Nigma Araneomorphae armiarma generoa da, Dictynidae familiakoa. Ipar Amerikan, Eurasian eta Afrikan aurkitzen dira.
The World Spider Catalogo 12.0-ren arabera hauek dira:[1]
- Nigma conducens (O. Pickard-Cambridge, 1876)
- Nigma flavescens (Walckenaer, 1830)
- Nigma gertschi (Berland & Millot, 1940)
- Nigma gratiosa (Simon, 1881)
- Nigma hortensis (Simon, 1870)
- Nigma laeta (Spassky, 1952)
- Nigma linsdalei (Chamberlin & Gertsch, 1958)
- Nigma longipes (Berland, 1914)
- Nigma puella (Simon, 1870)
- Nigma shiprai (Tikader, 1966)
- Nigma tristis (Spassky, 1952)
- Nigma tuberosa Wunderlich, 1987
- Nigma vulnerata (Simon, 1914)
- Nigma walckenaeri (Roewer, 1951)
- Lehtinen, 1967: "Classification of the cribellate spiders and some allied families, with notes on the evolution of the suborder Araneomorpha". Annales Zoologici Fennici, vol.4, p.199-468.