In synonymy:
Eustichothrix Dahl, 1886 = Nematogmus Simon, 1884 (Simon, 1894a: 672)

type Theridion sanguinolentum Walckenaer, 1841; gender masculine

N.B.: the synonymy of this genus with Cnephalocotes Simon, 1884, proposed by Wunderlich, 1970: 408, has not been accepted by later authors (see van Helsdingen, 1979b: 407); considered a senior synonym of Eustichothrix Dahl, 1886: 78 [urn:lsid:nmbe.ch:spidergen:04627] (type Theridion sanguinolentum Walckenaer, 1841) by Simon, 1894a: 672.

In synonymy:
Nematogmus javanus (Workman, 1896, T from Linyphia) = Nematogmus dentimanus Simon, 1886 (van Helsdingen, 1979b: 407).
Nematogmus rubecula (Canestrini, 1868, T from Linyphia) = Nematogmus sanguinolentus (Walckenaer, 1841) (Simon, 1884a: 615).
Nematogmus simoni (O. Pickard-Cambridge, 1873, T from Erigone) = Nematogmus sanguinolentus (Walckenaer, 1841) (Simon, 1884a: 615).

Nematogmus asiaticus Tanasevitch, 2014b: 83, f. 51-58 (Dmf).

Nematogmus cikaiensis Irfan, Zhang & Peng, 2022: 194, f. 228A-C, 229A-B (Df).

Nematogmus dentimanus Simon, 1886a: 155 (Dm).
Linyphia javana Workman, 1896: 64, pl. 64 (Dm) [urn:lsid:nmbe.ch:spidersp:061350].
Sphecozone dentimanus Simon, 1901k: 54.
Nematogmus dentimanus van Helsdingen, 1979b: 407, f. 1-7 (m, Df, T from Sphecozone, S of Linyphia javana).

Nematogmus digitatus Fei & Zhu, 1994: 293, f. 1-5 (Dmf).
Nematogmus digitatus Song, Zhu & Chen, 1999: 188, f. 107K-L, O-P (mf).
Nematogmus digitatus Song & Li, 2008b: 277e2, f. 1A-F, 2A-G (mf).

Nematogmus longior Song & Li, 2008b: 277e5, f. 3A-F, 4A-G (Dmf).

Nematogmus lushuiensis Irfan, Zhang & Peng, 2022: 199, f. 229C, 230A-C (Df).

Nematogmus membranifer Song & Li, 2008b: 277e8, f. 5A-F, 6A-G, 7 (Dmf).
Nematogmus membranifer Irfan, Zhang & Peng, 2022: 201, f. 231A-D, 232A-C, 233A-F (mf).

Nematogmus nigripes Hu, 2001: 548, f. 368.1-4 (Df).

Nematogmus rutilis Oi, 1960a: 166, f. 115-119 (Dmf).
Nematogmus rutilis Yaginuma, 1986a: 85, f. 46.1 (f).
Nematogmus rutilis Ono, Matsuda & Saito, 2009: 261, f. 39-43 (mf).

