.

Canu F., 1900 - Révision des Bryozoaires du Crétacé figurés par d'Orbi-
GNY. Deuxième partie - Cheilostomata - B.S.G.F., Paris, 3a sèrie,
tome XXVIII, pp. 334-463, pls. IV-VIII.

Canu F. & Bassler R. S., 1917 - A Synopsis of American Early Tertiary
Cheilostome Bryozoa - Smithsonian Institution, U. S. Nat. Mus., Bull.
96, pp. 1-87, pls. I-VI.

Jullien J., 1881 - Sur une nouvelle division des Bryozoaires Cheilostomiens
- Bull. Soc. Zool. France, 6° Voi., pp. 271 à 285.

Koschinsky C., 1885 - Ein Beitrag zur Kenntniss der Bryozoenfauna des
àlteren Tertiàrschichten des sudlichen Bayerns. I - Cheilostomata -
Palaeontographica, XXXII, III, F. Vili, pp. 1-73, pls. I-VII.

Orbigny A. d’, 1850-1851 - Paléontologie Frangaise. Terrains crétacés - Tome
V, pp. 1-1192, pls. 600-800.

Voigt E., 1930 - Morphologische und stratigraphische Untersuchungen iiber
die Bryozoenfauna der oberen Kreide - I Teil. Leopoldina, VI Band,
pp. 379-579, pls. 1-39.

218

J. prud’homme

Voigt E., 1956 - Untersuchungen iiber Coscinopleura Marss. (Bryoz. foss.)
und verwandte Gattungen - Mitt. Geol. Staatsinst. Hamburg, Heft
25, pp. 26-75, pls. 1-12, 7 figs.

Voigt E., 1957 - Bryozoen aus dem Kreidetuff von St. Symphorien bei
Ciply (Ob. Maastrichtien) - Inst. Royal des Se. Nat. de Belgique,
Bulletin, Tome XXXIII, n° 43, pp. 1-48, pls. 1-12.

Voigt E., 1967 - Oberkreide-Bryozoen aus den asiatischen gebieten der
UdSSR - Mitt. Geol. Staatsinst. Hamburg, Heft 36, pp. 5-95, pls. 1-34.

PLANCHE V - G = 20.

Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Fig. 5.
Fig. 6.
Fig. 7.
Fig. 8.

Onychocella dito (d’Orbigny).

Meudon. Campanien. coll. d’Orbigny n° 7830. Type.
« Rhebasia » dords (d’Orbigny).

Vendóme. Santonien. coll. d’Orbigny n° 7853. Type.

« Coltura » athulia (d’Orbigny).

Néhou. Sénonien. coll. d’Orbigny n° 7811. Type.

Ogiva actaea (d’Orbigny).

Fécamp. Coniacien. coll. d’Orbigny n° 7791. Type.

? Thyracella dorilas (d’Orbigny).

Sans localité. coll. d’Orbigny n3 7854.

Smittipora callìope (d’Orbigny).

Meudon. Campanien. coll. d’Orbigny n° 7819. Type.

Dimorpho celi aria callirhoe (d’Orbigny).

Royan. Maestrichtien. coll. d’Orbigny n° 7820. Type.

Ogivalia archosia (d’Orbigny).

Néhou. Sénonien. coll. d’Orbigny n° 7809.

PRUD’ HOMME J. Atti Soc.It.Sc.Nat. e Museo Civ.St.Nat.Milano,Vol.CVIII,

Pl. V

PLANCHE VI - G = 20.

Fig. 1. — ? Smittipora claudia (d’Orbigny).

Sans localité. coll.. d’Orbigny n° 7845. Type pi. 675.

Fig. 2. — Euritina eurita (d’Orbigny).

Sainte Maure. coll. d’Orbigny n° 7863. Type.

Fig. 3. — Rhagasostoma acmon (d’Orbigny).

Fécanrp. Coniac-ien. coll. d’Orbigny n° 7790.

Fig. 4. — ? Rhagasostoma aegon (d’Orbigny).

Villedieu. coll. d’Orbigny n° 7797. Type.

Fig. 5. — ? Rhagasostoma cybele (d’Orbigny).

Tours. Coniacien. coll. d’Orbigny n° 7838.

Fig. 6. — ? Rhagasostoma andromeda (d’Orbigny).

La Fiòche. Sénonien.. coll. d’Orbigny n° 7794. Type.

Fig. 7. — Dictuonia danae (d’Orbigny).

Tours. coll. d’Orbigny n° 7845. Type.

Fig. 8. — « Lateschara » achates (d’Orbigny).

Fécamp. Coniacien. coll. d’Orbigny n° 7789. Type.

PRUD’ HOMME J. Atti Soc.It.Sc.Nat. e Museo Civ.St.Nat.Milano,Vol.CVIII,

Pl. VI

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 219-224. 31-XII-19G8

lst I.B.A. International Conference on Brvozoa, S. Donato Milanese, Aug. 12th-16th, 1968
29. Groun 4: Evolutionary Patterns and Systematics.

Sten A. N. Schager (*)

REMARKS ON THE GENUS FLORIDINA Jullien, 1881

( Bryozoa )

Riassunto. — Si è creduto nel passato che il genere Floridina avesse
parecchie specie fossili nel Cretacico europeo e nel Terziario nord-americano.

Uno studio sul Vavicularium vicariante ( onycho celiar iuhn ) del genere con¬
siderato mostra come la maggior parte di queste specie appartenga ad altri
generi e famiglie e come il genere Floridma si sia sviluppato nel Terziario
superiore dell’ America del Nord.

Summary. — The genus Floridina has been considered to have several
fossil species in thè European Cretaceous and N. American Tertiary. An
investigation of thè vicarious avìcularium , thè onycho celiar ium, of thè genus
indicates that most of these species must belong to other genera and families
and that Floridina developed in thè upper Tertiary of N. America.

Zusammenfassung. — Es ist bisher angenommen worden, dass die Gat-
tung Floridina mehrere fossile Spezien in sowohl der europàischen Kreide
als im Tertiar Nord Amerikas habe. Eine Untersuchung des vikariirendes
Avikularium, das Onychocellarium, der Gattung zeigt dass die meisten Arten
zu anderen Gattungen und Familien gehòren mùssen, und das Floridina
in dem oberen Tertiar Nord Amerikas entstanden ist.

The family Onycho cellidae Jullien, 1881 was originally given
four genera based on modera species and several genera based
on drawings by d’Orbigny on material from thè upper Creta¬
ceous of Europe. Additional genera have, by later authors, been
based on both fossil and recent material.

(*) Geologiska Institutionen, Stockholms Universitet, Kungstensgatan 45
- Stockholm/Va, Sweden.

S. A. N. SCHAGER

220

Today are in generai only three genera, with modern spe-
cies, accepted : Onychocella, Smittipora and Floridina. Several
genera, wholly fossil, are also accepted. Floridina is characterized
by an autozooid with a cryptocyst that has an elliptic opesium with
symmetric opesiulae. Its ovicell is endozooecial. It lacks spinae.
Vicarious avicularia, of thè type called onychocellarium, are pre-
sent. No other type of avicularium may be observed. The ony¬
chocellarium has an elliptic opesium. The onychocellarium has
straight borders thè two distai ones being longer than thè two
proximal ones. The onychocellarium has a bimembraneous man¬
dile. This description is compiled from Jullien 1881, Levinsen
1909, Canu and Bassler 1920 and Bassler 1953.

The oldest species that has been named Floridina appears in
thè Coniaeian of Europe (Voigt 1967 a). Higher up in thè Cre-
taceous several species have been named Floridina not only in
Europe (Voigt 1923, 1930, Berthelsen 1962 and others) but
also in Asia (Voigt 1967 b). With thè end of thè Danian they
have not been reported from Europe. On thè other hand they
have been described from thè lower and middle Tertiary of E. and
S. N. America (Canu and Bassler 1917, 1919, 1920, 1923, 1927,
1933. Cheetham 1957, 1962, 1963 etc.) Canu and Bassler have
also introduced nam.es like Diplopholeos and Floridinella for forms
very similar to what has been called Floridina.

Many of these Cretaceous and Tertiary species are different
trom thè Floridina - description as they have spines, lack avi¬
cularia etc.

Most authors have not considered Jullien’s description of
thè onychocellarium, but have called all vicarious avicularia
onychocellarium if they have been found in species that look si¬
milar to Floridina. The present author does not share this view-
point. A study of thè onychocellarium in recent material will show
thè following characteristics.

There is a pair of very strong closing muscles that runs
from thè proximal - lateral parts of thè basai wall and via ten-
dons is attatched to thè distai - basai part of thè mandible. An
other pair of strong closing muscles runs from thè distai - la¬
teral part of thè basai wall to thè distai - basai part of thè man-

REMARKS ON THE GENUS FLORIDINA JULLIEN, 1881

221

dible. These four muscles (or tendons) need one or more open-
ings in thè cryptocyst. This opening or these openings must be
of certain size and shape. One singe opening muscle is located
in thè centrai line proximal to thè mandible. It runs from thè
basai wall to thè ectocyst. When thè ectocyst is depressed in its
proximal part, thè mandible will open. This opening muscle is
smooth, thè closing muscles have a striated pattern, which also
appears more or less spiralized. The onychocellarian opesium can
thus be either an ovai opening which goes far enough in proximal
direction to allow passage of thè opening muscle and thè tendons
from thè proximal closing muscles or it can be severa! small open¬
ings with one median proximal slit and several paired lateral-
distal slits. The size, shape and position of such slits will give
information on thè size of thè individuai muscles and on thè shape
of thè mandibular base. If thè avicularian opesium does not cor-
respond to these slits, thè muscles are not developed in thè cor-
rect way and thè avicularium is not an onychocellarium.

Also thè avicularian position in thè zoarium is important.
When a zooidrowdivides there shall always be an onychocellarium
as thè first zooid in thè distaì-lateraì row. The terminal row shall
always have an autozooid as thè next zooid. In thè typegenus of
thè family, Onychocella, no other positions for onychocellaria have
been observed. In thè typespecies of Floridina, F. antiqua (Smitt,
1873), which is encrusting, one might also find onychocellaria
where zooidrows beeome crowded owing to substratum factors. In
this latter case a zooidrow disappears and its last zooid is an ony¬
chocellarium. Which type of zooid that will develop appears to
depend on thè distribution of thè interzooidal Communications. The
norma! autozooid has one proximal-terminal and on each side one
proximal-lateral. Each of these pores is connected with distai
parts of proximal zooids. Likewise three distai zooids are in their
proximal parts connected with one autozooid by one distal-terminal
pore and on each side of thè latter one distal-lateral pore. When
a zooidrow divides thè distal-terminal pore goes to thè terminal
autozooid. One of thè distal-lateral pores becomes a proximal-
lateral pore in thè lateral onychocellarium. This zooid does not
have thè proximal-terminal pore. Under these circumstances there

009

S. A. N. SCHAGER

does not develop a normal polypide, thè zooid developes as an ony-
chocellarium. The zoarial surf ace can sometimes give thè impres-
sion that some autozooids are arranged in a circle around thè ony-
chocellarium (thè « nuclear effect » of Lagaaij 1952).

A review of a number of species named Floridina from thè
Cretaceous and Tertiary shows that thè majority of them, have
avicularia in thè wrong position, have avicularia with a different
opesium or lack avicularia wholly. These species do not have ony-
chocellaria, they cannot belong to thè Onychocellidae, and they
are thus not Floridina- species.

In thè opinion of thè present author there is only one, or
possibly two, species that can be accepted as Floridina. The type-
species F. antiqua (Smitt, 1873) is found living in thè warm
waters on both sides of thè American continent and also on thè
W. African coast (Cook 1964). It has been reported fossil from
thè Eocene (Canu and Bassler 1920, Cheetham 1957 and 1963).
These fossil specimens do all refer to a species of an other genus.
The present distribution indicates however that thè species had
developed before thè closing of thè Isthmus of Panama, and it
could be expected fossil in thè upper Tertiary of C. America.
Dr. Scolaro, Georgia, USA has (personal communication, Aug.
1968) informed thè present writer that he has collected thè species
in thè Miocene of Florida.

The second species is Floridina parvicella (Canu and Bass¬
ler, 1923). It was first reported from thè Pliocene of S. Carolina
and has later been reported living in thè Gulf of Mexico (La-
gaaij, 1963). Dr. Maturo, Florida, USA has (personal commu¬
nication, Aug. 1968) found it also off Florida. There may be
doubts if this is a species or only a variety, it is characterized
by tubercles in thè interzooidal cornes. These tubercles were not
observed by Canu and Bassler but are present also in thè fossil
material (Lagaaij 1963, p. 178).

REMARKS ON THE GENUS FLORIDINA JULLIEN, 1881

223

REFERENCES

Bassler R. S., 1953 - Treatise on Invertebrate Paleontology, Part G, Bryo-
zoa - Kansas, pp. G 1-G 253.

Berthelsen 0., 1962 - Cheilostome Bryozoa in thè Danian Deposits of
East Denmark - Geol. Surv. Denmark, II Ser., No. 83, Copenhagen,
pp. 1-290, pls. 1-28.

Canu F., & Bassler R. S., 1917 - A Synopsis of American Early Tertiary
Cheilostome Bryozoa - U.S.N.M. Bull. 96, Washington, pp. 1-87,
pls. 1-6.

Canu F., & Bassler R. S., 1919 - Fossil Bryozoa from thè West Indies -
Carnegie Inst. of Washington, Pubi. No. 291: III, Washington,
pp. 75-102, pls. 1-7.

Canu F., & Bassler R. S., 1920 - North American Early Tertiary Bryo¬
zoa - U.S.N.M. Bull. 106, Washington, pp. 1-879, pls. 1-162.

Canu F., & Bassler R. S., 1923 - North American Later Tertiary and
Quaternary Bryozoa - U.S.N.M. Bull. 125, Washington, pp. 1-302,
pls. 1-47.

Canu F., & Bassler R. S., 1933 - The Bryozoan Fauna of thè Vincetown
Limesand - U.S.N.M. Bull, 165, Washington, pp. 1-108, pls. 1-21.

Cheetham A., 1957 - Eocene - Oligocene Boundary, Eastern Gulf Coast Re-
gion - Transact. Gulf Coast Ass. Geol. Soc., Voi. 7, pp. 89-97.

Cheetham A., 1962 - Eocene Bryozoa from thè McBean Formation in Geor¬
gia - Micropaleontology, Voi. 8, No. 3, New York, pp. 323-336, pls. 1-2.

Cheetham A., 1963 - Late Eocene Zoogeography of thè Eastern Gulf Coast
Region - Geol. Soc. Amer., Meni. 91, New York, pp. 1-113, pls. 1-3.

Cook P., 1964 - Polyzoa from West Africa. I. Notes on thè Steganoporel-
lidae, Thalamoporellidae and Onychocellidae (Anasca, Coilostega) -
Rés. Sci. Campagnes ‘ Calypse’, Fase. 6, Paris, pp. 43-78, pi. 1.

Jullien J., 1881 - Note sur une nouvelle Division des Bryozoaires Cheilosto-
miens - Soc. Zool. France, Bull. 6, Paris, pp. 271-285.

Lagaaij R., 1952 - The Pliocene Bryozoa of thè Low Countries - Maastricht,
pp. 5-233, pls. 1-26.

Lagaaij R., 1963 - New Additions to thè Bryozoan Fauna of thè Gulf of
Mexico - Pubi. Inst. Mar. Sci., Voi. 9, Texas, pp. 162-236, pls. 1-8.

Levinsen G. M. R., 1909 - Morphological and Systematic Studies on thè
Cheilostomatous Bryozoa - Copenhagen, pp. 1-431, pls. 1-24.

d’Orbigny A., 1850-1852 - Paléontologie Francarne, Terrains Crétacés -
Voi. 5, Paris, pp. 1-1191, pls. 600-800.

Smitt F. A., 1873 - Floridan Bryozoa, part II - Kongl. Svenska Vet. Akad.
Handl. Voi. 11, Stockholm, pp. 1-83, pls. 1-13.

224

S. A. N. SCHAGER

VoiGT E., 1923 - Ùber einige neue und wenig bekannte Bryozoen der Gat-
tung Floridina aus dem Danien von Faxe - Medd. Dansk. Geol.
Foren., Voi. 6, Copenhagen, pp. 20:3-20:9, one piate.

Voigt E., 1930 - Morphologische und Stratigraphische Untersuchungen ùber
die Bryozoenfauna der oberen Kreide - Leopoldina, voi. 6, Halle,
pp. 397-579, pls.. 1-39.

Voigt E., 1967a - Òkologisc-he und Stratigraphische Untersuchungen an
Bryozoen der oberen Kreide - Ber. Deutsch. Ges. Geol. Wiss., A, Geol.
Palàont., Voi. 12, Berlin, pp. 479-491.

Voigt E., 1967b - Oberkreide-Bryozoen aus den Asiatischen Gebieten der
UdSSR - Mitt. Geol. Staatsinst. Hamburg, Heft 36, Hamburg,
pp. 5-95, pls. 1-34.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 225-286, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
30. Group 4: Evolutionary Batterns and Systematics.

John S. Ryland (*)

TERMINOLOGICAL PROBLEMS IN BRYOZOA

Riassunto. — Una terminologia precisa è essenziale per il progresso della
Briozoologia. In questo lavoro, parole, la cui ortografia è sbagliata (olocyst)
o che sono state formate male (cardelli) o che sono di origine oscura (opesia),
sono state chiarificate etimologicamente mentre alcune altre parole, di signi¬
ficato confuso o ambiguo (anter, poster, porta, vanna, zooecium, ooecium,
gonoecium, gonozooid) sono state discusse per arrivare a definizioni soddi¬
sfacenti. Indi, la classificazione di ovicelle dei Cheilostomata viene riconsi¬
derata sulle basi di quattro attributi descrivibili: a) il metodo di formazione
(indipendente o dipendente dallo zooide distale); b) la posizione relativa allo
zooide distale (prominente, sub-immersa o immersa); c) la posizione dell’aper¬
tura ovicellare (iperstomiale o ipostomiale) ; d) il modo di chiusura (cleitrale
o acleitrale). Finalmente l’A. suggerisce che questa Conferenza crei un Co¬
mitato per la Terminologia, comprendente due geologi e due zoologi, per
preparare un glossario di termini usati in Briozoologia da sottomettere alla
prossima Conferenza Internazionale.

Summary. — An unambiguous terminology is essential for thè progress
of bryozoology. In this paper some words mis-spelt (olocyst), wrongly formed
(cardella) or of obscure origin (opesia) are clarified etymologically, while
some others of confused or ambiguous meaning (anter, poster, porta, vanna,
zooecium, ooecium, gonoecium, gonozooid) are discussed to arrive at satisfac-
tory definitions., The classification of cheilostome ovicells is then reconsidered
on thè basis of four describable attributes, namely, (a) method of formation
(independent of or dependent on thè distai zooid), (ò) position relative to thè
distai zooid (prominent, subimmersed or immersed), (c) situation of thè ovi-
cellar opening (hyperstomial or hypostomial), and (d) method of closure
(cleithral or acleithral). Slight modifications to existing terminology are pro-
posed. Finally it is suggested that this Conference should set up a Committee
on Terminology, comprising two geologists and two zoologists, to prepare a
draft glossary of terms used in bryozoology for submission to thè next Inter¬
national Conference.

(*) University College of Swansea, Department of Zoology - Swan-
sea, U. K,

,T. S. RYLAND

226

The subject of terminology may sound unexciting, but its
fundamental importance is obvious: an International Conference
on Bryozoa would be impossible unless all thè participants under-
stood most at least of thè special terms used to describe bryozoans.
A clear, precise and economical terminology facilitates communi-
cation between teacher and student, and is essential far thè easy
exchange of information and ideas between research workers.
The terminology used by bryozoologists at thè moment, however,
is frequently obscure in both application and derivation ; it is even
sometimes ambiguous. Thus Hyman (1959: 285) observed: «The
study of ectoprocts is burdened with a large and fantastic ter¬
minology, much of it dating from a period when thè structure of
thè animals was not understood. Hence thè terminology lacks re¬
lation to terms employed for other groups of animals. Frequently
thè ectoproctologists seem to get themselves entangled in their own
terminology, using thè same word (e.g., aperture) in several dif-
ferent senses ».

As generaliy understood, terminology is simply thè System
of terms belonging to any Science or subject; but its etymological
definitimi is thè scientific study of terms. The two meanings are
not so far divcrced as might be supposed, for thè inventor of new
technical terms must pay due attention to etymology, particularly
in thè formation of diminutives and other compound words. It is
appropriate here to draw attention to a most valuable book on
thè subject, Composition of Scientific Words (Brown, 1956). Lack
of care and/or knowledge leads to thè introduction of miscon-
structed or wrongly spelt words, of which thè following are some
examples.

Cardellae. Introduced by Jullien (1888: 52) as a Latin
plural, with French equivalent cardelles, for thè processes inside
thè cheilostome orifice on which thè operculum pivots. I am not
aware that cardelle exists in vernacular French and, in thè ab-
sence of any definite indication, assume that cordella must have
been intended as a diminutive of Latin cardo, -inis (masc.), a
hinge. The correct diminutive of cardo, however, would be car-
dunculus (pi. cardunculi), which is admittedly rather ponderous.
Fortunatelv, an alternative exists, for some authors refer to these
structures as condyles (or condyli, thè Latin plural derived from

TERMINOLOGICAL PROBLEMS IN BRYOZOA

TióvòvXog, a prominence), which seems altogether much more sa-
tisfactory.

Olocyst. Introduced by Canu & Bassler (1920: 47), follow-
ing Jullien (1888: 46), for thè smooth, non-porous frontal wall
of certain cheilostomes (e.g., Hippothoa). Olocyst is an example
of incorrect transliteration, for it is derived from òlog, entire,
together with xvoug, a sac or celi. Unfortunately Canu & Bass¬
ler, like Jullien, failed to realize that thè aspirated. vowel (ó)
is always preceeded in transliteration by h, so that thè correct
rendering of òlog is holos, familiar in many compound words.
Olocyst, therefore, is simply a misspelling of h olocyst, Another
example of confused spelling concerns zooid, but I have discussed
this in an earlier paper (Ryland, 1967: 844).

Opesia. Introduced by Jullien (1888: 67) as a French
word opésie for thè centrai opening in thè cryptocyst of many
anascans. He gives thè derivation from òmjota, buttonhole, a word
which did not exist in classical Greek. Latinisation of this gives
opesia (fem.), but Canu & Bassler, presumably inadvertently,
rendered it as opesium . This incorrect spelling has persisted in
thè literature.

On thè subject of muddles introduced by Canu & Bassler,
I have earlier (Ryland, 1967: 346) pointed out their transposition
of porta and vanna, which apply to thè opereulum, with anter
and poster, which apply to thè orifice. Subsequently, however,
Hastings (in litt.) drew my attention to some additonal compli-
cations concerning these words. Jullien (1903: 16) gave thè
following def initions : « L’ orifice . . . se divise en deux régions
bien distinctes, à chacune desquelles est dévolue une fonction dif-
férente : la région antérieure . . . , c’est la région polypidienne qui
est limitée en avant par la lèvre antérieure de Torifice ou
anter ... ; la lèvre operculaire qui ferme la région polypidienne
scappellerà la porta...; la région postérieure de Forifice sert
uniquement à rentrée à la sortie de Teau ambiante dans cette
poche à eau, que nous avons nommée compensatrix ou compen-
satrice, et se trouve limitée en arrière par la lèvre postérieure
de Torifice ou poster. . . . La lèvre de Fopercule qui ferme la com-
pensatrice s’appellera la vanne ou vanna ». Thus anter and
poster were introduced to describe thè rim of thè orifice, not
thè corresponding parts of its lumen.

228

J. S. RYLAND

Neverthele-ss, Brown (1952: 32) stated of thè anter that it is:

« Generally understood as that part of thè orifice distai to
thè condyles in some Ascophora » (i.e., that anter and poster
should be regarded as parts of thè lumen, rather than of thè
rim). In thè same year, however, Lagaaij (1952: 15) repeated
exactly Jullien’s definitions for anter and poster, but extended
thè meanings of porta and vanna to include thè corresponding
part of thè orifice itself. Unless definitions for these terms can
be agreed, a very confusing situation could arise. My own in-
clination is to foìlow thè usage proposed by Brown. Two further
examples of words redefined are heterozooid and gymnocyst
(Levinsen, 1909: v and Borg, 1926: 188, 190 footnote).

Zooecium. Hyman (1959: 287) drew a distinction between
thè cystid and thè zooecium, although broadly speaking both
describe thè body wall of thè zooid. The history of thè two words
was reviewed by Ryland (1967: 344), who accepted Hyman’s
distinction between thè complete body wall including its living
layers (thè cystid) and thè durable calcareous element of thè wall
(thè zooecium). Subsequent correspondence, however, suggests
that many zoologists would be very happy to see thè word zoo¬
ecium disappear entirely from bryozoan terminology. Its deriva¬
ti un from ohtog implies that it is a house inhabited by a separate
entity, a « zooid », as a worm lives in a tube: whereas in reality
thè exoskeleton is just part of thè zooid wall, and is often per-
meated by strands of living tissue. In a standard geological text-
book it is stated that : « In thè most familiar Bryozoa thè auto-
zooid lives in a chitinous or calcareous tube, thè zooecium, which
is in reality an external envelope, though commonly included by
zoologists as an integrai part of thè wall of thè zooid » (Shrock
& Twenhofel, 1953: 200). So long as zooecium remains in use,
I am afraid that this appalling misconception will continue.

Brood chambers. The terminology applied to thè brood
chambers in Bryozoa is complex and not entirely satisfactory.
Where thè complete structure is clearly a zooid morph, as in
many cyclostomes, it is properly termed a gono zooid, from
yóvos, offspring (Levinsen, 1909, as gonozooecium ; Borg, 1926).
The cheilostome equivalent of thè gonozooid is thè so-called go-
noecium of thè Adeonidae (Hincks, 1887: 152; Harmer, 1957:
788; Powell, 1967 a, 1906): but a gonoecium, literally, is a brood

TERMINOLOGICAL PROBLEMS IN BRYOZOA

chamber of any description, irrespective of whether it is a zooid
morph or not. Smitt(1867: 473) used kònhus, which Borg(1926:
386), translated as gonoecium (cf. djurhus = zooecium), when
discussing thè idea that cyciostome brood-chambers might be
diclinous.

Levinsen (1909: v, 282) more prc-perly called thè reproduc-
tive zooids of thè Adeonidae gonozooecia (i.e., gonozooids). Me-
trarabdotos (Cheetham, 1968) presents a more difficili! case,
since thè parent zooid is differentiated distally as an ovisac; but
if these ovisacs are not homologous with ovicells, then thè whole
structure is again a gonozooid. The safest label bere would be
simply female or reproductive zooid. Where special female ovicel-
late zooids occur (e.g., in Hippothoa ), it is misleading to use thè
term gonozooid (cf. Harmer, 1957: 641; Powell, 1967 a : 1906).
If a distinctive name is reallv needed, gynaecozooid (yvvrj,
yvvcuxóg, a female) might be appropriate, with androzooid
(àvijo, àvÒQÓg, a male) available for any specialised male coun-
terpart. It must be realized, however, that thè situatimi found in
Hippothoa is only an extreme instance of a widespread pheno-
mencn. Ovicellate zooids by definition are distinguished by thè
possession of ovicells, and often also by an orifice of different

size, shape and location (see p. 231): where should thè line be
drawn ?

The special brood chamber characteristic of manv cheilosto-
mes is variouslv termed an o vi ce 11 or ooecium. I believe that
some authors have refrained from using thè latter word in thè
belief that it connotes a modified zooecium. Even if valid, this
objec-tion could not be maintained if thè term zooecium were to
be discarded ; des-criptively and etymologically ooecium is satis-
factory if a latinized terminology is considered desirable.

The term ooeciostome, which has been used to describe
thè opening of thè cyciostome gonozooid, would obviously be far
better employed as thè name for thè ooecial orifice in cheilosto-
mes. For thè opening of a gonozooid or other brood-chamber go-
noeciostome might be appropriate.

Canu & Bassler (1920: 54) summarized a complicated and
poorly explained terminology for describing ovicells. It seems
clear, however, that their proposals, and thè gratuitous alterations

230

J. S. RYLAND

made to those of earlier authors, were based on inadequate ana-
lysis of thè kind of feature they were trying to describe. Their
mistake was to make unrelated attributes appear to be alter-
natives, and in consequence their classification is unsatisfactory
and obscure.

There appear to be at least four independent attributes of
ovicells that require characterization (see Fi g. 1):

1) Method of formation. (a) In some genera, e.g., Phy-
lactella, Crepidacantha, thè ovicell develops on thè distai wall of
thè parent zooid quite independentlv of thè future distai zooid
(Fig. 1 A), although in some instances thè distai zooid may sub-
sequently grow around thè ovicell (Brown, 1954: 244, footnote 2).
Ovicells of this type were termed independent by Levinsen
(1909: 62), but Canu & Bassler substituted an extraordinarily
inappropriate alternative, recumbent. ( b ) Other ovicells develop
relatively later, and from their inception rest on thè frontal wall
of thè distai zooid or its precursor (which is why it is so mis-
leading to describe thè independent ovicell as recumbent). Le-
vinsen termed this second type of development depende nt
(Fig. 1 B-H).

Fig. 1. — Some types of ovicell foimd in thè Cheilostomata, seen in optical
section. The cystid is indic-ated by a thick line (black for thè parent zooid,
hatehed for thè distai zooid) which does not necessarily indicate thè presence
of calcification. Thus both thè frontal and basai walls of thè zooid may be
entirely membranous; similarly, thè distal/proximal wall has usually only
a single shared calcified layer. The ovicellar structure demonstrated by
Silén is assumed throughout, and thè diagrams illustrate thè various ways in
which thè basic ovicell can be related to thè parent and distai zooids. The
operculum is shown in thè normal closed position, but open and alternative
closed positions are indicated by heavy broken lines. Based on thè published
illustrations of Levinsen (1909), Canu & Bassler (1920), Silén (1944 b) and
Powell (1967 b). A - independent, prominent, hyperstomial, acleithral; B - de-
pendent, prominent, hyperstomial, acleithral; C - dependent, prominent, hy¬
perstomial, pseudocleithral, with a partial cover from thè distai zooid; D -
dependent, prominent, hyperstomial, facultatively cleithral; E - dependent,
subimmersed, hyperstomial, perfectly cleithral ; F - dependent, subimmersed,
hypostomial; G - dependent, separated endozooidal; H - dependent, endo-

zooidal.

TERMINOLOGICAL PROBLEMS IN BRYOZOA

231

232

J. S. RYLAND

2) Position relative to thè distai zooid. Irrespective
of its mode of formation, an ovicell may be (a) prominent, i.e.
resting superficially upon thè distai zooid (Fig. 1 A-D), (b) partly
embedded or sub immerse d in it (Fig. 1 E-F), or (c) wholly
immersed in it (Fig. 1 G-H) (Hincks, 1880). The distai zooid
is generally another autozooid, but may be a kenozooid, as in Cri¬
brilina (Levinsen, 1909 : 56), or an avicularium, as in Spir alaria
(Levinsen, 1909 : 125) in which thè distai zooid may be an auto¬
zooid, an avicularium or a kenozooid (Hastings, in litt.). (a) and
(b) together have generally been known as hyperstomial (Le-
vinsen, 1902), but I suggest that thè manner in which this term
has been defined is slightly illogical. (c) is thè endozooidal ovi¬
cell (endozooecial, Levinsen, 1902). It appears to be inherent in
thè definition of thè endozooidal ovicell that it is overgrown by
thè frontal wall of thè distai zooid (Fig. 1 G-H). It is not true,
however, that prominent or subimmersed ovicells are never over¬
grown in this way. Silén (1944 b) has shown that there is no
fundamental difference between thè way in which hyperstomial
and endozooidal ovicells devetop.

3) Situation of thè ovicellar opening. (a) Most com-
monly thè ovicell opens superiorly to thè orifice of thè parent
zooid (Fig. 1 A-E). This condition was described as superovi-
cellate by Jullien (1888: 35). (b) The alternative situation, in
which thè ovicell opens below thè orifice he called s ubo vi cel¬
iate (Fig. 1 F-H). When Levinsen (1902, 1909) proposed thè
terms hyperstomial and endozooidal (as endozooecial), he evid-
ently overlooked Jullien’s earlier categories of super- and sub-
ovicellate. Jullien’s terminological definitions were thè more
precise, being based on thè position of thè ovicellar opening. Le-
vinsen ought to have used thè same criteria when defining his
own terms, especially hyperstomial, but in fact used position of
thè ovicell relative to thè distai zooid. In thè interest of clarity,
thè definition of a hyperstomial ovicell should be one that opens
above thè orifice , though in practice it would continue to have its
currently accepted connotation.

It is possible (at least in theory) for an ovicell to be only
partially immersed in thè distai zooid and yet open below thè
orifice (Fig. 1 F): it would be thus hypostomial (= subovicel-
late), but not endozooidal. Jullien placed thè special temale zooids
of Hippothoa in this category.

TERMINOLOGICAL PROBLEMS IN BRYOZOA

4) Method of cl os ure. (a) Many ovicells have no closing
device other than thè membranous inner vesicle which seals thè
opening (Fig. 1 A-B), although this may be somewhat chitinized
(Levinsen, 1909 : 57 ; Silén, 1944 a, fig. 19). This condition was
described as aneucleithral (àvsv, without; xXeìQqov, a bolt or
means of closure) by Jullien (1888: 45) and Canu & Bassler
(1920: 54), but, since aneli- suggests derivation from à- or àv -
(without) plus ev- (weil), a combination of suffixes which occurs
in certain scientific words, it would be better to use thè shorter
and unambiguous acleithral. Acleithral hyperstomial ovicells
may be recognized in fossil material, according to Canu & Bass¬
ler, by thè facts that thè ovicell does not overlap thè orifice and
its opening is perpendicular to thè orifice (Fig. 1 A-B). (b) In
other hyperstomial ovicells, generally those exhibiting some degree
of immersion in thè distai zooid, thè opening may be sealed by
thè slightly raised operculum of thè parent zooid. Jullien des¬
cribed as cleithral this condition, which can be recognized in
fossil material (Canu & Bassler, 1920: 54) by thè fact that thè
ovicell overlaps thè orifice so that its opening obliquely faces thè
orifice (Fig. 1 C-F).

Canu & Bassler appear correct in believing that grades of
perfection within thè cleithral System can be distinguished, but
their terms are unacceptable. (i) The most primitive condition,
really acleithral, but classified as cleithral by Jullien, is where
thè operculum in its traverse between closed and open momen-

tarily seals off thè ovicell (Fig. 1 C), but is never normally held
in that positi on. This might be termed pseudocleithral (xpevòrjg f
false), and is thè situation found, e.g., in Smittina. (ii) In other
genera thè operculum can occupy one or other of two closed po-
sitions, thè upper sealing off thè ovicell, thè lower closing thè
orifice only (Fig. 1 D). This occurs, e.g., in Penta/pora (Hastings
& Ryland, 1968). Canu & Bassler called this subcleithral, a
compound word that is etymologically objectionable : faculta-
tively or imperfectly (see iii) cleithral seems better. (iii) In
what appears to be thè most developed state, thè normal position
of thè operculum in an ovicellate zooid is in thè upper position.
It thus permanently closes a common orifice and is perfectly
cleithral. Whether thè operculum is able to return to thè lower

234

J. S. RYLAND

position (Fi g. 1 E), but usually does not, or whether it cannot
(Fig. 1 F), or whether both situations occur, cannot be stated at
present. In Ho.plopoma thè calcified wall fabricates an « orifice »,
just like that of thè non-ovicellate zooid, below thè common ori¬
fice, but thè opereulum always appears to dose thè common
orifice. Perhaps thè rim of thè latter functions as a stop. In
anascans (e.g., in Micropora , examined for me by Dr. Anna B.
Hastings) there is no calcified orifice as such, and it is perhaps
to be expected that thè opereulum should dose only thè common
orifice. Nevertheless, it would be unwise to assume that thè con-
dition illustrated in Fig. 1 E cannot exist. Here is a clear example
of thè need to study living material.

Further problems related to ovicells remain, even with
respect to thè types here discussed, and some special kinds of
ovicell have not been mentioned at all. The terminology of thè
layers needs to be sorted out: Silén’s (1944 b) alterations to
established usage seem to me to be unacceptable. There are also
severa! questions concerning thè structure and degree of calcifi-
cation of thè ectocyst (sensu Levinsen); thè extent of thè con-
tribution (if any) from thè distai zooid; and thè occurrence of
ovicellar covers in which secondary calcification from thè parent,
distai or adjacent zocids spreads over thè ovicell. These are mor-
phological complications which Silén did not have to consider.
His study clarified our understanding of ovicellar structure, but
requires to be extended to more complex examples.

I wish to thank Dr. Anna B. Hastings for examining speci-
mens, and for correspondence about thè structure of ovicells.

Epilogue.

I have discussed briefly just a few technical terms which are
etymologically or bryozoologically unsatisfactory. There are many
more. This Conference would undoubtedly render a valuable Ser¬
vice to Science if it were to set up a committee to prepare a Glos¬
sarli of Terms relating to thè Study of Bryozoa. This committee
should perhaps comprise four members : 1) a taxonomic or mu-
seum zoologist, 2) a zoologist from a teaching establishment, 3) a
geologist interested in post-Palaeozoic Bryozoa, and 4) a specialist

TERMINOLOGICAL PROBLEMS IN BRYOZOA

9 3 5

Aj • J • *

on thè Palaeozoic. The terms of reference might be: to compile
a list of descriptive terms applied to Bryozoa, giving for each
1) author and date of introduction ; 2) etymological derivation ; 3)
thè originai definition ; 4) a reworded or emended definition (il
necessary) agreed by thè Committee as being appropriate to thè
present time. If this proposai be accepted, thè Committee might
be asked to present its draft Glossary for thè generai conside-
ration of members at thè 2nd International Conference of thè
I.B.A.

REFERENCES

Borg F., 1926 - Studies on recent cyclostomatous Bryozoa - Zool. Bidr. Upps.,
X, pp. 181-507.

Brown D. A., 1952 - The tertiary cheilostomatous Polyzoa of New Zealand -
London, British Museum (Naturai History), 405 pp.

Brown D. A., 1954 - On thè polyzoan genus Crepidacantha Levinsen - Bull.
Br. Mìrs. nat. Hist. (Zool.), II, pp. 241-263.

Brown R. W., 1956 - Composition of scientific words - Washington, privately
published, 882 pp.

Canu F. & Bassler R. S., 1920 - North American early tertiary Bryozoa -
Bull. U. S. Nat. Mus. CVI, pp. 1-879, pls. 1-162.

Cheetham A. H., 1968 - Morphology and systematics of thè bryozoan genus
Metrarabdotos - Smithson. mise. Collns, CLIII, No. II, pp. 1-121,
pls. 1-18.

Harmer S. F., 1957 - The Polyzoa of thè Siboga Expedition, Part IV, Cheilo-
stomata Ascophora, II - Siboga exped., XXVIII d, pp. 641-114/, pls.
42-74.

Hastings A. B. & Ryland J.. S., 1968 - The characters of thè polyzoan genera
Pentapora and H ipp o dipi o sia, with redescriptions of P. foliacea (Ellis
& Solander) and H. verrucosa Canu - J. Linn. Soc. (Zool.), XLVII,
505-514.

Hincks T., 1880 - A history of thè British marine Polyzoa - London, van
Voorst, cxli + 601 pp., 83 pls.

