In synonymy:
Astratea Thorell, 1890 = Medmassa Simon, 1887 (Deeleman-Reinhold, 2001: 345, contra Deeleman-Reinhold, 1995c: 44)
Megaera Simon, 1877 = Medmassa Simon, 1887 (Karsch, 1880c: 374, preoccupied, replacement name)

type Megaera frenata Simon, 1877; gender feminine

N.B.: replacement name for Megaera Simon, 1877b: 87 [urn:lsid:nmbe.ch:spidergen:05563], preoccupied in Diptera by Robineau-Desvoidy, 1830; considered a senior synonym of Astratea Thorell, 1890a: 364 [urn:lsid:nmbe.ch:spidergen:04803] (type A. insignis Thorell, 1890) by Deeleman-Reinhold, 2001: 345 (contra Deeleman-Reinhold, 1995c: 44).

Transferred to other genera:
Medmassa andina Simon, 1898 -- see Corinna
Medmassa armata Simon, 1896 -- see Koppe
Medmassa australiensis (L. Koch, 1873) -- see Miturga
Medmassa bicolor Hogg, 1900 -- see Nyssus
Medmassa fusca Hogg, 1900 -- see Nucastia
Medmassa laurenti Lessert, 1946 -- see Mandaneta
Medmassa lesserti Strand, 1916 -- see Procopius
Medmassa nitida Lawrence, 1937 -- see Pronophaea
Medmassa pallipes (L. Koch, 1873) -- see Creugas
Medmassa proxima Lessert, 1923 -- see Pronophaea
Medmassa pusilla Simon, 1896 -- see Creugas
Medmassa semiflava Simon, 1896 -- see Battalus
Medmassa venezuelica Caporiacco, 1955 -- see Corinna
Medmassa vidua Lessert, 1923 -- see Pronophaea

In synonymy:
Medmassa hiekae Berland, 1922 = Medmassa semiaurantiaca Simon, 1909 (Haddad & Bosselaers, 2010: 3).

Nomina dubia:
Medmassa brunneolanceata Caporiacco, 1955: 369 (j, Venezuela) -- Bonaldo, 2000: 34.
Medmassa glabra Caporiacco, 1947a: 27 (j, Guyana) -- Bonaldo, 2000: 34.
Medmassa nyctalops Simon, 1909f: 377 (f, Equatorial Guinea/Bioko) -- Haddad & Bosselaers, 2010: 11.
Medmassa septentrionalis Caporiacco, 1954: 116 (j, French Guiana) -- Bonaldo, 2000: 34.

Astratea celebensis Deeleman-Reinhold, 1995c: 46, f. 5 (Df).
Medmassa celebensis Deeleman-Reinhold, 2001: 353, f. 541 (f).

Medmassa christae Raven, 2015: 28, f. 2c, 11a-d, 135 (Df).

Medmassa diplogale Deeleman-Reinhold, 2001: 354, f. 542-554 (Dmf).

Megaera frenata Simon, 1877b: 88, pl. 3, f. 11 (Dj).
Medmassa frenata Simon, 1898a: 198.
Medmassa frenata Deeleman-Reinhold, 2001: 348, f. 521-526 (j).

Astratea insignis Thorell, 1890a: 365 (Df).
Medmassa insignis Simon, 1898a: 198.
Astratea insignis Deeleman-Reinhold, 1995c: 45, f. 1-4 (f, T from Medmassa).
Medmassa insignis Deeleman-Reinhold, 2001: 349, f. 527-535 (f, Dm).

Agroeca kltina Barrion & Litsinger, 1995: 174, f. 99a-e (Df).
Medmassa kltina Deeleman-Reinhold, 2001: 346, 397 (T from Agroeca, may be a junior S of M. tigris).

Medmassa lingshui Lu & Li, in Lu et al., 2023b: 29, f. 7A-C, 8A-B (Dm).

Medmassa postica Kadam, Tripathi & Sankaran, in Sankaran, Kadam & Tripathi, 2024: 141, f. 1C, 6A-J, 7A-B (Df).

Liocranum pulchrum Thorell, 1881: 213 (Df).
Medmassa pulchra Simon, 1898a: 195.

Medmassa sagax Tripathi, Kadam & Sankaran, in Sankaran, Kadam & Tripathi, 2024: 234, f. 1A-B, 2A-G, 3A-F, 4A-G, 5A-E (Dmf).

Medmassa semiaurantiaca Simon, 1909f: 376 (Df).
Medmassa hiekae Berland, 1922: 74, pl. A4, f. 3 (Dj) [urn:lsid:nmbe.ch:spidersp:025290].
Medmassa semiaurantiaca Haddad & Bosselaers, 2010: 3, f. 1-14 (Dm, f, S of Medmassa hiekae).
Medmassa semiaurantiaca Ramírez, 2014: 230, f. 158A-B (m).
Medmassa semiaurantiaca Haddad et al., 2023: 55, p. 54: 1-2, p. 55: 1-9 (mf).

Astratea tigris Deeleman-Reinhold, 1995c: 47, f. 6-10 (Dmf).
Medmassa tigris Deeleman-Reinhold, 2001: 351, f. 536-540 (mf).

Medmassa torta Jin, Zhang & Zhang, 2019: 469, f. 8A-H, 9A-C (Dm).