Literature records of tintinnid distributions (272 references, 1899 to 1992) were plotted with a computer. Distributions at the genus level revealed several distinct biogeographic patterns: cosmopolitan, neritic, warm-water, boreal, and austral. Some of the factors that may account for these patterns are examined. At the species level, certain disjunct distributions are examined, including the bipolar distribution of Acanthostornella norvegica and the interoceanic distributions of tropical tintinnids. Endemicism of species within certain genera, such as Codonellopsis, was also found.

Photomicrographs of 5 species of Cymatocyl~s were digitised, binarised and edited by hand to remove large debris contaminating the images. An artificial neural network (back-propagation of error) was trained to categorise 201 of these specimens after pre-processing the data by Fourier transformation. Of the 299 trials which were carried out, 28% demonstrated better than 70% correct categorisation of the data used in the training sets. The best performing network learned to differentiate the training data set with an error rate of 11 U/;,. The same network gave an error rate of 18% when presented with previously unseen data. The results of training back-propagation of error networks are presented and the performance and limitations are discussed and compared with more classical rnorphometric and clustering techniques for the taxonomic separation of marine plankton. This automatic technique demonstrates the potential of neural network pattern classifiers for addressing the difficult taxonomic task of congeneric classification and also has wider implications for the automatic identification of field samples of marine organisms

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Ballast tanks of cargo shlps arriving in Coos Bay, Oregon. USA, from various Japanese ports were sampled from October 1987 to January 1991. A total of 33 tintinnid species from 15 genera were identified from ballast water samples. Live tintinnids were observed on occasion. Many of the species that were observed in these ballast water samples have also been found In the nearby Stralt of Juan d e Fuca, but others have never been reported in the eastern Paciflc. The presence of tintlnnids in ballast water obfuscates any conclusions about the natural distributions of these species. This study suggests that ballast water has been a vector for tintinnid transport for many years, and that ~t may no longer be possible to determine the natlve distributions for many tlntlnnld specles KEY WORDS: Tintinnid Ciliate . Exotic organisms . Ballast water . Biogeography

Tintinnids were collected from Buzzards Bay. Massachusetts. USA, from October 1987 to September 1988. Tintinnids were collected by screening 3 1 of seawater with a 20 pm mesh. Eight stations throughout the bay were sampled at monthly or twice-monthly intervals. A total of 30 species of tlntinnids were recorded, half of which were members of the genus Tintinnopsis. Tintinnid abundances ranged from 0 to 3.3 X 103 cells I-'. Tintinnlds were least abundant at the Cape Cod Canal and in northern Buzzards Bay, and most abundant at the New Bedford sewage outfall. Unlike dinoflagellates, tintinnids did not show higher abundances in New Bedford Harbor than in the main part of the bay. The effect of screening tintinnid samples with a 20 pm mesh screen was examined by comparisons of abundance of tintinnids in screened and unscreened whole-water samples concentrated by gravitational sedimentation. Tintinnid abundance estimates were significantly higher in the screened samples.