The purpose of this application, under Articles 29 and 55.3 of the Code, is to remove homonymy between the family-group names phycinae Swainson, 1838 (Osteichthyes, Gadiformes, phycidae) and phycinae Lyneborg, 1976 (Insecta, Diptera, therevidae). It is proposed that the stem of the genus-group name Phycus Walker, 1850, on which the insect family-group name is based, be emended to change the family-group name to phycusinae, leaving the fish family-group name, based on Phycis Walbaum, 1792, unaltered. An issue regarding the type-species of Phycis Walbaum, 1792, came to light in this process, namely that the previously assumed type species, Tinca marina (attributed to Walbaum (1792) and considered a junior synonym of Blennius phycis Linnaeus, 1766), is a nomen nudum. So, an additional purpose of this application, under Articles 78.1 and 81.1 of the Code, is to maintain the prevailing usage of Blennius phycis Linnaeus, 1766 as the de facto type species of Phycis Walbaum, 1792 by setting aside all previous type species designations and designating Blennius phycis Linnaeus, 1766 as the type species.