1. Philosophical and Methodological Concerns.- The framing of biogeographic hypotheses.- Quantitative methods and biogeographic analysis.- 2. The Pleistocene and its Aftermath.- Late glacial and Holocene diatom successions in the Gulf of Maine: response to climatologic and oceanographic change.- Seaweed biogeography of the North Atlantic: where are we now?.- 3. Evolutionary Ecology and Adaptation.- Behavioural, morphological and genetic changes in some North Atlantic populations of the barnacle Semibalanus balanoides.- Herbivory and evolution of nongeniculate coralline algae (Rhodophyta, Corallinales) in the North Atlantic and North Pacific.- 4. Approaches to Speciation.- The application of DNA-DNA hybridization in seaweeds and DNA divergence between some amphi-Atlantic Cladophora (Cladophorales, Chlorophyta) species.- Genetics of morphology and growth in Laminaria from the North Atlantic Ocean — implications for biogeography.- Sexual compatability and species concept in Ectocarpus siliculosus (Ectocarpales, Phaeophyceae) from Italy, North Carolina, Chile, and New Zealand.- 5. Kelp Evolution.- The distribution and evolution of the Laminariales: North Pacific — Atlantic relationships.- Molecular evolution in the Laminariales: a review.- 6. Taxonomy and Biogeography.- Evolutionary biogeography of the North Atlantic Antithamnioid algae.- Distribution and evolution of non-coralline crustose red algae in the North Atlantic.- A preliminary phylogenetic analysis of the Phyllophoraceae, Gigartinaceae and Petrocelidaeeae (Rhodophyta) in the North Atlantic and North Pacific.- 7. Biogeographic Provinces.- Algal provinces in the North Atlantic — do they exist?.- 8. Evolution of Floras in the Arctic and Atlantic Oceans.- Role of the Arctic Ocean as a bridge between theAtlantic and Pacific Oceans: fact and hypothesis.- Biogeography of the marine red algae of the North Atlantic Ocean.- Taxonomic Index.