The purpose of this application, under Article 81.1, is to set aside Retepora angulata Hall, 1852 and Retepora angulata Hall as applied by Foerste, 1887 as type species of the Palaeozoic bryozoan genus Phylloporina Ulrich in Foerste, 1887 and to designate Retepora trentonensis Nicholson, 1875 as the type species. Both R. angulata and R. trentonensis have been cited as type species of the cosmopolitan early Palaeozoic genus Phylloporina from 1900 to the present, with R. trentonensis being more commonly cited. Morphological details of R. angulata Hall, 1852 and R. angulata sensu Foerste, 1887 have only recently been determined. They are not consistent with the morphology of species assigned to and described as Phylloporina, even by authors who have cited R. angulata as the type species, whereas virtually all adequately described Phylloporina species appear to be congeneric with R. trentonensis. We request that R. trentonensis be designated as type species in conformity with the current concept of the genus.