Hydroidomedusae de l'Institut royal des Sciences naturelles de Belgique

Non siphonophoran hydrozoans from the collections of the RBINS, including 769 species, are presented according to the most current use in the actual literature. These collections house type material of 66 nominal species and varieties. For each species, and whenever possible, the locality, the reference number in the collection, the number of specimens, of colonies and of microscopic slides, the mode of preservation (alcohol, formalin, dry) and the date of collecting are given.