The purpose of this application, under Article 81.2.3, is to conserve the generic name Phoronis Wright, 1856 and the specific name Phoronis muelleri Selys Longchamps, 1903 in their accustomed use. Both names are well known and included in all major textbooks on zoology and in hundreds of papers. However, a parallel set of older names, Actinotrocha Müller, 1846 and A. branchiata Müller, 1846 (and other ‘species of Actinotrocha’) are very often used in papers on phoronid larvae, so the conditions for reversal of precedence using Article 23.9.1.1 are not met. The name Phoronis is the base for the names phoronidae, Phoronidea and Phoronida in various uses for the family, order, class, and phylum dating from Hatschek (1888). A strict application of the Principle of Priority would create confusion, and the Commission is therefore asked to use its plenary power to suppress the generic name Actinotrocha Müller, 1846 and the specific epithet branchiata Müller, 1846 (as published in the binomen Actinotrocha branchiata) for the purposes of the Principle of Priority.