Hincks T., 1887 - Criticai notes on thè Polyzoa - Ann. Mag. nat. Hist. (Ser. 5),
XIX, pp. 150-164.

Hyman L. H., 1959 - The invertebrates : smaller coelomate groups - New
York, McGraw-Hill, 783 pp.

Jullien J., 1888 - Bryozoaires - Mission scient. Cap Horn, 1882-1883, VI,
Pt. I, pp. 1-92.

Jullien J. (in Jullien J. & Calvet L.), 1903 - Bryozoaires provenant des
campagnes de l’Hirondelle (1886-1888) - Résult. Camp, scient. Prince
Albert I, XXIII, pp. 1-188.

Lagaaij R., 1952 - The Pliocene Bryozoa of thè Low Countries - Meded. geol.
Sticht., Ser C, V (5), pp. 1-233.

236

J. S. RYLAND

Levinsen G. M. R., 1902 - Studies on Bryozoa - Vidensk. Meddr dansk naturh.
Foren., 1902, pp. 1-31.

Levinsen G. M. R., 1909 - Morphologic-al and systematic studies on thè cheilo-
stomatous Bryozoa - Copenhagen, Nationale Forfatteres Forlag, 431 pp.
Powell N. A., 1967 a - Sexual dwarfism in Cribrilina annidata (Cribrilini-
dae - Bryozoa) - J. Fish Res. Bd Can., XXIV, pp. 1905-1910.

Powell N. A., 1967 b - Polyzoa (Bryozoa) - Ascophora - from north New
Zealand - « Discovery » Rep., XXXIV, pp. 199-394.

Ryland J. S., 1967 - Polyzoa - Oceanogr. Mar. Biol. Ann. Rev., V, pp. 343-369.
Shrock R. R. & Tavenhofel W. H., 1953 - Principles of invertebrate paleon-
tology - New York: McGraw-Hill, 816 pp.

Silén L., 1944 a - The anatomy of Labiostomella gisleni Silén (Bryozoa Pro-
toc-heilostomata) - K. svenska VetenskAkad. Handl., XXI, No. VI,

pp. 1-111.

Silén L., 1944 b - The main features of thè development of thè ovum, embryo
and ooecium in thè ooeciferous Bryozoa Gymnolaemata - Ark. Zool..
XXXV A, No. XVII, pp. 1-34.

Smitt F. A., 1967 - Kritisk fòrteckning òfver Skandinaviens Hafs-Bryozoer
Ofvers. K. VetenskAkad. Forh., XXIII, pp. 395-534.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 237-240. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
31. Group 4: Evolutionary Patterns and Systematics.

Enrico Annoscia (*)

PROBLEMS OF METHODOLOGY
IN STUDYING AND DESCRIBING BRYOZOA

Riassunto. — Vengono presi in considerazione i metodi per la raccolta
delle misure biometriche, le diagnosi e la terminologia briozoologica e ven¬
gono suggerite alcune soluzioni.

Summary. — The measurements methods, descriptions and terminology
are taken into consideration and suggestions about these topics are given.

Résumé. — Les méthodes de mesuration biometrique, les diagnostiques et
la terminologie bryozoologique sont pries en consideration et discutées, et
quelques Solutions sont suggérées.

The subject of rny talk unintentionally follows thè remarks
of thè colleague Ryland. I was not able to read his text, but
only a short abstract and I saw that generally speaking we all
strongly require to clarify thè terminology that we use in descri-
bing Bryozoa. « An unambiguous terminology is essential for thè
progress of Bryozoologv » writes Ryland in thè abstract of his
paper. I completely agree with him. As economie paleontologist
working in an Oil Company, I felt all thè load of an old, impre¬
cise and blundering terminology which requested me an attention
out of proportion with its reai importance in mv work. Every
time specialists create a terminology, this is for a better unders-
tanding and not for uselessly complicating matters with equivo-

(*) AGIP Direzione Mineraria, Servizio Geologico, Laboratorio Paleon¬
tologico - San Donato Milanese, Milan (Italy).

238

E. ANNOSCIA

cations which only splitting hairs philologists are able to under-
stand. Yet, to split hairs does not mean Science.

This fact forced me to elaborate a first multilingual Glos-
sary (in press) of Bryozoological terms which might be used as
a basis for building up a finally simple and clear terminology.
I so far gathered more than 1000 terms, as many as those com-
prised in thè basic English!

Since thè problem of terminology was investigated by
dr. Ryland, I don’t want to spend many words on it, but I would
like not to talk on terminology and semantics only: I would
like to start when a Bryozoologist takes a sample in his hands
until he describes its species.

Rather than a paper, my talk will be a series of proposals
with some discreet suggestions.

We should all start from a fixed weight (for instance
100 gr.) of dry sample and we should give data on thè percen-
tage of dry residue after washing and thè percentage of organic
residue either referred to thè total dry residue or to thè whole
dry sample, beside thè percentage of Bryozoa referred to thè
total organic residue.

We will that way able to collect little by little a mass of
uniform data which can be immediately compared one another
without being manipulated or converted.

Statistica! research on fossil as well as living populations
are to-day more and more developing, being considerably helped
by thè use of Electron Computers. It is to-day unpossible to
compare faunas studied by different Authors, because thè neces-
sary data lacks or are inadequate. Consequently, it would be
advisable for all of us to give biometrie measurements in thè
same way, even if in that case we do not intend to carry on a
reai statistical study. However, we will that way allow other
people to do that easily.

To give to-day measurements as « Lz = 0,5 — 0,9 mm » does
not make sense if also number of measured specimens, mean,
standard deviation, observed range, etc. are not indicated. I think
this is obvious to all and does not require any further expla-
nation.

As to thè symbols used for measurements, they are really
too many. I enumerated 47 in my Glossary, but they are not all.

PROBLEMS OF METHODOLOGY IN STUDYING ETC.

239

But thè worst of it is that many Bryozoologists use thè same
symbols with a different meaning (fors instance « La » for area
width as well as opening width ; «Lo » for opesium width and
orificium width, etc.). Shall we put also this field in order ?

Let us now consider thè diagnoses of new genera and species.
Since Latin slowly became obsolete, no common scientific lan-
guage exists any more. Everybody started writing diagnoses in
his language either because he doesn’t know other languages or
for laziness or even nationalism. In conclusion, we need a reai
polyglot for interpreting thè thousands and thousands of new
diagnoses which are being given in so many language to-day. The
new nations which are beginning to carry on scientific research
did not yet begin to write diagnoses in Swahili, Arabie, Kurdish
and so on. But don’t worry: we will get them soon ! Somebody
may say that thè important languages are few; well, I defy any-
body to know them all!

My proposai to résumé Latin might appear a selfish one
because Italian is a neo-Latin language, but we cannot for get
that an age-long scientific tradition supports thè use of Latin.
We might come to a compromise: diagnosis in thè language ac-
cording to which thè text is written, aecompanied by a Latin
and/or English translation aside.

The paradigms of sistematic descriptions are mainly written
in Latin to-day: Derivatìo nominis, Species-typus, Diagnosis ,
Locus typicus, Stratum typicum and from here on thè Latin
mysteriously stops and everybody undaunted keeps paradigming
in his language: Affinities, Variations and differences, Remarks,
Measurements, Geologie Age, Occurrence, Cali number and so
on. Would it not be better to extend thè use of Latin to all para¬
digms : Collatio for Affinities, variations and differences; Notae
for Remarks; Mensurae for micrometrie measurements; Aetas
for Geologie age or Stratigraphical range ; Reperto for Occur¬
rence, Collected specimens or Observed material; Locatio for Cali
number; and so on?

Advantages are evident; whatever language be used in thè
text, we immediatelv know where to find thè requested data,

7 v

saving that way hours of translating work.

Latin terminology should be extended to thè whole morpho-
logical nomenclature. We Bryozoologists, unlike other specialists,

240

E. ANNOSCIA

have thè advantage of already commonly using Latin or Latin-
li ke terms (Opesium, Zoarium, Zooecium and so on) (that they
have or not a common meaning for everybody, this is another
thing). It would be advisable not to loose this advantage, but
on thè contrary to extend thè Latin nomenclature also to thè
body parts which do- not have it yet (wall, axial region and
so on). Once more thè advantages are clear to everybody; what-
ever be thè language used for thè text, we know at least what
we are talking about.

Many other thìngs should be settled and I join with Ryland’s
proposai to establish a Committee on Terminology to prepare a
draft Glossary of terms used in Bryozoology for submission to
thè next International Conference. This Committee should also
state thè rules for thè symbols to be used in giving biometrie
measurements, thè way itself of taking them and thè way to
present them, too. The suggestions of this Committee of course
do not constitute a law, but are only Recommendations which we
all will freely have to follow.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 241 -244. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968
32. Group 4: Evolutionary Patterns and Systematics.

Robert L. Anstey - Thomas G. Perry (*)

BIOMETRIC PROCEDURES IN TAXONOMIC STUD1ES

OF PALEOZOIC BRYOZOA

(Preliminary Repoi't)

Riassunto. — Poiché una specie paleontologica è definita da un insieme
di caratteri tassonomici e poiché da un solo zoarium si possono ottenere
molte misure di ciascun carattere tassonomico, i Briozoi si prestano in modo
particolare alla descrizione quantitativa e all’analisi statistica.

L’analisi quantitativa fornisce criteri obiettivi per la descrizione e la
differenziazione delle specie e permette inoltre una valutazione obiettiva
delle variazioni morfologico-strutturali nell’ambito di un taxon. In tal modo
la rigorosa definizione dei taxa per mezzo di studi quantitativi li rende più
utili per la stratigrafia e per gli studi filogenetici e paleoecologici.

Com’è messo in evidenza dagli istogrammi di 17 specie di Briozoi pa¬
leozoici, la distribuzione dei caratteri tassonomici si avvicina per lo più ad
una curva normale di frequenza o Gaussiana.

La normalità della distribuzione dei caratteri tassonomici è verificata
statisticamente per mezzo del « Kolmogorov-Smirnov 1 - sample test».

La normalità della distribuzione è un requisito richiesto per l’appli¬
cazione dei procedimenti statistici parametrici.

I procedimenti statistici analitici hanno la loro più valida applica¬
zione nel differenziare gli zoaria di specie differenti e nello stabilire l’ap¬
partenenza di diversi zoaria alla stessa specie biologica.

E’ necessario fare un programma per determinare il numero minimo
di misure richieste per l’applicazione di questi « tests » statistici anche per
ridurre al minimo i tempi ed il lavoro e per evitare l’utilizzazione di un
numero superfluo di misure.

II numero di esemplari può essere stimato statisticamente solo per
quelle specie per le quali sono state date la media e la deviazione-standard
dei caratteri tassonomici.

(*) Indiana University, Bloomington, Indiana (USA).

242

R. L. ANSTEY - T. G. PERRY

In aggiunta alla normalità, i procedimenti statistici parametrici richie¬
dono una selezione delle misure fatte a caso, l’omogeneità della varianza
ed in generale un egual numero di misure.

Soddisfatti i requisiti richiesti, il « 2-sample t-test » può essere utiliz¬
zato per differenziare i valori medi dei caratteri tassonomici di due specie
diverse. Similmente si può usare l’analisi parametrica della varianza, utiliz¬
zando l’« F-test », per determinare se gli zoaria in esame siano o no appar¬
tenenti alla stessa popolazione biologica.

Se i requisiti richiesti non sono soddisfatti, devono essere usati i pro¬
cedimenti statistici non parametrici e della libera-distribuzione. Il corrispon¬
dente del « t-test » è il « Mann Whitney U-test » e il corrispondente del¬
l’analisi parametrica della varianza è il « k-sample Kruskal-Wallis test ».

E’ ovvio che i procedimenti statistici non devono essere considerati
come la panacea di tutti i problemi tassonomici perchè si richiede il giu¬
dizio di tassonomi competenti per accertare quali caratteri sono di valore
diagnostico sufficientemente alto da poter essere sottoposti ai procedimenti
statistici e per stabilire il livello della sicurezza statistica desiderata.

Summary. — Data suggest that frequency distributions of numerical
taxonomic characters of Paleozoic bryozoans commonly approximate norma-
lity, thereby permitting application of parametric statistical tests. Norma-
lity can be tested by calculating normal probabilities and using goodness-of-
fit procedures. Sample randomness can be evaluated by means of thè 1-
sample runs test. The requisite number of measurements for taxonomic
studies can only be determined statistically. The mean and standard de-
viation should be considered as absolutely necessary in any numerical taxo¬
nomic study. Ternary diagrams provide an effective means of showing con-
comitant variation in three taxonomic characters.

Résumé. — Les données suggèrent que les distributions de fréquence
des caractères taxonomiques et numériques des bryozoaires paléozo'iques ap-
prochent la plupart du temps la normalité, qui est une nécessité préalable à
la réalisation des procédés statistiques paramétriques. La normalité peut
ètre mise a l’épreuve par le calc-ul des probabilites normales, et Tempio!
des procédés de « goodness-of-fit ». Le «randomness» de l’échantillon peut
ètre évalué par le moyen du « 1-sample runs test». Le nombre nécessaire
de mesures pour les études taxonomiques ne peut ètre determinò que pal¬
la statistique. Le moyen et la deviation normale doivent ètre considérés
comme absolument nécessaires pour les études taxonomiques et numériques.
Les diagrammes ternaires pourvoient un moyen efficace de montrer la va¬
riation concomitante dans trois caractères taxonomiques.

Because a paleontologie species is an unique aggregation of
taxonomic characters and because a single zoarium will commonly
provide many measurements of each taxonomic character, bryo¬
zoans are particularly amenable to quantitative description and

BIOMETRIC PROCEDURES IN TAXONOMIC ETC.

243

statistica! analyses. Quantitative treatment furnishes objective
criteria for thè description and differentiation of species and
further provides an objective evaluation of inherent morphologic
-structural variation within a taxon. Thus, thè rigorous definition
of taxa by quantitative studies makes them more useful for stra-
tigraphic, phyletic, and paleoecologic investigations.

In contrast to thè philosophy that is strongly insinuated by
thè typological approach, quantitative studies have clearly reve-
aled that considerable morphologic-structural variability charac-
terizes most bryozoan taxa. As suggested by histograms for 17
Paleozoic bryozoan species, thè distribution of taxonomic charac-
ters most commonly approximates a norma! or Gaussian frequency
curve. The normality of distribution of taxonomic characters has
been verified statistically by means of thè Kolmogorov-Smirnov
1-sample test, Normality of distribution is a prerequisite for thè
application of parametric statistical procedures.

The most powerful means of presenting measurable taxo¬
nomic characters is through descript ive statistical procedures.
Measures of centrai tendency, which include mean, median, and
mode, indicate thè tvpical development of each character in a
species or a biological population. In contrast, measures of varia¬
bility, which include range, standard deviation, coefficient of
variability, and confidence intervals, demonstrate thè limits of
departure of each taxonomic character from its nomi. Ternary
diagrams are useful in displaying thè concomitant variation of
three taxonomic characters and are potentially of value in com-
paring species.

Analytical statistical procedures have their greatest use in
differentiating zoaria of different species and in affirming that
several zoaria belong to thè same biological population. A sam¬
pling design is necessary to determine thè minimum number ol
measurements that is required for thè application of these sta¬
tistical tests and also, in thè interest of time and effort, to avoid
utilization of a superfluously large number of measurements.
Sample size can only be estimated statistically for those species
for which thè mean and standard deviation of taxonomic charac¬
ters have been given. In addition to normality, parametric sta¬
tistica! procedures require random selection of measurements,
homogeneity of variance, and generally equal numbers of mea-

244

R. L. ANSTEY - T. G. PERRY

surements. Provided that thè foregoing prerequisites are met,
thè 2-sample t-test can be utilized to differentiate thè mean
values of taxonomic characters of two different species.

Similarly, parametric analysis of variance utilizing thè F-test
can be employed to determine that several zoaria do or do not
belong to thè same biological population. If thè preeeding prere¬
quisites are not satisfied, nonparametric or distribution-free
statistical procedures must be employed ; thè analogue of thè
t-test is thè Mann Whitnev U-test, and thè analogue of thè para¬
metric analysis of variance is thè k-sample Kruskal-Wallis test.

Statistical treatment must not be regarded as thè panacea
of all taxonomic problems because thè judgment of thè competent
taxonomist is required to ascertain which characters are of suf-
ficiently high diagnostic value to receive statistical treatment and
to establish thè level of statistical confidence desired.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 245 - 246,t31-XII-1968

lst I.B.A. International Conferenee on Bryozoa, S. Denato Milanese, Aug. 12th-16th, 1968
33. Group 4: Evolutionary Patterns and Systematics.

Fritz Wiebach (*)

TAXONOMICAL AND OTHER REMARKS
ON FRESH WATER BRYOZOA

(Preliminary Report)

Riassunto. — L’A. riferisce brevemente sui recenti tentativi per una
migliore classificazione dei Phylactolaemata, su alcuni problemi da risol¬
vere, su alcuni recenti ritrovamenti e sulla necessità di trovare altri esem¬
plari di Hislopia e di Afvindella tanganyikae.

Summary. — A. deals with recent attempts for a more solid taxonomy
of Phylactolaemata, some problems to be solved, some recent findings and
thè necessity to find samples of Hislopia and Afvindella tanganyikae.

This lecture mainly deals with thè Phylactolaematous Bryo¬
zoa, and thè division is thè following one :

1. - recent attempts for a more solid taxonomy of Phylactolae¬

matous genera

2. - some hints given to field and laboratory workers

3. - some problems to be solved

4. - some recent findings

5. - samples wanted in particular.

1. - A short survey is given on thè systems of Phylacto¬
laematous genera such as established by Marcus (1942), Toriumi
(1956), Abricossov (1959) and Lacourt (1968). A number of
twelve genera are considered as valid ones, viz. Fredericella,

(*) Schlossgebiet 15, Plòn, Holstein, Germany (W.).

246

F. WIEBACH

Plumatella, Hyalinella, Afrindella, Stolella, Stephanella, Gelati¬
nella (so called tubular forms), Lophopus, Lophopusella, Lopho-
podella, Pectinatella, Cristatella (so called gelatinous forms), out
of which Afrindella and perhaps also Gelatinella may want
reconsideration.

2. - For a reliable classification all possible characteris-
tics should be used, not only statoblasts, as is done by Lacourt
in his recent « Monograph of thè Freshwater Brvozoa Phylacto-
laemata » (1968). In addition to Rogick’s and Brown's factors
for classification are suggested median sections and diagrams of
statoblasts and separatimi of statoblasts into halves and or quar-
ters by heating them in potash lve. Some objections are made to
Lacourt’s procedure of classification, and a respective example
is given. A parti cular request is addressed to all field workers
who may collect freshwater Bryozoa, viz. to keep a number of
unfixed statoblasts in dry condition for later rearing purposes.

3. - Some problems to be solved : A) Plumatella repens
and Plumatella, fungosa are they valid species or only ecological
variations of one and thè sanie species? B) thè problem of thin-
walled floatoblasts (leptoblasts) ; C) thè degree of alliance between
Plumatella emarginata and Plumatella casmiana; D) thè occur-
rence of piptoblasts in Plumatella samples ; E) thè problem of
geminate colonies ; F) are Afrindella and Gelatinella valid ge¬
nera? G) is Afrindella tanganyikae a Tanganvika endemite or
not? H) is Urnatella gracilis an immigrant in Europe?

4. - Some recent findings: A) Bulbella abscondita (Gym-
nolaemata Ctenostomata ) in river Elbe ; B) Plumatella casmiana
in Italy; C) Plumatella casmiana and Lophopodella canteri in
Bulgaria.

5. - More samples wanted of A) thè species Afrindella
tanganyikae, B) thè genus Hislopia, especially from Africa
(« missing link » between findings in South America and Asia).

Atti Soc. It. Se. Nat. e Museo Civ. St Nat. Milano - 108: 247-257, 31-XII-1968

lst I.B.A. International Conferente on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

34. Group 5: Biogeography and Biostratigraphy.

Enrico Annoscia (*)

STATUS OF THE BRYOZOOLOGICAL STUDIES
AND COLLECTIONS IN ITALY

Riassunto. — Viene dato un breve ragguaglio sullo stato degli studi
briozoologici in Italia negli ultimi ventanni.

Vengono inoltre presentati i risultati di un’ inchiesta tesa ad accertare
la consistenza e lo stato delle collezioni briozoologiche nei Musei italiani.

Un elenco delle più recenti contribuzioni sui Briozoi pubblicate in Italia
chiude la breve nota.

Summary. — A brief excursus about research on tossii and living Bryo¬
zoa carried out in Italy in thè last twenty years and thè results of an in-
quiry on thè Bryozoa collections status in Italian Museums are here re-
ported.

A list of thè latest papers on Bryozoa published in Italy is following
at thè end.

Introduction.

The studies of thè Bryozoa in Italy did not meet with thè
favour of thè studente, although our outerops from Palaeozoic to
Pleistocene and seas are rich in Bryozoa.

Italian was thè first great bryozoologist, F. Imperato (?1550-
1631?); we had in Italy A. Manzoni, in thè past century, A. Ne-
VIANI e C. Zirpolo in this century ; nevertheless, thè Italian bryo-
zoologists have been always numbered on one’s fingers. For this
reason thè status of bryozoological studies in Italy is at thè be-
ginning: nearly all has stili to be done.

(*) AGIP Direzione Mineraria, Servizio Geologico, Laboratorio Paleon¬
tologico, San Donato Milanese (Milan), Italy.

248

E. ANNOSCIA

Many type localities are already recognized and published,
but many others have to be searched and described, particularly
thè Palaeozoic and Mesozoic ones.

Only few bryofaunas are well described and illustrated ;
many of those described in thè past should be revised.

Very few bryofaunas were compar ed with malacofaunas and
microfaunas present in thè same geologie section and in thè adja-
cent sections, in order to establish exact locai and regional strati-
graphical ranges.

A large part of holotvpes and paratypes of thè Italian species
established by ancient Authors are lost or their present location
is unknown.

Only in thè latter years thè studies of thè Bryozoa were re-
sumed, either suggested by thè need of oil research (Annoscia
in thè AGIP Paleontological Laboratory of S. Donato Milanese)
or suggested by scientific interests (Accordi, Braga, Caretto,
Ceretti, Viganò in thè Geologie or Zoological Institutes of va-
rious Universities, Carrada, Sacchi, Ranzoli, Renzoni and Ren-
zini in thè Zoological Stations).

A criticai catalogne together with an Atlas of Italian fossil
and living species (revised names of species with their descrip-
tion, stratigraphical and geographical ranges and good figures)
and a revised list of thè Italian type-localities would be welcome.
On thè other hand, many years of work of many workers will be
necessary for this purpose.

A similar project together with a brief report on thè status
of byozoological studies and collections is to be suggested to all
bryozoologists for their own countries. This might be thè only
way to achieve a satisfactory outline on thè bryozoological studies
status all over thè world.

A card catalogue, like that by Ellis & Messina for Fora-
minifera and Ostracoda, must be thè final point of arrivai of our
young I.B.A.

The status of thè collections of Bryozoa in Italian Museums
is not better than thè status of studies. Italian Museums, either
thè autonomous or thè University ones, suffered more or less
serious damages during thè World War II. Most collections were
destroyed and those which are stili available are very badly ar-
ranged.

STATUS OF THE BRYOZOOLOGICAL STUDIES ETC.

249

I sent, last december 1967, a questionary to about fourty Mu-
seums in oraer to make an inventory of bryozoological collections
present in Italy. Only 12 compiled cards were returned to me!

In some Museum, no bryozoological collection is even present.
Some other Museums could not establish thè consistence of their
collections since an inventory of them was lacking.

Bryozoological studies status.

The Italian bryozoologists are presently very few.

In thè Universities are operating: Giampiero Braga at Padua
Geological Institute on Tertiary Bryozoa; Enzo Ceretti at Bolo¬
gna Geological Institute on Palaeozoic Bryozoa. Pier Giuseppe
Caretto (Turin Geological Institute) published only a paper on
Tertiary Bryozoa and Bruno Accordi (Director of thè Rome Geo¬
logical Institute) published in thè past some brief papers on Co-
nescharellina from Tertiary of Venetia.

For living Bryozoa, Antonio ViGANÒ is working at thè Zoo-
logical Institute of Perugia.

In thè autonomous Institutions, only Gian Carlo Carrada is
presently working on living Bryozoa from fresh or brackish wa-
ters lakes at thè Zoological Station of Naples. Finally, thè writer
is thè sole bryozoologist working for thè Industrv.

Nevertheless, lists of Bryozoa are sometimes published to-
gether with studies of other fossils by severa! Authors, and some
Zoologists (Sacchi, Ranzoli, Renzini, Rossi etc.) published in
thè past brief papers on Bryozoa.

I summarized thè history of thè bryozoological studies in Italy
from Imperato (1599) until Neviani (1948) with a compiete an-
noted bibliographv in a work now in press. I think it is useless
to repeat here what has been previouslv described. I rather like
to inforni about thè studies published in thè last twenty vears.
The bibliographic references, when not reported at thè end of this
paper, may be found in Annoscia (1968) (2), since thè whole bi-
bliography is too long to be reported here.

Palaeozoic.

The sole Palaeozoic Bryozoa were described by Ceretti (1963-
1967) from Carnia (Pontebba, Pramollo Pass and Auernig Moun-

250

E. ANNOSCIA

tain). The 55 described species belong to genera Fenestella, Po-
lypora, Penniretepora, Rhabdomeson, Rhombogova, Streblotrypa ,
Coeloconus, Rhombocladia and Sulcoretepora. 29 species are new.
The studied beds belong to Upper Carboniferous.

Nicosia & Del Bono (1956) reported some Bryozoa from
Upper Ordovician of Iglesias Province (Sardinia).

Mesozoic.

Detailed studies on thè Mesozoic Bryozoa were not published
so far.

Sacchi Vialli (1964 a-b) reported Cerioporai?) cf. orbìgnyi
and Neuropora sp. from Upper Sinemurian of Saltrio (Varese,
Lombardy). AGIP (1959) and Cita (1965) published two great
Atlases of Italian Microfacies ; in their plates some unnamed Me¬
sozoic Bryozoa are illustrated.

Coenozoic.

Many studies were published on Italian Coenozoic Bryozoa.
In thè examined period of time, thè first paper was published by
Accordi (1947) on two new species of Coneschar eliina from Pria-
bonian of Verona province (Venetia). He returned on thè same
topic in 1951 and 1965.

In 1949 Comaschi Caria published an important work on
Sardinia flora and fauna. It is a list of all fossil species found
there, with a list of type localities and a list of species arranged
according to geoehronology.

She published again on Sardinian fauna with lists of Bryo¬
zoa from Miocene of Cagliari environments (1959, 1960, 1963).
The species are not described and illustrated.

Braga published four papers from 1963 to 1968 on thè Eo¬
cene Oligocene and Miocene brvofauna from Berici and Lessini
Mountains, Treviso environments and thè Venetia type-localities
studied by Reuss and Hoppenheimer in thè last century.

The species are more than one hundred, well described and
illustrated.

The writer, for oil research purposes, has carried out some
studies on Bryozoa, publishing a big work on Biology, Systema-
tics, Oil research, Bibliography and Nomenclature and several

STATUS OF THE BRYOZOOLOGICAL STUDIES ETC.

251

studies on Palaeozoic and Tertiary bryofaunas from Italy and
Africa. Many of his research are unpublished and are summa-
rized in another paper delivered in this sanie Conference.

Some Bryozoans, without description, were reported by Mi-
RIGLIANO (1953) from Tirrenian of Gallipoli (Lecce province, sou¬
thern Italy) and by Floridi A (1960) from Tortonian of Rosolini

(Sicily).

Caretto (1966) published a new classification of some Plio¬
cene Bryozoa, previously described as Hydrozoa, from Piemont

and Emilia.

Living Bryozoa.

Systematical studies on living Bryozoa were carried out by
Carrada, Sacchi and Viganò.

Carrada (1964) published his research on Plumatella f ungosa
and Paludicella articidata from brackish waters of Cabras lake
(Sardinia) and, with thè cooperatimi of Sacchi, published some
research on Victor ella pavida (1962, 1964) from Fusaro and Pa¬
tria lakes (Naples).

Sacchi & Renzoni (1961, 1962) and Sacchi (1964) published
their research on Victorella pavida , Bowerbanìcia gracilis and Co-
nopeum seurati from thè sanie lakes.

Ranzoli (1962, 1964) described Zoobotryon verticillatum and
E le etra posidoniae (studies on sexual behaviour and breeding in
thè Laboratory).

Viganò (1964-1966) studied thè biogeography, distribution
and colonization of Bryozoa in Italian fresh waters lakes.

Some living Bryozoa are listed by Relini (1966) in thè « foul-
ing » of Genua Harbour, by Parenzan (1957, 1960, 1961, 1962) in
thè Gulf of Naples and Mar Grande of Taranto, and by Rossi
(1961) in a facies with Gorgonids from Mesco Point (Gulf of

Genua).

Collections in Museums.

For thè reader’s convenience, I list here thè Italian Museums
according to thè alphabetic order of towns.

E. ANNOSCIA

252

Babi - University Geological and Palaeontological Institute (Ate¬
neo Building, Nicolai Street No. 2).

Collections : Bryozoa (C hello stornata and Cyclostomata ) from Up-
permost Pliocene of Venusium (Potenza prov., Southern
Italy) collected in 1953 by E. Annoscia.

Doctorate Thesis : E. Annoscia (1955).

Publìcations : E. Annoscia (1963, 1968 (4)).

Bryozoologists : Missing.

Bologna - University Geological and Palaeontological Institute
(Zamboni str. No. 67).

Collections : Bryozoa from Upper Carboniferous of Auernig Moun¬
tain (Pontebba, Udine prov.).

121 slides and 71 thin sections.

Doctorate Thesis : Not indicated.

Publications : E. Ceretti (1963, 1964, 1967); E. Ceretti & A. Po-
luzzi (1968 (7)).

Bryozoologists'. E. Ceretti (Palaeozoic Bryozoa) and A. Poluzzi.

Research under way : Probable stratigraphical meaning of Cyclo¬
stomata and Cheilostomata in thè limestones with Bryozoa
from Abruzzi.

Cagliari - University Geological and Palaeontological Institute -
Museum « D. Lovisato » (Sa Duchessa, 1).

Collections : «Meneghini Coll.» - Ordovician from Fluminimag-
giore. Ordovician from Portixeddu and Domusnovas (not
published). Jurassic from Pozzo Monte d’Ussi (Nurra) (Bryo¬
zoa not determined and not published). Cretaceous from
Punta Negra (Nurra) (Bryozoa not determined and not pub¬
lished, localities reported in Comaschi Caria (1949)). Eocene
trom Madonna del Rimedio (Orosei) (Bryozoa not determined,
localities reported in Comaschi Caria (1949)). Miocene from
Funtanazza (reported in De Angelis & Neviani (1897), Co¬
maschi Caria (1949) and Annoscia (1968)), from Bosa Ca¬
gliari, Frasca Cap, Castelsardo, Dolianova, Donigaia, Man-
das, St. Andrea Frius, Seebra Point (Segariu), Mora Moun-
tains (Torralba).

Doctorate Thesis : Subthesis in Palaeontology bv A. Porcu
(1965 (9)).

STATUS OF THE BRYOZOOLOGICAL STUDIES ETC.

253

Publications : G. Meneghini (1857); C. F. Parona (1887); E. Ma¬
riani & C. F. Parona (1887); G. De Angelis D’Ossat &
A. Neviani (1897); D. Lovisato (1901, 1902); G. Degli In¬
nocenti (1929); I. Comaschi Caria (1949, 1959, 1960, 1963);
E. Annoscia (1968).

Not all Bryozoa listed in above reported Authors are kept
in Museum « D. Lovisato ».

Bryozoologists : Missing.

Catania - University Geologica! Institute (Palazzo delle Scienze)
and

Florence - University Geological Institute (Lamarmora str. 4).
Collectìons, Publications and Bryozoologists are missing.

Milan - University Palaeontological Institute (Piazzale Gorini, 5).
Collectìons \ Bryozoa from Upper Devonian (Frasnian) of Chital,
Pakistan (Shogram Fm.) and from Upper Permian (Murga-
bian) of centrai Elburg, Iran (Ruteh Fm.).

Doctorate Thesis : Not indicated.

Publications : N. Fantini-Sestini (1965 (8)).

Bryozoologists : Missing.

Milan - Civic Museum of Naturai Sciences (Corso Venezia).

The Museum had serious damages by bombs during thè last
World War II. The rich collections are mostly destroyed. It
is not possible to establish now how many Bryozoans are stili
retained, since thè inventory is under way.

Some living Bryozoa are exhibited in thè Windows.

Modena - University Palaeontological Institute (University str.
No. 4).

Collections : Cheilo stornata and Cyclostomata from Pliocene of Ca-
steir Acquato (Piacenza prov.), S. Venanzio, S. Valentino and
Fossetta (Modena prov.). 39 slides.

Doctorate Thesis : Not indicated.

Publications : A. Manzoni (1875); I. Namias (1890).
Bryozoologists : Missing.

Naples - Zoological Station (Villa Comunale).

Collections : Unknown consistence.

254

E. ANNOSCIA

Publications : G. Zirpolo (1882, 1920, 1921, 1922, 1923, 1924,
1925, 1928, 1932, 1933); C. Sacchi (1964); C. Sacchi &
A. Renzoni (1962); G. C. Carrada & C. Sacchi (1962, 1964);
G. C. Carrada (1964).

Bryozoologists : G. C. Carrada.

Padua - University Geological and Palaeontological Institute
(Giotto str., 20).

Collections : « Gottardi Coll. » : Eocene from Montecchio Maggiore
(Vicenza prov., Venetia) - 105 slides.

« Fabiani Coll. » : Eocene from Berici Mountains - 41 slides.
« Braga Coll. » : Eocene, Oligocene and Miocene from Berici
and Lessini Mountains and Treviso hills (Possagno) - 300
slides.

« Coppi-De Gregorio Coll. » : Pliocene from Modena Apen-
nins - 21 slides.

Doctorate Thesis : M. Tomasi (1968 (10)).

Publications : The reported collections were published respecti-
vely by Gottardi (1885), Fabiani (1908), Braga (1963, 1965,
1968) (6).

The revision of thè « Coppi-De Gregorio Coll. » is under way.
Bryozoologists’. G. P. Braga (Tertiary).

Research under way: Revision of Upper Eocene Bryozoa Col-
lection by Gottardi and Pliocene « De Gregorio Coll. » (Doc¬
torate Thesis).

Statistica! study of two Priabonian species : Coneschar eliina
perfecta Accordi and Coneschar ellina veronensis Accordi
(Doctorate Thesis).

Palermo - University Geological and Palaeontological Institute
(Corso Calatafimi, No. 260).

Collections : « Cipolla Coll. » from Pliocene of Altavilla (Palermo
prov., Sicily).

Doctorate Thesis : Not indicated.

Publications : The collections were published by Cipolla (1920,
1921, 1924 and 1926/a).

Bryozoologists : Missing.

Perugia - University Zoological Institute (Elee di sotto Str.).
Collections : Not indicated.

STATUS OF THE BRYOZOOLOGICAL STUDIES ETC.

•>

Doctorate Thesis : Not indicateci.

Publications : A. Ytganò (1964, 1965, 1968) (11, 12, 13).
Bryozoologists : A. Viganò (living freshwater Bryozoa).

Pisa - University Palaeontological Institute (S. Maria str., No. 53).
Collections : « Neviani Coll.»: Coenozoic Bryozoa from Tuscany.

« De Stefani and Neviani Coll. » : Neogene from Calabria -
100 slides.

« Gioii Coll. » : Neogene from Pianosa Island.

Bryozoa from Neogene of Apulia collected by G. Taaani

(1967-68).

Doctorate Thesis : Not indicated.

Publications : The reported collections were published respecti-
vely by Neviani (1900/d); De Stefani (1884) and Neviani
(1901/f) ; Gioli (1889) and Neviani (1902/e).

Bryozoologists : Missing.

Remarle : The Museum of thè Institute underwent serious dama-
ges during thè last World War II; thè material mostly was
destroyed and what is stili retained is not well ordered.

San Donato Milanese (Milan prov.) - AGIP Direzione Minera¬
ria Paleontological Laboratory.

Collections : « Annoscia Coll. »: about 700 slides and 20 thin sec-
tions from Uppermost Devonian from Libyan CORI wells,
Jurassic from Morocco; Cretaceous from Tunisian and Ira-
nian AGIP wells; Eocene from Libyan CORI wells and Ve-
netia outerops ; Oligocene from Liguria ; Miocene from Libyan
outerops and CORI wells, from Tunisian and Nigerian AGIP
wells and from Sardinian and Emilian outerops; Pliocene
from Emilian outerops and from Lucania and Tuscany; Plei¬
stocene from Sicily ; Living Bryozoa from S. Remo, Sardinia
and Adriatic sea.

Publications : The reported collections were in part published by
Annoscia & Grignani (1968) and by Annoscia (1963, 1965,
1966 and 1968) (3) (4) (5).

Research under way : Stratigraphy of Funtanazza (Sardinia):

Oligocene-Miocene section.

Bryozoologists'. E. Annoscia.

256

E. ANNOSCIA

Turin - University Geologica] and Palaeontological Institut (Ca¬
renano Building, Accademia delle Scienze str., 5).

Collections : About 170 specimens of T repost ornata, Cyclos tornata,
Cryptostomata and C hello stornata from Silurian, Devonian,
Carboniferous, Permian, Jurassic, Cretaceous, Cenomanian,
Senonian, Maastricht ian, and Tertiary from Europe and
USA.

Doctorate Thesis: M. Ajazzi (1958 (1)).

Publications : P. G. Caretto (1966).

Bryozoologists : No Bryozoologist is employed here. P. G. Caretto
sometimes works here.

Verona - Civic Museum of Naturai History (Lungadige Porta
Vittoria, 9).

Collections « Zangheri Coll. » : Upper Pliocene from Capocolle
(Forlì prov., Romagna) - 48 slides.

Publications : The «Zangheri Coll.» was studied by Neviani
(1926) and Cipolla (1928) and revised by Annoscia (1966/a).

Bryozoologists : Missing.

REFERENCES

All thè references reported in thè text but not here are available in :
Annoscia (1968) (2).

(1) Ajazzi M., 1958 - Catalogo dei Briozoi del Museo Geologico di Torino -

Doctorate Thesis (unpublished), Turin.

(2) Annoscia E., 1968 - I Briozoi. Introduzione allo studio con particolare

riguardo per i Briozoi italiani e mediterranei - Palaeontographia Ita¬
lica, spec. pap., pp. 1-400, figs. 1-82, tbb. 1-21, pls. 1-24 (in press),
Pisa.

(3) Annoscia E., 1968 - The Bryofauna of thè Mesomiocenic « Al Jagh-

bub Fm. » in Eastern Cyrenaica (Libya) - III Coll. Afric. Micropai.
Cairo, March 1968 (in press).

(4) Annoscia E,, 1968 - I molluschi delle argille figuline di Venosa (Po¬

tenza, Italia meridionale) - IV Congr. Neog. Medit. Bologna, Sept.
1967 (in press).

(5) Annoscia E. & Geignani D., 1968 - Bryozoa, Pollen and Macrospores

from thè subsurf ace Uppermost Devonian rocks in Eastern Cyre¬
naica (Libya) - III Colloq. Afric. Micropai. Cairo, March 1968 (in
press).

STATUS OF THE BRYOZOOLOGICAL STUDIES ETC.

