The purpose of this application, under Article 75.5 of the Code, is to conserve the current usage of the generic name Halitherium Kaup, 1838 and the specific name of its type species, Pugmeodon schinzii Kaup, 1838 (currently Halitherium schinzii), for a taxon of fossil sirenian from Europe by designating a neotype for this nominal species. This is in response to a recent contention that, as nomina dubia, these two names are inapplicable to the two sympatric species of this genus purported to occur around the type locality of H. schinzii in the Mainz Basin and elsewhere in Europe. The existing holotype is an isolated premolar that is not unambiguously determinable to species, but the name Halitherium schinzii has been used in a substantial body of literature extending over nearly two centuries, to the near exclusion of other names, and without taxonomic ambiguity because of reference to other specimens than the type. The desired ends can be attained without sacrificing stability of nomenclature by designating the most suitable reference specimen as the neotype of Pugmeodon schinzii Kaup, 1838 under the plenary power and continuing to use the name Kaupitherium bronni (Krauss, 1858), with its own, different name-bearing type, for the other species.