The availability and authorship of Scalaria borealis Lyell, 1841 and Scalaria borealis Gould, 1852 have been subject of considerable debate. Both names are shown to be available and the latter, being preoccupied, should be called Opalia wroblewskyi (Mörch, 1875). Scalaria borealis Lyell, 1841 is confirmed as the type species of Acirsa Mörch, 1857; its current name is Acirsa borealis (Lyell, 1841). Lectotypes are designated for both species.