(6) Braga G. P., 1968 - Bryozoa from « Marne Rosse » (Red Marls) of Spi-

lecco (Gessini Mountains) - I Inter. Conf. on Bryozoa of IBA, S. Do¬
nato Milanese, Aug. 1968 (in press).

(7) Ceretti E. & Poluzzi A., 1968 - Sul probabile significato stratigrafico

della frequenza dei Ciclostomi e dei Cheilostomi nel calcare a Brio-
zoi dell’Abruzzo - IV Congr. Neog. Medit., Bologna, Sept. 1967 (in
press).

(8) Fantini Sestini N., 1965 - The Geology of Upper Djadjerud and Lar

Valleys (North Iran). Bryozoans, Brachiopods and Molluscs from
Ruteh Limestones (Permian) - Riv. Ital. Paleont. Strat., 71, 1, pp. 13-
110, Milan.

(9) Porcu A., 1965 - I Briozoi del Miocene della Sardegna - Doctorate

Thesis (unpublished), Cagliari Univers. Se. Fac. (Ac. Year 1964-65),
pp. 1-36, Cagliari.

(10) Tomasi M., 1968 - Lo stato attuale delle conoscenze sui Briozoi sal¬

mastri della Laguna di Venezia con particolare riguardo al Bacino
Chioggiotto - Doctorate Thesis (Unpublished), Padua Univ., Se. Fac.
(Ac. Year 1966-67), Padua.

(11) VlGANÒ A., 1964 - La colonizzazione delle sponde del Lago Trasimeno

da parte dei Briozoi del genere Plumatella ( Phylact . Plumatellidae ) -
Boll. Zool. XXXI, II (1964) (Atti XXXIII Conv. UZI) pp. 1251-1258,
fig. 1, pi. 1, Ed. Rosenberg & Sellier, Torino.

(12) VlGANÒ A., 1965 - Nuovi dati sui Briozoi delle acque interne italiane -

Boll. Zool. XXXII, (1965) (Atti XXXIV Conv. UZI) pp. 911-928, figs.
1-8, Ed. Rosenberg & Sellier, Turin.

(13) VlGANÒ A., 1968 - Aggiornamenti sui reperti di Briozoi dulcicoli nelle

acque italiane - Riv. Idrobiologia (Pubi. Riv. Biologia) V, 1-2, (Jan.-
Aug. 1968) pp. 33-36, Perugia.

Atti Soc. It. Se. Nat, e Museo Civ. St. Nat. Milano - 108: 258-260, 31-XII-1968

l3t I.B.A. International Conferente on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

35. Group 5: Biogeography and Biostratigraphy.

Elena I. Androsova (*)

BRYOZOA CYCLOSTOMATA AND CTENOSTOMATA
OF ANTARCTIC AND SUBANTARCTIC

(Preliminary Report)

Riassunto. — 18 specie di Cyclostomata e 2 di Ctenostomata sono state
determinate nelle collezioni della Spedizione Sovietica Antartica negli anni
1956-1958 (vascello « Ob »). I Briozoi sono stati trovati in 35 stazioni, 29
delle quali antartiche e 6 subantartiche (Isole Herd, Kerguelen, Isole Prin¬
cipe Edoardo, Isole Falkland, Patagonia e Cile meridionale).

6 specie sono nuove per l’Antartico, tra cui 3 specie nuove.

Dai dati nuovi e dei precedenti osservatori, 121 specie di Cyclostomata
e di Ctenostomata sono note ora per l’Antartico e il Subantartico. 13 però
sono dubbie e non sono state prese in considerazione in questo studio.

Summary. — 18 species of Cyclostomata and 2 Cteyiostomata were de-
termined from thè Collections of thè Soviet Antarctic Expedition in thè
years 1956-1958 (Vessel « Ob »).

The Bryozoa were found on 35 stations, 29 of which belonging to An¬
tarctic and 6 to Subantarctic (Herd isles, Kerguelen, Prince Edward isles,
Falkland isles, Patagonia and South Chile).

6 species are new for Antarctic (3 are new species).

Using our data and data of previous investigatoli, 121 species of Cy¬
clostomata and Ctenostomata are now known for Antarctic and Subantarc¬
tic. 13 of them are doubtful and are not taken into consideration in thè
analysis here given.

18 species of Cyclostomata and two of Ctenostomata had
been determined from thè collections of thè Soviet Antarctic Ex¬
pedition in thè years 1956-1958 (vessel «Ob»): Idmidronea ob-

(*) Zoologicheskii Institut Akademii Nauk SSSR, Leningrad, USSR.
Zoological Institute Academy of Sciences of U.S.S.R., Leningrad, U.S.S.R.

BRYOZOA CYCLOSTOMATA AND CTENOSTOMATA ETC.

259

teda- Borg; I. magna, sp. n. ; I. hula Borg; Idmonea atlantica For-
bes; I. pulcherrima Kirkpatrick ; Nevianipora milneana (Orb.);
Entalophora buskii Borg; E. conferta Ortmann; E. rogickiana,
sp. n. ; Entalophora sp. ; Fasciculipora ramosa Orb. ; F. meandrina
Borg. ; Fasciculipora sp., Hornera falklandica Borg ; H. smitti
Borg; H. lasarevi, sp. n., Pseudidmonea fissurata (Busk.); P. gra-
cilis sp. n. ; Alcyonidium mytili Dalyell; A. flabelliforme Kirkpa¬
trick.

The Bryozoa had been found in 35 stations, 29 of which
belong to Antarctic and 6 to Subantarctic (Herd isles, Kerguelen,
Prince Edward isles, Falkland isles, Patagonia, South Chile).

11 from thè 20 determined species had been gathered at thè
shoal of Antarctic, 7 species are from thè Subantarctic region
and two had been found both in Antarctic and Subantarctic.

Six species are new for Antarctic, three of them are described
as species novae: they are Entalophora rogickiana (in honour of
thè late Dr. Rogick), Hornera lasarevi and Idmidronea magna.
We describe also Fasciculipora sp. and Entalophora sp. ; there
was no opportunity to determine them because of poor data. The
last of thè six is Alcyonidium mytili , which was found in Suban¬
tarctic by other investigators and is widely distributed in thè
north hemisphere.

The other seven species, which we determined from Antarc¬
tic, had been found in this region before. They are Idmidronea
obtecta, I. hida, Hornera smitti, Alcyonidium flabelliforme, Fasci¬
culipora ramosa, Entalophora buskii, Idmonea atlantica.

We give three species new for Subantarctic. One of them,
Pseudidmonea gracilis, we describe as species nova. Two of them,
Idmonea pulcherrima and Entalophora conferta, were already
known from other parts of thè world. 4 other species, Ne¬
vianipora falklandica, Pseudidmonea fissurata, Fasciculipora
meandrina and Hornera falklandica were shown for this region
by previous Authors.

Using our data and data of previous investigators, 121 spe¬
cies of Cyclostomata and Ctenostomata are now known for An¬
tarctic and Subantarctic, 13 of which being doubtful. The last
are not taken into consideration in thè analysis we give.

There are altogether 59 species known from Antarctic. 22 of
them (37,3%) are found in high latitudes only and can be con-

260

E, I. ANDROSOVA

sidered as endemie of thè region. 20 species (33,9%) are known
both from Antarctic and Subantarctic and only 17 species (28,8%)
are distributed in other parte of thè World too.

In Subantarctic 49 species are known, which are not found
in Antarctic, 24 (48,9%) of which are distributed in Subantarctic
only, 25 had been found in other parte of thè Ocean.

From thè South America region 52 species are known; 13 of
which, that is 25%, are ìimited to it and 39 (75%) are found out-
side thè region also. From thè region of Tristan da Cunha there
are known 11 species, two of them being endemie. At thè isles
of Prince Edward 11 species are found, but all of them are known
from other parte of thè Ocean. At thè shoal of thè Kerguelen and
Herd isles 25 species are described, 4 of them (16%) being en¬
demie and others are characterized by broader destribution.

66 species of Bryozoa from both Antarctic and Subantarctic,
that is 61,1% — more then a half known for these regions - —
are endemie.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 261-284. 31-XII-1968

lst I.B.A. International Conferenee on Brvozoa, S. Donato Milanese, Aug. 12th-16th, 1968

36. Group 5: Biogeography and Biostratigraphy.

Frank J. S. Maturo, Jr. (*)

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA
OF THE EAST COAST OF THE UNITED STATES
EXCLUSIVE OF NEW ENGLAND

Riassunto. — 241 specie di Briozoi e 5 specie di Entoprocta sono stati
raccolti durante un’estensiva campionatura nella piattaforma continentale
atlantica tra l’Hudson Canyon e Key West.

137 specie (56% del totale) rappresentano un ampliamento della zona di
diffusione e circa 40 specie si pensa siano nuove.

Il modo di diffusione dei Briozoi mette chiaramente in luce V impor¬
tanza di Capo Hatteras come il maggiore punto di riferimento zoogeogra¬
fico e la dipendenza diretta o indiretta di questa fauna dalla Corrente del
Golfo. Soltanto il 12 % delle specie (29) sono diffuse estesamente a Nord
e a Sud del Capo. Le specie diffuse a N di Capo Hatteras comprendono
T8% del totale (19 sp.), povera cosa nella Provincia Virginiana che invece
vede ben rappresentati i gruppi bentonici. Almeno il 67% delle specie (165)
è diffuso a S di Capo Hatteras. Analisi preliminari dei dati della pro¬
fondità e della temperatura di queste specie non sembrano incoraggiare
l’ opinione circa la divisione di quest’area in Provincia Caroliniana (piat¬
taforma interna) e Provincia tropicale (piattaforma esterna).

Le tolleranze alla salinità e il substratum sembrano essere i fattori
critici che controllano la diffusione. Relativamente poche sono le specie che
si trovano negli ambienti di estuario o costieri soggetti ad abbassamenti
della salinità.

La maggioranza è stata trovata essenzialmente nell’ intera piattaforma
continentale con convenienti disponibilità del substratum come principale
fattore limitante.

La maggior parte delle specie sono limitate a plaghe isolate di de¬
positi conchigliari, di brecciame e di affioramenti di vecchie scogliere. La
maggior parte della piattaforma è un largo piano sabbioso dove si trovano
praticamente solo 4 specie: Cupuladria biporosa (71 stazioni), C. canariensis

(*) University of Florida, Department of Zoology - Gainesville, Florida,
32601 USA.

262

F. J. S. MATURO, JR.

(31 stazioni), C. doma (271 staz.) e Discoporella umbellata depressa (212
staz.).

L’attuale limite settentrionale di parte di questa fauna meridionale si
estende fino a poche miglia a N di Capo Hatteras, ma soltanto al largo
della costa nelle acque più profonde ai margini della Corrente del Golfo
e della piattaforma.

18 specie (7%) sono diffuse in direzione Nord verso la Georgia e 15
specie (69 c) non sono state raccolte più a Nord della Florida. Molte di
queste sono rappresentate da singole raccolte indicanti che sono probabil¬
mente molto rare e che la loro diffusione rimane imprecisata.

Questo studio è stato sostenuto dal NSF Grant G-24309 e dalla National
Academy of Sciences - National Research Council Senior Research asso¬
ciate con la Smithsonian Institution.

Summary. — About 241 species of Bryozoa and 5 species of Entoprocta
were collected. The major distributional patterns are clearly related to thè
barrier imposed by Cape Hatteras between thè Virginian Coastal Current
and thè Florida Current. Approximately 12% of thè species range exten-
sively north and south of Cape Hatteras; 8% reach their southern limit
and at least 67% reach their northern limit here. South of thè Cape most
of thè shelf is a broad sandy plain where 4 lunulitiform species are thè
dominant bryozoans, thè other species being limited to scattered patches of
shell litter, ballast deposits, and ancient reef outcrops.

Résumé. — Environ 241 espèces de Bryozoa et 5 espèces d 'Entoprocta
furent ramassées. Les dessins principaux de la distribution sont clairement
reliés à la barrière imposée par le cap Hatteras entre le courant de la
cote de la Virginie et le courant floridien. Environ 12% des espèces se
trouvent d’une fagon extensive au nord et au sud du cap Hatteras; 8% y
atteignent leur limite méridionale et au moins 67% y atteignent leur limite
septentrionale ici. Au sud de ce cap la plus grande partie du banc Conti¬
nental est une large piaine de sable où 4 espèces lunulitiformes sont les
bryozoaires dominants, les autres espèces étant limitées à des tàches épar-
pillées de débris d’écailles, de sédiments de lest, et d’anciens affleurements
de récifs.

Introduction.

Studies on thè bryozoan fauna of thè east coast of thè
United States have, for thè most part, been limited to collections
in thè shallow water areas immediately adjacent to thè coast,
incluaing sounds, bays, and estuaries. South of Woods Hole,
Massachusetts, these investigations have been quite limited. They
include thè reports by Hutchins (1945) on Long Island Sound;
Leidy (1855) on Rhode Island and New Jersey; Osburn (1932,
1944) on Chesapeake Bay; Verrill (1878), McDougall (1943),

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC.

263

and Pearse and Williams (1951) on North Carolina; Maturo
(1957, 1959, 1966) on North Carolina, and Florida; de Pour-
tales (1867), Smitt (1872, 1873), and Osburn (1914) on thè
Florida Keys. The greater part of thè Continental shelf in this
area has remained virtually unstudied for bryozoans except for
a tantalizing glimpse of a tropical offshore fauna in thè Beaufort,
North Carolina, region given by Osburn in scattered accounts
(notably 1940) and by Maturo (1957, 1966).

In thè summer of 1956, I received from Miss Maureen
Downey, now of thè Smithsonian Institution, and Dr. I. E. Gray,
Duke Marine Laboratory, a piece of reef rock obtained from a
Captain Fulcher of Morehead City, North Carolina. The rock
had been collected from thè « fishing banks », a series of exten-
sive reefs about 21 miles offshore in depths of 26 to 30 m
(13-15 fathoms) Southwest of Cape Lookout, North Carolina. The
main bank, as reported by Radcliffe (1914) from a survey con-
ducted by thè U. S. Fisheries Steamer Fish Haivk, lies in Lat.
34° 19' N., Long. 76° 59' W. and is thè largest reef known on
thè coast. From thè « Fulcher » rock, which measures about
37 cm on a side, were obtained an astonishing 77 species, only
8 of which were among thè 66 species previously reported for
thè Carolina coast. These species were all common inhabitants
of thè Gulf of Mexico and thè Caribbean Sea. This finding led
to thè hypothesis that thè bryozoan fauna of thè Gulf of Mexico
and Caribbean Sea reaches its northern limit off thè North
Carolina coast, perhaps at Cape Hatteras. An investigation was
started to test thè hypothesis.

Sources of Materials.

Specimens for study were obtained from a number of
sources :

Commercial shrimp boats were chartered for dredging and
trawling operations on thè Continental shelf and slope off Cape
Lookout and Cape Hatteras, and on Coastal reefs off Fernandina
Beach, Florida.

Several dredging trips off Sapelo Island, Georgia, were made
using thè facilities of thè University of Georgia Marine Institute.

264

F. J. S. MATURO, JR.

A Scuba diving team was employed to collect reef fragments
and parts of rocky outcrops south of Cape Lookout, Beaufort,
New River Inlet, North Carolina, and off Fernandina Beach,
Florida. This team provided thè most successful means of collect-
ing on rough bottom. Divers secured lines around large rocks
which were then hauled aboard by winehes.

Extensive collections of dredged material from shelf tran-
sects north and south of Cape Hatteras and Cape Lookout were
obtained through thè generosity of Dr. I. E. Gray and Dr. Maxi¬
mo Cerame-Vivas. Some collecting trips were jointly sponsored
with these colleagues.

About 500 lots (up to 25 or more species per lot) of bryo-
zoan specimens from several hundred stations off Georgia and
northern Florida were made available for studv by Mr. Milton
Gray of thè Sapelo Island Research Foundation. The station sites
ranged from thè Coastal estuaries and marshes to shelf localities
about 100 miles out.

Approximately 700 lots representing about 302 stations be-
tween thè Hudson Canyon and Kev West were received from thè
Bureau of Commercial Fisheries. This material was collected by
thè U. S. Geological Survey - Woods Hole Oceanographic Institu-
tion program of study of thè Atlantic Continental margin of thè
United States. The research vessel Gosnold occupied stations on
a grid pattern of 10 nautical miles (18 km) throughout thè length
and width of thè Continental shelf and slope in this area. Biolog¬
ica! samples were taken principally with a large (250 kg)
Campbell grab which reccvered about 0.2 cubie meter of sedi-
ments from an area of 0.6 square meter (Emory and SCHLEE,
1963).

Resumé of thè Rhysica! Environment.

The Continental shelf between Cape Cod, Massachusetts, and
Key West, Florida, has been divided by zoogeographers into three
marine provinces, namely, thè Virginian, Carolinian, and Tropi¬
ca! (Johnson, 1934; Hedgpeth, 1953; Cerame-Vivas and Gray,
1966). As revised by thè criticai study of Cerame-Vivas and
Gray, thè Virginian Province extends from Cape Cod to Cape

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC. 265

Hatteras ; thè Carolinian Province covers thè inner shelf from
Cape Hatteras to Cape Kennedy, Florida, and thè northern Gulf
of Mexico ; thè Tropical Province is thè outer shelf along thè
southeastern coast, extending as far north as thè latitude of
Oregon Inlet (north of Cape Hatteras). These provinces have
different marine climates which are established by thè circula-
tion patterns of thè Coastal water masses and major geographical
features such as prominent capes. Cape Hatteras is thè focal
point fon these provinces, serving as a boundary between cooler
northern waters and warmer southern water s. The boundary
here results from several interdependent factors which have been
succinctly summarized by Cerame-Vivas and Gray (p. 261) as
follows :

«... 1) thè Gulf Stream is closer to Cape Hatteras than
to any point north of Cape Kennedy, Florida ; thè warm Florida
Current follows thè edge of thè Continental shelf northward from
thè Straits of Florida to well north of Diamond Shoals [Cape
Hatteras] before swinging away from thè coast and away from
thè shelf ; 2) a cool Virginian Coastal Current flows southward
from Cape Cod, routinely turns seaward off Cape Hatteras,
eventually to be absorbed (Ford and Miller, 1952); 3) thè Caro¬
linian Coastal Current, probably originating in part from run-
off from thè sounds and in part from a back eddv of thè Florida
Current, flows southwesterly from Cape Hatteras (Gray and
Cerame-Vivas, 1963); 4) water masses south of Cape Hatteras
lack persistent continuity with thè water masses north of thè
Cape (Bumpus, 1955); 5) thè winter surface isotherms of this
region are closely packed, reflecting a formidable temperature
barrier during thè cooler months of thè year (Parr, 1933);
6) under certain meteorological conditions this barrier between
water masses may be broken and thè cooler waters of thè Virgin¬
ian Coastal Current then flow into Raleigh Bay [area between
Cape Hatteras and Cape Lookout], augmenting thè Carolinian
Coastal Current (Bumpus and Pierce, 1955; Gray and Cerame-
Vivas, 1963) ».

Distinctive temperature regimes are thus established in thè
three provinces, thè differences being particularly accentuated
in winter. In thè vicinity of Cape Hatteras bottoni temperatures

266

F. J. S. MATURO, JR.

in winter in thè Virginian Province have been reported to reach
as low as 4-4.5°C (Cerame-Vivas and Gray, 1966; Harrison, Nor-
cross, Pore, and Stanley, 1967), while at thè same latitude in
thè Tropical Province, bottoni temperatures were 19.5°C (Cerame-
Vivas and Gray). Winter surf ace temperature averages for thè
Carolinian and Tropical Provinces are 11-17°C and 17-23°C, re-
spectively (based on data by Anderson, Moore, and Gordy, 1961).
In summer thè surface temperature differences between thè
Carolinian and Tropical Provinces disappear so that thè water
temperature over thè whole southeastern shelf averages 26-29°C.
Cerame-Vivas and Gray report that botto-m temperatures are
only a few degrees lower, even at 200 meters. Thermal stratifi-
cation occurs in summer in thè Virginian Province; bottoni
temperatures here are usually much colder than thè surface tem¬
peratures, especially as depth increases (Harrison et al ., 1967).
A new study by Walford and Wicklund (1968) compiles monthly
surface and botto-m temperature averages from many sources ;
thè persistence of thè thermal barrier at Cape Hatteras is strik-
ingly illustrateci.

Results.

Text figure 1 shows thè stations from which bryozoans were
collected during thè Gosnold cruises. Blank spots in thè orderly
sampling pattern were also sampled but no bryozoans were recov-
ered. The number of species identified from each station is also
indicated. The other collecting sites were not plotted in thè
figure because they were sampled by non-standardized methods
(trawl and dredge) and because they were too concentrated for
thè illustration scale employed. These stations cluster principally
on either side of Cape Hatteras from Oregon Inlet to Cape
Lookout, and in a broad band across thè shelf off thè coast of
Georgia.

Fig. 1. — Map of thè study area showing thè locations of thè Gosnold
stations from which bryozoans and entoprocts were obtained. The
number in each circle refers to thè number of species found at that
station. The 200 m and 2000 m depth contours are indicated; thè
edge of thè Continental shelf corresponds roughly with thè 200 m line.

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC.

268

F. J. S. MATURO, JR.

Two hundred forty-six species have been recognized in thè
material collected (Table 1). This number will change to some
extent as final studies are ccmpleted ; some species will doubt-
lessly be combined and others divided but thè figure is reasonably
final. For purposes of comparison, thè number of species of
bryozoans and entoprocts known from other Western Atlantic
localities is :

Eastern Canada to Woods Hole: about 120

Present Study Area:
Gulf of Mexico :
Brazil :

246

216

230

In spite of thè large number of species recovered in thè
present study, a fair amount of bias in thè sampling methods
has selected against two groups of bryozoans : thè chitinous cten-
ostomes and thè oral-like species of thè cheilostome family
Reteporidae. The ctenostomes, being non-calcareous and fre-
quently inconspicuous, all but disappear when removed with their
substrate from thè water which supports them. Under these
circumstances even a well-trained eye will overlook them. The
reteporids look so much like hydrozoan corals that most sorters
will assign them as coelenterates, hence they onlv fortuitously
fall into thè hands of a bryozoolcgist. Another source of bias
derives from thè fact that relativelv few of thè station sites
were in estuaries and bays, thereby missing a number of species
which are typical of these environments. Finally, since it is
impossible to keep everything in a sample haul, only « repre-
sentative » aliquots of thè sample could be retained for exam-
ination, plus any obvious specimens which were picked out at
thè time thè haul was made. Hence uncommon species might
have been missed.

Approximately 40 species have so far defied identification
with known species and are probably new. Five of these have
now been described (Maturo, 1966; Maturo and Schopf, 1968).

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC.

209

Of thè 246 species found, 137 (56%) represent new range
extensions (Table 1). These range extensions can be categorized
as follows :

A. First records for thè western North Atlantic
Ocean :

B. First records for north of thè Straits of
Florida for species known from thè Gulf of
Mexico and thè Caribbean Sea :

C. First records north of Cape Hatteras for
species known from regions south :

D. First records for south of New England for
species known from northern regions :

E. First records for south of Cape Hatteras for
species known from northern regions :

21 species

85 species
38 species
13 species
2 species

Lest categories C and E be misleading some additional com-
ment should be made. In thè first instance, all of these « south¬
ern » species were reccvered from thè deeper water shelf areas
well offshore which are stili under thè influence of thè Gulf
Stream. In thè second case, thè two « northern » species found
south of Cape Hatteras, Alcyonidium parasiticum (Fleming) and
Cribriima punctata Hassall, should no longer be considered
northern but rather as widespread eurythermal species.

Discussion.

The zoogeographical implications of thè data are shown in
thè major groupings of Table 1 and are summarized in text
figure 2.

Twenty-nine species (12%) range extensively north and south
of Cape Hatteras. This agrees closely with thè total estimated
by Osburn (1912) to be widely distributed « cosmopolitan »
species and in fact includes essentially thè sanie species. Cerame-
Vivas and Gray (1966) found 14% of thè benthic macroinverte-
brates of thè Carolina coast to be widespread on both sides of
Cape Hatteras.

Only 8% of thè species (19) were found restricted to thè
Virginian Province in thè Hatteras area. This finding corre-

270

F. J. S. MATURO, JR.

sponds well with a similar paucity of characteristic species in
this province reported by Cerame-Vivas and Gray. They found
a low 11.4% of thè species in this category.

At least 67% of thè species (165) range from thè vicinity
of Cape Hatteras southward. The total should be compared with
thè total of 27 species known to have this distribution prior to
this report. The actual northern limit of pari of this southern
fauna extends a few miles north of thè Cape, but only offshore
in thè deeper waters at thè edge of thè Gulf Stream and thè shelf.

As pointed out earlier Cerame-Vivas and Gray divided thè
shelf in this region into a Carolinian and a Tropical Province.
The boundary between these provinces was estimated by analysis
of bottoni temperatures and thè affinities of thè faunal assem-
blages from each collecting station. Likewise, each station was
assigned to a particular province. The bryozoan material from
sixteen of these stations both north and south of Cape Hatteras
was examined by me and then each station was independently
assigned to a province. Fi ve were attributed to thè Virginian
Province and 11 to thè Tropical Province. The designations
agreed perfectly with assignments of these stations by Cerame-
Vivas and Gray (personal communication). Preliminary analysis
of thè distribution of thè species from thè « Tropical Province »
stations does not appear to show any of them limited to thè outer
shelf. Instead they seem to be widespread over thè shelf wher-
ever suitable substrates can be found. Since these species are
known to occur in thè Gulf of Mexico, Straits of Florida, and
thè Caribbean Sea, I am unable to recognize a Carolinian Prov¬
ince at thè present time. Is is unfortunate that I could not
examine material from stations whose other fauna led Cerame-
Vivas and Gray to assign them to thè Carolinian Province.

Nevertheless, another striking agreement does exist between
thè two studies. If one combines thè percent of species in thè
present study which range from Cape Hatteras south with thè
percent of thè remaining two categories (see below) adjusted
for shelf species only, thè result is that 76% of thè total number
of species most probably reach their northern limit at Cape Hat¬
teras. The adjusted figure from Cerame-Vivas and Gray is 74.4%
after combining thè percent of species limited to thè Tropical

THE DISTRIBUTIONAL PATTERN 0 F THE BRYOZOA ETC.

271

Province (34.6%), thè percent of species limited to thè Carolin-
ian Province (23.7%), and thè percent common between them
(16.1%).

Fig. 2. — Distribution of bryozoan and entoproct species in thè
marine benthic provinces in thè Cape Hatteras region. The distri¬
bution of species from other parts of thè shelf is also summarized.

Contour is 200 m.

Eighteen species (7%) were found no farther north than
Georgia. Additional collecting would probablv extend thè recor ds
of nine species to thè vicinity of Cape Hatteras. The remaining
nine are not shelf species but were collected from thè Blake
Plateau.

F. J. S. MATURO, JR.

272

Fig. 3. — Distribution of Gosnolcl
stations where Discoporella umbel¬
lata depressa (Conrad) was found.
The 200 m contorti' is indicated.

Fig. 4. — Distribution of Gosnold
stations where Cupuladria doma
(d’Orbigny) was found. The 200 m
contour is indicated.

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC.

273

Fig\ 5. — Distribution of Gosnold
stations where Cupuladria biporosa
Canu & Bassler was found. The
200 m contour is indicated.

Fig\ 6. — Distribution of Gosnold
stations where Cupuladria canarien-
sis (Busk) was found. The 200 m
contour is indicated.

274

F. J. S. MATURO, JR.

Fig. 7. — Distribution of Gosnold
stations where Mamillopora cupula
Smitt was found. The 200 m contour
is indicated.

Fig\ 8. — Distribution of Gosnold
stations where Hippopleurifera mu¬
cronata (Smitt) was found. The 200 m
contour is indicated.

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC.

275

Fifteen species (6%) were collected only off Florida. Many
of these are represented by single collections, indicating that thè
species are probably very rare. Range limits are obviously diffi-
cult to determine under these circumstances.

The study clearly demonstrates thè effectiveness of Cape
Hatteras as a barrier to thè dispersal of bryozoans and thè depen-
dence of a major portion of this fauna directly or indirectly on
thè Gulf Stream. The resulta, however, do not resolve thè ques-
tion of whether or not some species common to both thè Beaufort
area and thè Gulf of Mexico have a disjunct distribution, i. e.,
are absent from thè stenohaline (high salinity) area of peninsular
Florida. Thorough investigations of thè inlets and estuaries of
that area are lacking but are being planned. One of thè most
often cited examples of disjunct distribution, Hippoporina
(= H ippo dipi o sia) americana (Verrill), in fact does not occur
south of Cape Hatteras, and thè southern citations of what was
thought to be this species confuse at least two species (Maturo
and Schopf, 1968).

Salinity tolerances and substrate seem to be thè criticai
fa-ctors affecting distribution. Relati vely few species occur in
estuar ine or nearshore environments subject to lowered salinity.
These are thè 29 species with widespread distribution both north
and south of Cape Hatteras. As noted from text figure 1, bryo¬
zoans were found at practically all Gosnold stations south of
Cape Hatteras. The great variety of species found on thè shelf
in this area is by no means evenly distributed; thè presence or
absence of species clearly reflects thè type of bottom (substrate)
being sampled. Areas of ancient reef outcrops, ballast deposits,
or shell litter are inhabited by a remarkable number of species,
for example, thè 77 species on thè « Fulcher » rock or 28 species
on a 10 cm pelecypod valve. However, most of thè shelf here is
a broad, sandy plain where virtually only four species occur:
Discoporella umbellata depressa (Conrad) at 212 stations (fig. 3),
Cupuladria doma (d’Orbigny) at 271 stations (fig. 4), Cupuladrìa
biporosa Carni and Bassler at 71 stations (fig. 5), and Cupuladria
canariensis (Busk) at 31 stations (fig. 6). These well-known lu-
nulitiform species frequently occur in great numbers and are char-
acteristic of stable sandy bottoms in various parts of thè Atlan-

276

F. J. S. MATURO, JR.

Table I.

Preliminary list of species collected. Species are arranged alphabetic-ally by
order g-roups under thè geographical ranges. New range records are indi-
cated by an asterisk and thè nearest previous report is given. The
scientific names assigned are in some cases tentative working names subject
to revision as current systematic studies proceed.

Species

Nearest Previous
Report

Species

Nearest Previou
Report

Species ranging extensively north and south of Cape Hatteras:

Aetea anguina (Linnaeus)

*Bugula fulva Ryland
*Bugula stolonìfera Ryland
Bugula turrita Desor
* Chorizopora brongniarti
( Audouin)

Cleidochasma contractum
( Waters)

*Conopeum reticulum

(Linnaeus)

* Cribrilina punctata Hassall
Electra hastingsae Marcus
Hippoporidra sp.

* Hippoporina porosa (Verrill) Massachusetts
Hippoporina verrilli Maturo
& Schopf

Hippoporina sp. « A »

Membranipora tennis Desor
Microporella ciliata (Pallas)

Parasmittina nitida (Verrill)

Schizoporella cornuta Gabb &

Horn

Species ranging from Cape Hatteras north:

* Amphiblestrum flemingi

(Busk) Massachusetts

* Amphiblestrum quadrata

(Hincks) Bay of Fundy

'■'Amphiblestrum ? septentriona-

lis (Kluge) Gulf of St. Lawrence

^Callopora craticula (Alder) Massachusetts

* Callopora dumerilli (Audouin) Maine

Callopora sp.

Schizoporella « unìcornis »

auctt.

Tessaradoma gracile (Sars)

Turbicellepora clichotoma

(Hincks)

Aeverrillìa armata (Verrill)

Aeverrillia setìgera (Hincks)

* Alcyonidium parasiticum

(Fleming) Massachusetts

Alcyonidium polyoum
(Hassall)

Amathia ridonici (Heller)

Angumella palmata van
Beneden

Bowerbankia gracilis Leidy

Barentsia timida Verrill
Barentsia laxa Kirkpatrick
Pedicellina cernua (Pallas)

* Cellaria fistulosa auctt. Massachusetts

Celleporella hyalina
(Linnaeus) 1

Cryptosula pallasìana (Moli)1
Electra hastingsae Marcus 1
* Electra pilosa (Linnaeus) Chesapeake Bay

* Haplota clavata (Hincks) Massachusetts

Hippoporina americana
(Verrill)

Britain

Gulf of Mexico

Beaufort, N. C.
Massachusetts

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC.

(

Species

Nearest Previous
Report

Species

Nearest Previous
Report

Scruparia ambigua

Alcyonidium verrilli Osburn

(d’Orbigny)

Massachusetts

* Arachnidium fibrosum Hincks Britain

Tegella unicornis (Fleming*)

Massachusetts

Triticella elongata (Osburn)1
Crisia eburnea (Linnaeus)

Species ranging from Cape Hatteras south:

'Aetea ligulata (Busk)2
: Aetea sica (Couch)

■Aetea ‘Hruncata
(Landsborough) 2
Aimulosia sp. « B »

'Alderìna smitti Osburn
Allantopora sp.

'Antropora tincta (Hastings)

’Aplousina gigantea Canu &
Bassler 2

: Arthropoma Cecili (Audouin)
'Arthropoma circinata (Mac-
Gillivray)

'Beania hirtissima (Heller)

Puerto Rico
Tortugas

Tortugas

Straits of Florida

Panama (Pacific
coast)

Beaufort, N. C.
Gulf of Mexico

Tristan de Cunha
Gulf of Mexico;
Bermuda

Beania intermedia ( Hincks)

'Bellulopora bellula (Osburn) Gulf of Mexico
Bracebridgia subsulcata
(Smitt)

Bugula marcusi Maturo
Bugula microoecia Osburn Tortugas
Bugola neritina (Linnaeus)

'Caberea boryi (Audouin)

ICalyptotheca sp. « A »

Caulibugula dendrograpta
(Waters)

Caulibugula pearsei Maturo
'« Cellepora » coronata Smitt Straits of Florida
Celleporaria albirostris
( Smitt)

: Celleporaria ? aperta (Hincks)

Celleporaria sp. « B »

Celleporaria magnifica
(Osburn)

Celleporina hassalli ( Johnston)

Straits of Florida

Gulf of Mexico

Tortugas; Bermuda

Straits of Florida
Indian Ocean

Chaperia sp.

* Cigclisula serrulata (Smitt) Gulf of Mexico
*Cig elisola turrita (Smitt) Straits of Florida

*Cleidochasma porcellanum

(Busk)2 Straits of Florida

*« Coleopora » tubolosa (Canu

& Bassler) Straits of Florida

*Copidozoum tenuirostre

(Hincks) Straits of Florida

■Crassimar girateli a leucocypha

Marcus2 Gulf of Mexico

* C i assimarg inai ella pyriformis

(Canu & Bassler) Panama (Pacific

coast)

* Crassimar ginat ella tuberosa

(Canu & Bassler)1 Straits of Florida

*Crepidacantha poissoni teres

Hincks" Gulf of Mexico;

Bermuda

Crepida cantila s et ig era

( Smitt) 2 Straits of Florida

CCrib rii aria radiata (Moli)2 Beaufort, N. C.

* Cribrilina floridana Smitt Straits of Florida
*Cupuladria biporosa Canu &

Bassler Gulf of Mexico

* Cupuladria cana rieri sis

(Busk) Florida

|* Cupuladria doma (d’Orbigny) 2 Beaufort, N. C.

Cupuladria loweni (Gray)

'■'Cycloper iella rubra Canu &

Bassler 2 Caribbean Sea

*Discoporella umbellata depres¬
sa (Conrad)2 Beaufort, N. C.

Drepanophora tubercolata

(Osburn) Tortugas

-■'E schar ina pesanseris (Smitt) 2 Miami, Florida

278

F. J. S. MATURO, JR.

Species

Nearest Previous
Report

Species

* E sellar ina vulgaris (Moli) 2 Gulf of Mexico
*Exechonella antillea (Osburn) Miami, Florida
*Exochella longirostris Jullien Gulf of Mexico
*Fenestrulina malusi

(Audouin)2 Gulf of Mexico;

Bermuda

*Floridina antiqua (Smitt)2 Miami, Florida
*Floridina parvicella Canu &

Bassler

*Gemelliporella glabra (Smitt)
*H- ippa l iosina rostrigera

( Smitt)

*H ippopleurif era mucronata
( Smitt)

*Hippopodina bernardi
Lagaaij 2

*H ippoporella floridana
Osburn

*H ippoporella palliolata
(Canu & Bassler)

H ippoporella uvulifera
(Osburn)

*Hippoporidra calcarea
( Smitt) 2

* IHippoporina aculeata (Canu
& Bassler) 2
* Hippothoa flagellum
Manzoni 2

* Labioporella granulosa (Canu
& Bassler)

*« Lagenipora » verrucosa
Canu & Bassler 2
« Lagenipora » sp.
*Mamillopora cupida Smitt
*Mastigophorella porosa
( Smitt) 2

* Membranipora arborescens
(Canu & Bassler) 2
Membranipora savarti

(Audouin)

Membranipora tuber culata
(Bosc) 2

* M e rubi " anip or ella aragoi
(Audouin) 2

Gulf of Mexico
Miami, Florida
New River Inlet,

N. C.

Florida

Gulf of Mexico
Gulf of Mexico
Straits of Florida

Florida

Miami, Florida
Tortugas

Straits of Florida
Straits of Florida
Straits of Florida
Miami, Florida
Beaufort, N. C.

Brazil

* Micropor a coriacea

(Johnston) 2
Microporella sp. « G »

* Micropor ella marsupiata

(Busk) 2

* Microporella pontifica
Osburn 2

* Microporella tractabilis Canu
& Bassler2

* Molila patellaria Smitt

* Monopor ella divae Marcus
*« Myriozoum » ovum Smitt
*Nellia tenella (Lamarck)
*Parasmittina crosslandi

(Hastings)

*Parasmittina fraseri Osburn

* Para smitt ina numma

(Marcus) 2

*Parasmittìna signata
( Waters)

Parasmittina sp.

* Par a smitt ina spathulata

(Smitt)2

Parasmittina sp. « X »
Parasmittina sp. « Y » 2
* Parellisina curvirostris
( Hincks) 2

* Parellisina latirostris Osburn
*Petr alleila bisinuata (Smitt)
*« Phylactella » aviculif era
Osburn 2

*Reptadeonella violacea
(Johnston) 2
Retevirgula sp. « A »
'•'Retevirgula sp. « B » ( peri -
porosa auctt)

* Retevirgula caribbea
(Osburn)

Rhynchozoon rostratum
(Busk)

* Schizoporella canni Osburn 2

Nearest Previous
Report

Straits of Floride

Madeira

Gulf of Mexico

Gulf of Mexico
Florida

Gulf of Mexico
Florida Keys
Tortugas

Panama (Pacific
coast)

Mexico (Pacific
coast)

Brazil

Gulf of Mexico

Miami, Florida

Cuba

Gulf of Mexico
Straits of Floridi

Tortugas
New River Inlet,
N. C.

Gulf of Mexico
Gulf of Mexico

Straits of Floridi

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC.

