Abstract
The hydrographic conditions off N.W. Europe permit a variety of “southern” littoral organisms to extend around the west and north coasts of the British Isles and across to Norway, although they may be scarce or absent from the eastern half of the English Channel and the southern North Sea. Recent notable additions to this group of species are Ammonia sulcata recorded by Dons (1945) for localities near Bergen and Alesund, and known since 193G, and Patella aspera recorded by KOLSTAD (1959) for localities between Stavanger and Bergen.