Theridion sanguinolentum Walckenaer, 1841: 326 (Df).
Linyphia rubecula Canestrini & Pavesi, 1868: 858 (f).
Linyphia rubecula Canestrini, 1868a: 173 (Dmf) [urn:lsid:nmbe.ch:spidersp:061614].
Linyphia rubecula Canestrini, 1868c: 200 (Df).
Erigone simonii O. Pickard-Cambridge, 1873a: 756, pl. 65, f. 12 (Dmf) [urn:lsid:nmbe.ch:spidersp:061615].
Linyphia rubecula Lebert, 1877: 158.
Nematogmus sanguinolentus Simon, 1884a: 615, f. 431-432 (mf, T from Theridion, S of Erigone simoni and Linyphia rubecula).
Eustichothrix sanguinolenta Dahl, 1886: 78.
Nematogmus sanguinolentus Chyzer & Kulczyński, 1894: 123, pl. 4, f. 46, pl. 5, f. 2 (mf).
Nematogmus sanguinolentus Becker, 1896: 120, pl. 11, f. 8 (mf).
Nematogmus sanguinolentus Bösenberg, 1902: 211, pl. 18, f. 296 (mf).
Nematogmus sanguinolentus Simon, 1926: 428, 513, f. 761 (mf).
Nematogmus sanguinolentus Miller, 1947: 39, pl. VII, f. 2 (f).
Nematogmus sanguinolentus Yaginuma, 1960: 45, f. 43.4 (m).
Nematogmus sanguinolentus Oi, 1960a: 165, f. 112-114, 120 (mf).
Nematogmus sanguinolentus Wiehle, 1960a: 391, f. 712-721 (mf).
Nematogmus sanguinolentus Yaginuma, 1971: 45, f. 43.4 (m).
Nematogmus sanguinolentus Tystshenko, 1971: 265, f. 899, 902 (mf).
Nematogmus sanguinolentus Miller, 1971: 280, pl. LIX, f. 29-30 (mf).
Nematogmus sanguinolentus Namkung, Paik & Yoon, 1972: 92, f. 6 (m).
Nematogmus sanguinolentus Millidge, 1977: 25, f. 83 (m).
Nematogmus sanguinolentus Yaginuma, 1986a: 85, f. 46.2 (mf).
Nematogmus sanguinolentus Song, 1987: 152, f. 113 (f).
Nematogmus sanguinolentus Irie & Saito, 1987: 19, f. 13 (m).
Nematogmus sanguinolentus Hu & Wu, 1989: 172, f. 143.1-4 (mf).
Nematogmus sanguinolentus Chikuni, 1989b: 56, f. 44 (mf).
Nematogmus sanguinolentus Feng, 1990: 136, f. 111.1-3 (m).
Nematogmus sanguinolentus Tanasevitch, 1990: 104, f. 24.2, 24.57 (mf).
Nematogmun sanguinolentus Chen & Gao, 1990: 110, f. 137 (m).
Nematogmus sanguinolentus Chen & Zhang, 1991: 174, f. 172.1-3 (mf).
Cnephalocotes sanguinolentus Heimer & Nentwig, 1991: 138, f. 388 (mf).
Nematogmus sanguinolentus Millidge, 1993c: 146, f. 23 (f).
Nematogmus sanguinolentus Pesarini, 1996: 423, f. 45-46 (mf).
Nematogmus sanguinolentus Song, Zhu & Chen, 1999: 188, f. 107M-N, Q (mf).
Nematogmus sanguinolentus Song, Zhu & Chen, 2001: 141, f. 77A-D (mf).
Nematogmus sanguinolentus Namkung, 2002: 194, f. 17.46a-b (mf).
Nematogmus sanguinolentus Namkung, 2003: 196, f. 17.46a-b (mf).
Nematogmus sanguinolentus Lee et al., 2004: 100, unnumbered f. (f).
Nematogmus sanguinolentus Bosmans, 2007: 135, f. 130-135 (mf).
Nematogmus sanguinolentus Song & Li, 2008b: 277e11, f. 9A-F, 10A-G (mf).
Nematogmus sanguinolentus Lee, Kang & Kim, 2009: 131, f. 37a-c (mf).
Nematogmus sanguinolentus Ono, Matsuda & Saito, 2009: 261, f. 30-33 (mf).
Nematogmus sanguinolentus Zhu & Zhang, 2011: 135, f. 86A-B (f).
Nematogmus sanguinolentus Yin et al., 2012: 513, f. 240a-e (mf).
Nematogmus sanguinolentus Suzuki et al., 2018: 32, f. f (m).
Nematogmus sanguinolentus Fu, 2018: 38, f. 5-5.A-G, pl. 9 (mf).
Nematogmus sanguinolentus Suzuki et al., 2023: 50, f. 7H-K (mf).
Nematogmus sanguinolentus Méndez, Marquerie & Domènech, 2024: 76, f. 7A-C (m).

Lophocarenum stylitum Bösenberg & Strand, 1906: 159, pl. 10, f. 196 (Dm).
Nematogmus stylitus Oi, 1960a: 163, f. 110-111, 121-124 (m, Df, T from Lophocarenum = Pelecopsis).
Nematogmun stylitus Chen & Gao, 1990: 110, f. 138 (m).
Nematogmus stylitus Ono, Matsuda & Saito, 2009: 261, f. 34-38 (mf).
Nematogmus stylitus Yin et al., 2012: 514, f. 241a-e (mf).