279

Species

Nearest Previous
Report

Species

Nearest Previous
Report

Schizoporella carvalhoi

Marcus 2 Brazil

Schizoporella floridana

Osburn

Schizoporella rugosa (Osburn) Puerto Rico
Scrupocellaria bertholleti

(Audouin) Tortugas; Bermuda

Scrupocellaria harmeri

Osburn

Scrupocellaria regularis
Osburn

Setosellina goèsi (Silen)
Smittina smittiella Osburn

Gulf of Mexico
Straits of Florida;
Bermuda

Straits of Florida
Gulf of Mexico

Smittipora levinseni (Canu &

Bassler) Straits of Florida

■ Smittoidea reticulata (Mac-

Gillivray) Gulf of Mexico

'Stephano sella {Buf fondiaria) Straits of Florida;
divergens (Smitt)2 Bermuda

■'Stylopoma informata

(Lonsdale) Tortugas

Synnotum aegyptiacum
(Audouin)

Tetraplaria dichotoma
(Osburn)

Thalamoporella falcifera
(Hincks)

Thalamoporella gothica flori¬
dana Osburn

* Tremo gas ferina granulata

Canu & Bassler Straits of Florida

*Tremoschizodina lata (Smitt) Straits of Florida
*Triporula stellata (Smitt)2 Tortugas
* Trypostega venusta Norman 2 Straits of Florida
ITurbicellepora sp. « A »

Turbicellepora margaritacea
(Pourtales)

*Vittaticeìla contei (Audouin) Puerto Rico;

Bermuda

Cribrilinidae A
Hippoporinidae A
?Hippoporinidae

Schizoporellidae A 2
Schizoporellidae B
Smittinidae A
Smittinidae : Porella -like

Alcyonidium sp. « A »

Alcyonidium hauffi Marcus
Alcyonidium mamillatum

Alder

Amathia alternata Lamouroux
Amathia convoluta Lamouroux
Amathia distans Busk
Arachnidium sp.

* Arachnoidea evalinae

Marcus Brazil

Arachnoidea sp.

socialis Hincks Britain; Brazil

Nolella dilatata (Hincks)

Nolella gigantea (Busk)

Sundanella sibogae (Harmer)

ITerebripora sp.

Zoobotryon verticillatum
(delle Chiaje)

C risia sp. « A »

C risia sp. « B »

*Crisulipora occidentalis

Robertson Brazil

Crisulipora l orientai is Canu
& Bassler

Diaperoecia floridana Osburn
Dìaperoecia rugosa Osburn Puerto Rico

r Entalophora delicatula (Busk) Straits of Florida

* Lichenopora buskiana Canu &

Bassler Panama (Pacific

coast)

* Lichenopora floridana (Canu

& Bassler) Gulf of Mexico

Lichenopora sp.

* Plagioecia dispar Canu &

Bassler 2 Straits of Florida

280

F. J. S. MATURO, JR.

Species

Nearest Previous
Report

Species

Nearest Previous
Report

*?Plagioecict floridann (Canu

& Bassler) Straits of Florida

*Platonea arcuata (Canu &

Bassler) Straits of Florida

Prob oscina sp. « A »

‘IStomatopora sp.

* Pervia pourtalesi (Smitt)
Tubulipora sp. « A »
Cyclostomata B

*Loxos omelia Mota Nielsen

Straits of Florida

Miami, Florida

Species ranging northward to Georgia but not collected farther north; species found off Georg'ia only:

lAlderina sp.

*Brettìa cornigera Busk 1 2 3 British Virgin

Islands

Bugula grayi Maturo
Bugula rylandi Maturo
Caulìbugula sp.

*Codonel lina moni ferrandi

(Audouin) Gulf of Mexico

Porella sp. « A » 3
« Schizellozoon » elongatum
Canu & Bassler3
* Sertella marsupiata ( Smitt) 3
Smittoidea sp. 3 Straits of Florida

Species found off Florida only:

* Calyptotheca tornata Harmer Philippines
* Coleopora americana Osburn Puerto Rico
*Columnella brasiliensis

( Busk) 4 Puerto Rico

Hippoporella pusilla (Smitt)

Hippothoa « eburnea » (Smitt)

‘ÌHippothoa sp.

Margaretta cereoides
(Solander)

'•'Micropor ella o rien t a lis

Harmer Panama (Pacific

coast)

* Steganoporella magnilabris Straits of Florida;
(Busk) Bermuda

*« Trematooecia » turrita

Osburn (not Smitt) Puerto Rico

Celleporidae A3
Farciminariidae A3
Flustridae : IChartella 3

Alcyonidium sp. « B »

IHornera sp. 3

Loxocalyx sp.

Parellisina sp.

'fRhynchozoon solidum Osburn Tortugas

* T remogasterina malleolus

Canu & Bassler Gulf of Mexico

Flustridae A 3
Schizoporellidae C

Buskia sp.

Crisia elongata Milne Edwards

1 Found south of Cape Hatteras to Beaufort, N. C., area in shallow waters
immediately adjacent to thè shore.

2 Found north of Cape Hatteras in Tropical Province.

3 From Blake Plateau ; not a shelf species.

Off shelf in Straits of Florida.

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC.

281

tic shelf (Lagaaij, 1963; Marcus and Marcus, 1962; Cook, 1963,
1965a, 1965b, 1965c). They have somehow escaped appropriate
attention for a major component of thè fauna of thè southeast
coast of thè United States. Interestingly, these species must re-
present thè only firm substrate larger than a sand grain in some
areas and are themselves used as a substrate for other bryozoans
and entoprocts. It was a fairly common occurence to find Ba-
rentsia laxa Kirkpatrick, or a small ctenostome or cheilostome
growing on them.

Mamillopora cupula Smitt has a growth form similar to thè
cupuladrias and is found in thè same habitat (fig. 7). It is not
nearly as common as these and tends to be restricted more to
thè outer shelf.

Finally, after having examined such a large collection from
essentially one region, thè southeast coast, I was left with thè
distinct impression that shell litter from thè shelf in this area
had a characteristic appearance. This seemed to be thè result of
being incrusted with a common bryozcan assemblage, thè most
conspicuous species being Hippopleurif era mucronata (Smitt).
This species has a bright red-brown to red orange color and forms
characteristic patches on shell debris. It is much more common
and widespread on thè southeast shelf than is shown by its dis-
tribution in thè Gosnold collections (fig. 8). Most shell samples
in thè M. Gray - Sapelo Collection from thè broad shelf off Geor¬
gia contained this species.

Acknowledgments.

I wish to recognize thè generous contribution of specimens made by
Dr. Maximo Cerame-Vivas, University of Puerto Rico, Dr. I. E. Gray,
Duke University, thè late Mr. Milton Gray, Sapelo Island Research Foun¬
dation, Dr. R. L. Wigley, Bureau of Commercial Fisheries, and Miss Mau-
reen Downey, Smithsonian Institution. Special thanks are extended to Miss
Patricia L. Cook, British Museum (N. H„), whose gracious hospitality, re-
markable patience, and generous contribution of time and knowledge made
thè satisfactory completion of museum comparisons possible. I am indebted
to Dr. David Pawson and Dr. A. Andersson for facilities provided at thè
U. S. National Museum and thè Naturhistoriska Riksmuseet, Stockholm,
respectively. I wish to thank Miss Downey for her help with thè USNM
collections; Dr. H. K. Brooks, Herbert Eppert, and Reginald Scolaro of

282

F. J. S. MATURO, JR.

thè Geology Department, University of Florida, who rendered valuable
Services as a SCUBA diving diving team; thè Duke Marine Laboratory
and thè University of Georgia Marine Institute for providing generous use
of their facilities; Dr. Thomas Hopkins, Mr. Arnold Ross, and especially
Dr. Scolaro, for invaluable aid as research assistants.

This study was supported by an NSF Postdoctoral Fellowship at thè
Duke Marine Laboratory, by NSF Grant G-24309, and by a National Acad-
emy of Sciences - National Research Council Research Associateship at thè
Smithsonian Institution. The manuscript was prepared during tenure of a
Visiting Research Associateship at thè University of Georgia Marine Institute.

REFERENCES

Anderson W. W., Moore J. E. & Gordy H. R,, 1961 - Water Temperatures
off thè South Atlantic Coast of thè United States, Theodore N. Gill
Cruises 1 - 9, 1953-54 - U. S. Fish & Wildlife Service Spec. Sci. Rept.,
Fisheries No. CCCLXXX, pp. 1-206.

Bumpus D. F., 1955 - The Circulation over thè Continental Shelf south of
Cape Hatteras - Trans. Amer. Geophys. Union, XXXVI, pp. 601-611.

Bumpus D. F. & PiERCE E. L., 1955 - The Hydrography and Distribution of
Chaetognaths over thè Continental Shelf off North Carolina - Pa-
pers Mar. Biol. Oceanogr. Deep Sea Res., Ili (Suppl.), pp. 92-109.

Cook P. L., 1963 - Observations on Live Lunulitiform Zoaria of Polyzoa -
Cah. Biol. Mar., IV, pp. 407-413.

Cook P. L., 1965 a - Notes on thè Cupuladriidae (Polyzoa, Anasca) - Bull.
Brit. Mus. (N. H.) Zool., XIII, No. V, pp. 151-188.

Cook P. L., 1965 b - Polyzoa from West Africa. The Cupuladriidae - Bull.
Brit. Mus. (N. H.ì Zool.. XIII, No. VI, pp. 189-228.

Cook P. L., I965 c - Notes on Some Polyzoa with Conical Zoaria - Cah.

Biol. Mar., VI, pp. 435-454.

Cerame-Vivas M. J. & Gray I. E., 1966 - The Distributional Pattern of
Benthic Invertebrates of thè Continental Shelf off North Carolina -
Ecology, XLVII, No. II, pp. 260-270.

Emory K. O. & Schlee J. S., 1963 - The Atlantic Continental Shelf and Slope,
a Program for Study - Geol. Surv. Cir. CDLXXXI, pp. 1-11.

Ford W. L. & Miller A. R., 1952 - The Surf ace Layer of thè Gulf Stream

and Adjacent Waters - Jour. Mar. Res., XI, pp. 267-280.

Gray I. E. & Cerame-Vivas M. J., 1966 - The Circulation of Surface Waters
in Raleigh Bay, North Carolina - Limnol. and Oceanogr.., Vili,
pp. 330-337.

Harrison W., Norcross J. J., Pore N. A. & Stanley E. M., 1967 - Circu¬
lation of Shelf Waters off thè Chesapeake Bight - U. S. Dept. Com¬
merce, ESSA Prof. Paper, III, pp. 1-82, 5 maps.

THE DISTRIBUTIONAL PATTERN OF THE BRYOZOA ETC.

283

Hedgpeth J. W., 1953 - An Introduction to thè Zoogeography of thè Northern
Gulf of Mexico with reference to thè Invertebrate Fauna - Pubi.
Inst. Mar. Sci., Ili, pp. 111-124.

Hutchins L. W., 1945 - An Annotated Checklist of thè Saltwater Bryozoa
of Long Island Sound - Trans. Conn. Acad. Arts Sci., XXXVI, pp.
533-551.

Johnson C. W., 1934 - List of Marine Mollusca of thè Atlantic Coast from
Labrador to Texas - Proc. Boston Soc. Nat. Hist., XL, pp. 1-204.

Lagaaij R., 1963 - Cupuladria canariensis (Busk) - Portrait of a Bryo-
zoan - Palaeont. VI, Pt. I, pp. 172-217.

Leidy J., 1855 - Contributions toward a Knowledge of thè Marine Inver¬
tebrate Fauna of Rhode Island and New Jersey - Jour. Acad. Nat.
Sci. Philadelphia, ser. 2, III, pp. 135-152.

Marcus E. & Marcus E., 1962 - On some Lunulitiform Bryozoa - Boi. Fac.
Fil., Cièn. Letr. Univ. S. Paulo, No. CCLXI, Zoologia XXIV, pp. 281-
324.

Maturo F. J. S., Jr., 1957 - A Study of thè Bryozoa of Beaufort, North
Carolina, and Vicinity - Jour. Elisha Mitchell Sci. Soc., LXXIII, No. I,

pp. 11-68.

Maturo F. J. S., Jr., 1959 - Seasonal Distribution and Settling Rates of
Estuarine Bryozoa - Ecology, XL, No. I, pp. 116-127.

Maturo F. J. S., Jr., 1966 - Bryozoa of thè Southeast Coast of thè United
States: Bugulidae and Beaniidae (Cheilostomata : Anasca) - Bull.
Mar. Sci., XVI, No. Ili, pp. 556-583.

Maturo F. J. S., Jr., 1959 - Seasonal Distribution and Settling Rates of
Type Material : Reexamination of Species from New England and Ber¬
muda named by A. E. Verrill, J. W. Dawson, and E. E. Desor - Po¬
stilla, No. CXX, pp. 1-95.

McDougall K. D., 1943 - Sessile Marine Invertebrates at Beaufort, North
Carolina - Ecol. Mon., XIII, pp. 321-374.

Osburn R. C., 1912 - The Bryozoa of thè Woods Hole Region - Bull. Bur.
Fish., XXX, pp. 201-266.

Osburn R. C., 1914 - Bryozoa of thè Tortugas Islands, Florida - Carnegie
Inst. Wash. Pubi., CLXXXII, pp. 181-222.

Osburn R. C., 1932 - Bryozoa of Chesapeake Bay - Ohio Jour. Sci. XXXII,
pp. 441-476.

Osburn R. C., 1940 - Bryozoa of Porto Rico with a Resumé of thè West
Indian Bryozoan Fauna - N. Y. Acad. Sci., Sci. Surv. Porto Rico
and Virgin Islands, XVI, pp. 321-486.

Osburn R. C., 1944 - A Survey of thè Bryozoa of Chesapeake Bay - Mar¬
yland Dept. Res. and Educ. Pubi. LXIII, pp. 1-59.

Parr A. E., 1933 - A Geographic-ecological Analysis of thè Seasonal Chan-
ges in Temperature Conditions in Shallow Waters along thè Atlantic
Coast of thè United States - Bull. Bingham Oceanogr. Coll., IV,
No. Ili, pp. 1-90.

284

F. J. S. MATURO, JR.

Pearse A. S. & Williams L. G., 1951 - The Biota of thè Reefs off thè Car-
olinas - Jour. Elisha Mitc-hell Sci. Soc., LXVII, pp. 133-161.

Pourtales L. F. de, 1867 - Contributions to thè Fauna of thè Gulf Stream
at Great Depths - Bull. Mus. Comp. Zool., I, pp. 106, 110, 111.

Radcliffe L., 1914 - The Offshore Fishing Grounds of North Carolina -
U. S. Bur. Fish. Econ. Cir., No. Vili, pp. 1-6.

Smitt F. A., 1872 - Floridan Bryozoa, collected by Count L. F. de Pourtales.
Part I - Kongl. Svenska Vetensk. Akad. Handl., X, No. XI, pp. 1-20.

Smitt F. A., 1873 - Floridan Bryozoa, collected by Count L. F. de Pourtales.
Part II - Kong’l. Svenska Vetensk. Akad. Handl., XI, No. IV, pp. 1-84.

Verrill A. E., 1878 - In: Coues and Yarrow - Notes on thè Naturai History
of Fort Macon, North Carolina, and Vicinity - Proc. Acad. Nat. Sci.
Philadelphia, pp. 304-305.

Walford L. A. & Wicklund R. I., 1968 - Monthly Sea Temperature Struc-
ture from thè Florida Pleys to Cape Cod. - Serial Atlas of thè Ma¬
rine Environment, Folio XV.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 285-294. 31-XII-.1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

37. Group 5: Biogeography and Biostratigraphy.

Ariadna Mikhailovna Yaroshinskaya (*)

THE EARLY DEVONIAN
AND EIFELIAN BRYOZOA FROM THE ALT AI

(Translated from Russian into Eng’lish by S. R. Raskolenko)

Riassunto, — I depositi devonici dei Monti Aitai, nella regione del sincli-
norio « Anuiski-Chuiski », contengono una fauna varia ed abbondante, in
gran parte rappresentata da Briozoi.

Uno studio paleontologico-stratigrafico dettagliato e la raccolta in serie
di Briozoi in sezioni diverse per facies hanno permesso di precisare la loro
distribuzione temporale ed areale.

I risultati dello studio sui Briozoi sono qui comparati con i dati degli
studi sui Brachiopodi, sui Coralli, sugli Stromatoporoidei, sui Pesci e sulla
Flora.

Questo studio ha permesso di effettuare una serie di sostanziali retti¬
fiche nello schema del Devonico dell’Altai, confermato nel 1964 nella Con¬
ferenza sulla Stratigrafia della Siberia centrale.

Uno studio monografico sui Briozoi infradevonici ed eifeliani dei depo¬
siti del sinclinorio « Anuiski-Chuiski » ha permesso di stabilire quattro com¬
plessi a Briozoi in successione, dei quali tre appartengono ad un’età infra-
devonica ed il quarto mostra affinità con 1 Eifeliano.

Vengono descritte alcune particolarità della forma della colonia, dello
scheletro e della struttura parietale dei Briozoi devonici di questa regione
e la loro stretta dipendenza con le condizioni di vita.

Si fanno considerazioni su una particolare diffusione geografica dei
Briozoi in periodi diversi dell’esteso Devonico inferiore e medio.

Summary. — A various and abundant fauna, mostly composed by Bryo¬
zoa, is present in thè area of thè Anuiski-Chuiski Synclinorium (Aitai
Mountains).

A detailed paleontological and stratigraphical study and a collected
succession of Bryozoa samples in sections with different facies permitted
me thè observation of their chronological and geographical ranges.

(*) Ob-Irtishskaya Ekspediziya, Tomsk, USSR.

286

A. M. YAROSHINSKAYA

The results of thè study on Bryozoa are here compared with thè results
of thè studies on Brachiopoda, Corals, Stromatoporoidea , Fishes and Flore.
This study allowed me to essentially modificate thè Devonian scheme of
Aitai, confirmed in 1964 during thè Conference on thè Middle Siberia
Stratigraphy.

A monographical study on Early Devonian and Eifelian Bryozoa from
thè deposits of Anuiski-Chuiski Synclinorium enabled me to establish a
succession of four Bryozoa units, three of which belonging to Early Devo¬
nian and thè fourth showing Eifelian affinity.

Some peculiarities of asty, skeletal and wall structures of Devonian
Bryozoa of this area and their dose relationships with growth conditions
are here reported.

Remarks on a peculiar geographical distribution of Bryozoa in different
periods of thè widespread Early and Middle Devonian are here made.

(Italian and English summaries were translated by E. Annoscia from
thè Russian Author’s abstract).

The most complete and wide deposits of thè lower Devon
and Eifelian are represented in thè North and Central Aitai
within thè limits of Anuiski-Chuiski synclinorium. In thè lower
Devon of thè Aitai thick terrigenous series with bands and ben-
ches of limestones are widespread. Their abundant and variable
fauna of Brachiopods, Pelecypods, Trilobites, Bryozoa, Rugosa
Corals, Stromatoporoids and others is known. From thè terrige¬
nous deposits of thè Ganin spring and thè Peschanaya River thè
Brachiopods, Pelecypods and Trilobites were studied and des-
cribed by L. L. Khalfin (L. L. Khalfin, 1948, 1967). On thè
evidence of this fauna L. L. Khalfin in thè lower Devon of
Anuiski-Chuiski synclinorium described three series and referred
them to Siegenian stage (Ganin series), to lower Coblenzian
(Kondratjev series) and to upper Coblenzian (Medvedevskaya
series).

N. L. Bublichenko (1951) had contrary opinion. He referr¬
ed all these series to Eifelian stage. Last time E. A. Elkin and
R. T. Grazianova (1967) were of thè same opinion. We collected,
studied and described Bryozoa from thè deposits studied by L. L.
Khalfin (Ganin series) and by E. A. Elkin (deposits along thè
Ganin spring and thè Kuvash River).

Four complexes of Bryozoa are given below:

1. from thè deposits of thè Ganin series (pseudotogatovyi
and paramnigenievyi horizons of Siegenian age by L. L. Khalfin;

THE EARLY DEVONIAN AND EIFELIAN BRYOZOA FROM THE ALTAI

287

kireevsky and matveevsky horizons of Eifelian age by E. A.
Elkin) ;

2. from thè lower Devonian limestones of thè Ganin spring
(Ganin horizon of thè lower Devon by E. A. Elkin);

3. from thè Kuvash series (from thè Kuvash River - Ku-
vash horizon of Eifelian by E. A. Elkin);

4. from thè middle Devonian limestones of thè Ganin
spring (Kuvash horizon of thè Eifelian by E. A. Elkin).

The complex of Bryozoa from thè stratotype of thè Ganin for-
mation on thè right bank of thè Ganin spring is thè oldest (table 1).
There Bryozoa are developed in thè terrigenous rocks which con-
sist of green-grey limestone siltstones. Trepostomes are abund-
ant. The following species are given:

Gamella frequens Yaroshinskaya
Lioclema subramosum Ulrich et Bassler
Pseudobato stornella spinata Astrova
Leptotrypella semiramosa Astrova
Eridotrypa minuta Astrova
Eridotrypa vestirà Yaroshinskaya
Ensipora tennis (Hall).

Species Lioclema subramosum Ulr. et Bassler and Ensipora
tennis (Hall) are known from thè lower Gelderberg of North
America, from burubaiski horizon (Siegen) of Kazakhstan and
from thè Bolsheneverskaya formation of thè lower Devon of
upper Priamurjya.

Species Eridotrypa minuta Astr., Pseudobato stornella spinata
Astr., Leptotrypella semiramosa Astr., are known from thè bors-
hovski horizon of Podolia. The deposits developed above thè
Ganin spring and referred by E. A. Elkin to thè matveevsky
and kuvashsky horizons are analogous of thè Ganin forma¬
tion. Here, beside new species, abundant representatives of thè
species Lioclema subramosum Ulr. et Bassi., Ensipora tennis
(Hall) and also such species as Paralioclema morosovae Astr. and
Fistidipora orbicidata Astr. are discovered. They are known from
thè barshovsky horizon of Podolia and from Ludlow of thè Big
Zelenez Island.

Table I.

Distribution of thè lower Devonian and Eifelian bryozoan complexes of thè Aitai .

Lower

Devon

Ganin

Kuvask

Middle

Devonian

deposita

Names of thè species

strata

banda

series

Distribution and age

III

complex

Lioclema subramosum Ulr. et Bassi.

lower gelderberg,

N. America

L. khalfini sp. nov.

Pseudobatost omelìa spinata Astr.

borshovsky horizon,
Podolia

Paralioclema morozovae Astr.

borshovsky horizon,
Podolia

Anomalotoechus una sp. nov.

Eridotrypa minuta Astr.

chortkovsky horizon,
Podolia

E. vestirà Yar.

Leptotrypella pervulgata sp. nov.

Leptotrypella semiramosum Astr.

chortkovsky horizon,
Podolia

Gamella frequens Yar.

Ensipora tennis (Hall.)

lower gelderberg,

N. America

S ernie oscinium parvulus sp. nov.
Lioclema multiacantoporum Astr.

Lioclema ganiense Astr.

Pseudobatost omelia celebrata Yar.

Paralioclema magnum Astr.

losishensky bands
Mining Aitai

Reteporina ubensis Nekh.

Reteporina nativa sp. nov.

Fene stella sp.

S ernie oscinium sp.

Ensipora altaica Astr.

Lioclema kuvashensis sp. n.
Pseudobatost omelia spinato formis

sp. nov.

Anomalotoechua bublitshenkoi Nekh.

losishensky bands
Mining Aitai

Eridotrypa nekhoroshevi Yar.

E. ampia sp. nov.

Fenestella perforata sp. nov.

F. glarea sp. nov.

F. kuvashensis sp. nov.

Lioclema jakovlevi (Schoen.)

Eifel, Givet,
Mounting Aitai,
Kusbasz.

Lioclema salairiense Moroz.

Eifel, Kusbasz.

Lioclema vulgatum sp. nov.

Fistulipora devonica sp. nov.

THE EARLY DEVONIAN AND EIFELIAN BRYOZOA FROM THE ALTAI 289

Thus, this complex of Bryozoa indicates thè lower Dev-
onian age of thè Ganin formation, more exactly thè lower
part of thè lower Devon. The second complex of Bryozoa is
discovered in thè lower Devonian limestones on thè right bank of
thè Ganin spring, referred by E. A. Elkin to thè Ganin horizon.
The Bryozoa were studied from thè grey limestones and from
thè bands of platy clayey limestones.

They d.iffer from thè first complex with their specific and
generic composition. Difference is in absence of common species
( Gamella frequens sp. n. is thè only common species). Cryptosto-
mata are rather numerous. The genera Reteporina , Hemitrypa,
Fenestella appeared.

Beside thè genus Reteporina ubensis Nekh. which is wid-
espread in losishensky strafa G) of thè Aitai, all species of Cryp-
tostomata are new. Presence of new species of genera Eridotrypa
and Ensipora indicates thè Early Devonian age of this com¬
plex. The deposits of grey limestones developed near Khomichev
ravine and on thè left bank of thè Solovjikha River are probably
thè analogues of thè deposits of thè Ganin horizon. Similar bryo-
zoan species are — Lioclema multiacanthoporum Astr., Paralio-
clema magnimi Astr.

The third bryozoan complex was studied from thè Kuvash
series, developed on thè right bank of thè Kuvash River. Here
abundant Bryozoa with different composition are discovered in
grey siltstones and clayey limestones. These deposits are younger
than thè Ganin formation and thè lower Devonian limestones
of thè Ganin horizon. Abundant fenestellids indicate thè young
age of thè Kuvash series. Such new species as Fenestella glarea
sp. nov., Fenestella perforata sp. nov., Semicoscinium amurense-
formis sp. nov. show great affinity with thè middle Devonian
species of thè Mountain Aitai and thè Far East. Development
of fenestellids and presence of thè representatives of thè genera
Eridotrypa and Ensipora say about existence of this complex in
thè Early Devon. Presence in thè deposits of thè Ganin and
Kuvash horizons of Pseudobato stornella celebrata sp. nov., Ensi¬
pora altaica sp. nov. gives possibility to propose that thè latter

(x) Losishensky strata is mixed-lower-middle Devonian and it is required
more detail study.

290

A. M. YAROSHINSKAYA

are of different age and partially correspond to thè deposits of
thè Ganin horizon.

The fourth complex of Bryozoa is studied from grey limes-
tones developed along thè right bank of thè Ganin spring. The
Bryozoa here are abundant, but have monotypical composition.
We know only two genera : Lioclema and Fistulipora. The repre-
sentatives of thè species Lioclema jakovlevi are abundant. This
species is widespread in Givetian deposits of thè Mountain Aitai,
Kusnez basin and Minusa kettle and rarely in Eifel of thè Mining
Aitai. Species Lioclema salairiense Moroz. is developed in ma-
montovsky sfrata of Eifel of thè Salaira. The representatives
of new species of genera Lioclema and Fistuli'pora show affinity
with thè species from lebedyansky strafa of Givetian formation
of thè Kusnez basin. This bryozoan complex is of thè middle
Devonian age. Stratigraphic eviden.ce on Bryozoa from Devon
are confirmed by thè fauna of Tabulata, Rugosa corals, Stroma-
toporoids, fishes and flora (2).

Here thè brief geologica! and facies characteristics of our
bryozoan complexes are given.

In all three Early Devonian complexes locai forms are domi-
nant; species known from other regions and countries are rare,
although some species, for example American Lioclema subramo-
sum , is abundant. In thè first complex among bryozoan species
thè Trepostomata are dominant. Besides particularly endemie
species, there are 5 species identical with podolian ones ( Fistu -
lipora orbicidata Astr., Eridotrypa minuta Astr., Pseudobato-
stomella spinata Astr., Pseudobato stornella morosovare Astr.,
Leptotrypella semiramosa Astr).

The north American species are also widespread, especially
Lioclema subramosum Ulr. et Bassi, and Ensipora tennis (Hall).
It is evident that thè Devonian basin of thè Mountain Aitai at
that time was connected with thè European and north American
basins. In thè second complex of Bryozoa, Podolian and north
American elements are absent. Fauna of basins of adjacent regions
are presenti some species appear, common with Bryozoa of thè
Kusnez, Minusa and Mining Aitai basins. It is visible weak con-

(2) Fauna was studied by thè siberian workers - N. V. Mironova,
V. K. Khalfina, S. K. Cherepnina, A. A. Sergienko, Flora -by S. A. Stepanov.

THE EARLY DEVONIAN AND EIFELIAN BRYOZOA FROM THE ALTAI

291

nection with thè Kazakhstan Sea. In thè third complex there
are few species, elements of American and European fauna are
absent and species morfological common or identical with species
from thè Mining Aitai and East Siberia basins are very common :
from ten known here species one is common and three ones are
similar to thè Bryozoa of thè Mining Aitai and East Siberia;
thè left species are particularly endemie. The fourth (Eifelian)
complex is characterized by abundance of Bryozoa of thè order
Trepostomata i with monotypic specific and generic composition.
Geographical type of this Bryozoa was under thè influence of
fauna of thè Kusnez and Minusa basins.

A remark should be made about thè difference of thè com-
plexes of Early Devonian Bryozoa of thè Mountain Aitai and
Middle Asia.

From all known Early Devonian Bryozoa of thè Mountain
Aitai (63 species), only two new species ( Hemitrypa nativa Yar.,
Hemitrypa sandalicoformis sp. nov.) have affinity with Early
Devonian Bryozoa of Middle Asia where there are many fenes-
tellids.

In deposits of thè lower Devon and Eifel of thè Mountain
Aitai thè Bryozoa refer to thè terrigenous and carbonate rocks.

Characteristic feature of Bryozoa of thè first complex of
thè Ganin formation is abundance of Trepostomata and few
Cystoporata and Crypto stornata. Cystoporata are in limestones
and as a ride they are in bioccenosis with Tabulata and Stroma-
toporoids. They consist of large covered colonies, forming often
small offsets (locai genus Gamella ) and rarely thin covered lami¬
nate colonies as genus Fistulipora.

Abundant different Trepostomata are in thè lower part of
thè Ganin formation in thin limestone-clay bands. Especially spe¬
cies Lioclema subramosum Ulr. et Bassi, is abundant with large
branches, rarely with covered colonies and mature region. Bran-
ches of genera Eridotrypa, Leptotrypella, thin, net-like colony of
genera Semicoscinium and Fenestella and banded-like colony of
genus Ensipora are found. Whole colonies or large fragments are
absent. The length of fragmental branches and nets of Bryozoa
is not larger than 10 mm, rarely 3-5 mm. The fragments of colony

A. M. YAROSHINSKAYA

292

are not rounded, mature region is well preserved. Probably,
colonie® of Bryozoa partly in their life-time, partly after their
death were broken by swell and were buried near thè inhabited
place. Widespread thin branching bilateral symmetrical and thin
net Bryozoa, lived probably in cairn waters, where they can
attach to thè soft bottom. (Astrova, 1959). Here and there Bryo¬
zoa of this complex are in thè terrigenous-clay rocks, and in thè
bright-grey clayey limestones.

On thè clay bottom thè Bryozoa are monotypical by thè form
of colonies (species of genera Lioclema, Pseudobato stornella, Lep-
totrypella). They had long branching colonies. Some branches
were in width 0,03-0,07 mm and their length was 8-15 cm.
Together with Bryozoa branches of Thamnoporids, shells of
Brachiopods and fish remnants are seen. Development of branch¬
ing colonies well preserved after death and absence of covered
and sinter forms say about normal sea circumstances and about
cairn waters. In clay limestones we see abundant large well
preserved thick branch colonies of Trepostomata (genera Lio¬
clema, Paralioclema, Leptotrypella, Pseudobato stornella) and
large fragments of wide banded with bilateral symmetrical
colonies of genus Ensipora. Different Tabulata and Rugosa
corals are here. In thè upper part of thè Ganin formation
we can see depauperation of bryozoan fauna. There are only
species Lioclema subramosum Ulr. et Bassi., Ensipora tennis
(Hall) and Gamella frequens Yar. During thè deposition of thè
upper part of thè Ganin formation thè Bryozoa lived in unfa-
vourable conditions (probably shoaling and desalting). In thè se-
cond complex we see two groups of Bryozoa according to thè dif¬
ferent types of sediments. The first group is in limestone-clay
bands, among terrigenous rocks. It consists of thè fragments of
large-meshed colonies of Cryptostomata with thick bands (genera
Reteporina, Hemitrypa, S ernie oscinium, Fenestella).

The species of genus Lioclema with branching or small cone-
like shape of colonies, covering pebble and also large bran¬
ching colonies of genus Paralioclema with well mature region,
thickened walls and abundant megacanthopores are represented
in these sediments among Trepostomata. The character of colony

THE EARLY DEYONIAN AND EIFELIAN BRYOZOA FROM THE ALTAI

293

and presence of genus Hemitrypa with secondary net indicate
that thè Bryozoa lived in near-shore part of basin, in condition
of strong development of water. The second group of Bryozoa
is represented by abundant, but exclusively monotypical Cysto-
porata. These Bryozoa are in bright-grey limestone and repres¬
ented by genera Gamella and Fistulipora.

Abundant Gamella covered corals and develop large or la¬
minate colonies with offsets of different length. Often we see thè
whole colonies and no fragments. Covered colonies of genus Fi¬
stulipora are rare and are represented by small fragments.

Beside Cystoporata there are Tabulata, Rugosa and Stro-
matoporoids. The representatives of genus Gamella in thè first
and in thè second complex are in limestones with terrigenous
mixture and only together with Tabulata and Stromatoporoids.
Probably thè species of this genus can live only in clear water
and belong to stenobiontic organism. The Bryozoa of thè third
complex are found in limestone-clay bands : they are abundant
thin colonies of genera Fenestella and Semico scinium of good
preservation. Beside abundant Fenestella we find branches of
genera Lìoclema, Eridotrypa , Pseuclobato stornella.

Almost all of them have thin branching colonies, small
acanthopores and thin walls, thickened on thè periphery. Covered
and large colonies are found rarely. The Bryozoa of thè third
complex lived in cairn shallow sea. Well preserved thin colonies
of 10-18 mm of length indicate that thè Bryozoa after death
were not transported.

The Bryozoa of thè fourth complex are developed in bright-
grey limestones. They forni crowded covered colonies. Large cove¬
red and branching colonies of genera Lìoclema and Fistulipora
are dominant. The width of thè branches is 0,8-1, 5 c-m.

Bryozoa in these limestones are found sporadica! and thè
other fauna is absent. In these sediments abundant Tabulata,
Stromatoporoids and Rugosa are found. Abundance and diffe-
rence of sea fauna in limestone indicate thè good condition of
life, light, aeration, salinity.

294

A. M. YAROSHINSKAYA

REFERENCES

Astrova G. G., 1959 - Siluriiskie Mshanki tsentral’noi i zapadnoi Tuvi -
(Silurian Bryozoa from Central and West Tuva), Isd. Ak. Nauk SSSR.

Astroya G. G., 1964 - Mshanki borshchovskovo i chortkovskovo gorizontov
Podolii - (Bryozoa from thè Borshovsky and Chortkovsky horizons
of Podolia), Trudi Paleont. In-Ta. T. XCVIII. Isd. Ak. Nauk SSSR.

Bublichenko N. L., 1951 - 0 knige L. L. Khalphina « Fauna i stratigra-
phiya Devonskikh otlozhenii Gornovo Altaya i neskol’ko zamechanii
o Devone Altaya voobshche » - (On L. L. Khalfin’s book: Fauna
and stratigraphy of Devonian deposits of thè Mountains Aitai and
some notes on thè Aitai), Isv. AN. Kaz. S.S.R., ser. Geol., vip. 14.

Gratsianova R. T. & Elkin E. A., 1967 - Devon Gornovo Altaya. Strati-
graphiya Paleozoya srednei Sibiri - (Devon of thè Aitai Mountains.
Stratigraphy of Middle Siberia), Izd. « Nauka », Sibirskoe otdelenie.

Nekhoroshev V. P., 1948 - Devonskie Mshanki Altaya - (Devonian Bryozoa
from thè Aitai), Paleontologiya SSSR, T. Ili, eh. 2, vip. 1, Izd.
ANCCCR.

Khalfin L. L., 1948 - Fauna i stratigraphiya Devonskikh otlozhenii Gornovo
Altaya - (Fauna and Stratigraphy of Devonian deposits of thè Aitai
Mountains), Izvestiya Tomskovo Politekhnicheskovo In-Ta, T. 65, vip. 1.

Khalfin L. L.., 1967 - Ob Altaiskom tipe nizhnevo Devona. Stratigraphiya
Paleozoya srednei Sibiri - (On thè Altai-type of Power Devon. Strati¬
graphy of Paleozoic of Middle Siberia), Izd. «Nauka», Sibirskoe
Otdelenie.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 295-297. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

38. Group 5: Biogeography and Biostratigrapliy.

Sumio Sakagami (*)

STUDY ON THE UPPER PALEOZOIC BRYOZOA OF JAPAN
AND THE THAI-MALAYA DISTRICTS

(Preliminary Report)

Riassunto. — Attualmente sono conosciute in Giappone 181 specie di
Briozoi e 87 sono note nel distretto maleo-tailandese.

Benché vi siano soltanto tre specie in comune tra questi due distretti,
le loro associazioni generiche sono intimamente in relazione l’una con l’altra.

Le nostre conoscenze dei Briozoi silurici e devonici dei distretti giappo¬
nese e maleo-tailandese sono molto limitate e si auspicano ulteriori studi su
di essi.

Summary. — At present 181 species of Bryozoa are known from Japan
and 87 species from thè Thai-Malaya distriets. Although there are only
three species in common between these two distriets, their generic assem-
blages are intimately related eac-h other.

Our knowledge of thè Silurian and Devonian Bryozoa from Japan and
thè Thai-Malaya distriets are very limited and future study on them is
desired.

At present 181 species of Bryozoa are known from Japan and
87 species from thè Thai-Malaya distriets. Although there are
only three species in common between these two distriets ( Fistu -
lipora timorensis, Fenestella cf. retiformis and Fenestella cf. tri-
serialis ), their generic assemblages are intimately related each
other.

Among thè interest ing genera known from Japan and thè
Thai-Malaya distriets, Nipponostenopora and Hayasakapora are

(*) Hokkaido University of Education, Department of Geology, Hako-
date, Japan.

296

S. SAKAGAMI

established criginally from Japan. Nipponostenopora is a Carbo-
niferous genus and Hayasakapora is a Permian one. These two
genera were recently recorded from sfrata of equivalent geolo-
gical ages in thè USSR.

The genus Hexagonella although not known from thè Per¬
mian of Japan, has been recorded from thè Permian of Thailand
(3 spp.), thè Salt Range (3 spp.), Australia (6), Timor (1) and
thè Ural region (1). Although it can be distinguished from Mee-
Jcopora by thè presence of hexagonal ridges, generic identifica-
tion by only thin section is difficult, and for such reasons it is
probable that Hexagonella occurs also in Japan.

The genus Prismopora which has been reported from thè
Devonian to Permian of thè United States and thè Permian of
Australia, is also known from thè Japanese Carboniferous and
Permian strafa. It is noted that thè genus Ascopora which is
common in European Russia is known only from thè Permian of
Thailand and not from elsewhere in southeast Asia, Australia
and Japan.

Some species of Streblascopora which form thè Streblasco-
pora marmionensis group are widely distributed in thè Circum-
Pacific and thè Russian regions.

Our knowledge of thè Silurian and Devonian Bryozoa from
Japan and thè Thai-Malaya districts are very limited and fu¬
ture study on them is desired.

In generai, thè Japanese Carboniferous bryozoan fauna shows
intimate relationship with those known from Turkestan, thè
Kuznetz and Donetz basins, and also has yielded species widely
distributed in both thè USSR. and USA., such as Meekopora ap-
proximata Ulrich, Rhombopora exigua Ulrich, Fenestella trise-
rialis Ulrich and others. At present nothing is known of thè Up¬
per Carboniferous Bryozoa in Japan. In thè Thai-Malaya district,
in spite of thè small faunas from thè Power Carboniferous, thè
bryozoan faunas contain both European and North American ele-
ments. The Bryozoa from EB-49 in Thailand are similar to thè
species described from thè United States of America and are pro-
bably Lower Uralian in age.

