SBF Volume 50, Part 1: North-West European Thecate Hydroids and Their Medusae: Part 1: Introduction, Laodiceidae to Haleciidae

Hydroids and medusae are among the most exquisitely beautiful and intriguing of marine invertebrate groups – and the history of their science reads like a detective story. The 'normal' life cycle alternates between sexual, freeswimming medusae and asexual, benthic hydroids, but every conceivable variation appears somewhere within the group. It was many years before even the basic life cycle was recognised, so that hydroids and medusae were described and classified independently of each other. The unraveUing of the ensuing tangle has provided a major systematic challenge.

This is the first work to provide descriptions of all the North-west European thecate hydroids since that of Thomas Hincks in 1868 – and the first ever to include keys to their identification. It is the first on leptomedusae since Sir Frederick Russell's book, published in 1953, and the first to bring them all together in the Leptothecatae. Inevitably, the author felt the need to provide more taxonomic, and other, information than is usual in a Synopsis, which resulted in a bulky typescript. To have edited that down into the conventional Synopsis format would, in the publisher's opinion, have destroyed much that is of value in the work. The publisher thus decided to publish it in two parts, trying to ensure that each was complete in itself, whilst recognising that few people would purchase one part without the other. Thus, the Introduction and the extensive list of References appear only once; whilst the Glossary is found in both.