Bulletin of Zoological Nomenclature 44(4) December 1987 237 Case 2604 Dioctophyme Collet-Meygret, 1802 (Nematoda): proposed confirmation of spelling (CIOMS Case No. 7) M. E. Tollitt Formerly of The Secretariat , International Commission on Zoological Nomenclature Abstract. The purpose of this application is to confirm, at the request of the Council for International Organizations of Medical Sciences (CIOMS), the spelling of a parasitic nematode worm name in the form Dioctophyme. This is preferred to the alternative spelling Dioctophyma as it maintains the integrity of the original orthography. There has been no clear cut preference for either name over the last 50 years. 1. Collet-Meygret (1802, p. 463) proposed 'dioctophyme' for a genus of parasitic worm from the kidney of a dog. In explaining the etymology Collet-Meygret remarked, 'j'ai adopte le mot dioctophyme , compose de di, venant de dis (deux fois), octo (huit), phyma (tubercule) . . .'. 'Voici quels sont les caracteres du genre dioctophyme'. As far as can be assertained the genus remained without included species until Rudolphi (1808, p. 84), who included the single species Strongvlus gigas Rudolphi, (1802p. 115). 2. Unfortunately, due to differing interpretations of Collet-Meygret's etymo-logical explanation, the form of the name has varied between Dioctop/iyma and Dioctophyme. It seems that Bosc (1803, p. 255) was the first author to use the spell-ing Dioctophyma, while Lamouroux (1824, p. 515) argued that Collet-Meygret had used Dioctophyme as a vernacular and proposed Dioctophyma as the correct latin version. 3. The variable spelling of the generic name has also affected the family name which has been spelled both as dioctophymidae, first proposed by Railliet (1915, p. 493), based on Dioctop/iyme and as dioctophymatidae, first proposed, it is believed, by Chitwood & Chitwood (1950, p. 25, although attributed to Railliet) and appar-ently based on Dioctophyma (see Harwood et al.. 1941). If the current proposals are accepted the former spelling would be correct. 4. Usage of the various spellings, both for generic and family names, has varied over the years. A review of the Zoological Record over the last 25 years suggests that Dioctophyma might have been preferred, although there were a number of excep-tions. From 1981 Dioctophyme was used almost exclusively. However, influential general works such as Soulsby (1982) give Dioctophyma, whilst the definitive and widely used CIH key to vertebrate nematodes (Anderson & Bain. 1982) favours Dioctophyme. In short, there is and never has been clear cut usage of either name be it generic or family. A decision on which spelling to use would clearly be in the interest of stability.