In synonymy:
Janus C. L. Koch, 1846 = Synemosyna Hentz, 1846 (Peckham & Peckham, 1888: 93, by S of the type species)
Simonella G. W. Peckham & E. G. Peckham, 1885 = Synemosyna Hentz, 1846 (Galiano, 1966a: 341)
Transferred to other genera:
Synemosyna atrogaster (Mello-Leitão, 1941) -- see Sympolymnia
Synemosyna edwardsi Cutler, 1985 -- see Sympolymnia
Synemosyna ephippiata Hentz, 1846 -- see Peckhamia
Synemosyna formosana (Saito, 1933) -- see Myrmarachne
Synemosyna lauretta G. W. Peckham & E. G. Peckham, 1892 -- see Sympolymnia
Synemosyna lucasi (Taczanowski, 1871) -- see Sympolymnia
Synemosyna melanura Mello-Leitão, 1917 -- see Sympolymnia
Synemosyna procera Thorell, 1877 -- see Toxeus
Synemosyna pumilio Karsch, 1880 -- see Myrmarachne
Synemosyna transversa Mukerjee, 1930 -- see Myrmarachne
In synonymy:
Synemosyna bicolor (G. W. Peckham & E. G. Peckham, 1892) = Synemosyna americana G. W. Peckham & E. G. Peckham, 1885 (Cutler, 1981a: 343)
Synemosyna claustrorum (Mello-Leitão, 1933) = Synemosyna aurantiaca Mello-Leitão, 1917 (Galiano, 1966a: 348)
Synemosyna gibberosa (C. L. Koch, 1846, T from Janus) = Synemosyna formica Hentz, 1846 (Peckham & Peckham, 1888: 93)
Synemosyna mastigostyla (Mello-Leitão, 1917) = Synemosyna aurantiaca Mello-Leitão, 1917 (Galiano, 1966a: 348)
Synemosyna peckhami (Mello-Leitão, 1933) = Synemosyna myrmeciaeformis Taczanowski, 1871 (Galiano, 1966a: 367)
Synemosyna simplex (Chamberlin, 1925) = Synemosyna decipiens O. Pickard-Cambridge, 1896 (Galiano, 1966a: 355)
Synemosyna ypsilon (Piza, 1937) = Synemosyna aurantiaca Mello-Leitão, 1917 (Galiano, 1966a: 349)
Nomina dubia:
Synemosyna bimaculata (Mello-Leitão, 1917c: 139, 1933a: 58, pl. 1, f. 3, f, Brazil, originally in Simonella) -- Galiano, 1966a: 354
Synemosyna fasciata Mello-Leitão, 1922a: 222 (f, Brazil) -- Galiano, 1966a: 357
Synemosyna fissidentata (Szombathy, 1913: 34, 57, f. 10-11, f, Paraguay, originally in Simonella) -- Galiano, 1966a: 357
Synemosyna lunata (Walckenaer, 1837: 387, m, USA, originally in Myrmecium) -- Galiano, 1966a: 360
Synemosyna magniscuti Mello-Leitão, 1939h: 292, f. 13-14 (m, Brazil) -- Galiano, 1966a: 367
Synemosyna rubra (Walckenaer, 1837: 387, mf, USA, originally in Myrmecium) -- Galiano, 1966a: 360
Synemosyna subtilis (Taczanowski, 1871: 122, f, Guyana, originally in Janus) -- Galiano, 1966a: 376