In any scientific discipline, meetings with presented papers and discussions are the most effective stimulus to the advancement of knowledge. Nemerteans have long been largely neglected because their taxonomy is difficult: the need for histological study of serial sections has proved inhibiting to most zoologists. During the last twenty years, however, this intriguing phylum has attracted the attention both of increasing numbers of taxonomists as well as of workers interested in many aspects of, for example, their ecology, evolution, physiology and fine structure. The enthusiam stemming from the First International Meeting held in Philadelphia during December 1983 made it abudantly clear that regular meetings of this type should be continued. The Second, at the Tjärnö Marine Biological Laboratory in Sweden (August 1986), emphasized the importance of such international gatherings. The Third Meeting was held in Britain, at Y Coleg Normal, Bangor, North Wales, August 10--15, 1991, with 24 participants from six countries. This volume records most of the papers given at the conference.

Inhalt

One: Ecology.- Life cycles of nemerteans that are symbiotic egg predators of decapod Crustacea: adaptations to host life histories.- Nemertea inhabiting the Haploops (Amphipoda) community of the northern Øresund with special reference to the biology of Nipponnemertes pulcher (Hoplonemertea).- Aspects of the biology of Pantinonemertes californiensis, a high intertidal nemertean.- The infestation and dispersion patterns of Carcinonemertes spp. (Nemertea) on their crab hosts.- Carcinonemertes pinnotheridophila sp. nov. (Nemertea, Enopla, Carcinonemertidae) from the branchial chambers of Pinnixa chaetopterana (Crustacea, Decapoda, Pinnotheridae): description, incidence and biological relationships with the host.- Ecological studies of the nemertean fauna in an estuarine system of the northwestern Gulf of Mexico.- Two: Taxonomy and Phylogeny.- Methods of classifying nemerteans: an assessment.- Phylogeny, natural groups and nemertean classification.- Major characters and enoplan systematics.- Observations on the morphology of some North American nemertines with consequent taxonomic changes and a reassessment of the architectonics of the phylum.- A reassessment of the systematics and a proposal for the phylogeny of some cosmopolitan Lineus species (Nemertea).- A proposal for a check-list of characteristics to be used in the description of palaeonemertean species.- The genus Valdivianemertes Stiasny-Wijnhoff 1923 (Nemertea, Enopla, Hoplonemertea): nomenclatural status and proper systematic position.- Paralineopsis taki gen. et sp. nov., a littoral heteronemertean from Japan, provided with special proboscideal, circulatory and sensory organs of significance to nemertean systematics.- Riserius pugetensis gen. n., sp. n. (Nemertina: Anopla), a new mesopsammic species, and comments on phylogenetics of some anoplan characters.- Enzyme electrophoresis, genetic identity and description of a new genus and species of heteronemertean (Nemertea, Anopla) from northwestern Spain and North Wales.- Morphological variation in the palaeonemertean Tubulanus annulatus (Montagu 1804).- Three: General Biology.- Evidence for a FMRFamide-like peptide in the heteronemertine Cerebratulus lacteus Leidy.- Molecular approaches to the study of evolution and phylogeny of the Nemertina.- The influence of light and sea water temperature on the reproductive cycle of Lineus ruber (Heteronemertea).- Patterns of trace metal accumulation in Swedish marine nemerteans.