Art Weil, Leonard Brown & Bruce Neville 1999 Published Evolver sri. (Via C. Federici, 1 -00147 Rome, Italy) 244pp. ISBN 88-8299-002-8. A4 Hardback.
Originally reviewed by Kevin Brown 2000.
Published in Journal of Conchology (2000), VOL.37, NO.1
The Epitoniidae, although including some of the World's most elegant shells, has long been a neglected family. A few of the larger species are illustrated time and again in popular shell books - there is probably no general book on tropical shells which does not illustrate Epitonium scalare - yet the vast majority of the nearly 600 smaller species have been largely overlooked. There have been few even regional monographs and certainly no worldwide overview of the family, so this volume is very welcome and goes a long way to redress the balance and place the Wentletraps firmly on the conchologi- cal map.
The authors have included details of some 565 species with truly worldwide cover- age including species from polar and tropical regions, shallow and deep water (15,300 feet in one case). For each species a clear, concise, description is given emphasising those features most useful in identification - usually features of shell structure/sculpture; including size of shell, number of costae and varices, details of basal ridge and umbili- cus, details of protoconch where known. Details of the distribution of each species are also given, although the authors acknowledge that distribution patterns are poorly known for many species, and that new records are constantly changing the known picture.
The species accounts are divided into eight broad chapters dealing respectively with the Epitoniidae of the Western Atlantic, the Eastern Atlantic and Mediterranean Sea, South Africa and Mozambique, the North West Indian Ocean and Red Sea, the Indo- Pacific, Japan, Australia and New Zealand, and finally the Eastern Pacific. Within each regional section the species are arranged alphabetically by genera, and alphabetically within each genus. This geographic arrangement is convenient for a field collector or anyone studying a particular regional fauna, but, to my mind, has a number of draw- backs. Many species have distribution patterns which overlap several of these broad regions. To give a couple of examples. Boreoscala greenlandica (Perry, 1811) "Occurs in the North Atlantic only as far south as Long Island but is quite common off Norway, Iceland and Greenland It also occurs off Alaska in the Pacific Ocean making it circumpolar." Similarly Opalia crassilabrum (Sowerby, 1844) "Ranges from the Philippines and the Red Sea to Natal, South Africa" Each of these species could have been placed in three of the Authors' regions. Thus to positively identify a species it may be necessary to refer to several of the regional chapters, and it is unfortunate that the regional accounts do not end with a list of additional species covered in other sections which also occur in the region.
Epitonium couturier! (de Boury, 1912) highlights a different problem "Because this species was described based on a specimen from an unknown habitat, we are uncertain whether it should form part of the Indo-Pacific fauna and are placing it in this chapter with much uncertainty".
Another difficulty with the geographic arrangement is the separation of closely related species. Under the Western Atlantic, Narrimania azelotes (Dall, 1927) we are told "This species is rather similar to N. concinna from the Eastern Atlantic. While there are differences, it is not clear whether there are two species or a single variable one". Yet Narrimania concinna (Sykes, 1925) appearing some 20 pages later in the Eastern Atlantic section has no cross reference to N. azelotes, which is particularly annoying as, of the two, only N. azelotes is illustrated.
The descriptions are accompanied by 507 illustrations, mostly photographs but including a few drawings, depicting some 494 of the species covered. The illustrations are conveniently placed opposite the text relating to each species. Inevitably, given the large number of photographs and the small size of many of the specimens illustrated - down to 1.7 mm, there are a few pictures which are a little fuzzy. The vast majority of the photographs are, however, of excellent quality. Moreover nearly 150 of the shells illustrated are type specimens enormously increasing the scientific value of the book. For each specimen illustrated, as well as species name, locality data and the size of the specimen is given. This is helpful given the varying magnifications used for illustrations on the same page. Museum references are also given for the type specimens.
The authors have included brief notes on Epitoniid biology, with references to more detailed studies, some very helpful notes on identifying Epitoniidae emphasising which features are most useful to distinguish species, and a very useful description of the many genera and subgenera within the family which clearly gives diagnostic features for each genus/subgenus - in Opalia for example shells are "characterised by the presence of microscopic spiral pits on the surface of the shell....", it also gives type species for each genus. The bibliography at six pages may seem short for a book covering a family of this size, but this probably reflects the general lack of previous study of the group. The bibli- ography is also largely restricted to 20th century publications.
A large section of the book - some 34 pages - is devoted to a list of "Authors in Epitoniidae", in which is listed details of nearly 1,100 taxa proposed within the family. For each species information given includes author and date of description, current generic placement, size of the species, distribution of the species and whether the species is considered valid or should be rewarded as a synonym of another species. This list is presented in an innovative format, being arranged alphabetically by author. The index is comprehensive for both species and genera references so that although the book is arranged geographically rather than strictly taxonomically, it is easy to extract details of for example the species in a particular genus, or the many synonyms of Gyroscala lamel- losa (Lamarck, 1822).
The authors have synthesised an enormous amount of information and presented it in a clear and readily accessible format, although our current knowledge of the family is constantly undergoing change, reflecting previous lack of study, this volume undoubt- edly presents a base line for future workers to build upon. It will be a standard refer- ence for both professional scientists and amateur collector for many years to come.