Molluscs: Prosobranch and Pyramidellid Gastropods

To those acquainted with the study of molluscs both at amateur and professional level, the name of Alastair Graham will be familiar as signifying an expertise on the subject of the Prosobranchia which is rarely equalled at the present time. Together with his colleague, Dr. Vera Fretter, he has worked at Reading University for some 40 years with generations of undergraduates to enhance our knowledge of the animals which comprise these two major groups within the Class Gastropoda. The second edition of Professor Graham's original version of this guide has been eagerly awaited.

Molluscs: Prosobranch and Pyramidellid Gastropods is no. 2 in the New Series of Synopses of the British Fauna, which was originally published by The Linnaean Society. The Synopses were described in the first edition (1971) as being 'field and laboratory books designed to meet the needs of amateur naturalists, sixth-from pupils and undergraduates, though they should also be of value to professional zoologists.' As a matter of general interest, since the publication of Synopsis no. 2, 38 further volumes have been published on a wide range of invertebrate groups, designed to bridge the gap between the popular guide and the more specialist monographs and treatises.' The 1971 edition of the Synopsis under review was a handy-size booklet ofll2 pages dealing with 139 species in 48 families. The new version has been greatly expanded to cover 281 species in 59 families, and covers the same geographical area as that used by this Society in its Sea Area Atlas of the Marine Molluscs of Britain and Ireland, with the exclusion of area 48 which includes the Faeroes. The Biology section has been expanded and includes hints on collection and preservation. A series of keys is provided, these being more workable than one key to cover all 281 species. The first key in this edition leads to the identification of non-marine species; for marine species four further keys lead to family and for identification to genus and spedes, reference must be made to additional keys dispersed appropriately through the text.

The contents of the book are so organized that each species is figured on the right hand page, with the text on the left. The text is headed by the 'currently accepted name' with its author and date. Where different, the original but superseded name and all junior synonyms are listed, these bring includcd (with some unexplained exceptions) in the systematic index at the end of the book. Textual information includes a short section giving diagnostic characters. A fuller description follows giving further shell characters, some features of the animal and information about habitat, food and breeding where this is known. Scant information on distribution is given and it is disappointing to note that some of this has not been brought up to date. For example, Marstomopsis schelhi is listed in the key as being found 'in canals near Manchester only' whereas records are in print for this spedes from Norfolk and Suffolk. Similarly, Tmncatella subcylindrica is described as being 'limited to a part of its original range in Dorset' although sites at Pagham and Warsash have now been recorded.

The most striking feature of this book is the assemblage in one volume of the beautiful drawings of shells by the Danish artist, Poul Winther which serve as an invaluable adjunct to the text for identification purposes. These have been previously published in a series of Supplements to the Journal of Molluscan Studies entitled The Prosobranch Molluscs of Britain and Ireland. Issued in nine parts between 1976 and 1986 (with a concluding part containing corrections, additions and an index awaiting publication) some of the earlier Supplements are now out of print. However, the existence of these drawings in published form with a more comprehensive text is a factor which should be borne in mind by a potential purchaser.

Certain corrections have been incorporated into the new Synopsis. Revised drawings have been substituted for Littorina neritoides and Onoba semicostata and a new figure for Littorina obtusata has been included. Mysteriously, Littorina mariae remains unfigured. Some of the Littorina saxatilis segregates still lack appropriate figures and the diagram illustrating spiral ridges of shells of the Littorina species in transverse section which appeared in the appropriate Supplement now carries a corrected heading. Anomalies still exist, however. It has been pointed out to me by Dr. Michael Kerney that the drawing of Acicula fusca, published in Part 3 of Tht ProsobraHch Molluscs of Britain and Ireland in 1978 and which has been criticized for its inaccurate figuring of the aperture and for the inclusion of a non-existent sutural detail, has been reprinted without alteration. The drawing of Bithynia leachi is considered to be poor and does not show the spiral structure of the central portion of the operculum. The drawing of Pomatias elegans is inaccurate and no mention is made that this species is now known for Ireland. Valvata macrostoma, a threatened rarity and which is to be included in the Red Data Book, carried a perfectly acceptable drawing in the relevant Supplement and although this species is included in the Synopsis, no drawing accompanies the text. Nor is any mention made of the synonym V. pulchtUa which is in wide use on the Continent. Revision of the Turbsmlla species results in T. multilirata and T. verticalis being excluded and T. fulvocincta being elevated to specific level.

This brings me to the vexed question of nomenclature. Although the Introduction of the book refers to the 'currently accepted name', to the best of my knowledge the nomenclature used has not been previously published as an entity. The most recently published list (Directory of the British Marine Fauna and Flora - a coded checklist of the marine fauna and fora of the British Isles and its surrounding seas) edited by Christine Howson and published by the Marine Conservation Society in 1987, contains a Mollusca section largely prepared by Shelagh Smith. However Ponder (1985, A review of the genera of the Rissoidae (Mollusca: Mesogastropoda: Rissoacea) Records of the Australian Museum (suppl. 4)) is cited as a reference in the MCS list and also by Graham in the publication under review yet differences occur in suggested nomenclature for this family between the two publications. Indeed, in the first dozen pages of Graham differences with the MCS list are evident, i.e. Acmaea virginia of Graham becomes Tectura virginia in MCS, Colisella tessulata becomes Tectura testudinalis, Patella aspera becomes Patella ulyssiponensis and so on. This will all be very confusing to marine workers and while the experts continue to disagree, those in search of a clearly defined and consistent nomenclature will continue to wonder which names to adopt.

Returning to the format and layout of the book, a degree of ambivalence exists in my mind. Although aesthetically pleasing, the restriction of figures to the right hand page and the text to the left results in many pages where a drawing occupies one third of a page and the text perhaps half a page. There arc also twelve blank pages in the book where a figure is lacking or to facilitate the adopted layout. It might be argued that space has been left for a worker's own field notes and sketches but the effect of so much unprinted space is to produce a book some 400 mm thick, which would require a 'pocket' of extravagant proportions! Further, although the Synopses are published with soft covers such a thick paperback is unlikely to prove durable in use and a hard cover would have been advisable.

Molluscs: Prosobranch and Pyramidellid Gastropods encapsulates Professor Graham's life work involving countless hours in the field, laboratory and at the desk. It is very disappointing and a great pity therefore that the book has been priced at a figure which is so excessive as to put it well beyond the reach of so many sections of its potential readership, particularly those workers without easy access to the libraries of the institutions, museums and universities who will be the principal purchasers of this Synopsis.