15 sites were surveyed, in 3 main categories: 1. west coast, exposed or semi-exposed; 2. east coast, mainly sheltered; 3. brackish water lochs. Brief descriptions of each site are given, with mollusc-orientated notes on habitats and other species. 117 species were found alive. The most interesting discoveries were, in addition to the specialised brackish water species (see species lists), amongst the chitons, with a further example of Acanthochitona sp. ('a handsome red one') being found on the Monach Islands. Amongst the Gastropoda, Diodora graeca, found at Aird an Runair and at Lochmaddy by SMBA, is a new live record for the Outer Hebrides, elegantly establishing a continuation of distribution between Ireland and Orkney. Species lists of molluscs on smaller algae are appended, as are recording forms.