Dalla Torre, 1893: 64; Emery, 1922c: 205; Ettershank, 1966: 157 (checklist); Smith, 1979: 1401 (North America); Bolton, 1995b: 63.
Emery, 1882a: 278 (Europe, Algeria); Emery, 1922c: 205 (diagnosis); Creighton, 1950a: 241 (North America, review); Ettershank, 1966: 157 (diagnosis, review of genus); Bernard, 1967a: 241 (diagnosis); Bolton, 1976: 296 (diagnosis, review of genus); Bolton, 1995a: 1047 (census); Sanetra & Buschinger, 2000: 95 (phylogeny).
Extant: 0 valid species (2 obsolete combinations)