Selected synonymic references
Undella marsupialis: Brandt, 1906-1907
Undella marsupialis, forma subangulata: Jörgensen, 1924
Undella marsupialis, forma subcylindrica: Jörgensen, 1924
Undellopsis (Undellopsis) marsupialis: Kofoid and Campbell, 1929
Undellopsis (Undellopsis) lineata: Kofoid and Campbell, 1929
Undellopsis (Undellopsis) pacifica: Kofoid and Campbell, 1929
Undellopsis subangulata: Kofoid and Campbell, 1929; Balech, 1975
Undellopsis cubitum: Kofoid and Campbell, 1929; 1939
Undellopsis marsupialis: Balech, 1975