The distribution, origins and taxonomy of Tricellaria inopinata d’Hondt and Occhipinti Ambrogi, 1985, an invasive bryozoan new to the Atlantic Author Dyrynda, P. E. J. School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea. SA 2 8 PP, Wales, UK P.Dyrynda@swan.ac.uk Author Fairall, V. R. School of Biological Sciences, University of Wales Swansea, Singleton Park, Swansea. SA 2 8 PP, Wales, UK BDFairall@swan.ac.uk Author Ambrogi, A. Occhipinti Sezione Ecologia, Dip. Genetica e Microbiologia, Via Sant’Epifanio, 14 27100 Pavia, Italy Occhipin@unipv.it Author d’Hondt, J. - L. Muséum National d’Histoire Naturelle, Lab. de Biologie des Invertébrés marins et Malacologie, 57 Rue Cuvier 75005 Paris, France text Journal of Natural History 2000 2000-10-30 34 10 1993 2006 journal article 310614 10.1080/00222930050144828 6ad26aa8-4bdb-45d2-85d8-8aa6f4e968a0 1464-5262 10083127

Table 1. Diagnostic characteristics distinguishing Tricellaria inopinata, T. occidentalis and T. porteri (the form and variation of the scutum can be regarded as the key diagnostic feature).

Character	T. inopinata	T.occidentalis	T. porteri
Internode length (number of autozooids)	very variable, recorded range 3-19	majority of three, some fi ve	variable, recorded range 3-13
Marginal spines (excluding scuta)	proximal external spine sometimes bi fi d	proximal external spine never bi fi d	proximal external spine sometimes bi fi d
Spines within branch axils	one large, centrally positioned	two large, central space between	two small, central space between
Scutum morphology	vary within a single colony from a slender projection, perhaps forked, to an extensive structure with wavy/spiky margin (often cervicorn-like)	slender or slightly spatulate	consistently large and reniform
Lateral avicularia	sometimes present	present on majority	present on a
	on majority of marginal autozooids (at least within proximal internodes), variable in size	of marginal autozooids	minority of marginal autozooids