The generic assemblages of thè Japanese Permian Bryozoa
resemble those of thè Permian of Timor island, Australia and
Vancouver island, and some genera are related to those of India,

STUDY ON THE UPPER PALEOZOIC BRYOZOA OF JAPAN ETC.

297

China and thè USSR. The Thai-Malayan bryozoan fauna is closely
related to those from thè Permian of Timor island, Australia,
Japan and Vancouver island, and bear characters common with
those of European Russia, thè Moscow basin, and thè Ural moun-
tains.

The research on these bryozoans are progressing and thè
results are expected to contribute to thè biostratigraphy, correla-
tion, taxonomy and other problems.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 298-299. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese. Aug. 12th-16th, 1968

39. Group 5: Biogeography and Biostratigrapliy.

Gisela Illies (*)

ON SOME CYCLOSTOMATOUS BRYOZOA
FROM THE MIDDLE JURASSIC
OF SOUTHERN GERMANY

(Preliminary Report) (**)

Riassunto. — Vengono descritti i caratteri distintivi di Proboscina al-
fredi Haime, 1854, un briozoo Cyclostomata multiseriale con sezione tra¬
sversa arcuata, presente nel Bajociano superiore della Germania meridionale.

Summary. — Features of Proboscina alfredì Haime, 1854 with arched
cross section, from Upper Bajocian of Southern Germany, are here investi-
gated.

The features of Proboscina alfredi Haime, 1854, a multiserial
cyclostome Bryozoan with arched cross-section, found in thè
Upper Bajocian of southern Germany will be investigated. The
shape of thè zooecia depends on their situation within a branch.
A zooecium develops from thè budding layer to thè frontal piane.
A zooecium consists of thè endozone and thè exozone. The endozone
consists of thè budding, rounding and interzooecial regions. The
zooecia, being located along thè medium line of a branch, differ
from those situated at thè lateral borders of thè branch by unfi-
nished growth of thè latter ones. The development of thè zooecia

(*) Geologisches Institut der Universitàt - Karlsruhe, Germany (W).

(**) The complete text of this paper will be published under thè title:
« Multiseriale Bryozoa Cyclostomata mit gewolbtem Zweigquerschnitt aus
dem Dogger des Oberrheingebietes » in : Oberrheinische geologische Abhand-
lungen, 17 (2), pp. 217-249, pi. 1-5, Karlsruhe, October 1968.

ON SOME CYCLOSTOMATOUS BRYOZOA ETC.

299

originateci from thè growing zones forming thè ends of thè bran¬
ches. The growing zone demonstrates thè overlapping arrange¬
ment of thè zooecia. The gonozooecium is an enlarged exozone of
a tube lying within thè frontal layer of thè colony as fiat as thè
zooecia. The bifurcations of thè branches and thè origin of thè
colonies will be treated.

All thè attributes mentioned above are coincident within
numerous varieties of thè described species, in spite of thè mani-
fold figurations of thè branches.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 300-302, 31-XII-1968

lst I.B.A. International Conferente on Brvozoa, S. Donato Milanese, Aug. 12th-16th, 1968

40. Group 5: Biogeography and Biostratigraphy.

Krister Brood (*)

STENOLAEMATOUS ECTOPROCTS
FROM THE DANIAN DEPOSITS
OF SWEDEN AND DENMARK

( Bryozoa )

(Preliminary Report)

Riassunto. — L’A. dà notizie preliminari su un suo ampio lavoro in cui
vengono descritti gli Ectoprocta Stenolaemata provenienti dai depositi Da-
niani della Svezia meridionale e della Danimarca.

Si tratta di 75 specie (delle quali 24 nuove) appartenenti a 40 generi
(dei quali 3 nuovi). Vengono istituite 3 nuove famiglie e 5 famiglie vengono
invalidate.

Infine l’A. ripudia totalmente la tradizionale classificazione di Canu e
di Bassler e propone un nuovo sistema basato sulla classificazione preco¬
nizzata da Borg.

Summary. — A. gives a preliminary report about a big work in which
he describes Stenolaematous Ectoprocts from Danian deposits of southern
Sweden and Denmark.

In this work 75 species (24 new) belonging to 40 genera (3 new) and 3
new families are described.

The generally accepted classification by Canu and Bassler is totally
rejected and a System built on thè classification founded by Borg for living
species is suggested.

Zusammenfassung. — Stenolaemate Ectoprocten aus Dan-Ablagerungen
in Siid-Schweden und Dànemark sind beschrieben worden.

75 Arten (24 neue Arten) aus 40 Gattungen (3 neue Gattungen) und
3 neue Familien beschrieben worden.

(*) Universitet i Stockholm, Geologiska Institutionen, Stockholm, Sweden.

STENOLAEMATOUS ECTOPROCTS FROM THE DA DANIAN ETC.

301

Die allgmein angenommene Klassifizierung der Canu und Bassler ist
vollstàndig verworfen, und anstelle ein System, aufgebaut auf die von Borg
entworfene Klassifizierung jetzlebenden Arten, vorgeschlagen worden..

Stenolaematous ectoprocts from thè Danian deposits of
Southern Sweden and Denmark are described. Three new fami-
lies, Filisparsidae for Filisparsa and Nevianipora\ Borgellidae
for Borgella ; Tubigerinidae for Tubigera ; three new genera,
Pseudotervia, referred to Crisinidae; Borgella, referred to Bor¬
gellidae ; Silenopora, referred to Heteroporidae ; and 24 new
species are proposed. Totally 75 species belonging to 40 genera
are described. The ovicells of 65 species are described and illu-
strated. One suborder, Dactylethrata, is rejected, and thè weak
arguments for accepting Rectangidata are discussed. The gene-
rally accepted classification of Canu and Bassler is totally re¬
jected, and a System built on thè classification formed by
Borg for modera species is suggested. Thus thè families Diape-
roeciidae , Oncousoeciidae, Plagioceiidae, Tretocycloeciidae, and
Leiosoeciidae, are rejected. Cytididae is removed from Cancellata
and placed in Tubidiporina, Corymboporidae is moved from Ce-
rioporina to Tubuliporina.

Special interest has been devoted to thè differences in zoa-
rial growthform and variations in shape and size of thè ovicells
in species and genera. The studies show that Berenicea, Repto-
midtisparsa, Cavai ia, Pergeìisia, Plagioecia, and Mesenteripora
are synonyms of Diastopora; Cryptoglena, Cavarinella , Parleio-
soecia, Radiocavaria, and Reptomidticlausa are synonyms ; Des-
mepora, Homeosolen, and Truncatidipora do not differ from
Oscidipora; Domopora, Stellihag enotria, and Tholopora are sy¬
nonyms of Radiopora; Bimidticavea, Tecticavea are complex co-
lonies of Radiocavea; Discocavea, Paricavea, Semimulticavea,
Unicavea, Orosopora and Heteroporella are all synonyms of
Dispor ella. Variations in thè shape of thè ovicells that are pos-
sibly due to ecological conditions are commonly found in species
of Entalophora and Diastopora. So are Diaperoecia- and Plagio-
ecm-shaped ovicells found in thè same species.

302

K. BROOD

A short summary of thè terms used for describing kenozooids
and pores are given. Dactylethra, firmatopores, mesopores, and
nematopores are kenozooids ; Tergopores and vacuoles are pores.
Cancelli is a term for extrazooidal cavities and should be res-
tricted for Lichenoporidae.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milane - 108: 303-311, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

41. Group 5: Biogeography and Biostratigraphy.

Gian Piero Braga (*)

BRYOZOA FROM THE « MARNE ROSSE »

OF SPILECCO

(LESSINI MOUNTAINS, VERONA)

Riassunto. — Dopo un accenno alla complicata situazione geologica del¬
l’area da cui provengono i campioni esaminati, vengono fatte alcune consi¬
derazioni sulla interessante fauna a Briozoi delle « marne rosse » dello
« Spilecciano » di Spilecco, mettendo in particolare risalto il valore del ri¬
trovamento quale nuovo contributo alla migliore conoscenza dei Briozoi del
Veneto.

Summary. — Following a hint on thè complicated geology of thè area
from which thè examined specimens come, some considerations on thè in-
teresting Bryozoan fauna of thè « marne rosse » of « Spilecciano » of Spi¬
lecco are made, giving a particular stress to thè value of thè finding as
a new contribution to a better knowledge of thè Bryozoa in thè Veneti a
region.

Résumé. — Après un coup d’oeil à la situation géologique compliquée
de la zone d’où proviennent les échantillons examinés, on fait quelques con¬
siderations sur la faune intéressante à Bryozoaires dégagée des « marne
rosse » du « Spilecciano » de Spilecco, soulignant son valeur pour une meil-
leure connaissance des Bryozoaires du Veneto.

Introduction.

The following brief notes are intended as some preliminary
remarks on an interesting Bryozoan fauna originating from thè
« marne rosse » of thè « Spilecciano » at Spilecco (Fig. 1). Even
though its existence had already been pointed out by Schweig-

(*) Istituto di Geologia dell’Università di Padova e la Sezione Geolo¬
gica del Centro di Studio per la Geologia e la Petrografia del C.N.R.

304

GP. BRAGA

Hauser (1952, p. 20), no one had taken thè initiative of studv-
ing it. From a quick analysis this fauna turned out to be an
almost new element in thè overall knowledge existing on thè Ter-
tiary Bryozoa of thè Venetia region (Braga, 1963-1966).

I hope to enlarge upon this subject with a deeper paleonto¬
logica! studv at a future date. I believe, however, that this simple
indication has already a remarkable importance. As a matter of
fact, to my knowledge, this is thè first time that a Bryozoan
fauna belonging to Paleocenic levels and very common in thè
Dano-Montian beds of North-West Europe is reported in Italy.

Short Geological Notes on thè Spilecco Zone.

The reconstruction of a stratigraphical series in thè sur-
roundings of Spilecco is rather complicated because of thè many
faults, mainly vertical, that have greatly dislocated thè Creta-
ceous-Eocenic series and due to thè presence of volcanic rocks
levels appearing as flow basalts, hyaloclastites, tuffs, layered

BRYOZOA FROM THE « MARNE ROSSE » ETC.

305

volcanoclastic rocks and to thè precariousness of thè outcrops.
This can be seen in thè geological sketch map herewith enclosed
and even better in thè stratigraphic cross-section of pictures 1
and 2 (x).

The most ancient format ions of thè series are represented
by whitish, lightly clayey and thickly stratified limestones,
that can be attributed to thè Middle-Lower Cretaceous (Bian-

Fig. 2. — Geological sketch map of thè Spilecco zone.

Simbols - 1 : detrites ; 2 : slope slide detrites ; 3 : basaltic nec-k ; 4 : argil-
lites with Palrnae; 5. nummulitic limestones; 6: Eocenic layered volcano¬
clastic rocks; 7: hyaloclastites and pillow-breccias ; 8: flow basalts ; 9: Spi¬
lecco limestones; 10: Paleocenic layerd volcanoclastic rocks; 11: Scaglia
rossa (a: Maastrichtian ; b: Turonian-Santonian) ; 12: Biancone; 13: main
faults; 14: minor faults; 15: points of collection of Paleocenic Bryozoa;
16: points of collection of Eocenic Bryozoa.

C) The geological sketch map and thè cross-section are taken from a
study done by G. Barbieri and F. Medizza published in thè « Meni. Ist. Geol.
e Min. Univ. Padova ».

306

GP. BRAGA

cone) and by thè thinly grained reddish marly limestones (Sca¬
glia rossa) of thè Upper Cretaceous. The boundary with thè Pa-
leocenic sediments is merely paleontologie (based on thè Disco-
cyclinae , Nummulites and planktonics F or am ini fera) as thè « Sca¬
glia rossa » is found with thè sanie facies in thè Maastrichtian
as well as in thè Paleocene togheter with thè interposition of a
characteristic hard-ground.

SPI LECCO

ci mi t e ro

i , i , i , i

tWi

l-l-l-l

Fig. 3. — Geological cross-section A-A' (Bolca-Spilecco).

Simbols - l:Quaternary detrites; 2: argillites, siltites, lignites with Palmae
and Crocodilus vicetinus ; 3: nummulitic limestones; 4: flow basalts; 5:
hyaloclastites and pillow-breccias ; 6: layered volcanoclastic rocks; 7: Spi-
lecco limestones; 8: Scaglia rossa (a: Maastrichtian; b: Turonian-Santo-
nian); 9: Biancone.

Some reddish coarse-grained, hard richly fossiliferous lime¬
stones emerge on thè Scaglia. Among thè macrofossils we find
many Bryozoa, Fish teeth, Echinoids fragments, Brachiopods and
macroforaminifera. The benthonic and thè planktonic, thè latter
in a lesser quantity, microforaminifera are well represented.

As previously said, basalt flows, hyaloclastites and tuff le-
vels are inserted in thè limestones.

This heterogeneous formation, a few meters thick, was called
Spilecciano by Fabiani (1912 and 1915) and he identified it as
representative of thè Lower Eocene. Recalling here thè history
of thè vicissitudes encountered by thè FabianTs Spilecciano is
not befitting. It may be noted that thè terni Spilecciano, as Fa-

BRYOZOA FROM THE « MARNE ROSSE » ETC.

307

biani meant it, must be absolutely left out, as thè limestones of
Spilecco, because of thè fauna they contain, are not Eocenic, but
Paleocenic (Cita and Bolli, 1961).

As thè limestones and « marne rosse » of Spilecco contain
Bryozoa, thè subject of this study, they are of particular interest
here (fig. 2, 15a). From thè point of wiew of their fauna they
belong to thè Globorotalia aequa zone (according to Luterba-
cher, 1964) and therefore they should belong to thè Upper
Paleocene.

The series ends with some nummulitic limestones that can
be seen on thè bed of thè Purga di Bolca, of thè Cuisiano age,
where rare Bryozoa (fig. 2, 16b) have been isolated into some
mari levels, tuffs with Palmae and Molluscs, probably belonging
to thè Lower Eocene or to thè low part of Middle Eocene.

Considerations on thè Samples studied and on thè Bryozoan Fauna.

The sample residue gathered in correspondence with thè
« marne rosse » ( Globorotalia aequa zone) shows a very rich
fauna with particularly abundant maeroforaminifera ( Dìscocyc -
linae, Nummulites and Operculinae ), benthonic and planktonic
microforaminifera, small Corate, plates and spines of Echinoids,
stems of Crinoids and fragments of Molluscs ( Ostreidae ).

The inorganic residue is totally missing.

The Bryozoa are pretty well represented : among these, thè
Cyclost ornato are far more numerous than thè Cheilost ornata.
They appear in very soft, even if somewhat worn out (-), colonies,
but they exclude thè possibility of being reworked.

Thin QuadriceUaria colonies, fine Sertella fragments and
very numerous and fragile zoaria of Entalophora, Filisparsa and
Tervia are exceptionally kept in thè residue. The globose Cerio-
pora spheres are also frequent.

I am giving below here a list of thè fauna that for thè most
part has been only determined by genus, as I could only find vague
similarities in thè numerous foreign publications related to thè

(2) The worning out is probably partly due to some difficulty in clean-
ing and washing thè caleareous mari.

308

GP. BRAGA

Bryozoan faunas of thè Cretaceous and Paleocene and in thè few

ones on thè Lower Eocene (3).

The affinity with eocenic fauna, particularly with thè ones

of thè Venetia (Braga, 1963), is almost nil.

1. Quadricellarìa sp., very abundant. It can be compared with
Q. eie gans d’Orb.

2. F lustra sp., very rare.

3. Onyckocella sp., very rare. It has an affinity with 0. subpyri-
formis d'ARCH., but thè sizes, being slenderer, do not coin¬
cide.

4. Vibracella sp., rare. It seems similar to V. rimosa Marsson

5. Castanopora sp., very rare. To some extent it can be com¬
pared to thè Cribrilina asperula Mars.

6-7. Sertella beaniana King, abundant. The zoaria are more or
less slender, but they may be considered as variations of
thè species.

8. Sertella tuberculata (Reuss), rare.

9. Sertella sp., very rare. Very slender and with few apertures.

10. Porina sp., very rare. A sole specimen, badly kept.

11-14. Entalophora cf. macrostoma Milne-Edwards, very abun¬
dant. We have very numerous specimens that can be subdi-
vided into four groups according to their greater or lesser
frequency of thè apertures, that, however, may be included
in thè variability of thè species.

15-19. Filisparsa sp., very abundant. In this grouping too there
is a very great variability in thè position and frequency of
thè apertures. The zoaria remind us of some species of
Marsson, like F. gracilis, fragilis and pulchella.

20. Clavisparsa sp., rare. There is some likeness to thè Entalo¬
phora turbinata Mars.

21-22. Idmonea sp., abundant. Specimens very similar to I. gra-
cillima Reuss, but much slenderer.

23. Idmonea sp., very rare. A sole very worn out specimen.

24. Idmonea sp., abundant. Zoaria with two little tubes on each
side, one of which scarcely developed.

(3) I wish to thank Dr. Noél Mongereau for his courtesy in accepting
to examine these interesting faunas himself.

BRYOZOA FROM THE « MARNE ROSSE » ETC.

309

25-28. Tervia sp., very abundant. The 25-26 specimens are like
Tervia bialternata Gregory ; thè others are very slenderer.

29. Bicrisina sp., rare. Very fiat specimens with small and nu-
merous apertures.

30. Tubulipora sp., rare.

31. Ceriopora sp., very abundant. Numerous spheroidal and
mushroom-like specimens.

Beside these samples, there are in thè residue other nume¬
rous specimens whose systematical position is not well established.

Another cleaned residue was picked up in an immediately
higher level and it has appeared substantially similar to thè pre-
vious one, even if less rich in its specimens.

Also thè residues from marls intercalated with nummulitic
limestones of Lower Eocene contain some Bryozoa, however, their
number is very small. From a quick observation many species
seem to have remained unchanged. This should not amaze us as
thè same can be observed in other zoological groups, like for
instance, thè benthonic Foraminifera, which perhaps are less
sensitive to light variations and less influenced by thè persistence
of particular environmental factors.

Stratigraphic and Paleoecological deductions.

Very little can be said on thè possibility of this fauna, as
it has been determined, of being of any use for establishing thè
Paleocenic age of thè « marne rosse ». This has already been
shown through thè macroforaminifera and planktonic Forami¬
nifera by previous Authors (Schweighauser, 1953; Cita and
Bolli, 1961; Medizza, 1965).

We can only stress thè existence of a certain similarity of
this fauna! association with thè Bryozoa of thè Upper Cretaceous
and thè Paleocene of thè Northern basins.

The pre-eocenic age of these Bryozoa is evidenced not only
by thè examination of thè Cy ciò stornata / C beilo stornata very high
ratio, but also by thè total absence of stili living species (Buge
and Starch in Piveteau, 1952) and by thè total lack of thè spe¬
cies that are extensively found in thè « marne a Briozoi » level

310

GP. BRAGA

of thè Upper Eocene scattered all over thè Venetia region
(Braga, 1963).

Once a systematic and paleontologica! study has been fini-
shed, its main value lays in its contribution toward thè knowledge
of a new fauna and, perhaps, of numerous new species.

From thè paleoecological point of view, we realize that we
are here in thè presence of essentially branched out and very
fragile colonies, living therefore in very cairn waters, associated
with algal meadows, that supplied, beside a favourable environ-
ment for their living, thè only suitable support for their settle-
ment. The marno-argillaeeous facies of Spilecco with its thin
sediments, could not by itself provide a substratum for thè buil¬
ding of thè colonies.

The existence of this Bryozoan fauna and thè wealth of ma-
croforaminifera, such as Nummulites and Discocyclinae, confirms
also thè belief that at this point thè sea had to be very shallow,
i.e. about one hundred meters deep.

From thè paleogeographic point of view this fact goes very
well along thè line of thè regressive cycle that occurred in thè
Paleocene and linked to thè early stages of thè alpine orogenesis
that caused thè formation of shallow seas, or to emerged zones
that are also thè place of concomitant effusive manifestations
with thè formation of volcanic isles. This paleogeographic set-up
was scattered all over thè Trentino-Venetia area (Piccoli, 1966).

REFERENCES

Braga G. P., 1963 - Briozoi del Terziario Veneto (1° Contributo) - Boll. Soc.
Pai. Ital., voi. 2, n. 1, pp. 16-55, 9 text figs., 4 pls., Modena.

Cita M. B. & Bolli H. M., 1961 - Nuovi dati sull’età paleocenica dello Spi-
lecc-iano di Spilecco - Riv. Ital. Paleont. Stratigr., voi. 67, pp. 369-392,
2 text figs., 2 pls., Milano.

Fabiani R., 1912 - Nuove osservazioni sul Terziario fra il Brenta e l’Astico
- Atti Acc. Se. Veneto-Trentino-Istriana, Ser. 3, voi. 5, pp. 94-128,
1 pi., Padova.

Fabiani R., 1915 - Il Paleogene del Veneto - Meni. Ist. Geol. Univ. Padova,
voi. 3, pp. 1-336, 36 text figs., 9 pls., geol. map 1:50.000, Padova.

Luterbacher H. P., 1964 - Studies in some Globorotalia from thè Paleocene
and Lcwer Eocene of thè Central Apennines - Eclog. Geol. Helv.,
voi. 57, pp. 631-730, 134 text figs., Basel.

BRYOZOA FROM THE « MARNE ROSSE » ETC.

311

Medizza F., 1965 - Ricerche micropaleontologico-stratigrafiche sulle forma¬
zioni al limite tra Cretaceo e Terziario nell’alta valle del Chiampo
(Lessini Orientali) - Meni. Ist. Geol. Miner. Univ. Padova, voi. 25,
pp. 1-41, 5 text figs., 3 pls., Padova.

Piccoli G., 1966 - Studio geologico del vulcanismo palogenico veneto - Meni.
Ist. Geol. Miner. Univ. Padova, voi. 26, pp. 1-100, 16 text figs., 5
pls., Padova.

Piveteau J., 1952 - Traité de Paléontologie - I : Protistes, Spongiaires, Coe-
lentérés, Bryozoaires (Bryozoa by E. Buge), pp. 782, pls. & text figs.,
Masson et C. Ed., Paris.

Schweighau SER J., 1953 - Micropàontologische und stratigraphische Unter-
suchungen in Paleocaen und Eocaen der Vicentin (Norditalien) -
Schweiz. Palàont. Abh., voi. 70, pp. 97, 13 pls., Basel.

AUTHORS PARTICULARLY CONSULTED

Bassler R. S. (1953); Berthelsen 0. (1962); Braga G. P. (1966); Bry-
done R. M. (1906, 1910, 1914, 1916, 1917, 1929); Canu F. (1897, 1907-1910,
1919, 1920, 1922); Canu F. & Bassler R. S. (1917, 1920); Cheetham A.
(1966); Filliozat M. (1908); Goldfuss A. (1827-33); Gregory J. W. (1890.
1909); Labracherie M. (1961); Lang W. D. (1912); Larwood G. P. (1963);
Hagenow F. (1839, 1851); Malecki J. (1963); Marsson T. (1889); Orbignì
(d’) A. (1854); Pergens E. (1889, 1893); Prantl F. (1938); Stoliczka F
(1872); Ubaghs J. C. (1858, 1865); Walter B. (1966, 1967); Veenstra H. J
(1963); VoiGT E. (1924, 1949, 1951, 1953. 1957, 1959, 1962).

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 312-326. 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

42. Broup 5: Biogeography and Biostratigrapliy.

Monique Labracherie (*)

QUELQUES BRYOZOAIRES CHEILOSTOMES
DE LA FALAISE DE HANDIA

( BIARRITZ, FRANCE)

Riassunto. — Dai sedimenti calcarei della Falesia di Handia (Biarritz,
Francia) sono stati ottenuti vari esemplari di Briozoi.

Oggetto del presente studio è dare un elenco dei principali Cheilosto-
mata rinvenuti, descrivere alcune nuove specie e completare lo studio delle
forme che sono state descritte da d’ARCHiAC nel 1886 e da Canu nel 1910.

Summary. — Calcareous sediments of thè « Falaise de Handia (Biar¬
ritz) » have yielded various specimens of Bryozoa .

The object of thè present study is to make a list of thè main Cheilo-
stomata we found, to define some new species and also to complete thè study
of forni s which have been described by d’ÀRCHiAC in 1886 and Canu in
1910.

Résumé. — Les sédiments calcaréo-marneux de la Falaise de Handia
(Biarritz) ont livré une faune de Bryozoaires riche et variée.

L’objet de cette étude est de présenter les principaux Cheilostomes
rencontrés, de définir les espèces nouvelles et surtout d’apporter des préci-
sions sur les formes qui avaient été autrefois décrites par d’ARCHiAC en
1886 et Canu en 1910.

La faune recueillie dans les dépòts calcaréo-marneux de la
falaise de Handia (Biarritz) est riche.

Les tris des divers résidus de lavage n’ont malheureusement
pas fourni un matèrie! en parfait état de préservation. Du fait

(*) Université de Bordeaux, Laboratoire de Géologie - Talence, France.

QUELQUES BRYOZOAIRES CHEILOSTOMES ETC.

313

de la forte adhérence du sédiment nous avons du procèder à un
nettoyage plus poussé. Les échantillons libres furent alors traités
par les ultrasons pendant une durée de 7 à 10 heures dans un
bain d’eau naturelle ; cette méthode sans donner des résultats
spectaculaires a cependant facilité notre étude.

Les Cyclostomes sont numériquement importants mais peu
variés tandis qu’une plus grande diversification existe chez les
Cheilostomes.

Les Bryozoaires paléogènes du Sud de l’Aquitaine sont peu
connus. Il faut toutefois mentionner les travaux de d’ARCHiAc(l)
et ceux de Canu (6).

Ali cours de ce travail nous nous sommes plus particulière-
ment attaehés à apporter des précisions sur certaines espèces
cheilostomes qui avaient été décrites par ces auteurs et que nous
pensons avoir retrouvées. Il s’y a j oute de nombreuses autres
formes qui n’ont jamais été citées dans la région, parmi celles-ci
certaines apparaissent nouvelles, d’autres mieux connues ont une
plus large distribution géographique. Parmi ces dernières il faut
signaler :

Batopora multiradiata Reuss, Batopora stoliczkai Reuss, Cellaria
reussi (d’Orbigny), Chlidoniopsis vindobonensis (Reuss), Escha-
rìna procumbens (Reuss), Vincularìa monstruosa (Canu), Vincu-
laria polymorpha (Carni), Kionidella dactylus (d’Orbigny), Mem-
braniporella radiata (Reuss), Nellia temila (Lamarck), Onycho-
cella subpyriformis (d’Archiac), Poricellaria alata d’Orbigny, Po-
ricellaria complicata (Reuss), S crup o cellaria elliptica (Reuss),
Scrupocellaria gracilis Reuss, Sparsiporina elegans (Reuss), Ste-
nosipora protecta (Koschinsky), Steriosipora simplex (Koschin-
sky), Tubucellaria bipartita (Reuss). De très nombreux spécimens
appartenant au genre Sertella n’ont pu ètre déterminés spécifi-
quement.

Parmi les espèces qui paraissent nouvelles, quelques-unes n’ont
pas, du fait de leur rareté, été décrites au cours de cette étude.
Ces formes sont toutes présentes dans l’ Eocène du Nord de
TAquitaine ; en raison de leur importance numérique dans cette
région, leur diagnose complète sera donnée ultérieurement.

314

M. LABRACHERIE

Famille Calloporidae Norman, 1903

Genre Crassimarginatella Canu, 1900

Crassimarginatella macrostoma (Reuss)

PI. VII - Figs. 1-6.

1847 Cellaria macrostoma Reuss, p. 64, pi. 8, figs. 5-6.

1869 Bif lustra macrostoma (Reuss) Reuss, p. 274, pi, 33, figs. 12-13.

1877 Flustrellaria macrostoma (Reuss) Manzoni, p. 67, pi. 13, fig. 46.

1885 Membranipora macrostoma (Reuss) Koschinsky, p. 22.

1891 Membranipora macrostoma (Reuss) Waters, p. 11.

?1910 Membranipora quadrifascialis Canu, p. 842, pi. 16, fig. 1.

1949 Crassimarginatella macrostoma (Reuss) Buge, p. 264, fig. 1.

1963 Acanthodesia macrostoma (Reuss) Braga, p. 22, pi. 2, fig. 1.

Matériel. - Plus de 50 fragments.

Remar ques. - Les variations zoariales sont moins importantes
que celle signalées part Buge. La forme étalée est absente et les
types pseudovinculariiforme et vinculariiforme sont les plus
fréquents. Les aviculaires en tétha figurés par cet auteur n’ont
pu ètre retrouvés malgré un matériel abondant. Cependant très
rarement les zoécies qui se situent au départ de nouvelles rangées
zoéciales peuvent présenter certaines modifications. Un léger
étranglement s’observe dans la moitié supérieure délimitant une
partie distale petite, semicirculaire et une grande région proxi-
male elliptique. Les spécimens ne sont pas suffisamment préservés
pour dire si Fon peut les eonsidérer comme des aviculaires. Les
ovicelles sont par contre très nombreux et typiques.

Les dimensions des zoécies sont très variables. Elles sont
généralement plus faibles que celles que Fon peut relever sur les
figures de Reuss.

Dimensions'. Lz (10): 0,57 mm (0,42 - 0,75 mm)

lz (10): 0,28 mm (0,23- 0,32 mm)

ho (10): 0,32 mm (0,23- 0,37 mm)

lo (10): 0,15 mm (0,12-0,18 mm)

Distribution. - De l’Eocène supérieur au Miocène d’Europe.

QUELQUES BRYOZOAIRES CHEILOSTOMES ETC.

315

Famille Onychocellidae Jullien, 1882

Gerir© Smittipora Jullien, 1882

Smittipora ? sp.

PI. VII - Figs. 7-8.

Matériel. - 7 fragments.

Description. - Zoarium érigé, articulé, cylindrique, composé
de 6 rangées longitudinales de zoécies séparées par un sillon à
peine distinct.

Zoécies en forme de massue. Cadre périphérique étroit, lé-
gèrement surélevé.

Gymnocyste absent. Surface zoéciale concave profondément
déprimée du coté opésial.

Opésie terminale oblongue, largement arrondie du coté distai.

Ovicelles et hétérozoécies non observés.

Dimensions : Lz (6): 0,56 mm (0,50 - 0,58 mm)

lz (6): 0,24 mm (0,23 - 0,25 mm)

ho (6): 0,23 mm

lo (6): 0,08 mm

Remarques. - Cette espèce est voisine de Smittopora? sp.
Cheetham, 1966, elle présente le mème nombre de rangées zoé-
ciales cependant les zoécies sont plus élancées, le cryptocyste plus
profond, l’opésie plus allongée et étroite.

Elle se rapproche également de Smittipora midwayanica
Canu-Bassler, 1920, espèce à 8 rangées zoéciales et surtout de
Vincularia prismatica (v. Hagenow) Berthelsen, 1962 par la forme
de son opésie et ses mesures micrométriques. Cependant cette
dernière possède un nombre de rangées zoéciales plus élevé.

Elle montre aussi de fortes affinités avec une espèce ren-
contrée dans les couches les plus inférieures de V Eocène du
Nord de TAquitaine, cependant dans ce dernier cas quelques spé-
cimens ont permis robservation d’ hétérozoécies. Une description
en sera donnée ultérieurement.

316

M. LABRACHERIE

Famille Porinidae d’Orbigny, 1852

Genre Porina d’Orbigny, 1852

P orina coronata (Reuss)

PI. Vili - Figs. 17-19.

1847 Cellaria coronata Reuss, p. 62, pi. 8, fig. 3.

1869 Acropora coronata (Reuss) Reuss, p. 277, pi. 34, figs. 3-5.
1885 Porina coronata (Reuss) Koschinsky, p. 42, pi. 4, figs. 7-9
1891 Porina coronata (Reuss) Waters, p. 24, pi. 4, figs. 7-9.

1913 Acropora coronata (Reuss) Canu, p. 136, fig. 2.

1963 Porina coronata (Reuss) Braga, p. 30, pi. 3, figs. 14-15.

Matériel. - 50 fragments.

Remaroues. - Les spécimens de la falaise de Handia ne se
présentent jamais sous la forme cylindrique typique figurée par
Reuss et la plupart des autres auteurs. Waters en 1891 signale
une grande variabilité de l’espèce spécialement dans la forme du
zoarium, ceci n’a pu ètre vérifié, les rameaux sont toujours en
frondes bilamellaires, comprimées avec des zoécies disposées en
rangées régulières et alternes.

Le bombement péristomial n’est jamais observé.

Les aviculaires péristomiens sont généralement peu distincts
à Fexception de celui dirigé distalement et situé immédiatement
au-dessous de l’apertura. Les grands aviculaires à large mandi-
bule signalés par Waters sont plus rares mais existent sur tous
nos spécimens. Ils occupent entièrement la surface zoéciale entre
l’apertura et l’ascopore. Le rostre dirigé transversalement est
fortement sur èie vé.

Les caractéristiques signalées ci-dessous sont très constantes
et différencient cette forme de celle du Priabonien d’ Italie iden-
tifiée par Gp. Braga (3). Les différences observées justifieraient
peut-ètre la création d’une variété ou d’une sous-espèce, nous
hésitons cependant à le faire car une révision préalable des dif-
férentes formes de Waters semble indispensable.

Dimensions : Lz (8): 0,61 mm (0,52 - 0,68 mm)

lz (8): 0,32 mm (0,31-0,37 mm)
ho (8): 0,15 mm (0,15-0,16 mm)

QUELQUES BRYOZOAIRES CHEILOSTOMES ETC.

317

lo (8): 0,15 mm (0,13-0,17 mm)

L aviculaire : 0,35 mm

0 ascopore : 0,07 mm, situé à 0,26 mm de l’ori-

fice zoécial.

Distribvtion. - Eocène supérieur d’Europe.

Genre Beisselina Canu, 1913

Beìs selina sp.

PI. IX - Figs. 20-25.

Matériel. - Plus de 50 échantillons, souvent mal conservés.

Description. - Zoarium érigé, bilamellaire large de 1,5 à
2,5 mm avec des zoécies disposées alternativement et régulière-
ment en séries longitudinales qui deviennent transverses et obli-
ques au niveau des bifurcations.

Limites zoéciales peu distinctes, soulignées parfois par la pré-
sence de petites pores. Péristomes importants raprochés sur les
frondes calcifiées, plus petits et distants sur les branches moins
épaisses.

Ascopore toujours assez volumineux occupe une position mé-
diane entre les orifices zoéciaux voisins, se distingue très nette-
ment en vue interne dans les spécimens brisés.

Petits pores de la frontale peu nombreux et souvent peu vi-
sibles ne peuvent généralement pas ètre identifiés avec certitude
comme des aviculaires. Aviculaires frontaux multiples, polymor-
phes mais non observables régulièrement :

1. aviculaire au-dessus de Torifice péristomial souvent im-
mergé dans l’épaisseur de la frontale, plus rarement saillant;

2. aviculaires rares, petits, elliptiques dispersés sur la sur-
face zoariale ;

3. grands aviculaires accidentels.

Dimensions: Lz (5): 0,50 mm (0,47 -0,52 mm)

lz (5): mesurée entre 2 ascopores : 0,25 mm
ho (5): 0,14 mm (0,13-0,15 mm)

0 ascopore : 0,08 mm
Zoécies en vue interne :

Lz : 0,50 mm
lz: 0,26 mm

318

M. LABRACHERIE

Remar ques. - Nous ne pouvons pas identifier d’une facon cer-
taine cette espèce comme E sellar a ampulla d’Archiac, 1847. Canu
l’a décrite et figurée à nouveau en 1910 en expliquant certaines
variations. Il note en particulier la présence d’aviculaires qui n’ont
pas été signalés par d’ARCHiAC. Plus spécialement il précise « il y
a toujours un pore par zoécies » sous-entendant qu’il représente
certainement un aviculaire. Il est probable que ce dernier cor-
responde à ce que nous appelons ascopore, cependant l’originai? de
d’ARCHiAC déposé à l’Ecole des Mines est loin d’ètre aussi bien con¬
servò que le dit Canu et de ce fait aucun rapprochement valable
n’est possible.

Nous sommes en présence d’une espèce très déconcertante par
ses grandes variations ce qui est propre à toutes les Beisselma, ce¬
pendant elle en diffère par sa pauvreté en aviculaires et par son
gros ascopore toujours très distinctement visible.

Distribution. - Eocène de Biarritz.

Famille Stomachetosellidae Canu & Bassler, 1917

Genre Ochetosella Canu & Bassler, 1917

Ochetoseìla sp.

PI. Vili - Figs. 15-16.

Matériel. - 10 fragments.

Description. - Zoarium libre cylindrique vraisemblablement
bifurqué, formé de 6 ou 7 séries longitudinales de zoécies alternes.

Zoécies distinctes, séparées par un mince filet saillant, al-
longées, irrégulièrement hexagonales. Frontale légèrement con-
vexe, modérément épaisse. Surface irrégulièrement mamelonnée,
perforée de grosses aréoles pouvant former dans certains cas des
costules périphériques proéminentes. Aréoles subcirculaires ou el-
liptiques.

Orifice invisible extérieurement profondément enfoncé dans
le péristome épais, court, largement arrondi du coté distai, le bord
proximal fortement saillant forme une sorte de large lèvre re-
dressée légèrement sinueuse plus ou moins profondément entaillée.
Aviculaire? orai arrondi sans pivot assez déjeté latéralement.

Ovicelle non observé.

QUELQUES BRYOZOAIRES CHEILOSTOMES ETC.

319

Dimensions: Lz (8): 0,97 mm (0,88-1,12 mm)

lz (8): 0,48 mm (0,46 - 0,50 mm)
ho : difficilement mesurable
lo (8): 0,25 mm (0,22- 0,28 mm)

0 aviculaire : 0,10 mm

Remarques. - L’allure de la frontale avec ses épaississements
interaréolaires peut taire penser que nous sommes en présence de
branches assez àgées.

Cette espèce voisine de O. jacksonica Canu-Bassler, 1920 s’en
différencie par des zoécies légèrement plus courtes. Gomme dans
cette dernière espèce le péristome est incomplet mais la lèvre in-
férieure apparaìt plus large. D’autre part de très nombreuses
zoécies sont pourvues d’un aviculaire voisin de celui rencontré chez
O. robusta Canu-Bassler, 1920.

Famille Tubucellariidae Busk, 1884

Genre Tubucella Canu & Bassler, 1917

Tubucella canni n. sp.

PI. X - Figs. 26-32.

?1846 Pustulopora mamillata d’Archiac, p. 194, pi. 5, fig. 9.

?1862 Porina confluens Roemer, p. 194, pi. 5, figs. 9a, b.

?1910 P ormai?) mamillata (d’Archiac) Canu, p. 847, pi. 17, figs. 7-9.
Origine du noni: en hommage au paléontologiste F. Canu.

Holotype: Coll. Br. N° 991 (Fac. des Se. Bordeaux).

Paratypoides : 19 spécimens. Coll. Br. 992.

Localité-type : Biarritz: Falaise de Handia (échant. GA 18920).

Description. - Zoarium érigé, bilamellaire, cylindrique à aplati
formé de branches dichotomes. Zoécies disposées plus ou moins
régulièrement en rangées longitudinales et alternes avec un maxi¬
mum de 6 rangées zoéciales sur chaque coté.

