Selected synonymic references
Cyttarocylis undella: Ostenfeld and Schmidt, 1901
Ptychocylis undella var. a: Brandt, 1906-1907
Ptychocylis undella var. b: Brandt, 1906-1907
Ptychocylis undella var. c: Brandt, 1906-1907
Ptychocylis undella var. e: Brandt, 1906-1907
Ptychocylis undella var. f: Brandt, 1906-1907
Ptychocylis undella var. h: Brandt, 1906-1907
Ptychocylis undella var. i: Brandt, 1906-1907
Ptychocylis undella var. k: Brandt, 1906-1907
? Ptychocylis undella var. o: Brandt, 1906-1907
Epiplocylis undella: Jörgensen, 1924
Epiplocylis undella var. blanda: Jörgensen, 1924
Epiplocylis atlantica: Kofoid and Campbell, 1929
Epiplocylis blanda: Kofoid and Campbell, 1929
Epiplocylis constricta: Kofoid and Campbell, 1929
Epiplocylis exquisita: Kofoid and Campbell, 1929
Epiplocylis impensa: Kofoid and Campbell, 1929
Epiplocylis deflexa: Kofoid and Campbell, 1929
Epiplocylis lineata: Kofoid and Campbell, 1929
Epiplocylis pacifica: Kofoid and Campbell, 1929
? Epiplocylis obtusa: Kofoid and Campbell, 1929