Reversal of Precedence for Lineidae McIntosh, 1874 over Its Senior Synonyms Borlasiidae Diesing, 1862 and Nemertidae Ehrenberg, 1831 (Nemertea: Heteronemertea)

The three heteronemertean nominal species Ascaris longissima Gunnerus, 1770, Borlasia angliae Oken, 1815, and Nemertes borlasii Cuvier, 1816 have been considered as synonymous, denoting the same species to which the valid name Lineus longissimus (Gunnerus, 1770) has been applied. These three nominal species are the type species of the genus-group names Lineus Sowerby, 1806, Borlasia Oken, 1815, and Nemertes Cuver, 1816, respectively, which are in turn the type genera of the family-group names Lineidae McIntosh, 1874, Borlasiidae Diesing, 1862, and Nemertidae Ehrenberg, 1831. Therefore, Lineus Sowerby, 1806 (currently in use) is a senior subjective synonym of Borlasia Oken, 1815 and Nemertes Cuvier, 1816 (both currently not in use), while Lineidae McIntosh, 1874 (currently in use) is a junior subjective synonym of Borlasiidae Diesing, 1862 and Nemertidae Ehrenberg, 1831 (both currently not in use); in addition, Micruridae Ehrenberg, 1831 (not in use) is also a senior synonym of Lineidae McIntosh, 1874. Borlasiidae Diesing, 1862 and Nemertidae Ehrenberg, 1831 have not been used as valid after 1899, while Lineidae McIntosh, 1874 has been used in at least 216 works published by 437 authors since 1971 until 2021, thus satisfying the conditions stipulated in Article 23.9.1 of the International Code of Zoological Nomenclature. Borlasiidae Diesing, 1862 and Nemertidae Ehrenberg, 1831 are herein declared nomina oblita with respect to Lineidae McIntosh, 1874, the latter being regarded as a nomen protectum under Article 23.9.2 of the International Code of Zoological Nomenclature. However, reversed precedence of Lineidae McIntosh, 1874 over its senior synonym Micruridae Ehrenberg, 1831 requires a ruling by the International Commission on Zoological Nomenclature, as the latter name was used as valid between 1998 and 2009