1984 [= 1985] 239 p., numerous figures & photographs, paperbound. Lavori della Societa Italiane di Malacologia. Volume 21. Several annotations in the text and inserted notes by J.J. van Aartsen.Treated are the following groups: Triphoridae, Cyclostrematidae, Mitroidea, Hydrobiidae, Architectonicidae, Emarginula.