In synonymy:
Mezenia Simon, 1897 = Gayenna Nicolet, 1849 (Ramírez & Kochalka, 1993: 164, automatically with its replacement name Mezenina)
Mezenina Strand, 1932 = Gayenna Nicolet, 1849 (Ramírez & Kochalka, 1993: 164)

type Gayenna americana Nicolet, 1849; gender feminine

N.B.: considered a senior synonym of Mezenina Strand, 1932: 141 [urn:lsid:nmbe.ch:spidergen:04183] by Ramírez & Kochalka, 1993: 164; Mezenina is a replacement name for Mezenia Simon, 1897a: 101 [urn:lsid:nmbe.ch:spidergen:04712] (type M. dorsalis Simon, 1897), preoccuppied in fossil Hydrozoa by Stuckenberg, 1895; not a senior synonym of Abuzaida Keyserling, 1891 (Ramírez, 2003: 130, contra Mello-Leitão, 1925a: 457, see Arachnosia), nor of Samuza Keyserling, 1891 (Ramírez, 2003: 130, contra Petrunkevitch, 1911: 485, see Arachnosia).

Transferred to other genera:
Gayenna abdominalis (Nicolet, 1849) -- see Monapia
Gayenna absoluta Chamberlin, 1924 -- see Lupettiana
Gayenna affinis Tullgren, 1901 -- see Sanogasta
Gayenna alticola Simon, 1896 -- see Sanogasta
Gayenna andesiana Berland, 1913 -- see Josa
Gayenna approximata Tullgren, 1901 -- see Sanogasta
Gayenna bonariensis Mello-Leitão, 1940 -- see Sanogasta
Gayenna bonneti Mello-Leitão, 1947 -- see Arachosia
Gayenna chilensis Tullgren, 1902 -- see Tomopisthes
Gayenna cinerea Tullgren, 1901 -- see Acanthoceto
Gayenna citrina (Nicolet, 1849) -- see Monapia
Gayenna coccinea Simon, 1884 -- see Araiya
Gayenna colulata (Hogg, 1913) -- see Negayan
Gayenna cruziana Tullgren, 1901 -- see Monapia
Gayenna dilaticollis (Nicolet, 1849) -- see Monapia
Gayenna dixiana Chamberlin & Woodbury, 1929 -- see Anyphaena
Gayenna dubia Tullgren, 1901 -- see Sanogasta
Gayenna duplovittata Mello-Leitão, 1942 -- see Arachosia
Gayenna excepta Tullgren, 1901 -- see Negayan
Gayenna exigua Mello-Leitão, 1940 -- see Negayan
Gayenna fuegiana (Karsch, 1880) -- see Tomopisthes
Gayenna fuscotaeniata Keyserling, 1891 -- see Tasata
Gayenna gayi (Nicolet, 1849) -- see Philisca
Gayenna gemella (Nicolet, 1849) -- see Sanogasta
Gayenna ignota (Keyserling, 1887) -- see Sanogasta
Gayenna jollensis Schenkel, 1950 -- see Anyphaena
Gayenna keyserlingi (L. Koch, 1866) -- see Josa
Gayenna longiventris (Nicolet, 1849) -- see Oxysoma
Gayenna lutea (Nicolet, 1849) -- see Monapia
Gayenna maculatipes (Keyserling, 1878) -- see Sanogasta
Gayenna maculosa (Nicolet, 1849) -- see Sanogasta
Gayenna marginalis Banks, 1901 -- see Anyphaena
Gayenna marginata Keyserling, 1891 -- see Acanthoceto
Gayenna minuta (Keyserling, 1891) -- see Sanogasta
Gayenna minuta Banks, 1898 -- see Lupettiana
Gayenna minutissima Petrunkevitch, 1911 -- see Lupettiana
Gayenna monticola Chamberlin, 1916 -- see Sanogasta
Gayenna pallida Tullgren, 1902 -- see Araiya
Gayenna pampa (Holmberg, 1881) -- see Sanogasta
Gayenna paucilineata Mello-Leitão, 1945 -- see Sanogasta
Gayenna praesignis (Keyserling, 1891) -- see Arachosia
Gayenna proseni Mello-Leitão, 1944 -- see Arachosia
Gayenna punctulata Roewer, 1951 -- see Monapia
Gayenna reticulata Mello-Leitão, 1943 -- see Tasata
Gayenna riveti Berland, 1913 -- see Josa
Gayenna rufea (Nicolet, 1849) -- see Monapia
Gayenna rufithorax Tullgren, 1902 -- see Sanogasta
Gayenna saccata Tullgren, 1902 -- see Oxysoma
Gayenna sachalinensis Saito, 1935 -- see Anyphaena
Gayenna saniuana Chamberlin & Gertsch, 1928 -- see Anyphaena
Gayenna simoni Berland, 1913 -- see Josa
Gayenna skottsbergi Berland, 1924 -- see Sanogasta
Gayenna smaragdula (Nicolet, 1849) -- see Monapia
Gayenna stellata Simon, 1884 -- see Araiya
Gayenna striata (Keyserling, 1891) -- see Arachosia
Gayenna sulphurea (Nicolet, 1849) -- see Monapia
Gayenna taperae Mello-Leitão, 1929 -- see Tasata
Gayenna tridentata Simon, 1886 -- see Negayan
Gayenna trilineata Tullgren, 1901 -- see Sanogasta
Gayenna trimaculata Simon, 1904 -- see Philisca
Gayenna tripunctata Mello-Leitão, 1941 -- see Tasata
Gayenna unidentata Tullgren, 1901 -- see Monapia
Gayenna x-signata Keyserling, 1891 -- see Sanogasta

