This volume, 9C, in two parts, covers the Brachyura. With the publication of the ninth volume in the Treatise on Zoology: The Crustacea, we departed from the sequence one would normally expect. Some crustacean groups, mainly comprising the Decapoda, never had a French version produced, and the organization and production of these “new” chapters began independently from the preparation of the other chapters and volumes. Originally envisioned to encompass volume 9 of the series, it quickly became evident that the depth of material for such a volume must involve the printing of separate fascicles. The new chapters have now been completed, and the production of volume 9 was started while volumes 3 through 8 were (and in part still are) in preparation; with this vol. 9C-I & II this volume 9 is now concluded; vols. 1-5 have also been published and vols. 6-8 are being prepared.

This volume is in honour of Danièle Guinot (Muséum National d'Histoire Naturelle, Paris, France), and was born out of our admiration for Danièle s immense contributions to her discipline. She has helped reawaken interest on the systematics of brachyuran decapods crustaceans, the true crabs. Furthermore, she has significantly helped to redefine the study of the complete evolutionary process in crabs. A total of 35 of her colleagues have contributed to this volume, submitting papers on those aspects of the Brachyura to which Danièle, herself, has significantly contributed taxonomy, evolution, morphology, palaeontology and general biology of crabs. This volume is but a small tribute to a highly respected colleague and friend from the active band of researchers that she has helped so much over the years.

This book offers a comprehensive study of species- and genus-level diversity and chorology of the global freshwater fauna to date. It gives a state of the art assessment of the diversity and distribution of Metazoa in the continental waters of the world.