The spellings, authorships, and dates of publication of all the family-group names of the Phylum Echiura were reexamined critically, following strictly the International Code of Zoological Nomenclature. The following corrctions of current usage are noted: Bonelliidae Lacaze-Duthiers, 1858, instead of Baird, 1868; Echiuridae Quatrefages, 1847, instead of Balinville, 1827 (consisting of Echiurinae Quatrefages, 1847 and Thalassematinae Forbes & Goodsir, 1841, instead of Monro, 1927); and Ikedidae Bock, 1942, instead of Ikedaidae Dawydoff, 1959. Furthermore, the spelling of the here unadopted subfamilies Bonellinae, Acanthobonellinae, and Archibonellinae, all of which were originated by DattaGupta (1976), are corrected respectively to Bonelliinae, Acahthobonelliinae, and Archibonelliinae. The erroneous attribution of the family name Urechidae to Fisher & MacGinitie (1928) is also corrected to Monro (1927), although the former affiliation has already been entered into the Official List of Family-Group Names in Zoology.
