The concept of “superspecies,” as applied to a monophyletic group of allopatric or nearly allopatric taxa that are known or believed to have evolved to the species level, was introduced to the literature by E. Mayr and by B. Rensch. The concept is of great utility in many studies of evolution and zoogeography. The use of superspecies has been somewhat retarded by the absence of any formalized notation for them in Linnaean nomenclature. It is here proposed that brackets (= square parentheses) enclose the first named species of a superspecies: thus, superspecies Bubo [bubo], or Bubo [bubo] virginianus to indicate that the species virginianus is a member of the superspecies Bubo [bubo]. The term “allospecies” is suggested for the species comprising a superspecies. The use of parentheses ( ) should be restricted to indicating “semispecies,” that is, forms believed to be subspecies, but approaching, or possibly of, species status, e.g., Accipiter (gentilis) atricapillus.