Zoécies allongées, indistinctes extérieurement. Suture péristo-
miale peu visible. Frontale modérément épaisse, piane ou faible-
ment convexe. Surface perforée de gros pores évasés. Ascopore
légèrement plus gros que les autres pores frontaux, quelquefois
légèrement saillant se confond le plus souvent avec eux.

320

M. LABRACHERIE

Orifice petit, semi-circulaire, entièrement caché par le péris¬
tome. Péristome long, sessile sur la majorité de sa longueur, de-
vient libre et saillant dans la portion distale. Surface péristomiale
unitormément ponctuée de gros pores légèrement plus gros ou
identiques k ceux de la frontale, parfois les pores marginaux de-
viennent très volumineux et la surface costulée. Orifice secondaire
circulaire, petit.

Aviculaires frontaux ou marginaux multiples, polymorphes :

— 1 ou 2 aviculaires frontaux, arrondis ou triangulaires,
plus rarement en forme de spatule et très grands, placés au niveau
du péristome (indifféremment à droite ou à gauche lorsque l’avi-
culaire est unique, symétriquement lorsqu’ils sont doubles) en po-
sition presque intercédale ou très près de l’orifice zoécial. Rostre
pointu ou largement arrondi dirigé transversalement vers Y inté-
rieur, dans certains cas s’étend largement sur le péristome. Pivot
transversai complet ou condyles visibles dans les aviculaires trian¬
gulaires, aucune structure apparente pour les aviculaires arrondis ;

— aviculaires marginaux sporadiques, très grands, placés
sur la tranche des frondes, rostre pointu dirigé du coté proximal.
Pivot trans versai.

Ovicelle péristomial ; zoécie ovicellée à péristome très élargi,
globuleux.

Dimensions : Zoécies.

Lz (8): 0,96 mm (0,87 - 1,00 mm)
lz (8): 0,28 mm (0,25-0,31 mm)
ho (8): 0,12 mm (0,12-0,13 mm)
lo (8): 0,12 mm (0,12-0,13 mm)

Aviculaires frontaux.

— En forme de spatule:

Laf (5): 0,37 mm (0,35 - 0,40 mm)
laf (5): 0,26 mm (0,25 - 0,27 mm)

— Triangulaires :

Laf (5): 0,21 mm (0,18-0,27 mm)
laf (5): 0,15 mm (0,12-0,18 mm)

QUELQUES BRYOZOAIRES CHEILOSTOMES ETC. 321

— Arrondis :

0 af (5): 0,10 mm (0,09-0,11 mm)

Aviculaires marginaux.

Lam (3): 0,58 mm (0,56 - 0,60 mm)

lam (5): 0,30 mm (0,28-0,31 mm)

Remarques. - Cette espèce est très variable dans son aspect
externe en particulier dans la disposition et l’allure des aviculaires,
certaines zoécies peuvent en ètre totalement dépourvues. En vue
interne les zoécies régulièrement alternes offrent une très grande
régularité. La grosseur de l’ascopore le distingue parfaitement des
autres pores frontaux, il se situe à environ 0,18 mm au-dessous de
la ligne de suture péristomiale.

D’Archiac en 1846 signale dans le Lutétien supérieur de la
Goureppe une forme retrouvée plus fard par Canu en 1910 et
classée sous le nom de Porina{?) mamillata. D’après les figura-
tions de cet auteur il est vraisemblable que ce soit la mème espèce
que nous ayons à Handia. Malheureusement l’originai de d’ARCHiAC
a disparii et il n’a pas été possible de retrouver l’espèce dans la
collection Canu. Il semble d’ailleurs qu’il y ait eu de la part de
cet auteur confusion entre ascopore et aviculaire. Les grands avi¬
culaires marginaux ne soni jamais signalés, mais Canu n’avait
que peu d’échantillons. Il se peut également que ce soit la mème
forme signalée par Roemer, mais sa description et figuration
manquent de détails.

Deux autres Tubucella pourvues d’aviculaires mais très dif-
férentes ont été citées dans la littérature :

En 1991, Waters sous le nom de Porina(?) papillosa (Reuss)
décrit et figure une Tubucella avec aviculaires frontaux mais ces
derniers se situent au-dessous de l’orifice zoécial.

Enfin, en 1929, Canu et Bassler décrivent Tubucella avicu-
lifera. Cette espèce du Lutétien belge, qui se retrouve dans l’Eo¬
cène moyen du Nord de l’Aquitaine est parfaitement bien carac-
térisée par ses aviculaires frontaux alternants.

Distribution. - Eocène de Biarritz.

322

M. LABRACHERIE

Famille Cheiloporinidae Bassler, 1936

Genre Tetraplaria Tenison-Woods, 1879

Tetraplaria sp.

PI. VII - Figs. 9-12.

Matèrici - 6 fragments.

Description. - Zoarium cellariiforme. Internoeuds élancés tou-
jours incomplets à section cruciforme, composés de 4 rangées
zoéciales diamétralement opposées. Une doublé ouverture occupe
Textrémité proximale de Y inter noeud, seule préservée dans les
spécimens récoltés, constituée de la partie proximale très effilée
des deux premières zoécies.

Zoécies adjacentes et alternes, en forme de massue, arrondies
distalement, fortement rétrécies du coté proximal, bordées par
un large filet.

Frontale très fortement convexe en forme de tète d’épingle.
Surface perforée de nombreux pores subcirculaires, lisse dans la
région située immédiatement au voisinage de l’orifice zoécial.

Orifice subcirculaire, plongeant vers l’axe du zoarium, semi-
circulaire du coté proximal largement arrondi distalement.

Ovicelle hyperstomial, globuleux légèrement allongé, égale-
ment perforé.

Un seul exemplaire ovicellé.

Dimensions : Lz (4): 0,68 mm (0,62 - 0,75 mm)

lz (4): 0,26 mm (0,21-0,30 mm)

ho (4): 0,10 mm (0,08-0,11 mm)

lo (4): 0,12 mm

L ovicelle (1): 0,33 mm.

Remarques. - Cette espèce est très voisine de T. petila Chee-
tham, 1963. Cependant les deux petits tubercules oraux n’ont
jamais été observés. La frontale est moins largement ponctuée et
rovicelle apparait plus allongé.

Une autre espèce très voisine est Bigemellaria pedmiculata
Mac Gillivray, 1895, Tauteur signale un sinus sur la lèvre infé-
rieure qui apparait beaucoup plus étroit.

QUELQUES BRYOZOAIRES CHEILOSTOMES ETC.

.323

Famille Vittaticellidae Harmer, 1957

Gerire Ditaxipora Mac Gillivray, 1895

Ditaxipora labiata (Canu)

PI. VII - Figs. 13-14.

1910 Bactridium labiatum Canu, p. 846, pi. 16, figs. 7-8.

Description. - Zoarium érigé, probablement articulé, composé
d’ internoeuds élancés, bisériés, formés au moins de 10 zoécies
disposées alternati vement ; les orifices s’ouvrent sur une seule face.
Ouverture unique circulaire à l’extrémité proximale. Extrémité
distale non préservée.

Zoécies allongées, séparées par un sillon très distinct, bor-
dées par un petit fil saillant, étroit du coté frontal, visible sur-
tout sur les marges latérales et d’un large bourrelet du coté
dorsal.

Frontale légèrement convexe, divisée en 2 compartiments
légèrement déprimés par un système de crétes saillantes un peu
sinueuses en forme de T, la barre transversale est située immé-
diatement au-dessous de l’orifice.

Surf ace des dépressions latérales ponctuée. Pores frontaux
circulaires souvent irrégulièrement distribués quoique dans cer-
tains cas ils peuvent s’aligner en 4 rangées longitudinales, 2 de
part et d’autre de la créte médiane. Dorsale piane, surface per-
forée de 15 à 18 pores arrondis ou elliptiques irrégulièrement
distribués.

Orifice presque terminal sur la frontale ; le bord distai est
très largement arrondi, le bord proximal souvent peu visible à
peu près droit ; une paire de petits condyles situés très bas gé-
néralement peu distincts.

Aviculaire frontal placé sur le bord externe des zoécies au
niveau de Porifice. Rostre court pointu dirigé distalement et lé¬
gèrement vers Textérieur. Pivot transversal.

Ovicelle non observé.

Dimensìons\ Lz (6): 0,44 mm (0,43 - 0,46 mm)

lz (6): 0,32 mm (0,31-0,33 mm)
ho (6): 0,09 mm (0,08 -0,09 mm)
lo (6): 0,08 mm

L aviculaire (6): 0,12 mm (0,12-0,13 mm)

324

M. LABRACHERIE

Remarques. - Les spécimens trouvés à Handia sont certaine-
ment identifiables à Fespèce B. labiatum Canu, 1910 bien que l’il-
lustration donnée par cet auteur ne soit pas tout à fait suffisam-
ment nette pour ètre très affirmatif.

Dans sa description, Canu ne signale pas en effet les crètes
frontales pourtant très visibles sur la major ite des échantillons
récoltés, cependant, dans certains cas, la barre médiane longi¬
tudinale peut devenir presque invisible, seule persiste comme le
signale d’ailleurs Fauteur une sorte de lèvre saillante immédia-
ternent située au-dessous de Forifice.

Les mesures qui ont été données coincident avec celles que
Fon peut relever sur la figuration de Canu.

Il est évident que cette espèce n’appartient pas au genre
Bactridium. Stach en 1935 la classe dans le genre Ditaxiporina
ainsi qiFune autre forme de l’Eocène du Bassin Aquitain, Ditaxi-
pora luteciana Canu, 1913. Or ce genre est caractérisé par « thè
absence of median longitudinal band and by thè fairly occurrence
of avicularia on both sides of zooecia ».Ces 2 espèces semblent
ètre mal placées dans ce genre. Ditaxipora labiata (Canu) pré¬
sente de très grandes affinités avec Fespèce type D. internodia
(Waters). Cette dernière possède des mesures micrométriques plus
grandes quoique celles données plus tard par Stach soient plus
faibles et très voisines de celles des spécimens de B. labiatum de
Handia. Elle en diffère également par un compartimentage plus
poussé et un nombre de pores frontaux et dorsaux moins grand.

Distribution. - Auversien de Biarritz.

REFERENCES

(1) Archiac E. J. A. d’, 1846 - Description des fossiles recueillis par

M. Thorent dans les couehes à Nummulites des environs de Rayonne -
Mém. Soc. GéoL Fr. 2e sér., II, pp. 189-217, 4 pls.

(2) Bassler R. S., 1953 - Bryozoa - In treatise on Invertebrate paleontolog-y

de R. C. Moore. Part. G. New York, pp. 1-253, 175 figs.

(3) Braga Gp., 1963 - I Briozoi del Tertiario Veneto. 1° contributo - Boll.

Soc. Paleont. Ital., voi. 2, n° 1, pp. 16-56, 4 pls.

(4) Buge E., 1949 - Les Bryozoaires de POligocène de Basse Alsace - Bull.

Soc. Geol. Fr., 5e sér., XIX, pp. 623-628, 4 fig-s.

QUELQUES BRYOZOAIRES CHEILOSTOMES ETC. 325

(5) Canu F., 1907-1910 - Bryozoaires des terrains tertiaires des environs

de Paris - Ann. paléont., II, pp. 57-88, pls. 9-12 (1907), II, pp. 137-160,
pls. 19-22 (1907), III, pp. 61-104, pls. 6-7 (1908), IV, pp. 29-68, pls. 8-11
(1909), V, pp. 89-112, pls. 12-15 (1910).

(6) Canu F., 1910 - Les Bryozoaires fossiles des terrains du Sud-Ouest de

la France. V. Lutétien. VI. Bartonien - Bull. Soc. Géol. Fr. 4e sér.,
X, pp. 440-455, 4 pls.

(7) Canu F., 1913 - Etudes morphologiques sur trois nouvelles familles de

Bryozoaires - Bull. Soc. Géol. Fr., 4e sér., XIII, pp. 132-147, 10 figs.

(8) Canu F., 1914 - Contribution à l’étude des Bryozoaires fossiles XIV.

Bryozoaires du Stampien - Bull. Soc. Géol. Fr., 4e sér., XIV, pp. 147-
152, 1 pi.

(9) Canu F. & Bassler R. S., 1920 - North American early Tertiary Bryozoa

- Bull. U. S. nat. Mus., n° 106, pp. 1-879, 279 figs., 162 pls.

(10) Canu F. & Bassler R. S., 1923 - North American later Tertiary and

Quaternary Bryozoa - Bull. U. S. nat. Mus., n° 125, pp. 1-302, 38 figs.,
47 pls.

(11) Canu F. & Bassler R. S., 1929 - Bryozoaires éocènes de la Belgique

conservés au Musée d’ Histoire Naturelle de Belgique - Mém. Mus. r.
Hist. nat. Belgique, n° 39, pp. 1-69, 5 pls.

(12) Cheetham A. H., 1963 - Late Eocene zoogeography of thè eastern Gulf

Coast region - Mem. Geol. Soc. Anier. Neiv York, 91, pp. 1-113, 3 pls.,
34 figs.

(13) Koschinsky C., 1885 - Ein Beitrage zur Kentniss der Bryozoenfauna

der àlteren Tertiàrschichten des sùdlichen Bayerns, I. Cheilostomata

- Palaeontographica, Stuttgart, 32, pp. 1-73, 7 pls.

(14) Mac Gillivray J., 1895 - A Monograph of thè Tertiary Polyzoa of

Victoria - Trans. Proc. r. Soc. Victoria (n. s.) IV, pp. 1-166, 22 pls.

(15) Manzoni A., 1877 - Briozoi fossili del Miocene d’Austria ed Ungheria.

II. Parte - Denk. math.-nat. CI. k. Akacl. Wiss., XXXVII, n° 2, pp. 49-78,
17 pls.

(16) Meunier A., & Pergens E., 1886 - Les Bryozoaires du système montien

(Eocène inférieur) - Louvain 8e, pp. 1-14, 3 pls.

(17) Reuss A. E., 1847 - Die fossilen Polyparien des Wiener Tertiarbeckens.

Ein monographischer Versuch - Naturwissensch. Abhandl. II, n° 1,
pp. 1-109, 11 pls.

(18) Reuss A. E., 1868 - Zur fossilen Fauna der Oligocànschichten von

Gaas - Sitz k. Akacl. Wissens. Wien., LIX, pp. 446-488, 6 pls.

(19) Reuss A. E., 1869 - Palàontologische Studien ùber die àlteren Ter¬

tiàrschichten der Alpen. II Die fossilen Anthozoen und Bryozoen der
Schichtengruppe von Crosara - Denk. math. -nat. CI. k. Akacl. TFis-
seìis., XXIX, pp. 215-298, 20 pls.

(20) Roemer F. A., 1862-64 - Beischreibung* der norddeutschen tertiàren Poly¬

parien - Palaeontographica, Bd. 9, 6, pp. 203-230, 3 pls.

(21) Stach L. W., 1935 - Victorian Tertiary Catenicellidae, Part III - Proc.

r. Soc. Victorian (n. s.), 48, pp. 27-49, 5 figs.

(22) Waters A. W., 1891 - North Italian Bryozoa - Quavt. J. Geol. Soc.

London, XLVIl, pp. 1-34, 1 fig., 4 pls.

PLANCHE VII.
(Toutes les figures X 20)

Figs. 1-6. — Crassimarginatella macrostoma (Reuss). 1, échant. GA 18949,
spécimen pseudovinculariiforme montrant un ovicelle. 2, échant.
GA 18944, zoécies de régénération. 3, échant. 18949, vue frontale
d’un spécimen avec ovicelles brisés. 4,5, échant. GA 18941, spéci-
mens vinculariiformes. 6, échant. GA 18949, ? aviculaire.

Figs. 7-8. — Smittìpora? sp. 7, échant. GA 7597, fragment assez mal con¬
servò, chauffé et photographié sous une goutte d’eau. 8, échant
GA 7591, spécimen montrant une zoécie bien c-onservée.

Figs. 9-12. — T etraplaria sp. 9, 10, échant. GA 18919, extrémités proximales
très effilées des internoeuds. 11, échant. GA 7597, zoécies normales
montrant la surface zoéciale finement ponc-tuée. 12, échant. GA
7595, ovicelle sur un petit fragment.

Figs. 13-14. — Ditaxipora labiata (Canu). 13, échant. GA 18933, spécimen
en vue frontale montrant les crètes saillantes. 14, le mème en
vue dorsale.

LABRACHERIE M.

Atti Soc. It. Se. Nat. e Museo Civ.St. Nat. Milano, Voi. CVIII,

Pl. VII

PLANCHE Vili.
iToutes les figures X 20)

Figs. 15-16. — O chef osella sp. 15, échant. GA 18944, vue frontale d’un spé-
cimen assez bien conservò montrant le gros aviculaire. 16, échant.
GA 18938, spéc-imen montrant les costules périphériques saillantes.

Figs. 17-19. — Porina coronata (Reuss). 17, échant. GA 18920, extrémité
distale. 18, échant. GA 18930, spécimen médiocrement préservé.
19, échant. GA 18936, vue frontale montrant les grands aviculaires
à large mandibule et dans la région supérieure les aviculaires
péristomiens.

LABRACHERIE M

Atti Soc.It.Sc.Nat. e Museo Civ.St.Nat.Milano,Vol.CVIII,

Pl. Vili

PLANCHE IX.
(Toutes les figures X 20)

Figs. 20-25. — Beisselina sp. 20, échant. GA 18921, surface zoariale mon-
trant les petits aviculaires frontaux. 21, échant. GA 18949,
spécimen montrant l’ascopore volnmineux. 22, échant. GA 7597,
avic-ulaire immergé au-dessus de l’orifice péristomial visible sur
quelques zoécies. 23, échant. GA 18928, zoécies à péristomes petits
et très saillants. 24, échant. GA 18924, fragment usé. 25, échant.
GA 7597, vue interne de quelques zoécies montrant l’ascopore.

LABRACHERIE M.

Atti Soc. It. Se. Nat. e Museo Civ.St. Nat. Milano, Voi. CVIII,

Pl. IX

PLANCHE X.
(Toutes les figures X 20)

Figs. 26-32. — Tubucella cavui n. sp. 26, échant., GA 18920, spécimen à
péristome peu saillant et à aviculaires frontaux arrondis. 27,
échant. GA 18920, holotype. 28, éehant. GA 7597, vue frontale
montrant les grands aviculaires. 29, échant. GA 18942, spécimen
montrant l’aviculaire marginai. 30, échant. GA 18920, holotype,
aviculaire marginai. 31, échant. GA 18924, spécimen ovicellé. 32,
échant. 18924, vue interne montrant Tascopore.

LABRACHERIE M.

Atti Soc. It. Se. Nat. e Museo Civ.St.Nat.Milano,Vol.CVIII,

Pl. X

Atti Soc. It. So. Nat. e Museo Civ. St. Nat. Milano - 108: 327-344, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

43. Group 5: Biogeography and Biostratigraphy.

Louis David - Noèl Mongereau -

SlMONE POUYET (*) - S. RlTZKOWSKI (**)

LES BRYOZOAIRES DU CHATTIEN
DE LA REGION DE KASSEL
(HESSE - ALLEMAGNE)

Riassunto. — I Briozoi studiati provengono da 4 località situate nella
regione di Kassel (Assia, Germania) e sono stati raccolti nella facies a
sabbie marine di Kassel (« Kasseler Meeressand ») che rappresentano lo
strato-tipo del Chattiano tedesco.

La parte sistematica comprende un elenco delle specie (7 Cy ciò stornata
e 16 Cheilostcmata) , la loro diffusione in og'ni località e la loro distribu¬
zione stratigrafica.

Questa briofauna è presa a sostegno di alcune idee relative alla paleo¬
geografia e alla paleoecologia del Golfo di Kassel.

Summary. — The studied Bryozoa are obtained from four localities si-
tuated in thè area of Kassel (Hesse, Germany).. They are been collected in
thè facies of « Kasseler Meeressand » representing thè stratotype of thè ger-
man Chattian.

The systematical part includes a list of species (seven Cy ciò stornata
and sixteen C beilo stornata), their distribution in each locality as well as
their stratigraphical distribution. This bryozoa’s fauna shows some interes-
ting ideas relating to thè paleogeography and thè paleoecology of thè Kassel
Gulf.

Zusammenfassung. — Die untersuchten Bryozoen stammen von 4 Loka-
litàten der Umgebung von Kassel (Hessen, Deutschland). Sie wurden im

(*) Faculté des Sciences de Lyon, Département des Sciences de la Terre,

« Centre de Paléontologie Stratigraphique », Lyon, France - (**) Geoio-
gisch-paleontologisches Institut der Georg-August Universitàt, Gottingen,
Germany (W.).

L. DAVID - N. MONGEREAU - S. POUYET - S. RITZKOWSKI

« Kasseler Meeressand » aufgesammelt, der den Stratotyp des deutschen
Chatts darstellt.

Der systematisc-he Teil enthàlt eine Liste der Arten (7 Cyclostomata,
16 Cheilostomata), ihre Verteilung innerhalb jedes Vorkommens und ihre
stratigraphische Verbreitung. Diese Bryozoen-Fauna liefert bemerkens-
werte Anhaltspunkte fur Palaogeographie und Palòkologie des Kasseler
Golfes.

I - Introduction.

Les assises ayant livré la faune de Bryozoaires ici étudiée
sont celles du « Kasseler Meeressand » c’est à dire les assises-
tvpes du «Chattien» allemand (= Chattische Stufe) (W. Hinsch,
1958, p. 25). Il y a un intére! stratigraphique certain à connaitre
les associations de Bryozoaires rencontrés dans ces couches-types.

L’Oligocène supérieur du Nord de la Hesse a été révisé récem-
ment du point de vue stratigraphique (S. Ritzkowski, 1965).
Gràce en particulier à de nombreux sondages, les données classi-
ques ont pu ètre complétées largement. Les Foraminifères et
Ostracodes ont précisé la stratigraphie désormais établie sur des
profils verticaux plus continus.

Les Bryozoaires recueillis par S. R. proviennent de quatre
groupes de gisements, tous situés dans la région de Kassel
(fi g- 1):

1. - Alliberei : sondage preag 2715, au SE d’Ahlberg (S. R., 1965,

p. 96);

2. - Ahnetal : les assises du Kasseler Meeressand sont connues

en affleurements et un sondage traverse le Rupélien sous-
jacent (S. R., 1965, p. 100, fig. 22; 1967, p. 297, fig. 1);

3. - Oberkaufungen : sous ce noni sont rassemblés deux affleu¬

rements, l’un sur le versant ouest du Weinberg, l’autre sur
le Gelber Berg près de Niederkaufungen (S. R., 1965, p. 112-
114);

4. - Glìmmerode : cette coupé intéresse les assises du Kasseler

Meeressand sur 62 m d’épaisseur ; les assises sont très riches
en macro et microfossiles (S. R., 1965, p. 127, fig. 24; 1967,
p. 319, fig. 10).

LES BRYOZOAIRES DU CHATTIEN ETC.

329

Fig. 1. — Situation des gisements étudiés avec indication approxi-
mative du rivage du golfe de Kassel.

On voudra bien se reporter à l’ouvrage de S. Ritzkowski,
selon les références ci-dessus indiquées, pour avoir tous les détails
nécessaires sur le pian de la stratigraphie et de la lithologie.

Les Bryozoaires oligocènes européens sont encore relative-
ment mal connus. Les travaux les concernant sont pour la plu-
part anciens: ceux de R. A. Philippi, de A. E. Reuss, de
F. A. Roemer et de F. Stoliczka datent de 1843 à 1867. Plus

330

L. DAVID - N. MONGEREAU - S. POUYET - S. RITZKOWSKI

récentes sont les études de K. Hucke et E. Voigt (1929), de
F. Franke (1939), E. Dartevelle (1952) et de G. Braga (1966).

Deux d’entre nous (L. D. et S. P., 1968) ont donné une étude
paléontologique particulière de quelques Cheilostomes jusqu’à
présent mal connus.

Les Bryozoaires déterminés dans le Kasseler Meeressand
seront donc présentés ci-après sous la forme d’une simple liste
systématique ne comprenant ni synonymie, ni description. Chaque
espèce est présentée en suivant la classification de R. S. Bassler
{in Treatise of Invertebrate Paleontology, part G, 1953) avec
indication du nombre d’échantillons triés et déterminés dans
chaque prélèvement.

Il - Liste systématique (*).

Ordre Cyclostomata Busk, 1852

A - Sous-ordre Articulata Busk, 1859

Famille Crisiidae Johnston, 1847
C risia sp.

Un seul échantillon indéterminable spécifiquement.
Localité :

Glimmerode :

— 57 à 58 m (FSL n° 19935)

B - Sous-ordre Tubuloporina Milne-Edwards, 1838

Famille Tubuliporidae Johnston, 1838
Bitubigera biseriata (Philippi, 1843)

Localités :

Ahlberg, sondage Preag 2715:

— 44 à 45 m (FSL n° 19902, 1 échantillon)

— 45 à 46 m (FSL n° 19903, 1 éch.)

(:;:) Les échantillons conservés à la Faculté des Sciences de Lyon sont
désig’nés par FSL suivi du nombre de l’ inventaire g'énéral des collections
du Département des Sciences de la Terre. Le symbole GAU désigne les
échantillons conservés au « Geologisch-Paleontologisches Institut der Georg-
August-Universitàt » de Gottingen. (Orig. Nr. 632).

LES BRYOZOAIRES DU CHATTIEN ETC.

331

Ahnetal, affleurement 1 :

(FSL n° 19901, 1 éch. et GAU n° 632-1, 1 éch.)
Glimmerode :

— 57 à 58 m (FSL n° 19898, 1 éch. et GAU n° 632-2,
1 éch.)

— 80,5 à 81 m (FSL n° 19899, 1 éch.)

— 81,5 à 82 m (FSL n° 19900, 1 éch.)

Famille Entalophoridae Reuss, 1869
Entalophora macrostoma (Milne-Edwards, 1838)
Localités :

Ahlberg, sondage Preag 2715:

— 40 à 41 m (FSL n<> 19932, 3 éch)

— 45 à 46 m (FSL n° 19933, 1 éch.)

Ahnetal , affleurement 4:

(FSL n° 19934, 1 éch.)

Glimmerode :

— 48 à 49 m (FSL n° 19924-19925-19926, 30 éch. et
GAU n° 632-3, 10 éch.)

— 53 à 54 m (FSL n° 19927-19928, 2 éch.)

— 57 à 58 m (FSL n° 19929-19930, 9 éch.)

— 81,5 à 82 m (FSL n° 19931, 2 éch.)

C - Sous-ordre Cancellata Gregory, 1896

Famille Horneridae Gregory, 1899
Hornera biseriata Philippi, 1843

Localités :

Ahlberg , sondage Preag 2715:

— 40 à 41 m (FSL n° 19910, 1 éch.)

— 44 à 45 m (FSL n" 19911, 1 éch.)

— 45 à 46 m (FSL n° 19912, 1 éch.)

Glimmerode :

— 48 à 49 m (FSL n" 19907, 1 éch.)

— 53 à 54 m (FSL n° 19908, 1 éch. et GAU n° 632-4,

1 éch.)

— 80,5 à 81 m (FSL n° 19909, 2 éch.)

L. DAVID - N. MONGEREAU - S. POUYET - S. RITZKOWSKI

332

H ornerà concatenata Reuss, 1868

Locai ités :

Ahlberg, sondage Preag 2715:

— 30 à 31 m (FSL n° 19920, 1 éch.)

— 40 à 41 m (FSL n° 19921, 6 éch. et GAU n° 632-5,

3 éch.)

— 45 a 46 m (FSL n° 19923, 11 éch.)

Glimmerode :

— 33,5 à 34 m (FSL n° 19913, 3 éch.)

— 48 à 49 m (FSL n« 19914, 24 éch.)

— 49 à 50 m (FSL n° 19915, 25 éch.)

— 53 à 54 m (FSL n° 19916, 19 éch.)

— 57 à 58 m (FSL n« 19917, 12 éch.)

— 80,5 à 81 m (FSL n° 19918, 4 éch.)

— 81,5 à 82 m (FSL n° 19919, 2 éch.)

H ornerà tortuosa Roemer, 1863

Localités :

Ahlberg , sondage Preag 2715:

— 40 à 41 m (FSL n° 19896, 1 éch.)

— 45 à 46 m (FSL n° 19897, 1 éch.)

Glimmcrocle :

— 33,5 à 34 m (FSL n° 19891, 4 éch.)

— 48 à 49 m (FSL n° 19892, 2 éch.)

— 49 à 50 m (FSL n° 19893, 2 éch.)

— 53 à 54 m (FSL n° 19894, 4 éch.)

— 57 à 58 m (FSL n« 19895, 11 éch. et GAU n° 632-6,

4 éch.)

— 81,5 à 82 m (FSL n° 19904, 1 éch.)

Famille Petaloporidae Gregory, 1899
Reteporidea cancellata (Goldfuss, 1826)

Localités :

Ahlberg , sondage Preag 2715:

— 45 à 46 m (FSL n° 19906, 1 éch. et GAU n° 632-7,
2 éch.)

Glimmerode :

— 48 à 49 m (FSL n° 19905, 3 éch.)

LES BRYOZOAIRES DU CHATTIEN ETC.

Q •>
*y o *j

Ordre Cheilostomata Busk, 1852

A - Sous-ordre Anasca Levinsen. 1902

Division Malacostega Levinsen, 1902

Famille Membraniporidae Busk, 1854
Biflustra osnabrugensis Heuss* 1864

Localités :

Ahlberg , sondage Preag 2715 :

— 44 à 45 m (FSL n° 130023, 2 éch.)

Glimmerode :

— 53 à 54 m (GAU n° 632-8, 1 éch.)

— 80,5 à 81 m (GAU n° 632-9, 1 éch.)

— 81,5 à 82 m (FSL n° 130024, 3 éch.)

Division Coilostega Levinsen, 1902

Famille Lunulitidae Lagaaij, 1952
Lunulites subpiena Heuss-, 1855

A part quelques rares spécimens entiers, nous avons trouvé
de nombreux fragments à Ahlberg et Ahnetal où l’espèce consti-
tue à elle seule la presque totalité des Bryozoaires récoltés.

Localités :

Ahlberg , sondage Preag 2715:

— 26 à 27 m (GAU n° 632-10)

— 30 à 31 m (GAU n° 632-11)

— 36 à 37 m (FSL n° 130030)

— 40 à 41 m (FSL n° 130031, 2 éch. et GAU n° 632-12)

— 44 à 45 m (GAU n" 632-13, 3 éch.)

Ahnetal , affleurement 1 (FSL n° 130025-130026; 130064)
affleurement 4 (FSL n° 130027-130028 et GAU n° 632-14)
sondage :

— 0,20 à 0,70 m (FSL np 130029)

— 0,75 à 1,20 m (GAU n° 632-15)

— 1,10 à 1,50 m (GAU n° 632-16)

Oberkaufungen, Gelber Berg (GAU n° 632-17)

Weinberg (FSL n° 130032 et GAU n° 632-18)

(très nombreux échantillons dans tous les gisements).

334

L. DAVID - N. MONGEREAU - S. POUYET - S. RITZKOWSKI

Famille Steginoporellidae Bassler, 1952
SteginoporeUa elegans (Milne-Edwards, 1836)

Cette espèce n’existe pas dans les sonda ges, elle est très fra¬
gile et nous n’avons que 5 échantillons.

Localités :

Ahnetal, affleurement 4 (FSL n° 130033-130034, 3 éch. et
GAU n<> 632-19, 2 éch.)

Divisi on Pseudostega Levinsen, 1909

Famille Cellariìdae Hincks, 1880
Cellaria fistulosa Auct.

Localités :

Ahnetal , affleurement 4 (FSL n° 130035, 1 éch. et GAU
no 632-20, 1 éch.)

Glimmerode :

— 48 à 49 m (FSL n° 130036, 4 éch.)

— 53 à 54 m (GAU n° 632-21, 2 éch.)

— 80,5 à 81 m (FSL n° 130037, 1 éch. et GAU n° 632-22,
5 éch.)

B - Sous-ordre Ascophora Levinsen, 1909

Famille Hippoporinidae Bassler, 1935
Hipposera formosa (Duvergier, 1923)

Localités:

Glimmerode :

— 48 à 49 m (GAU n° 632-23, 15 éch.)

— 49 à 50 m (FSL n° 130050-130051, 6 éch.)

— 80,5 à 81 m (FSL m 130052, 1 éch.)

Famille Mucronellidae Levinsen, 1902
Smittina diplostoma (Philippi, 1843)

Localités :

Glimmerode :

— 49 à 50 m (FSL n° 130053-130069, 2 éch. et GAU
n° 632-24, 2 éch.)

LES BRYOZOAIRES DU CHATTIEN ETC.

335

Smittina sp.

Une dizaine de frangments bilamellaires, difficiles à ratta-
cher à une espèce connue.

Localités :

Glimmerode :

— 48 à 49 m (GAU n° 632-25, 1 éch.)

— 49 à 50 m (FSL n° 130054, 130066, 130067, 5 éch.)

— 53 à 54 m (FSL n° 130055, 1 éch.)

— 57 à 58 m (GAU n° 632-26, 2 éch.)

Reussia regularis (Reuss, 1866)

Localités :

Glimmerode :

— 48 à 49 m (FSL n° 130047, 130048, 130068, 10 éch.)

— 57 à 58 m (FSL n° 130049, 1 éch.)

Famille Reteporidae Smitt, 1867

Sertella sp.

Spécimens de petite taille indéterminables spécifiquement.
Localités :

Glimmerode :

— 53 à 54 m (GAU n° 632-27, 2 éch.)

— 57 à 58 m (GAU n° 632-28, 1 éch.)

Famille Tubucellariidae Busk, 1884
Tubucellaria sp.

Deux fragments de zoaria ne comprenant chacun que quel
ques zoécies. Il s’agit peut-ètre de T. cereoides (Ellis et Solander,
1786) mais il faudrait trouver d’autres spécimens pour pouvoir
Taffirmer avec certitude.

Loca li té :

Glimmerode :

— 48 à 49 m (FSL n° 130056, 2 éch.)

Famille Adeonidae Jullien, 1903
Adeonellopsis subter es (Roemer, 1863)

Localités :

Glimmerode :

— 48 à 49 m (FSL m 130043, 2 éch.)

— 49 à 50 m (FSL n" 130044, 5 éch.)

L. DAVID - N. MONGEREAU - S. POUYET - S. RITZKOWSKI

336

— 53 à 54 m (FSL n° 130045, 6 éch.)

— 57 à 58 m (GAU n° 632-29, 8 éch.)

— 80,5 à 81 m (FSL n° 130046, 1 éch., 130063, 1 éch.)

— 81,5 à 82 m (GAU n° 632-30, 5 éch.)

Bracebridgia polymorpha (Reuss, 1864)

Localités :

Ahlberg , sondage Preag 2715:

— 40 à 41 m (FSL n° 130038, 130065, 2 éch. et GAU
n° 632-31, 1 éch.)

— 44 à 45 m (FSL n° 130039, 3 éch.)

Ahnetal, sondage:

— 0,75 à 1,20 m (GAU n" 632-32, 1 éch.)

Glimm erode :

— 49 à 50 m (FSL n° 130040, 4 éch.)

— 53 à 54 m (GAU n° 632-33, 2 éch.)

— 81,5 à 82 m (FSL n° 130041, 1 éch.)

Meniscopora brongniarti (Milne-Edwards, 1836)

Localités :

Glimmerode :

— 49 à 50 m (FSL n° 130042, 1 éch. et GAU n° 632-34,
1 éch.)

— 57 à 58 m (GAU n* 632-35, 2 éch.)

Famille Myriozoidae Smitt, 1867
Myriapora truncata (Pallas, 1766)

Localités :

Glimmerode :

— 48 à 49 m (GAU n° 632-36, 5 éch.)

— 49 à 50 m (FSL n° 130057, 3 éch.)

— 57 à 58 m (GAU n° 632-37, 1 éch.)

C - Incertae sedis

« Eschara » fissimargo Reuss, 1866

N’ayant trouvé qirun seul spécimen avec sept cellules non
ovicellées, il est impossible pour V instant d’ intégrer cette espèce
dans un genre de Cheilostomes.

LES BRYOZOAIRES DU CHATTIEN ETC.

337

Localité :

Glimmerode :

— 81,5 à 82 m (FSL n° 130058, 1 éch.)

« Eschara » ivittei Heuss, 1864

Nous avons de nombreux fragments de zoaria. Là encore, les
ovicelles sont absentes d’où la difficulté de classer génériquement
cette espèce.

Localités :

Glimmerocle :

— 33,5 à 34 m (GAU n° 632-38, 2 éch.)

— 48 à 49 m (FSL n° 130059, 7 éch.)

— 49 à 50 m (GAU n° 632-39, 7 éch.)

— 53 à 54 m (GAU n° 632-40, 3 éch.)

— 57 à 58 m (FSL n° 130060, 3 éch.)

— 80,5 à 81 m (FSL n° 130061, 3 éch.)

— 81,5 à 82 m (FSL ir 130062, 1 éch. et GAU ir 632-41,
3 éch.)

HI - Conclusions.

A - Repartition par gisement

Nous donnerons d’abord les listes de répartition des espèces
pour chaque gisement ici étudié.

Ahlberg: Bitubigera biseriata

Entalophora macrostoma
H ornerà biseriata
H ornerà concatenata
H ornerà tortuosa
Reteporidea cancellata
Bif lustra osnabrugensis
Lunulites subpiena
Bracebridgia polymorpha

Ahnetal : Bitubigera biseriata

Entalophora macrostoma
Lunulites subpiena

338

L. DAVID - N. MONGEREAU - S. POUYET - S. RITZKOWSKI

Steginoporella elegans
Cellaria fistidosa
Bracebridgia polymorpha

Oberkaufungen :

Weinberg: Lunulites subpiena

Gelber Berg: Lunulites subpiena

Glimmerode : C risia sp.

Bitubig era biseriata
Entalophora macrostoma
H ornerà biseriata
H ornerà concatenata
Hornera tortuosa
Reteporidea cancellata
Biflustra osnabrugensis
Cellaria fistidosa
Hipposera formosa
Smittina diplostoma
Smittina sp.

Tubucellaria sp.
Adeonellopsis subter es
Bracebridgia polymorpha
M enis copora br ongniar ti
Myriapora truncata
« Eschara » fissimargo
« Eschara » wittei

Nous constatons d’abord que Lunulites subpiena est l’espèce
la plus abondante dans les trois gisements proches de Kassel mais
qu elle manque totalement à Glimmerode. Ce fait pourrait ètre du
à la proximité du rivage pour cette dernière localité mais nous
veuons que tous les Bryozoaires ont été entrainés par les courants
avant fossilisation.

La présence de Steginoporella elegans en un seul point traduit
simplement Textrème fragilité des zoaria.

Le gisement de Glimmerode est donc le plus riche en espèces ;
il n y a pratiquement aucune différence significative avec Ahlberg
ou avec Ahnetal qui sont plus pauvres. Il n’est pas possible de

LES BRYOZOAIRES DU CHATTIEN ETC.

339

chercher un parallélisme des assises les unes avec les autres: la
faune est hcmogène et il convient de la considérer dans son en¬
semble.

B - Biostratigraphie

Le tableau ci-après donne la répartition stratigraphique con-
nue des espèces déterminées :

Liste des espèces

I Cellaria fistulosa
Myriapora truncata

II Hornera concatenata
Bracebridgia polymorpha
Meniscopora brongniarti
Adeonellopsis subteres
Steginoporella elegans
Entalophora macrostoma
Reteporidea cancellata

'<D

/0>

a»

CJj

'<z>

,<D

i i

•

a»

+->

-y

III Reussia regularis
Hipposera formosa

IV Bitubigera biseriata
Hornera biseriata
Hornera tortuosa
Biflustra osnabrugensis
Lunulites subpiena
Smittina diplostoma

« Eschara » fissimargo
« Eschara » wittei

Fig. 2. — Tableau de répartition stratigraphique des espèces.

