Michael Kerney

1999. 264pp. ISBN 0 946589 48 8. 244 x 172 mm, hardback. £25 + P&P (£3.59 UK, £4.50 overseas). Harley Books, Freepost, Great Horkesley, Colchester CO6 4YY (Tel:01206 271216)

Those familiar with Michael Kerney's 1976 Atlas of the Non-Marine Mollusca of the British Isles will welcome this new version of the Atlas, which is now in hard covers and in a smaller format. It is not the sort of book which is read from cover to cover, consisting as it does of over 200 distribution maps of the Molluscs of the title. These maps form the meat in a sandwich, the top slice of which is an account of the mapping scheme and a brief introduction to the factors influencing mollusc distribution and a history of the British molluscan fauna. The bottom slice is a new set of maps of environmental factors (temperature, rainfall, chalk distribution, altitude etc.) which may influence mollusc distribution, together with an extensive list of recorders, references, etc.

Each map now contains extensive and updated information. There is a thumbnail drawing of an individual and some notes on its spread and habits, and precautions on the vagaries of identifications. These notes are extremely useful and supported by suitable references. The maps themselves are based on ten kilometre squares and the records before 1965 are presented differently from those since that date. Fossil records are also distinguished. The old 1976 atlas differentiated between pre 1950 and the then modern records. Given that Kerney states that one of the objectives of mapping is to "illumine change", it might have been beneficial to have attempted a more differentiated approach. Mapping is a dynamic process and this book can only represent a snapshot in time. How long can it be before the maps and, more importantly, the database from which they are derived will be available electronically? With publication intervals of twenty years, this might be the last paper-based version.

Individual species have also been updated. The new Arion species are properly recorded for the first time, (A. distinctus, A. owenii, A. flagellus). Name changes have been incorporated; thus Deroceras caruanae is now Deroceras panormitanum and Potamopyrgus jenkinsii is now Potamopyrgus antipodarum. Nevertheless, the links with the past have been maintained though the provision of comprehensive synonyms both in the maps and in the index.

As anyone with interests in specific species would, I immediately turned to a few species of interest. The entrepreneurial Boettgerilla pallens has extended from 5 records in the 1976 Atlas to dozens all over Britain and

Ireland in the new one. I note that this species has not been recorded from my home 10km square and I found it in my garden only last year. But I cannot complain, I did not send in a record card. Let us hope that browsing the atlas will stimulate us to be more careful in our observations and be more assiduous in sending in records.

Some wag once said that the Shackleton maritime reconnaissance aircraft was 100,000 rivets flying in close formation. My 1976 Atlas is similarly about 250 pages lying in close proximity on my library shelf. The new Atlas promises to be as useful as the old one has been. I hope the new hard binding can withstand the strain until I can log onto a continuously updated version on the Internet and perhaps contribute my records in the same fashion.

Anthony Cook, University of Ulster