This weighty book (c. 2 kg !), vol. 23 in the well-known Austrian series Catalogus Fossilium Austriae which publishes listings of all fossils on record from that country, presents the outcome of many years of literature studies. So far, volumes in this series had a complicated alphabetical/numerical numbering, originally intended to place them in a systematic order. This is now abandoned, triggered also by the fact that systematics have changed considerably in recent years. That, however, is not the only change. The format now is A4, a good quality of mat printing paper is used, type setting is modernised, and the body text (Helvetica) appears in two columns, with headings and species names in bold. Photo plates are now included as well; no fewer than 56 in the present volume. For many years now, the author has been a curator at the Naturhistorisches Museum Wien, having access to all those important and classic collections of species described from Austria, e.g. the Hoemes and Schaffer collns. Included also is material from other, mainly Austrian, institutes; it therefore comes as no surprise that numerous, if not most, of the illustrations in this volume are of types or figured specimens. This alone makes this volume a must for every European Cainozoic molluscan worker. The plan is that all Neogene bivalves from present-day Austria are listed and discussed in three volumes. The present one, volume 1, considers the Nuculacea up to and including the Unionacea. Taxonomy used, down to genus, is based on the Treatise of Invertebrate Paleontology (1969, 1971). In the References (p. xiv), the 1969 volume is erroneously referred to as ‘Treatise on Vertebrate Paleontology’. Other printing errors are rare, e.g. ‘Anonalodesmata’ (p. 1) and ‘terrains teriaires’ (p. 95) caught my eye.