340

L. DAVID - N. MONGEREAU - S. POUYET - S. RITZKOWSKI

Les deux espèces du groupe I ont une large répartition stra-
tigraphique et sont encore vivantes. Sur le pian stratigraphique,
elles n’apportent rien mais seront utiles pour la paléoécologie.

Les quatre premières espèces du groupe II sont connues de
l’Eocène.Oligocène de divers bassins d’Europe occidentale. Compte-
tenu de l’ imprécision des connaissances sur les faunes de Bryo-
zoaires, elles confirment l’àge oligocène. Les trois autres sont si-
gnalées jusqu’au Miocène supérieur mais leur répartition est cen-
trée autour de l’Oligocène.

Dans le groupe III, les deux espèces sont connues de l’Oligo¬
cène et du Miocène d’Europe. L’une d’elles, Hipposera formosa, a
été décrite dans 1 Aquitanien d’Aquitaine et devient ainsi repré-
sentée dans l’Oligocène d’Allemagne. On peut considérer que la
coexistence de ces espèces et de celles du groupe précédent est la
plus sure confirmation de l’àge oligocène.

Enfin, les huit espèces du groupe IV sont particulières à l’Oli¬
gocène d’Allemagne et n’ont pas encore été retrouvées aiìleurs.
Elles n’ont aucun intérèt stratigraphique immédiat. Ces formes
propres au golfe de Kassel sont des espèces ou des sous-espèces
géographiques dont on ne connait pas encore les relations réelles
avec les espèces des autres domaines marins proches (atlantique
aquitanien ou méditerranée par exemple). Il n’est cependant pas
nécessaire de faire intervenir à leur propos un phénomène d’en-
démisme tant que l’évolution des faunes de Bryozoaires ne sera
pas connue avec précision.

En résumé, les Bryozoaires du « Kasseler Meeressand » n’ap-
portent pour l’ instant aucune véritable précision stratigraphique
sur les terrains qui les renferment. Par contre leur connaissance
dans les assises-types du Chattien servirà de base à des compa-
ì aisons ultérieures avec les faunes d’autres bassins oligocènes eu-
ropéens. A titre d’exemple, on a souvent admis que les couches
chattiennes de Kassel étaient de mème àge que les faluns de La-
brède (Aquitanien inférieur) d’Aquitaine (cf. G. Denizot, 1957,
p. 54, 97): les faunes de Bryozoaires sont nettement différentes ce
qui exclut un àge identique ou bien traduit un long isolement géo-
gi aphique. I n tei problème serait à revoir à l’aide d’autres orga-
nismes et d’études plus détaillées.

LES BRYOZOAIRES DU CHATTIEN ETC.

341

C - Paleoecologie et Paleogeographie

L’ensemble des Bryozoaires recueillis se trouve dans des ro-
ches de faciès détritique relativement fin ; leur fossilisation traduit
une thanatocénose avec transport certain. Il ne faut donc rien
attendre de la localisation des gisements fossilifères. Toutes les ob-
servations qui suivent sont valables pour le golfe de Kassel dans
son ensemble sans qu’on puisse apporter des détails à l’intérieur.

Les premières déductions peuvent ètre tirées de l’étude des
rares espèces encore vivantes :

Cellaria fistulosa est une espèce cosmopolite, sténobathe su-
perficielle, vivant de préférence sur les fonds meubles de type
sableux. Son optimum de fréquence se situe entre 30 et 80 m de
profondeur.

Myriapora truncata est une espèce méditerranéenne, très
abondante de Ima 130 m avec maximum sur les fonds coralli-
gènes entre 30 et 60 m. Elle se rencontre aussi en Atlantique, à
faible profondeur, près des còtes d’Espagne et du Maroc. Il est

étonnant qu’une tede espèce se rencontre dans un golfe dépendant
de l’Atlantique septentrional ; il faut remarquer cependant qu’elle
a déjà été citée dans le Pliocène des Pays-Bas ce qui conduirait à

admettre une vaste répartition au Tertiaire suivie d’une régression
(ou migration) durant le Quaternaire.

Rien ne laisse supposer la moindre dessalure de la mer : tous
les groupes présents sont ceux qui, dans la nature actuelle, sont
sténohalins.

Le classement des échantillons d’après les critères de forme
zoariale mis au point finalement par M. Labracherie et J. Prud’-
homme (1966) montre que la quasi totalité de la faune est com-
posée de colonies clressées, rigides ou flexibles, auxquelle s’ajoutent
les seuls types lunulitiformes. L’absence de formes encroiitantes ou
unilamellaires confirme l’existence prédominante de la biocénose
coralligène. Il ne faut cependant pas oublier que la dispersion des
gisements fossilifères et leur caractère de thanatocénose peut ca-
cher une sélection mécanique post-mortem des Bryozoaires par
les courants.

342

L. DAVID - N. MONGEREAU - S. POUYET - S. RITZKOWSKI

Sans éliminer la possibilité d’autres biotopes à Bryozoaires,
on peut raisonnablement admettre la prédominance de la biocénose
coralligène installée soit sur un substrat rocheux, soit plus prò-
bablement sur un fond meublé concrétionné.

En examinant la carte de répartition du substratum du « Kas-
seler Meeressand » (S. R. 1965, p. 77, fig. 19), on voit que le Trias
a pu jouer le ròle de substrat rocheux au début de V invasion ma¬
rine. Par la suite, les fonds rocheux ayant peu à peu disparu, les
zones sableuses avec coquilles et débris de coquilles ont été con-
crétionnés par les Algues, Bryozoaires ... et ont servi de support
à la biocénose coralligène.

Sur les fonds détritiques còtiers vivaient sans doute les Cel¬
laria qui se rencontrent aussi dans la biocénose coralligène ; sur les
fonds sableux, mème instables, devaient vivre les Lunulites en
grande abondance.

En résumé, le golfe de Kassel, durant le Chattien, devait ètre
largement cuvert sur l’Océan Atlantique ; sa profondeur ne devait
guère excéder 100 m. En dehors de la zone littorale peu profonde,
hétage circalittoral comprenait des fonds meubles parfois biologi-
quement concrétionnées pour permettre V installation de biocéno-
ses coralligènes qui, ailleurs, étaient installées sur des fonds ro¬
cheux (ex. Trias). La profondeur de ces faciès à Bryozoaires devait
ètre de 30 à 50 m environ, avec éclairement réduit (végétaux
sciaphiles). La salinité devait ètre normale et les courants très
faibles. De temps en temps, des courants plus violents mettaient
fin à Texistence des biocénoses coralligènes, arrachant les colo-
nies de Bryozoaires et les répartissant avec les particules détri¬
tiques dans les gisements qui sont les leurs aujourd’hui.

Ceci représente une vision synthétique, autrement dit « mo-
yenne » de la paléoécologie et de la paléogéographie du golfe de
Kassel. Ceci n’a donc aucune valeur absolue et seules de longues
études détaillées pourraient permettre de mieux saisir le détail
de la géographie du golfe à chaque moment de Y histoire du
Chattien.

LES BRYOZOAIRES DU CHATTIEN ETC.

143

BIBLIOGRAPHIE

Braga G., 1966 - Briozoi dell’Oligocene di Possagno (Trevigiano occiden¬
tale) - Boll. Soc. Pai. t., 4, 2, pp. 216-244, 3 figs., 1 tab., 3 pls.

Canu F. & Bassler R. S., 1931 - Bryozoaires oligocènes de la Belgìque -
Mém. Mus. r. Hist. nat. Belg., Bruxelles, n° 50, pp. 1-26, 2 figs.,
pls. I-IV.

Dartevelle E., 1952 - Bryozoaires fossiles de l’Oligocène de l’Allemagne -
Palàont. Zeits., Stuttgart, Bd 26, n° 3-4, pp. 181-204, 2 figs.

David L. & Pouyet S., 1968 - Les Bryozoaires Cheilostomes du Chattien de
la région de Kassel (Hesse, Allemagne) - Trav. Lab. Géol. Fac. Sci.
Lyon, NS, n° 15 sous presse, 2 pls.

Denizot G., 1957 - Tertiaire - France, Belgique, Pays-Bas, Luxembourg -
Lexique intern. Strati. Europe, fase. 4a VII, éd. C.N.R.S., Paris et
Congr. géol. Intern.

Franke F., 1939 - Die Bryozoen des Unteroligocàns von Magdeburg - Abh.
Mus. u. Vorgesch. Magdeburg, Bd VII, Hft I, pp. 59-67, pls. II-III.

Hinsch W., 1958 - Tertiaire - Allemagne du Nord. Lexique intern. Strati,
Europe, fase. 5h I., Ed. C.N.R.S., Paris et Congr. géol. Intern.

Hucke K. & Voigt E., 1929 - Beitràge sur Kenntniss der Fauna des nord-
deutschen Septarientones - Z. deutsch. geol. Ges. Berlin, t. 81, pp. 159-
168, pls. VI-VII.

Koschinsky C., 1885 - Ein Beitrag zur Kenntniss der Bryozoenfauna der
àlteren Tertiàrschichten des sudlichen Bayerns. I Abth.. Cheilosto-
mata - Palaeontographica, Stuttgart, Bd XXXII, pp. 1-73, pls. I-VII.

Labracherie M. & Prud’homme J., 1966 - Essai d’interprétation de paléo-
milieux gràce à la méthode de distribution des formes zoariales chez
les Bryozoaires - Bull. Soc. géol. Fr., Paris, 7a sér., t. Vili, pp. 102-
106, 1 tabi.

Labracherie M. & Prud’homme J., 1967 - Observations paléoécologiques sur
les Bryozoaires des formations classiques du Blayais - Act. Soc. Linn.
Bordeaux, Bordeaux, t. 104, sér. B, n° 10, 10 pp., 2 pls.

Philippi R. A., 1843 - Beitràge zur Kenntniss der Tertiàrversteinerungen
des nordwestlichen Deutschlands - Fischer éd., Kassel, 88 p., Ili pi.

Reuss A. E., 1847 - Die Fossilen Polyparien des Wiener Tertiàrbeckens -
Haid. Naturwiss. Abh., Wien, t. II, pp. 1-109, pls. I-XI.

Reuss A. E., 1855 - Beitràge zur Charakteristik der Tertiàrschichten des
nordlichen und mittleren Deutschlands - Sitz. k. Akad. Wiss., Wien,
Bd XVIII, pp. 197-273, pls. I-XII.

Reuss A. E., 1864 - Zur Fauna des deutschen Oberoligocàns. II Abthei-
iung - Sitz. k. Akad. Wiss., Wien, Bd L, Abt. I, pp. 614-691, pls.
VI-XV.

344

L. DAVID - N. MONGEREAU - S. POUYET - S. RITZKOWSKI

Reuss A. E., 1866 - Die Foraminiferen, Anthozoen und Bryozoen des deut-
schen Septarienthones - Denks. k. Akad. Wiss., Wien, t. XXV, pp. 117-
214, Il pls.

Reuss A. E., 1869 - Zur fossilen Fauna der Oligocànschichten von Gaas -
Sitz. k. Akad. Wiss., Wien, Bd LIX, Abt 1, pp. 446-488, pls. I-VI.

Ritzkowski S., 1965 - Das marine Oligozàn im nordlichen Hessen Strati-
graphie und Palàogeographie - Thèse, Gòrich et Weiershàuser éd.,
Marburg, 194 pp., 28 figs.

Ritzkowski S., 1967 - Mittel-Oligozàn, Ober-Oligozàn und die Grenze Rupel/
Chatt im nordlichen Hessen - Neues Jb. Geol. Palàont., Stuttgart,
Abh. 127, H. 3, pp. 293-336, 12 figs., 3 tabb.

Roemer F. A., 1863 - Die Polyparien des norddeutschen Tertiàr-Gebirges -
Palaeontographica, Wien, Bd IX, pp. 1-47, pls. I-V.

Stoliczka F., 1862 - Oligocane Bryozoen von Latdorf in Bernburg - Sitz. k.
Akad. Wiss., Wien, t. XLV, pp. 71-94, 3 pls.

V IGNEAUX M., 1949 - Révision des Bryozoaires néogènes du Bassin d’Aqui-
taine et essai de classification - Mém. Soc. géol. Fr., Paris, t. XXVIII,
fase. 1-3, mém. 60, pp. 1-155, pls. I-XI.

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 345-360, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

44. Group 5: Biogeography and Biostratigraphy.

Robert Lagaaij (*)

FIRST FOSSIL FINDS OF SIX GENERA
OF BRYOZOA CHE1LOSTOMAT A

Riassunto. — I generi Cothurnicella, Crepis, Beania, Synnotum, Pasy-
thea e Savignyella (e le quattro famiglie corrispondenti Cothumicelliclae,
Beaniidae, Epistomiidcie e Savignyellidae) non erano stati finora descritti
come fossili.

Le fotografie delle specie in questione, una tavola di distribuzione e
carte della diffusione recente e fossile nel mondo di qualcuno di tali ge¬
neri documentano queste scoperte e le loro implicazioni.

Appare da queste carte che la diffusione circumtropicale recente dei
generi Cothurnicella, Synnotum e fors’anche di altre forme articolate di
piccola taglia, non può essere spiegata come conseguenza di un trasporto a
grande distanza da parte delle navi nei tempi storici, ma è il risultato di
una diffusione così estesa osservabile già nel Miocene.

Summary. — The genera Cothurnicella, Crepis, Beania, Synnotum, Pa-
sythea and Savignyella (and four of thè corresponding families, viz. Co-
thumicellidae, Beaniidae, Epstomiidae and Savignyellidae) have not pre-
viously been reported as fossils. Photographs of thè fossil specimens con-
cerned, a range chart, and maps of thè Recent and fossil distribution ot
some of these genera on a global scale serve to document these new finds
and their implication.

It appears from these maps that thè circumtropical Recent distribution
of thè genera Cothurnicella, Synnotum and perhaps other small-sized jointed
forms as well is not to be explained by long-distance transport on ships
in historical times, as has sometimes been advanced, but has been inherited
from an equally wide distribution in thè Miocene.

(*) B.I.P.M. (Bataafse Internationale Petroleum Maatschappij N. V.) -
’s-Gravenhage, The Netherlands.

340

R. LAGAAIJ

Résumé. — Les genres Cothumicella, Crepis, Beania, Synnotum, Pasy-
tliea et Savignyella (et quatre des familles correspondantes, viz. Cothurni-
cellidae, Beaniidae, Epistomiidae et Savignyellidae ) n’ont pas été décrits
cornine fossiles auparavant. Des photographies des espèces en question, un
tableau d’extension et des cartes de distribution récente et fossile de quel-
ques uns de ces genres à l’échelle du globe, documentent ces nouvelles dé-
couvertes et leurs implications.

Il ressort de ces cartes, que la distribution circumtropicale récente des
genres Cothumicella, Synnotum et peut-ètre aussi d’autres formes articu-
lées de petite taille, ne doit pas ètre expliquée, comme cela a parfois été le
cas, par un transport à longue distance sur bateau durant les temps histo-
riques, mais résulte d’une distribution tout aussi étendue observable au
Miocène déjà.

Introduction.

The bryozoan fossils dealt with in this paper are all charac-
terized by their small size. This is no mere coincidence. They
all belong to forms which in thè living state either formed arti-
culated colonies, with internodes consisting of one to a few zooecia
each connected by chitinous joints and with a radiculate or sto-
lonate base ( Cothumicella , Synnotum , Pasythea and Savignyella),
or formed a System of loosely incrusting single zooecia intercon-
nected by tubular connections ( Crepis , Beania). Both zoarial types
are consistent with growth on perishable non-calcareous algal
substrates or on higher marine plants, and thè dead colonies are
liable to fall apart into their individuai components (internodes,
triads, axial kenozooecia, disconnected autozooecia) before burial
in thè sediment. In thè process of washing and sieving such se-
diment for microfaunal analysis, these small fossils are concen-
trated in thè finer sieve fractions (< 450 y).

Cothumicella.

Cothumicella was introduced in 1858 by Wyville Thompson
for thè highly characteristic delicate Recent species Cellaria py-
riformis Bertoloni, 1810. No other species have been referred
to Cothumicella, which has thus remained a monotypical genus
until thè present day.

Three Lower Miocene records of Cothw^mcella pyriformis,
one from Aquitaine, France, thè two others from East Java and

FIRST FOSSIL FINDS OF SIX GENERA OF BRYOZOA

34'

Madura, Indonesia, have recently been published elsewhere (La-
GAAIJ, 1968). The map of thè Recent and fossil distribution of
this species issued on that occasion is reproduced here (fig. 1),
with thè addition of two new fossil records, viz.

a) From a dark-coloured clay underlying thè yellow Point
Addis Limestone on thè W side of Point Addis, Victoria, Au¬
stralia, i.e. from thè basai part of thè Oligocene Jan Juc For-
mation (Faunal Unit 4 of Carter, 1964, pp. 42, 53). 1 specimen
(PI. XI, fig. 4). R. J. Foster ded. ; and

b) from thè Miocene Montserrat glauconitic Sandstone
Member, Manzanilla Formatimi, San José River, Trinidad, W. I.
Sample Du 21, collected by Mr. R. Dubey. Numerous specimens.

However incomplete this map may be, it is evident that thè
wide Recent distribution of C. pyriformis in thè tropical-warm
temperate latitudes was already established in Mid-Tertiary times.

These records, however, do not constitute thè oldest known
occurrence of thè genus, since a considerably older occurrence

Fig. 1. — World distribution of CothurniceUa pyriformis (Bertoloni).

348

R. LAGAAIJ

in thè Upper Eocene of Cuba has come to my notice. The spe¬
cimens concerned were found in a sample, B.322, from thè Ja-
baco Formation, collected by Dr. P. J. Bermudez 1 km S. of in¬
genio Saratoga, Matanzas Province, Cuba (see Bermudez, 1950,
p. 248).

The two available specimens (PI. XI, figs. 7-10) are approxi-
mately twice thè size of those of C. pyriformis. The differentia-
tion in « head » and « tali » portions is less pronounced, and thè
point of attachment for thè distai zooecium is situated slightly
more proximally, but thè generai habit is entirely that of thè
genus. The zooecia are strongly compressed laterally, and thè
convex (dorsal) side has a sharp, almost keeled, edge, as in C. py-
riformis. Of interest is thè presence of three pairs of opesiules
in this early form (PI. XI, fig. 7).

The material in hand is too scanty to serve as thè basis for
thè introduction of a new species, but it does establish thè known
range of thè genus Cothurnicella and of thè family Cothurnicel-
lidae as Upper Eocene - Recent.

Crepis.

The genus Crepis was introduced by Jullien (1883, p. 523)
for a uniserial deep-water species, C. longipes , incrusting on rock
fragments dredged from 1068 and 2018 m off northern Portugal.
Specimens identified as belonging to thè same species were sub-
sequently found in shallow water on hydroid and bryozoan sub-
strates near New Guinea (29 m), Singapore (6-7 fms) and Port
Darwin (Harmer, 1926, p. 318), and in thè Malacca Straits (35 m)
(Silén, 1941, p. 69). Two other Recent species, C. verticillata
Harmer and C. decussata Harmer, are on record from east In-
donesian and north Australian waters.

The fossil specimens of Crepis in my possession come from
a hand-auger sample, h7 (5 m), from thè Lower Miocene (Ter-
tiary e5) Tuban Formation, Prupuh, East Java, Indonesia (x).

(x) For thè stratigraphical position with respect to thè planktonic for-
aminiferal zonation of this and other Indonesian samples referred to in thè
following- pages reference is made to van der Vlerk & Postuma (1967,
Table I).

FIRST FOSSIL FINDS OF SIX GENERA OF BRYOZOA

349

Only single zooecia have been found (PI. XII, figs. 1-2). They taper
proximally and presumably were originally arranged in a linear
series (lateral communication pores are lacking), thè narrow tu-
bular connecting parts having been broken off. They are being
referred to Crepis, and not, for example, to Pyripora , on account
of their well-developed proximal cryptocyst. Yet thè fossils are
not quite identical with thè Recent type species. I have had an
opportunity to compare them with a specimen of Crepis longipes
from Singapore (29.9.13.82) in thè British Museum (Naturai
History) and have noted that they are slightly larger and that
thè distai progression of their cryptocyst is distinctly less ad-
vanced, resulting in a larger opesia. They are therefore probably
best referred to provisionally as Crepis aff. longipes. They are
associated with an assemblage originating in shallow water.

This find establishes thè known range of thè genus as Lower
Miocene - Recent.

Beania.

The genus Beania Johnston, 1840, has not, to my knowledge,
been previously reported as a fossil (see Bassler, 1953, p. 182).
Moreover, thè Beaniidae rank among thè 13 families of Cheilo-
stomata of which no fossil representatives are known (Larwood,
1967, p. 390). A possible exception must be made for thè record
of Stolonella sp. from thè Eocene of thè Ludon well, given bv
Labracherie (1961, p. 47, pi. II, fig. 8). At any rate, thè follow-
ing finds provide convincing evidence that Beania already existed
in thè Eocene of thè Caribbean province.

Beania bermudezi sp. nov.

(PI. XI - Figs. 11-14)

Holotype : The ovicelled specimen (single zooecium) figured
on PI. XI, figs. 13-14, from thè Jabaco Formation (Upper Eocene),
1 km S. of ingenio Saratcga, Matanzas Province, Cuba. B.322.
Dr. P. J. Bermudez Coll, (see Bermudez, 1950, p. 248). « In-
genio » is used in Cuba for sugar mill. U.S.N.M. Cat. No. 651153.

350

R. LAGAAIJ

Paratypes : The seven remaining specimens (single zooecia)
found in thè above sample. U.S.N.M. Cat, Nos. 651154-651155.

Other material : One specimen (single zooecium) from thè
Lorna Candela Formation (Middle Eocene), at Loma Candela,
on thè road from San Diego de los Banos to Paso Reai, Pinar
del Rio Province, Cuba. B.261. Dr. P. J. Bermudez Coll, (see
Bermudez, 1950, p. 244).

Diagnosis : Beania with four tubular connections, 7-9 closely
spaced spine (base)s on either side of thè opesia, and a fairly
large ovicelh

Description : Zooecia boat-shaped, heavily calcified for thè
genus, tubular part short and tapering proximally, expanded part
wide and shallow. Opesia large, occupying thè entire front of thè
expanded part of thè zooecium, its sides straight and parallel and
set with closely-spaced spine bases, 7-9 on either side. A lateral
connecting tube was originally given off from thè proximal half
of thè expanded part on either side. A dorsal connecting tube
was originally given off from a prominent base on thè dorsal
face. Oriceli at thè distai extremity of thè zooecium, large and
somewhat reclining, flanked by two short oblique spines.

Measurements :

Holotype (fertile) U.S.N.M. Cat. No. 651153

Lz = 1.08 mm.
lz = 0.33 mm.
ho - 0.60 mm.
lo = 0.20 mm.

Paratypes (sterile) U.S.N.M. Cat. Nos. 651154-651155

Lz (3) 0.85 (0.041) mm., 0.80 - 0.90 mm.

lz (7) 0.31 (0.025) mm., 0.26 - 0.35 mm.

ho (3) 0.473 (0.021) mm., 0.45 - 0.50 mm.

lo (7) 0.156 (0.022) mm., 0.13-0.175 mm.

Remarks : Among thè various Recent species of Beania ,
B. bermudezi resembles B. regularis Thornely and B. mirabilis

FIRST FOSSIL FINDS OF SIX GENERA OF BRYOZOA

351

JOHNSTON in having four connecting tubes, but is at once distin-
guished from both by its large ovicell.

This ancient occurrence of Beania is interesting in thè light
of Harmer’s ideas on thè evolution within thè genus. Harmer
(1926, pp. 411, 420) regards B. mirabilis as thè most highly mo-
dified representative of thè genus, and in his view thè reduction
of thè number of directly connected neighbour zooecia from six
to four would constitute one of thè advanced evolutionary featu-
res in this species, others being thè loss of thè ovicell and of thè
avicularia, Our finding of an Eocene representative of Beania
with only four connecting tubes does not necessarily invalidate
Harmer’s views, but it does put such a development further back
in geologica! time, viz. before thè Middle Eocene.

The species is named after Dr. P. J. Bermudez, Caracas,
Venezuela, in recognition of his help and encouragement.

Distribution : Middle and Upper Eocene of Cuba.

Synnotum.

Synnotum is another of these small-sized genera which have
not previously appeared in thè fossil record. In addition to thè
type species, Synnotum aegyptiacum (Audouin, 1826), there are
two other Recent species known at present, which are conf'ined
to thè tropical Indo-West Pacific (Harmer, 1926). S. aegyptia¬
cum, on thè other hand, has a typically circumtropical to warm-
temperate Recent distribution (Fig. 2). A number of Recent oc-
currences shown on this map constitute new records and are
among those listed in thè Appendix. The fossil specimens in my
possession are all Miocene, or Mio-Pliocene, in age and come from
thè following localities :

a) Sample Ct 5971, Lower Miocene (Tertiary fi/2), Arnih,
Madura Island, Indonesia, collected by Mr. M. R. Cleintuar. 1
specimen.

b) Sample from handauger hole 7 (5 m), Tuban Forma-
tion, Lower Miocene (Tertiary e5), Tuban Formation, Prupuh,
East Java, Indonesia. 1 specimen.

352

R. LAGAAIJ

Fig\ 2. — World distribution of Synnotum aegyptiacum (Audouin).

c) Sample Du 21, Montserrat Glauconitic Sandstone Mem-
ber of Manzanilla Formation, Middle or Upper Miocene, San
Jose River, Trinidad, W. I., collected by Mr. R. Dubey. 1 spe¬
cimen.

ci) Sample DB 345, Savaneta Member of Springvale For¬
mation, Upper Miocene, Couva Main Road, gorge upstream of
bridge B 1/6, collected by Dr. D. A. J. Batjes. 1 specimen.

e) Sample « Cubagua 8 », Cubagua Formation, Upper Mio¬
cene, La Caldera Canyon, Cubagua Island, Venezuela, collected
by Dr. P. J. Bermudez. 1 specimen.

/) Sample vS 105, Tubarà Formation, Mio-Pliocene, San
Juan de Acosta, Departamento Atlantico, Colombia, S. A., col¬
lected by Dr. J. Van Soest. Severa! speeimens (PI. II, figs. 3-4).

g) Sample C 11A, « Mio-Pliocene », Great Corn Island, Ni¬
caragua, collected by Mr. H. Van Kuijk. 4 speeimens.

FIRST FOSSIL FINDS OF SIX GENERA OF BRYOZOA

These finds estabiish thè known range of Synnotum, and
that of thè family Epistomiidae to which it belongs, as Lower
Miocene - Recent.

Pasythea.

For severa! years I have been collecting data on thè Recent
and fossil distribution of this interesting genus and a sizeable
dossier has been assembled. Severa! fossil species have been
found, which together are distributed over five continents.

Within thè scope of thè present paper, however, only thè
oldest occurrence is of direct concern. This is thè form (triads)
figured on PI. XII, figs. 5-6 from thè Middle Eocene Loma Candela
Formation, at Loma Candela, on thè road from San Diego de
los Banos to Paso Reai, Pinar del Rio Province, Cuba. Sample
B. 261, collected by Dr. P. J. Bermudez (see Bermudez, 1950,
p. 244). The distai tubular prolongation in thè triads is consi-
dered a primitive character. Axial kenozooecia (PI. XII, fig. 7)
have also been found.

These observations estabiish thè known time-stratigraphical
range of Pasythea as Middle Eocene - Recent. It is obvious,
therefore, that Davis’s scheme of thè phylogeny of thè Pasy-
theidae (1934, p. 238) needs emendation. Pasythea now appears
as in part contemporaneous with, and not just as a far descen-
dant of, thè Eocene-Oligocene genus Dittosaria Buse, 1866. Their
common ancestor, if any, is to be sought in beds of pre-Middle
Eocene age.

Savignyella.

The ancient species Eucratea lafontii Audouin, 1826, which
is thè type species of Savignyella Levinsen, 1909, is widely dis¬
tributed in tropical - warm temperate latitudes (Fig. 3). On this
map a number of Recent occurences of this species are shown
which constitute new records. These are listed separately in thè
Appendix. A second Recent species, 5. otophora (Kirkpatrick,
1890), is found in thè tropical Indo-West Pacific. Until recentlv
no fossil representatives of thè genus were known, but these have
now turned up at thè following Younger Tertiary localities in thè
Caribbean and in thè Far East:

354

R. LAGAAIJ

Fig. 3. — World distribution of Savignyella lafontii (Audouin).

a) in a sample, « Cubagua 8 », from thè Cu.ba.gua Forma-
tion (Upper Miocene), collected by Dr. P. J. Bermudez from La
Caldera Canyon, Cubagua Island, Venezuela. 2 specimens.

5) in a sample, C 11A, from thè « Mio-Pliocene » of Great
Corn Island, Nicaragua, collected by Mr. H. Van Kuijk. 16 spe¬
cimens.

c ) in a sample, Tu 823, from thè Miocene Chipola Forma-
tion, collected by Dr. R. J. Scolaro from Farley Creek, near
Clarksville, Calhoun County, Florida. 2 specimens (PI. XII,
figs. 8-9) depositerà in thè collection of thè United States National
Museum. U.S.N.M. Cat. Nos. 651156 - 651157.

All three finds refer to Savignyella lafontii (Audouin).

d) in a sample, Be 1421, from thè Middle Miocene (Ter-
tiary f3) of Kali Ambunten, Madura Island, Indonesia, collected
by Mr. E. Th. Van Der Bent. 5 mediocre specimens (PI. XII,

FIRST FOSSIL FINDS OF SIX GENERA OF BRYOZOA 355

figs. 10-11), which closely resemble S. otophora (Kirkpatrick),
thè only notable difference being thè absence in thè fossils of
thè 3-5 larger luterai pores (rootlet foramina) which both Kirk¬
patrick and Harmer (1957) observed in their Recent material.

The above finds extend thè known stratigraphical range of
thè genus and of thè family Savignyelliclae into thè Miocene.

Remarks ori thè time-stratigraphical and thè geographical distribution.

The range chart (Fig. 4) summarizes our present knowledge
of thè time-stratigraphical distribution of thè six genera discus-
sed here, and which until now had been considered as Recent
only. Fossil discoveries of this kind are interesting in two ways.
They enable us to apply thè Recent environmental requirements
of these genera to thè Tertiary samples in which they have now
been found. They may also change our concepts of thè evolution
within families or higher taxonomic units (see remarks under
Pasythea).

MILUON

YRS.

l—

—

t—

>—

- \ _

PLEISTOCENE

- 1

- a

—

M -

PLIOCENE

MIOCENE M

OLIGOCENE

EOCENE M

Fig\ 4.. — Time-stratigraphical range chart of thè six genera discusseci in

this paper.

356

R. LAGAAIJ

A few remarks are pertinent in connection with thè maps
of thè Recent and tossii geographical distribution of some of
thè species concerned (Figs. 1-3). What Cothurnicella pyriformis,
Synnotum aegyptiacum, and Savignyella lafontii have in common
is their wide tropical - warm temperate Recent distribution. Ini-
tially it was a matter of surprise to me to find that their Miocene
distribution - or what is known of it - turned out to be equally
wide. On further consideration, however, this should not have
been so surprising. The fact that a shallow-water marine ben-
thonic species has a completely circumtropical Recent distribution
has an important palaeontological implication, viz. that, as Ekman
(1953, p. 36) has implied, it must have lived in Miocene times.
Moreover, it should already have attained a circumtropical dis¬
tribution in thè Miocene, because connections between thè Gulf
of Mexico and thè Eastern Pacific have been severed after thè
Lower Pliocene (Schuchert, 1935, pp. 29, 378) and those bet¬
ween thè Mediterranean and thè Indian Ocean ceased to exist
in thè Lower Miocene (Ruggieri, 1967, p. 284). This theoretical
consideration is to a greater or lesser extent proved bv thè maps
of thè Recent and fossil distribution of thè three above-mentioned
species.

Acknowleclg ements .

Collecting microfossils of thè type dealt with in this paper is as often
a matter of good neighbours as it is of good luck. Among thè many friends
and colleagues who kindly gave me access to sample material in their pos-
session or contributed interesting specimens, I should like to thank in par-
ticular: Mr. R. Wright Barker, Dr. D. A. J. Batjes, Dr. P. J. Bermudez,
Mr. J. Brouwer, Mr. R. Dubey, Dr. A. J. Keij, Dr. R. J. Scolaro and
Dr. I. M. van der Vlerk.

The photographs have been taken by Mr. W. Geluk.

Permission of Bataafse Internationale Petroleum Maatschappij N. V.
to publish this paper is gratefully acknowledged.

Appendix.

Listed below are Recent oceurrences of Synnotum aegyptia¬
cum and Savignyella lafontii that constitute new records ; some
of these are shown on Figs. 2 and 3. The material is kept at

FIRST FOSSIL FINDS OF SIX GENERA OF BRYOZOA

357

thè Koninklijke / Shell Exploratie en Produktie Laboratorium,
Volmerlaan 6, Rijswijk, Netherlands.

a) Synnotum aegyptiacum.

T 1281 Persian Gulf. Lat. 25-45'—' " N, Long. 55-43'20" E. 40 m.
18 specimens (internodes). Dr. A. J. Keij Coll.

T 950 Persian Gulf. Lat, 25°1'45" N, Long. 54°23'40" E. 25 m.
3 specimens (internodes). Dr. A. J. Keij Coll.

T 835 Persian Gulf. Lat. 25°55'35" N, Long. 53-2'30" E. 50 m.

I specimen (internode). Dr. A. J. Keij Coll.

D 79 Nigeria. Lat. 4°14'41" N, Long. 6°56'58" E. 8 fms. 1 spe¬
cimen (internode).

D 78 Nigeria. Lat. 4°14'05" N, Long. 6-51'59" E. 9 fms. 1 spe¬
cimen (internode).

D 75 Nigeria, Lat, 4°12'58" N, Long. 6-36'52" E. 8 fms. 1 spe¬
cimen (internode).

D 98 Nigeria, Lat. 4°09'20" N, Long. 5-38'25" E. 14 fms. 5 spe¬
cimens (internodes).

D 213 Nigeria. Lat. 6°21'26" N, Long. 4-09'52" E. 7 fms. 1 spe¬
cimen (internode).

D 155 Nigeria, off Lagos. Lat, 6°21'59" N, Long. 3°24'02" E.

6 fms. 1 specimen (internode).

H. Ms. « Owen » stn. 16. Nigeria. Lat. 4°03' N, Long. 6°26' E.

II fms. 2 specimens (internodes).

Stn. 1197. W. of Tobago Island, W. I. Top of core. 41 fms.

Severa! specimens (internodes). Orinoco Shelf Expedi-
tion Coll. See Koldewijn (1958).

Los Testigos, Venezuela, 50 m. 20 specimens (internodes). Dr. P. J.
Bermudez ded.

1812 Tampa Bay, Florida. Lat, 27°38'09" N, Long. 82-37'27" W.
414 fms. 2 specimens (branches). Dr. D. Moore Coll.

1815 Tampa Bay, Florida, Lat. 27-36'17" N, Long. 82°43'18" W.

7 fms. 2 specimens (branches). Dr. D. Moore Coll.

358

R. LAGAAIJ

« Cavalier » 1956 Stn. 299. South of Calcasieu Pass, Louisiana.

Lat. 28°59'15" N, Long. 93°30'15" W. 11 fms. 1 specimen
(internode).

Matagorda Bay, Texas. 10 ft below present Colorado River Delta
surface. 1 specimen (internode).

b) Savignyella lafontii.

T 1281 Persian Gulf. Lat. 28<’54/— " N, Long. 55°43'20" E. 40 m.
1 specimen. Dr. A. J. Keij Coll.

T 923 Persian Gulf. Lat. 25°18'50" N, Long. 54°15'20" E. 36 m.

5 specimens. Dr. A. J. Keij Coll.

W 1223 Persian Gulf. Lat. 25°59' N, Long. 51°40' E. 21 m.
7 specimens. Dr. A. J. Wells Coll.

D 99 Nigeria. Lat. 4°05,44" N, Long. 5°35'37" E. 17 fms.
1 specimen.

D 155 Nigeria, off Lagos. Lat. 6,21'59" N, Long. 3°24'02" E.
4 specimens.

Stn. 1197 W. of Tobago Island, W. I. Top of core. 41 fms.

Several, mostly incomplete, specimens. Orinoco Shelf
Expedition Coll. See Koldewijn (1958).

Los Testigos, Venezuela, 50 m. 12 specimens. Dr. P. J. Bermudez
ded.

Bahia de la Habana, Cuba. 16 specimens. Dr. P. J. Bermudez ded.
« Atlantis » 1951 Stn. 165. Lat. 28°43'30,/ N, Long. 83°56/ W.

« Atlantis » 1951 Sten. 165. Lat. 28,,43'30" N, Long. 83°56' W.
17 fms. 3 specimens.

« Atlantis » 1951 Stn. 164. Lat. 28°41' N, Long. 84°02 W. 17 fms.

6 specimens.

«Cavalier» 1956 Stn. 21. Lat. 28‘>45'16" N, Long. 95°15/24'/ W.
10.5 fms. 1 specimen.

FIRST FOSSIL FINDS OF SIX GENERA OF BRYOZOA

359

REFERENCES

Bassler R. S., 1953 - Bryozoa. In Moore R. C. (Editor) - Treatise on In¬
vertebrate Paleontologi). Part G. Kansas, pp. 1-253.

Bermudez P. J., 1950 - Contribucion al estudio del Cenozoico cubano. Mem.
Soc. Cub. Hist. Nat., XIX, 3, pp. 205-375.

Carter A. N., 1964 - Tertiary Foraminifera from Gippsland, Victoria and
their stratigraphical significance. Geol. Surv. Victoria Mem., XXIII,
pp. 1-154, pls., 1-17.

Davis A. G., 1934 - English Lutetian Polyzoa. Proc. Geol. Assoc., XLV, 2,
pp. 205-245.

Ekman S., 1953 - Zoogeography of thè Sea. London, pp. i-xiv, 1-417.

Harmer S. F., 1926 - The Polyzoa of thè Siboga Expedition. II. Cheilosto-
mata Anasca. Rep. Siboga Exped., XXVIIIb, pp. i-viii, 181-501,
pls. 13-34.

Jullien J., 1883 - Dragages du Travailleur. Bryozoaires. Espèces draguées
dans POcéan Atlantique en 1881. Bull. Soc. Zool. France, VII (1882),
pp. 497-529, pls. 13-17.

Koldewijn B. W., 1958 - Sediments of thè Paria-Trinidad shelf. Rep. Ori-
noco Shelf Exped., Ili, pp. 1-109, pls. 1-11.

Labracherie M., 1961 - Les Bryozoaires éocènes du sous-sol du Bordelais.
Observations paléontologiques et biostratigraphiques. Thèse 3e Cycle.
Bordeaux.

Lagaaij R., 1958 - Fossil Bryozoa reveal long-distance sand transport along
thè Dutch coast. Proc. Kon. Ned. Akad. Wetensch., (B), LXXI, 1,
pp. 31-50, pi. 1.

Larwood G. P., 1967 - Bryozoa ( partim ). In Harland W. B., et al. (Editors)

- The Fossil Record. London (Geological Society), pp. 379-395.

