Family EPISTOMIIDAE Gregory, 1893

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Introduction

This small family Epistomiidae was introduced by Gregory (1893) for the European genus Epistomia. Harmer (1926) referred the genus Synnotum (Pieper 1881) to the Epistomiidae and described three species. The type species is Loricaria aegyptiaca Audouin (1826 in Savigny), Synnotum aegyptiacum has a world-wide distribution in tropical and subtropical waters (Harmer 1926). Synnotum is characterised by its straggling, semi-erect colonies, attached by rhizoids. Erect branches have a complex budding pattern and are composed of pairs of autozooids, each pair facing towards one side of the branch and separated from the next pair by a cuticular joint. Erect branches may attain 30 mm in height. Avicularia occur on most autozooids; usually one is sessile, the other pedunculate, prompting Ryland (1982) to note that the family shared characters with both the Scrupocellariidae (Candidae) and the Bicellariellidae. Embryos are brooded in enlarged zooids (gynozooids).

S. aegyptiacum has been described from Victoria and New South Wales as Notamia gracilis by MacGillivray (1890) who was correcting an earlier assignment of the species to Calwellia gracilis. Hastings (1932) listed S. aegyptiacum from the Great Barrier Reef, where Ryland (1974) noted that it formed part of a 'bryozoan turf' on the under side of rocks.

Reproductive and degeneration-regeneration cycles in Epistomia were described by Dyrynda (1981).

The family Epistomiidae, and the genus Synnotum, have a fossil record extending from the Lower Miocene (Lagaaij 1968).

Diagnosis

Colony erect or adnate, articulated, with zooids in paired internodes. Zooids with largely membranous frontal. Avicularia pedunculate and adventitious. Embryos brooded in gonozooids or large hyperstomial ovicells.

General References

Audouin, V. 1826. Explication sommaire des planches de Polypes de l'Egypte et de la Syrie, publiées par J.C. Savigny, member de l'Institut; offrant un exposé des caractères naturels des genres avec la distinction des espèces. pp. 225-244 in Jonard, E.F. (ed.). Description de l'Égypte, ou, Recueil de observations et des recherches qui ont été faites en Égypte pendant l'expédition de l'armée française, publie par les ordres de Sa Majesté l'empereur Napoleon le Grand. Histoire Naturelle. Paris : De L’Imprimerie Imperiale Vol. 1(4) 339 pp.

Dyrynda, P.E.J. 1981. A preliminary study of patterns of polypide generation-degeneration in marine cheilostome Bryozoa. pp. 73-81 in Larwood, G.P. & Nielsen, C. (eds). Recent and Fossil Bryozoa. Fredensborg : Olsen & Olsen.

Gregory, J.W. 1893. On the British Palaeogene Bryozoa. Transactions of the Zoological Society of London 13: 219-279

Harmer, S.F. 1926. The Polyzoa of the Siboga Expedition. Part 2. Cheilostomata Anasca. Siboga-Expéditie Report 28B: 183-501

Hastings, A.B. 1932. The Polyzoa, with a note on an associated hydroid. Scientific Reports of the Great Barrier Reef Expedition 1928-1929 4(12): 399-458

Lagaaij, R. 1968. First fossil finds of six genera of Bryozoa Cheilostomata. (Proceedings of the First International Conference on Bryozoa; Annoscia,E, ). Atti della Società Italiana di Scienze Naturali e del Museo Civico di Storia Naturale di Milano 108: 345-360

Macgillivray, P.H. 1890. Description of new or little-known Polyzoa. Part 13. Transactions and Proceedings of the Royal Society of Victoria ns 2: 106-110

Pieper, F.W. 1881. Eine neue Bryozoe der Adria, Gemellaria (?) avicularia. Jahresbericht des Westfälischen Provinzial-Vereins für Wissenschaft und Kunst 9: 43-48

Ryland, J.S. 1974. Bryozoa in the Great Barrier Reef Province. Proceedings of the 2nd International Coral Reef Symposium 1: 341-348

Ryland, J.S. 1982. Bryozoa. pp. 743-769 in Parker, S.P. (ed.). Synopsis and classification of living organisms. New York : McGraw-Hill.

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