Selected synonymic references
Undella hyalina: Daday, 1887a; Brandt, 1906-1907; Kofoid and Campbell, 1929; Balech, 1959, 1975
Undella hyalina var. a: Brandt, 1906-1907
Undella hyalina var. b: Brandt, 1906-1907
Undella hyalina var. c: Brandt, 1906-1907
Undella hyalina, forma attenuata: Jörgensen, 1924
Undella attenuata: Kofoid and Campbell, 1929
Undella bulla: Kofoid and Campbell, 1929
Undella declivis: Kofoid and Campbell, 1929
Undella dilatata: Kofoid and Campbell, 1929
Undella parva: Kofoid and Campbell, 1929
Undella peruana: Kofoid and Campbell, 1929
Undella mammilata: Kofoid and Campbell, 1929
Undella media: Kofoid and Campbell, 1929