Ruggieri G., 1967 - The Miocene and later evolution of thè Mediterranean
Sea. In Adams C. G. & Ager D. V., (Editors) - Aspects of Tethyan
Biogeography. System. Ass. Pubi., VII, pp. 283-290.

Schuchert C., 1935 - Historical Geology of thè Antillean-Carribbean Region.
New York, pp. i-xxvi, 1-811.

Silén L., 1941 - Cheilostomata Anasca (Bryozoa) collected by Prof. Sixten
Bock’s expedition to Japan and thè Bonin Islands 1914. Ark. f. Zool.,
XXXIIIa, 12, pp. 1-130, pls. 1-9.

\ lerk I. M. Van Der & Postuma J. A., 1967 - Oligo-Miocene Lepidocyclinas
and planktonic Foraminifera from East Java and Madura, Indonesia.
Proc. Kon. Ned. Akad. Wetensch., (B), LXX, 4, pp. 391-398.

PLATE XI.

1. Cothurnicella pyriformis (Bertoloni). Frontal view.

Lower Miocene (Tertiary e5), Tuban Formation, Prupuh,

East 3 ava, Indonesia.

2. Cothurnicella pyriformis (Bertoloni). Lateral view of fertile internode.

Ibidem.

3. Cothurnicella pyriformis (Bertoloni). Lateral view of sterile internode.

Ibidem.

4. Cothurnicella pyriformis (Bertoloni). Frontal view.

Oligocene, Jan Juc Formation, W side of Point Addis,

Victoria, Australia.

5. Cothurnicella pyriformis (Bertoloni). Frontal view.

Lower Miocene («Upper Aquitanian »), Falun de Lariey,
near Saucats (Gironde), France.

6. Cothurnicella pyriformis (Bertoloni). Lateral view.

Ibidem.

7. Cothurnicella ,sp. Frontal view.

Upper Eocene, Jabaco Formation, Matanzas Province, Cuba.

8. Cothurnicella sp. Lateral view of sanie specimen.

9. Cothurnicella sp.. Frontal view.

Upper Eocene, Jabaco Formation, Matanzas Province, Cuba.

10. Cothurnicella sp. Lateral view of same specimen.

11. Beania bermuclezi sp. nov. Frontal view of paratype. U.S.N.M. Cat.

No. 651154.

Upper Eocene, Jabaco Formation, Matanzas Province, Cuba.

12. Beania bermudezi sp. nov. Dorsal view of same specimen.

13. Beania bermudezi sp. nov. Frontal view of holotype. U.S.N.M. Cat.

No. 651153.

Upper Eocene, Jabaco Formation, Matanzas Province, Cuba.

14. Beania bermudezi sp. nov. Dorsal view of same specimen.

all figures X 50.

LAGAAIJ R.

Atti Soc.It.Sc.Nat. e Museo Civ.St. Nat. Milano, Voi. CVIII, Pl. XI

PLATE XII.

1. Crepis aff. longipes Jullien.

Lower Miocene (Tertiary e.-,), Tuban Formation, Prupuh,

East Java, Indonesia.

2. Crepis aff. longipes Jullien.

Ibidem.

3. Synnotum aegyptiacum (Audouin).

Mio-Pliocene, Tubarà Formation, San Juan de Acosta, Dpto.
Atlantico, Colombia.

4. Synnotum aegyptiacum (Audouin).

Ibidem.

5. Pasythea sp. Triad.

Middle Eocene, Lorna Candela Formation, Lorna Candela,

Pinar del Rio Province, Cuba.

6. Pasythea sp. Triad.

Ibidem.

7. Pasythea sp. Axial kenozooecium.

Ibidem.

8. Savignyella lafontii (Audouin). Lateral view. U.S.N.M. Cat. No. 651156.

Miocene, Chipola Formation, near Clarksville, Calhoun
County, Florida, U.S.A.

9. Savignyella lafontii (Audouin). Frontal view of sanie specimen.

10. Savignyella otophora (Kirkpatrick). Frontal view.

Middle Miocene (Tertiary f3), Kali Ambunten, Madura Island,
Indonesia.

11. Savignyella otophora (Kirkpatrick). Lateral view of sanie specimen.

all figures X 50.

LAGAAIJ R.

Atti Soc. It. Se. Nat. e Museo Civ.St. Nat. Milano, Voi. CVIII, Pl. XII

PIATE H

Atti Soc. It. Se. Nat. e Museo Civ. St. Nat. Milano - 108: 361 -368, 31-XII-1968

lst I.B.A. International Conference on Bryozoa, S. Donato Milanese, Aug. 12th-16th, 1968

45. Group 5: Biogeography and Biostratigraphy.

Madeleine J. Thoelen (*)

THE BRYOZOA FAUNA FROM THE SANDS OF DEURNE,

UPPER MIOCENE, AT DEURNE

( ANTWERPEN, BELGIUM)

Riassunto. — Le sabbie a Terebratula perforata Def rance (« Deurniano »)
sono state osservate a Rivierenhof nelle immediate vicinanze di Deurne (Ant-
werpen, Belgio). Questi depositi sabbiosi glauconitic-i raggiungono uno spes¬
sore di m 1,50 nella sola serie studiata.

Viene riportata una tavola di distribuzione delle 56 specie rinvenute e
vengono proposti un genere monospecifico Obliquostoma nov. gen. (Fa¬
miglia Phylactellidae) con la specie-tipo 0. dichotoma nov. sp. ed una nuova
specie Cellaria unicella nov. sp.

Dal punto di vista ecologico è da notare che questa tanatocenosi contiene
diverse specie paleoartiche insieme a diverse specie con distribuzione sub-
tropicale e tropicale.

Summary. — The Sands of Deurne with Terebratula perforata Defrance
(« Deurnian ») were observed at Rivierenhof in thè immediate neighbourhood
of Deurne (Antwerpen, Belgium). These glauconitic sandy deposits reached
a thickness of about 1,50 m in thè only section studied.

A distribution table of thè 56 species was made up.

One monospecific genus Obliquostoma i nov. gen. (Family Phylactellidae )
with type species 0. dichotoma nov. sp. and one species Cellaria unicella nov.
sp. are proposed herein.

From ecological point of view it is remarkable that this thanatocenosis
contains several typical palearctic species and also several species with sub¬
tropical and tropical distribution.

Résumé. — Les Sables de Deurne à Terebratula perforata Defrance
(« Deurnien ») ont été vus sur une épaisseur de 1,50 m au lieu-dit Rivie¬
renhof près de Deurne.

Un tableau de répartition stratigraphique des 56 espèces trouvées à cet
endroit a été établi.

(*) Universiteit te Leuven, Geologisch Instituut, Laboratorium voor Stra-
tigrafische Paleontologie en Mikropaleontologie, Leuven, Belgium.

362

M. J. THOELEN

Un nouveau genre monospécifique Obliquostoma dichtoma nov. gen.,
nov. sp. (famille Phylactellidae ) est proposé ainsi qu’une nouvelle espèce
Cellaria unicella nov. sp.

Du point de vue écologique il est remarquable qu’il s’agit d’une thana-
tocénose comprenant plusieurs espèces paléarctiques ainsi que plusieurs
espèces à répartition nettement tropicale et subtropicale.

Introduction.

During thè E3 road-works in 1967 at Antwerpen it was pos-
sible to take several samples of thè Sands of Deurne at Rivie-
renhof, Deurne, near thè type locality. The outcrop shows glau-
conitic sands with a thiekness of 1,50 m, especially rich in
Bryozoa. The accompanying fauna is rather poor. One can find
some molluscs, foraminifera, ostracods, corals, echinoderms, Di-
trupa sp., thè brachiopods Mannia nysti (Dewalque) and Tere-
bratula perforata Defrance; thè latter has been used in biostra-
tigraphy for calling thè Sands of Deurne « Sables à Terebratula
perforata ».

These sands are situated between underlying Sands of Ant¬
werpen (Miocene) and overlying Sands of Kattendijk (probably
Pliocene).

Further details can be found in « Lexique stratigraphique
international, voi. I, fase. 4a, p. 62-63, 1957 », and in De Meuter,
Laga, Ringele and Roose, 1967.

We thank Dr. L. Van de Poel as supervisor and Ir. W. P.
VAN Leckwijck, head of thè paleontological department.

Systematic description.

Phylum Bryozoa Ehrenberg, 1831
Familia Phylactellidae Canu and Bassler, 1917

Genus Obliquostoma nov. gen.

Type species: Obliquostoma dichotoma nov. sp., here des-
ignated.

Diagnosis: zoarium vincularian ; primary orifice semi-cir-
cular, facing distally, not visible exter iorly. Secondary orifice sub-
circular ; frontal wall bordered by areolae ; ovicell hyperstomial,
recumbent, with opening into thè peristomie.

THE BRYOZOA FAUNA FROM THE SANDS OF DEURNE ETC. 363

Discussion: thè Phylactellidae is a very heterogeneous fa-
mily, mostly recognized by thè structure of thè ovicell (hypersto-
mial, recumbent, with a large orifice). This new species cannot
be referred to any known genus of thè famìly, because of thè
constellation of following characters: cylindrical zoarium, dicho-
tomously branching, oblique apertura, frontal areolae. The new
genus looks like Psilopsella Canu and Bassler, 1927 ; it is how-
ever always different from it by thè vincularian mode of growth
and thè shape of thè primary orifice.

Obliquostoma dichotoma nov.gen., nov. sp.

(Piate XIII, fi g. 1 and 2)

Holotype : Slide B1026, deposited at thè Laboratorium voor
Paleozoologie, Universiteit te Leuven.

Paratypes: 10 zoaria fragments : Slides B1027-B1036.

Locus typicus: Rivierenhof, Deurne near Antwerpen,
Belgium.

Stratum typicum: Sands of Deurne (Upper Miocene).

Diagnosis: zoarium free, erect, cylindrical, dichotomously
branching; zooecia ovai, alternately arranged in six longitudinal
rows around a centrai axis. Primary orifice semi-circular, fac-
ing distally, invisible exteriorly; peristomie arched, peristomice
sub-circular, thè proximal lip often straight ; peristome gene-
rally poorly developed. Spines and avicularia absent ; frontal
wall fiat, bordered by a single or a doublé row of areolae. Ovicell
hyperstomial, deeply immersed; not conspicuous exteriorly, with
opening into thè peristomie.

Measurements (holotype): diameter of zoarium: 1,08-1,14
mm; length of thè zooecium: 0,82-0,88 mm (without ovicell);
breadth of thè zooecium: 0,33 mm; length of thè peristomice:
0,12-0,14 mm; breadth of thè peristomice: 0,14-0,15 mm.

Familia Cellariidae Hincks, 1880
Cellaria Ellis and Solander, 1786

Cellaria unicella nov. sp.

(Piate XIII, figs. 3, 4, 5, 6)

1926 - Cellaria sinuosa (Hassall): Canu, p. 764 (fide Lagaaij, 1952, p. 49).

Etymology: unicella is referred to thè autozooecia and thè
avicularia which have nearly thè same width and shape.

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366

Holotype: fragment of a zoarium, Slide B1008, deposited at
thè LaJboratorium voor Paleozoologie, Universiteit te Leuven.

Paratypes: 10 fragments of zoaria, Slides B1009-B1018.

Locus typicus: Rivierenhof, Deurne near Antwerpen,
Belgium.

Stratum typicum: Sands of Deurne (Upper Miocene).

Diagnosis: zoarium composed of long and slender cy-
lindrical internodes, reaching a maximum diameter of 0,95 mm
(average diameter of 20 specimens: 0,76 mm). Zooecia rhom-
boidal, arranged alternately in longitudinal rows, separated by
their raised joint-margins, which are sometimes worn. Orifice
situated in thè distai half of thè zooecium, transverse, trapezoidal
with thè proximal lip produced distally. The peristome is hardly
raised. Both a proximal and a distai pair of minute orai denticles
are present. Cryptocyst depressed, with a pair of conspicuous,
parallel ridges laterally to thè orifice. Avicularia rhombic, with
straight, acuminate, distally directed rostrum and an immersed,
relatively large, elliptical opesia. Ovicells entotoichal, with mi¬
nute, circular orifice, sometimes partly occupied by a large den-
ticle on thè proximal lip.

Measurements (holotype): length of thè zooecium: 0,41-
0,48 mm ; breadth of thè zooecium: 0,22-0,25 mm; height of thè
orifice: 0,05-0,06 mm; breadth of thè orifice: 0,10 mm; length of
thè avicularia : 0,40-0,50 mm ; breadth of thè avicularia : 0,22-
0,25 mm ; height of thè avicularian orifice: 0,09-0,13 mm; breadth
of thè avicularian orifice: 0,07-0,09 mm.

Affinities: this species differs from thè type species, C. fi-
stulosa, in thè shape of thè avicularia, thè Constant presence of
a distai pair of orai denticles and thè shape of thè opesia. From
C. mutabilis and C. sinuosa it can immediately be separated by
thè rhombic avicularia. C. neglecta Lagaaij always lacks thè orai
denticles and has somewhat smaller opesia and avicularia.

Genus assignment: thè present species is included in thè
genus Celiarla Ellis and Solander because of following character-
istics : thè cylindrical internodes of a typically jointed zoarium
with rhomboidal zooecia ; thè reduced opesia with thè proximal
border formed by a small median process, at thè sides of which
are a pair of condyles ; thè vicarious avicularia with circular
opesia ; thè entotoichal ovicells, inconspicuous in frontal view.

THE BRYOZOA FAUNA FROM THE SANDS OF DEURNE ETC.

> i

Distribution and ecology.

Table 1 shows thè systematic list of thè 56 species we found
in thè Sands of Deurne. Literature screening was done to find
out how these species are stratigraphically distributed.

After Buge (1964) we have made up a stratigraphical cor-
relation table (table 2). We can draw thè conclusion that 62%
of our species are known from thè Miocene and 75% freni thè
Pliocene.

Table 2.

Sands of Deurne (Miocene) 100%

Redonian

25%

( = 56 species)

Pliocene Belgium

35%

Eocene W. Europe

5,3%

Pliocene The Netherlands 51%

Oligocene W. Europe

Pliocene England

42%

Miocene Aquitaine

28%

Pliocene Italy

42%

Miocene W. Franee

51%

Vindobonian Vienna

35%

Pliocene Spain

12%

Miocene Italy

28%

Pliocene N. Africa

26%

Miocene Spain

16%

Pleistocene

25%

Miocene N. Africa

17%

Recent

42%

The results obtained by Lagaaij (1955) for thè Bryozoa of
thè Sands of Deurne are very similari 62% Miocene species and
70% Pliocene species. These proportions of Miocene-Pliocene spe¬
cies are inverted when it concerns thè Molluscs (Glibert and de
Heinzelin, 1955):

Pelecypoda: 75% Miocene, 63% Pliocene.

Gastropoda : 67% Miocene, 45% Pliocene.

The thanatocenosis contains essentially eurytherm species
but also typical palearctic species and species with a definite sub¬
tropical and tropical distribution.

Species occuring in warm to moderate waters are : Biflustra
savartii, Holoporella palmata , Cupuladria ca/na,riensis, Porella cer-
vicornis, Ter via irregularis , H ornerà frondiculata, Diaperoecia
major and Trigonopora nysti.

368

M. J. THOELEN

Species occuring in moderate to cold waters are : Crisia
eburnea , Berenicea patina, Idmonea notomale, Idmidronea atlan¬
tica, Sertella beaniana and « Schismopora » sp.

Eurytherm species : Cribrilaria radiata, Schizomavella auri-
cidata and Lichenopora hispida.

REFERENCES

Buge E., 1964 - Les faunes de Bryozoaires du Néogène de l’Ouest de la
France et leur rapports avec celles du Néogène Méditerranéen - Cur-
sillos y Conferencias del Instituto « Lucas Mallade », Fase. IX, pp. 163-
166, Madrid.

Canu F., 1926 - Contributions à l’étude des Bryozoaires fossiles. XX: Die-
sten d’Anvers (Belgique) - Bull. Soc. géol. France, (4), XXV (1925),
pp. 763-766.

De Meuter F., Laga P., Ringele A. and Roose V. - Compte rendu de
l’excursion du samedi 29 octobre 1966, faite à Deurne, près d’Anvers
- Bull. Soc. belge Géol., Paléontol. et Hydrol., LXXV, pp. 392-394,
Bruxelles.

Glibert M. et de Heinzelin de Braucourt, 1955 - La faune et l’àge mio¬
cène supérieur des Sables de Deurne. I. Descriptions, II. Conclusions -
Bull. Inst. roy. Sci. nat. Belg., T. XXI, n° 71 (pp. 1-27), n° 72 (pp. 1-12).

Lagaaij R., 1952 - The Pliocene Bryozoa of thè Low Countries and their
hearing on thè marine stratigraphy of thè North Sea region - Meded.
Geol. Sticht., C., V, n° 5, pp. 1-233, 29 fig., 26 pi., Maastricht.

Lagaaij R., 1955 - In Glibert et de Heinzelin loc. cit.

PLATE XIII.

Fig. 1. — Obliquostoma dichotoma nov. gen., nov. sp., holotype, 10

Fig. 2. — Obliquostoma dichotoma nov. gen., nov. sp., holotype, 20

Fig. 3. — Cellaria unicella nov. sp., paratype, 20 X-
Fig. 4. — Cellaria unicella nov. sp., paratype, 45 X-
Fig. 5. — Cellaria unicella nov. sp., holotype, 45 X.

Fig. 6. — Cellaria unicella nov. sp., holotype, 45 X-

THOELEN M. J.

Atti Soc. It. Se. Nat. e Museo Civ.St. Nat. Milano,' Voi. CVIII,

Pl. XIII

CONTENTS

Nangeroni G. & Conci C. - Foreword ..... Pag.

Annoscia E. - Conference Chairman Address .... »

du Bois Reymond Marcus E. - Ernst Marcus .... »

A scoli P. & Cook P. L. - Conference Report .... »

Group 1 : THE BRYOZOA IN OIL RESEARCH (R. Lagaaij
presidine)

1 - Annoscia E. - Palaeontological and Stratigraphical Re¬

search carried out by AGIP Direzione Mineraria Pa¬
laeontological Laboratory ...... »

2 - Boardman R. S. - Potential Use of Paleozoic Bryozoa in

Subsurface Exploration . »

3 - Gautier Y. V. - Bryozoa as Microfossils which may be

useful in Oil Research . »

Group 2 : ANATOMY, MORPHOLOGY AND SKELETAL
STRUCTURE (I. Vigeland presiding)

4 - Hillmer G. - Artificial Moulds for Studying thè Internai

Structure of Paleontological Objects .... »

5 - VoiGT E. - Homoeomorphy in Cyclostomatous Bryozoa as

demonstrated in Spiropora (Preliminary Report) . »

6 - Kaufmann K. W. - The Biological Role of B ligula- type

Avicularia ( Bryozoa ) (Preliminary Report) ...»

7 - Dunaeva N. N. - On thè Mode of Sexual Reproduction of

some Trepostomatous Bryozoa (Preliminary Report) . »

8 - Hillmer G. - On thè Variation of Gonozooecia of En-

crusting « Berenicea » - forms (Lower Cretaceous)

( Bryozoa ) (Preliminary Report) ......

9 - Illies G. - On thè Gonozooecium of Collapora straminea

(Phillips) ( Bryozoa Cy clostomata) ......

10 - SiMMA Krieg B. - On Variation and Special Reproduction

Habits of Aetea sica (Couch) ( Bryozoa ) (Preliminary
Report) . »

11 - Karklins 0. L. - Zooecial Boundary Patterns in thè

Middle Ordovician Genera of thè Families Rhinidic-
tyidae, Stictoporellidae and Ptilodictyidae ( Bryozoa ) . »

5-6

7-12

13-24

25-27

28-30

31-36

37-42

43-53

54-60

61-63

64-70

71-74

75-76

77-84

370

CONTENTS

12 - Tavener Smith R. - Skeletal Structure and Growth in

thè Fenestellidae ( Bryozoa ) (Preliminary Report) . . Pag.

13 - Banta W. C. - The Body Wall of thè Encrusting Cheilo-

stome Watersipora nigra (Canu and Bassler) ( Bryozoa )
(Preliminary Report) ........

14 - Larwood G. - Frontal Wall Structures of Cretaeeous and

Recent Cribrimorpha and other Cheilostome Bryozoa
(Preliminary Report) ........

15 - Rucker J. B. - Skeletal Mineralogy of Cheilostome

Bryozoa ...........

16 - Nye 0. B. - Aspects of Microstructure in Post Paleozoic

Cyclost ornata ( Bryozoa ) ........

17 - Sòderqvist T. S. - Observations on Extracellular Body

Wall Structures in Crisia eburnea L. ( Eetoprocta , Cri-
siìdae) . . . . • . . . . . 5 »

Group 3 : ECOLOLOGY AND PALEOECOLOGY (G. Lar¬
wood presiding)

18 - Jebram D. - A Cultivation Method for Saltwater Bryozoa

and an Example for Experimental Biology ...»

19 - Bushnell J. H. - Aspects of Architecture, Ecology and

Zoogeography of Freshwater Eetoprocta ...»

20 - Schopf T. J. M. - Generalizations regarding thè Phylum

Eetoprocta in thè Deep Sea (200-6000 m) ...»

21 - Cook P. L - Observations on Living Bryozoa ...»

22 - Flor F. D. - The Variation of Spiropora verticillata

Goldfuss 1827 from Upper Cretaeeous Deposits ( Bryozoa ) »

23 - Ghiurca V. - Le Biotope récifal à Bryozoaires du Mio¬

cène de la Roumanie ........

24 - Scolaro R. J. - Paleoecologic Interpretation of some Flo¬

rida Miocene Bryozoa (Preliminary Report) ...»

Group 4: EVOLUTIONARY PATTERNS AND SYSTEMA-
TICS (L. Pitt presiding)

25 - Boardman R. S. - Colony Development and Convergent

Evolution of Budding Pattern in Rhombotrypid Bryozoa »

26 - Cheetham A. H. - Evolution of Zooecial Asymmetry and

Origin of Poricellariid Cheilostomes ( Bryozoa ) . . »

27 - Moyano G. H. I. - Posición sistemàtica de los generos Ro-

mancheina, Escharoides, Cellarinella y Systenopora
( Bryozoa , Cheilostomata Ascophora) .... »

28 - Prud’homme J. - Révision de quelques types de la Collec-

tion d’Orbigny (Crétacé) conservée au Muséum d’His-
toire Naturelle de Paris ( Bryozoa ) .... »

85-92

93-96

97-100

101-110

111-114

115-118

119-128

129-151

152-154

155-160

161-164

165-173

174-178

179-184

185-194

195-211

212-218

CONTENTS

29 - Schager S. A. N. - Remarks on thè Genus Floridina

Jullien 1881 . PaV-

30 - Ryland J. S. - Terminological Problems in Bryozoa . »

31 - Annoscia E. - Problems of Methodology in Studying and

Describing Bryozoa

32 - Anstey R. L. & Perry T. G. - Biometrie Procedures in

Taxonomic Studies of Paleozoic Bryozoa (Preliminary
Report)

33 - Wiebach F. - Taxonomical and other Remarks on Fresh-

water Bryozoa (Preliminary Report) .... »

Group 5: BIOGEOGRAPHY AND BIOSTRATIGRAPHY
(N. Spjeldnaes presiding)

34 - Annoscia E. - Status of thè Bryozoological Studies and

Collections in Italy ....••••»

35 - Androsova E. I. - Bryozoa Cyclostomata and Ctenosto-

mata of Antarctic and Subantarctie (Preliminary Report) »

36 - Maturo F. J. S. - The Distributional Pattern of thè

Bryozoa of thè East Coast of thè United States ex-
clusive of New England .......

37 - Yaroshinskaya A. M. - The Early Devonian and Eifelian

Bryozoa from thè Aitai ......•»

38 - Sakagami S. - Study on thè Upper Paleozoic Bryozoa of

Japan and thè Thai-Malaya Districts (Preliminary
Report)

39 - Illies G. - On some Cyclostomatous Bryozoa from thè

Middle Jurassic of Southern Germany (Preliminary
Report)

40 - Brood K. - Stenolaematous Eetoproets from thè Danian

Deposits od Sweden and Denmark ( Bryozoa ) (Prelimi¬
nary Report)

41 - Braga G. P. - Bryozoa from thè « Marne Rosse » of Spi-

lecco (Lessini Mountains, Verona) ......

42 - Labracherie M. - Quelques Bryozoaires Cheilostomes de

la Falaise de Handia (Biarritz, France) ...»

43 - David L., Mongereau N., Pouyet S. & Ritzkowski S. -

Les Bryozoaires du Chattien de la Région de Kassel
(Hesse, Allemagne) . J . »

44 - Lagaaij R. - First Fossil Finds of six Genera of Bryozoa

Cheilostomata . . A .

45 - Thoelen M. - The Bryozoa Fauna from thè « Sands of

Deurne », Upper Miocene at Deurne (Antwerpen, Bel-
gium)

371

219-224

225-236

237-240

241-244

245-246

247-257

258-260

261-284

285-294

295-297

298-299

300-302

303-311

312-326

327-344

345-369

361-368

ALPHABETICAL INDEX

Androsova E. I. - Bryozoa Cy ciò stornata and Ctenostomata of
Antarctic and Subantarctic (Preliminary Report)

Annoscia E. - Conference Chairman Address .

Annoscia E. - Palaeontological and Stratigraphical Research
carried out by AGIP Direzione Mineraria Palaeonto¬
logical Laboratory ........

Annoscia E. - Problems of Methodology in Studying and
Describing Bryozoa ........

Annoscia E. - Status of thè Bryozoological Studies and Col-
lections in Italy ........

Anstey R. L. & Perry T. G. - Biometrie Procedures in Taxo-
nomic Studies of Paleozoic Bryozoa (Preliminary
Report) ..........

Ascoli P. & Cook P. L. - Conference Report . . . .

Banta W. C. - The Body Wall of thè Encrusting Cheilostome
Watersipora nigra (Canu and Bassler) ( Bryozoa ) (Pre¬
liminary Report) ........

Board man R. S. - Potential Use of Paleozoic Bryozoa in
Subsurface Exploration .......

Boardman R. S. - Colony Development and Convergent Evo-
lution of Budding Pattern in Rhombotrypid Bryozoa

Braga G. P. - Bryozoa from thè Marne Rosse of Spilecco
(Lessini Mountains, Verona) ......

Brood K. - Stenolaematous Ectoprocts from thè Danian De-
posits of Sweden and Denmark ( Bryozoa ) (Preliminary
Report) .

Bushnell J. H. - Aspects of Architecture, Ecology and Zoo-
geography of Freshwater Ectoprocta . . . .

Cheetham A. H. - Evolution of Zooecial Asymmetry and
Origin of Poricellariid Cheilostomes ( Bryozoa )

Conci C. - See Nangeroni G. & Conci C .

Cook P. L. - See Ascoli P. & Cook P. L .

Cook P. L. - Observations on Living Bryozoa . . . .

David L., Mongereau N., Pouyet S. & Ritzkowski S. - Les

Bryozoaires du Chattien de la Région de Kassel (Hesse,
Allemagne) .........

du Bois Reimond Marcus E. - Ernst Marcus . . . .

Pag. 258-260
» 5-6

» 25-27

» 237-240

» 247-257

» 241-244

» 13-24

» 93-96

» 28-30

» 179-184

» 303-311

» 300-302

» 129-151

» 185-194

» 4

» 13-24

» 155-160

» 327-344

» 7-12

ALPHABETICAL INDEX

373

Dunaeva N. N. - On thè Mode of Sexual Reproduction of

some Trepostomatous Bryozoa (Preliminary Report) . Pag .

Flor F. - The Variation of Spiropora verticillata Goldfuss

1827 from Upper Cretaceous Deposits ( Bryozoa ) . . »

Gautier Y. V. - Bryozoa as Microfossils which may be useful

in Oil Research .........

Ghiurca V. - Le Biotope récifal à Bryozoaires du Miocène

de la Roumaine .........

Hillmer G- - Artificial Moulds for Studying thè Internai

Structure of Paleontological Objects .... »

Hillmer G. - On thè Variation of Gonozooecia of Encrusting
« Berenicea » - forms (Lower Cretaceas) (Preliminary
Report) ...........

Illies G. - On thè Gonozooecium of Collapora straminea

(Phillips) ( Cyclostomata ) .......

Illies G. - On some Cyclostomatous Bryozoa from thè Middle

Jurassic of Southern Germany (Preliminary Report) . »

Jebram D. - A Cultivation Method for a Saltwater Bryozoa

and an Example for Experimental Biology ...»

Karklins O. L. - Zooecial Boundary Patterns in thè Middle
Ordovician Genera of thè Families Rhinidictyidae,
Stictoporellidae and Ptilodictyidae ( Bryozoa ) . . »

Kaufmann K. W. - The Biological Role of B ligula- type Avi-

vicularia ( Bryozoa ) (Preliminary Report) ...»

Labracherie M. - Quelques Bryozoaires Cheilostomes de la

Falaise de Handia (Biarritz, France) .... »

Lagaaij R. - First Fossil Finds of six Genera of Bryozoa

Cheilostomata ..........

Larwood G. - Frontal Wall Structures of Cretaceous and
Recent Cribrimorpha and other Cheilostome Bryozoa
(Preliminary Report) ....... »

Maturo F. J. S. - The Distributional Pattern of thè Bryozoa
of thè East Coast of thè United States exclusive of
New England ..........

Mongereau N. - See: David L., Mongereau N., Pouyet S. &

Ritzkowski S . »

Moyano G. H. I. - Posición sistemàtica de los generos Roman-
cheina, Escharoides, Cellarinella y Systenopora ( Bryo¬
zoa , Cheilostomata, Ascophora) ..... »

Nangeroni G. & Conci C. - Foreword ....•»

Nye 0. B. - Aspects of Microstructure in Post Paleozoic

Cyclostomata ( Bryozoa ) ........

Perry T. G. - See: Anstey R. L. & Perry T. G. . . . »

61-63

161-164

31-36

165-173

37-42

64-70

71-74

298-299

119-128

77-84

54-60

312-326

345-360

97-100

261-284

327-344

195-211

111-114

241-244

374 ALPHABETICAL INDEX

Pouyet S. - See: David L., Mongereau N., Pouyet S. &

Ritzkowski S . Pag.

Prud’Homme J. - Révision de quelques types de la Collection
d’Orbigny (Crétacé) conservée au Muséum d’ Histoire
Naturelle de Paris ( Bryozoa ) .......

Ritzkowski S. - See: David L., Mongereau N., Pouyet S. &

Ritzkowski S . »

Rucker J. B. - Skeletal Mineralogy of Cheilostome Bryozoa »

Ryland J. S. - Terminologica! Problems in Bryozoa . . »

Sakagami S. - Study on thè Upper Paleozoic Bryozoa of
Japan and thè Thai-Malaya Districts (Preliminary
Report) ...........

Schager S. A. N. - Remarks on thè Genus Floridina

Jullien, 1881 ..........

Schopf T. J. M. - Generalizations regarding thè Phylum

E ctoprocta in thè Deep Sea (200-6000 m) . »

Scolaro R. J. - Paleoecologic Interpretation of some Florida

Miocene Bryozoa (Preliminary Report) .... »

Simma Krieg B. - On Variation and Special Reproduction
Habits of Aetea sica (Couch.) ( Bryozoa ) (Preliminary
Report) ...........

Sòderqvist T. S. - Observations on Extracellular Body Wall

Structures in Crisia eburnea L. (E ctoprocta, Crisiidae) »

Tavener Smith R. - Skeletal Structure and Growth in thè

Fenestellidae ( Bryozoa ) (Preliminary Report) . . »

Thoelen M. J. - The Bryozoa Fauna from thè « Sands of
Deurne », Upper Miocene at Deurne (Antwerpen,
Belgium) ...........

Voigt E. - Homoeomorphy in Cyclostomatous Bryozoa as

demonstrated in Spiropora (Preliminary Report) . . »

Wiebach F. - Taxonomical and other Remarks on Freshwater

Bryozoa (Preliminary Report) ......

Yaroshinskaya A. M. - The Early Devonian and Eifelian

Bryozoa from thè Aitai ........

327-344

212-218

327-344

101-110

225-236

295-297

219-224

152-154

174-178

75-76

115-119

85-92

361-368

43-53

245-246

285-294

INDICE

Androsova E. I. - Briozoi Cyclostomata e Ctenostomata dell’An¬
tartico e del Subantartico (Nota preliminare)

Annoscia E. - Saluto del Presidente del Congresso

Annoscia E. - Le ricerche paleontologiche e stratigrafiche del
Laboratorio Paleontologico dell’AGIP Direzione Mineraria

Annoscia E. - Problemi di metodologia nello studio e nella de¬
scrizione dei Briozoi ...•••••

Annoscia E. - Stato degli studi briozoologici e delle collezioni
di Briozoi in Italia ...•••••

Anstey R. L. & Perry T. G. - Procedimenti biometrici negli
studi tassonomici dei Briozoi paleozoici (Nota preliminare)

Ascoli P. & Cook P. L. - Resoconto del Congresso .

Banta W. C. - La parete corporea del Cheilostomo incrostante
Watersipora nigra (Canu & Bassler) ( Bryozoa ) (Nota pre¬
liminare) ..•••••••*

Boardman R. S. - Possibile uso dei Briozoi paleozoici nell’esplo¬
razione del sottosuolo ........

Boardman R. S. - Sviluppo coloniale ed evoluzione convergente
nelle modalità della gemmazione dei Briozoi Rhombotrypidi

Braga G. P. - I Briozoi delle « Marne Rosse » di Spilecco (Monti
Lessini, Verona) .........

Brood K. - Gli Ectoprocta Stenolaemata dei depositi daniani di
Svezia e Danimarca (Nota preliminare) ( Bryozoa )

Bushnell J. H. - Aspetti dell’architettura, ecologia e zoogeografia
degli Ectoprocta dulcacquicoli ( Bryozoa ) . . . .

Cheetham A. H. - Evoluzione dell’asimmetria zoeciale e origine
dei Cheilostomata poricellaridi ( Bryozoa )

Conci C. - Vedi: Nangeroni G. & Conci C .

Cook P. L. - Vedi: Ascoli P. & Cook P. L. .

Cook P. L. - Osservazioni sui Briozoi viventi ....

David L., Mongereau N., Pouyet S. & Ritzkowski S. - I Briozo
del Chattiano della regione di Kassel (Assia, Germania)

du Bois-Reymond Marcus E. - Ernst Marcus

Dunaeva N. N. - Modalità della riproduzione sessuale di alcuni
Briozoi Prepostomi (Nota preliminare)

Flor F. - La variabilità di Spir opera verticillata Goldfuss dei
depositi supr acretacici ( Bryozoa ) ......

Pag.

258

237

247

241

179

303

300

129

185

155

327

161

376

INDICE

Gautier Y. V. - I Briozoi quali microfossili che possono essere utili

nella ricerca del petrolio ....... Pag.

Ghiurca V. - Il biotopo scopulare a Briozoi del Miocene della Ro¬
mania ............

Hillmer G. - Impronte artificiali per lo studio delle strutture in¬
terne dei corpi fossili .........

Hillmer G. - Sulla variabilità dei gonozooecia delle forme incro¬
stanti del tipo Berenicea (Cretacico inferiore) (Briozoi)

(Nota preliminare) .........

Illies G. - Sul gonozooeeium di Collapora straminea (Phillips)

( Bryozoa Cyclostomata) .........

Illies G. - Su alcuni Briozoi Ciclostomi meso-giurassici della

Germania meridionale (Nota preliminare) .... »

Jebram D. - Metodi di coltivazione dei Briozoi marini ed un esem¬
pio di biologia sperimentale ........

Karklins 0. L. - Modelli dei limiti zoeciali nei generi meso-ordo-
viciani delle famiglie Rhinidictyidae, Stictoporellidae e Pti-
lodictyidae ( Bryozoa ) .........

Kaufmann K. W. - Il ruolo biologico degli avicularia del tipo pre¬
sente in Bugula ( Bryozoa ) (Nota preliminare) ...»

Labracherie M. - Alcuni Briozoi Cheilostomi della Falesia di Han-

dia (Biarritz, Francia) .........

Lagaaij R. - Primi ritrovamenti fossili di sei generi di Briozoi

Cheilostomi ...........

Larwood G. - Strutture parietali frontali di Cribrimorpha cre¬
tacici e recenti e di altri Briozoi Cheilostomi (Nota pre¬
liminare) ...........

Maturo F. J. S. - Modelli della distribuzione dei Briozoi sulla costa

orientale degli Stati Uniti (escluso il New England) . . »

Mongereau N. - Vedi: David L., Mongereau N., Pouyet S. &

Ritzkowskx S. . »

Moyano G. H. I. - Posizione sistematica dei generi Romancheina,
Escharoides, Cellarinella e Systenopora ( Bryozoa , Cheilo-
stomata, Ascophora ) .........

Nangeronu Gr- & Conci C. - Presentazione ......

Nye i0. B. - Aspetti della microstruttura nei Cyclostomata post-
\ . paleozoici ( Bryozoa ) .........

PerrY - Vedi : Anstey R. L. & Perry T. G . »

Pouyet S. - Vedi: David L., Mongereau N., Pouyet S. & Ritz-

KOWSKI S . »

Prud’homme J. - Revisione di alcuni tipi della collezione d’Orbigny
(Cretacico) conservati nel Museo di Storia Naturale di Pa¬
rigi ( Bryozoa ) ..........

165

298

119

312

345

261

327

195

118

241

327

212

INDICE

or n

ó i i

Ritzkowski S. - Vedi: David L., Mongereau N., Pouyet S. &
Ritzkowski S. .

Rucker J. B. - Costituzione mineralogica dello scheletro dei Briozoi
Cheilostomi ..........

Ryland J. S. - Problemi di terminologia briozoologica .

Sakagami S. - Studio dei Briozoi supra-paleozoici dei distretti giap¬
ponese e maleo-tailandese (Nota preliminare)

Schager S. A. N. - Note sul genere Floridina Jullien, 1881
( Bryozoa ) ..........

Schopf T. J. M. - Generalizzazioni riguardanti il phylum Ecto-
procta nei mari profondi (200-6000 m) . . . . .

Scolaro R. J. - Interpretazione paleoecologica di alcuni Briozoi
miocenici della Florida (Nota preliminare) . . . .

Simma Krieg B. - Sulla variabilità e sulle caratteristiche modalità
della riproduzione di Aetea sica (Couch.) (Nota preliminare)
( Bryozoa ) ..........

Sòderqvist T. S. - Osservazioni sulla struttura delle pareti extra¬
cellulari in Crisia ebun'nea L. ( Ectoprocta , Crisiidae ) .

Tavener-Smith R. - Strutture scheletriche e accrescimento nei
Fenestellidae ( Bryozoa ) (Nota preliminare)

Thoelen M. J. - La briofauna delle « Sabbie di Deurne » (Mio¬
cene superiore di Deurne, Anversa, Belgio)

VoiGT E. - L’omeomorfismo nei Briozoi Ciclostomi com’è dimo¬
strato in Spiropora (Nota preliminare) . . . .

Wiebach F. - Note tassonomiche ed altre osservazioni sui Briozoi
dulcacquicoli (Nota preliminare) ......

Yaroshinskaya A. M. - I Briozoi infra-devonici ed eifeliani degli
Aitai ...........

Pag. 327

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Pavia — Editrice Succ. Fusi — 31 Dicembre 1968

Direttore responsabile: PROF. CESARE CONCI

Registrato al Tribunale di Milano al N. 6574

EDITRICE

SUCC. FUSI - PAVIA

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