This work would not have been possible without the assistance of many people who generously provided taxonomic expertise, computing advice, access to collections, and technical support. In particular, we would like to thank most sincerely: Haydon Bailey, Steve Culver, Adam Gasinski, Brian Huber, Bob Jones, Clive Jones, Michael Kaminski, Miriam Katz, Wolfgang Kuhnt, Norman MacLeod, Ewa Malata, Michel Moullade, Stefan Revets, Jane Swallow, Ellen Thomas, and John Whittaker. The project was funded by the Natural Environment Research Council (NERC).