Transferred to other genera:

Nigma gratiosa (Simon, 1881) -- see Ajmonia

Nigma linsdalei (Chamberlin & Gertsch, 1958) -- see Califorenigma

Nigma numidica (Denis, 1937) -- see Ajmonia

Nigma patellaris (Simon, 1910) -- see Ajmonia

Nigma tristis (Spassky, 1952) -- see Dictyna

In synonymy:

Nigma canariensis Wunderlich, 1987 = Nigma puella (Simon, 1870) (Wunderlich, 1992a: 429)

Nigma eburnea (Schmidt, 1982, T from Dictyna) = Nigma puella (Simon, 1870) (Wunderlich, 1992a: 429)

Nigma lobensis (Schmidt, 1976, T from Dictyna) = Nigma puella (Simon, 1870) (Wunderlich, 1992a: 429)

Nigma orientalis (Kulczyński, 1895, T from Dictyna) = Nigma flavescens (Walckenaer, 1830) (Lehtinen, 1967: 252)

Nigma pallens (Blackwall, 1859) = Nigma flavescens (Walckenaer, 1830) (Thorell, 1873: 433, sub Ergatis)

Nigma palmarum (Simon, 1885) = Nigma conducens (O. Pickard-Cambridge, 1876) (Simon, 1907e: 1, sub Dictyna)

Nigma variabilis (C. L. Koch, 1836) = Nigma flavescens (Walckenaer, 1830) (Chyzer & Kulczyński, 1891: 158, sub Dictyna)

Nigma viridis (Wider, 1834, T from Theridion) = Nigma flavescens (Walckenaer, 1830) (Simon, 1914: 63, sub Dictyna)

Nigma vulnerata (Simon, 1914) = Nigma walckenaeri (Roewer, 1951) (Lecigne et al., 2022: 28)

Homonym replaced:

Nigma viridissima (Walckenaer, 1802) -- see Nigma walckenaeri Roewer, 1951 Roewer, 1951