The purpose of this application, under Articles 70.2 and 23.9.3 of the Code, is to conserve the current usage of the generic name Coenosia Meigen, 1826, for a well-established genus of muscid flies. The type species of Coenosia has long been assumed to be Musca tigrina Fabricius, 1775. However, the correct type species is Musca fungorum De Geer, 1776, which is currently recognized as a valid species of Mycophaga Rondani, 1856, a genus of anthomyiid flies. Acceptance of Musca fungorum De Geer, 1776 as the type species of Coenosia would change the current concept of that genus to that of the anthomyiid Mycophaga, and the current muscid generic name Coenosia would become Caricea Robineau-Desvoidy, 1830 as the next available name. To avoid the nomenclatural instability that would result from following the Principle of Priority, it is proposed that all type fixations for Coenosia Meigen, 1826 prior to that of Musca tigrina Fabricius, 1775 by Westwood (1840) be set aside. In addition, it was noted that, because the genus-group names Coenosia Meigen, 1826 and Limosia Robineau-Desvoidy, 1830 have long been considered subjective synonyms of each other and are the type genera for respective family-group names, if the Principle of Priority were followed, the family-group name limosiinae Robineau-Desvoidy, 1830 would become the senior synonym of coenosiinae Verrall, 1888. To avoid the potential instability resulting from acceptance of the relative priority of these two family-group names, it is proposed that precedence be given to coenosiinae over limosiinae whenever the two are placed in the same family group.