In synonymy:
Giltayia Kishida, 1955 = Mastigusa Menge, 1854 (Kishida, 1955: 6, type species belongs to Mastigusa)
Paratetrilus Kishida, 1955 = Mastigusa Menge, 1854 (Kishida, 1955: 6, type species belongs to Mastigusa)

type Mastigusa acuminata Menge, 1854 (fossil); gender feminine

N.B.: type species is from Baltic amber; first used by Wunderlich, 1986: 67 for recent species previously misplaced in Tetrilus and placed in the Agelenidae; transferred from the Dictynidae to the Hahniidae by Wheeler et al., 2017: 607 [not explicitely, but the type genus of Cicurininae, Cicurina Menge, 1871, was transferred] and to the Cybaeidae by Castellucci, Scharff & Luchetti, 2023: 6; transfer to the Cicurinidae by Murphy & Roberts, 2015: viii not sufficiently justified and was not accepted here; considered a senior synonym of Giltayia Kishida, 1955: 6 [urn:lsid:nmbe.ch:spidergen:05828] (type Cryphoeca arientina Thorell, 1871) and of Paratetrilus Kishida, 1955: 6 [urn:lsid:nmbe.ch:spidergen:05829] (type Tetrilus lucifuga Simon 1898), because both type species belong to Mastigusa (both genera were considered nomina nuda in Agelenidae by Yaginuma, in Brignoli, 1983c: 468).

In synonymy:
Mastigusa impudica (Simon, 1875, T from Cicurina) = Mastigusa arietina (Thorell, 1871) (Simon, 1898a: 262, sub Tetrilus).
Mastigusa recisa (O. Pickard-Cambridge, 1908) = Mastigusa diversa (O. Pickard-Cambridge, 1893) (Castellucci, Luchetti & Scharff, 2024: 16).

Hahnia pratensis Westring, 1861: 318 (mf; misidentified per Thorell, 1871a: 165).
Cryphoeca arietina Thorell, 1871a: 165 (D, new name for Hahnia pratensis sensu Westring).
Cicurina impudica Simon, 1875a: 24, pl. 5, f. 2 (Dm) [urn:lsid:nmbe.ch:spidersp:060269].
Cicurina arietina Simon, 1875a: 25.
Tuberta arietina Chyzer & Kulczyński, 1897: 156, pl. 6, f. 21 (mf).
Tetrilus arietinus Simon, 1898a: 261, 268, f. 261 (m, S of Cicurina impudica).
Tetrilus arietinus O. Pickard-Cambridge, 1901a: 10, pl. A, f. 2 (m).
Tetrilus arietinus Simon, 1937: 1022, 1044, f. 1592-1593 (mf).
Tetrilus arietinus Bristowe, 1939: 168, f. 14 (f).
Tetrilus macrophthalmus Locket & Millidge, 1953: 23, f. 17A-C (mf; misidentified per Wunderlich, 1986: 69; probably Mastigusa diversa?).
Tetrilus arietinus Locket & Millidge, 1953: 24, f. 17D (mf, S of Tetrilus diversus).
Giltayia arietina Kishida, 1955: 6 (T from Tetrilus).
Tuberta arietina Lehtinen, 1967: 272, f. 347, 349 (mf, T from Tetrilus).
Tetrilus macrophthalmus Locket & Millidge, 1967: 182, f. 5D-E (m; misidentified per Wunderlich, 1986: 69; probably Mastigusa diversa?).
Tetrillus arietinus Miller, 1971: 179, pl. XXIX, f. 19 (m).
Tetrilus arietinus Tystshenko, 1971: 163, f. 461 (m).
Tetrilus macrophthalmus Brignoli, 1971c: 116, f. 31-34 (mf; misidentified per Wunderlich, 1986: 69).
Tetrilus macrophthalmus Klausen, 1974: 192, f. 2-4 (mf; misidentified per Wunderlich, 1986: 69).
Tuberta arietina Palmgren, 1977a: 10, f. 1.25-29 (mf).
Tetrilus macrophthalmus Roberts, 1985: 166, pl. A (mf; misidentified per Wunderlich, 1995c: 463; probably Mastigusa diversa?).
Mastigusa arietina Wunderlich, 1986: 69, f. 68-69, 74, 80-87 (mf, T from Tuberta).
Tuberta arietina Heimer & Nentwig, 1991: 366, f. 950 (mf).
Mastigusa macrophthalma Roberts, 1995: 251, f. (mf; misidentified per Wunderlich, 1995c: 463; probably Mastigusa diversa?).
Mastigusa arietina Wunderlich, 1995c: 464, f. 12 (m).
Mastigusa macrophthalma Roberts, 1998: 268, f. (mf; misidentified per Wunderlich, 1995c: 463; probably Mastigusa diversa?).
Mastigusa arietina Trotta, 2005: 159, f. 174-175 (mf).
Mastigusa arietina Almquist, 2007: 321, f. 282a-f (mf).
Mastigusa macrophthalma Azarkina & Trilikauskas, 2012: 205, f. 2-4 (f; misidentified per Castellucci, Luchetti & Scharff, 2024: 16).
Mastigusa arietina Zamani et al., 2020: 582, f. 7A-C (f).
Mastigusa arietina Castellucci, Scharff & Luchetti, 2023: 2, f. 1a-b (mf).
Mastigusa arietina Seropian et al., 2023: 245, f. 31 (f).
Mastigusa arietina Castellucci, Luchetti & Scharff, 2024: 12, f. 1, 2a-d, 3a-c, 6a-d, 8a, 9a-d, 10a-e, 11a-b, 12a (mf).

Cryphoeca diversa O. Pickard-Cambridge, 1893a: 148, f. 2 (Df).
Cryphoeca recisa O. Pickard-Cambridge, 1908a: 123, pl. A, f. 1-3 (Df) [urn:lsid:nmbe.ch:spidersp:060270].
Tetrilus recisus Jackson, 1913: 23.
Tetrilus diversus Simon, 1937: 1044.
Mastigusa diversa Castellucci, Luchetti & Scharff, 2024: 16, f. 7a-c, 12b, 13a-e, 14a-b (mf, removed from S of Mastigusa arietina, rejecting Simon, 1937: 1044, S of M. recisa, rejecting Locket & Millidge, 1953: 24).

Tetrilus lucifuga Simon, 1898a: 261, f. 259.
Tetrilus lucifuga Simon, 1898f: 9 (Df).
Paratetrilus lucifuga Kishida, 1955: 6 (T from Tetrilus).
Mastigusa lucifuga Wunderlich, 1986: 69, f. 79 (f, T from Tuberta).
Mastigusa lucifuga Castellucci, Luchetti & Scharff, 2024: 19, f. 15a-b .

Tuberta arietina macrophthalma Kulczyński, in Chyzer & Kulczyński, 1897: 156, pl. 6, f. 21 (Dmf).
Tuberta arietina macrophthalma Gerhardt, 1921: 98, f. 9 (m).
Tetrilus macrophthalmus Simon, 1937: 1023, 1044 (elevated from subspecies, S of Tetrilus recisus; rejected by Castellucci, Luchetti & Scharff, 2024: 16).
Tetrilus macrophthalmus Loksa, 1969: 114, f. 77C-E (mf).
Mastigusa macrophthalma Wunderlich, 1986: 70, f. 75, 88-90 (mf, T from Tuberta).
Mastigusa macrophthalma Castellucci, Luchetti & Scharff, 2024: 20, f. 2e, 8b, 12c, 16a-e, 17a-b (mf).