In synonymy:
Gayenna dorsalis (Simon, 1897, T from Mezenina) = Gayenna americana Nicolet, 1849 (Ramírez & Kochalka, 1993: 165).

Nomina dubia:
Gayenna albiventris (Nicolet, 1849: 434, f, Chile, originally in Clubiona) -- Ramírez, 2003: 120.
Gayenna gibbosa (Nicolet, 1849: 436, f, Chile, originally in Clubiona) -- Ramírez, 2003: 120.
Gayenna lepida (Nicolet, 1849: 432, f, Chile, originally in Clubiona) -- Ramírez, 2003: 120.
Gayenna lineata (Nicolet, 1849: 435, f, Chile, originally in Clubiona) -- Ramírez, 2003: 44.
Gayenna puella (Nicolet, 1849: 426, f, Chile, originally in Clubiona) -- Ramírez, 2003: 120.
Gayenna pulchella (Nicolet, 1849: 432, f, Chile, originally in Clubiona) -- Ramírez, 2003: 120.

Nomen nudum:
Gayenna sakisimana Kishida, 1959: 374 (Japan/Okinawa) [urn:lsid:nmbe.ch:spidersp:054939] -- Yaginuma, in Brignoli, 1983c: 538.

Gayenna americana Nicolet, 1849: 451, pl. 4, f. 2 (Dmf).
Mezenia dorsalis Simon, 1897a: 101 (Df) [urn:lsid:nmbe.ch:spidersp:056829].
Mezenia dorsalis Tullgren, 1902: 67, pl. 7, f. 4 (f).
Mezenina dorsalis Strand, 1932: 141 (generic replacement name).
Gayenna americana Ramírez & Kochalka, 1993: 165, f. 1-9 (mf, S of Mezenina dorsalis).
Gayenna americana Ramírez, 1995a: 370, f. 29, 32 (mf).
Gayenna americana Ramírez, 1995b: 92, f. 20, 29 (mf).
Gayenna americana Ramírez, 2003: 121, f. 12A-C, 13E-G, 16A-E, 17A-D, 62A-B, 63A-D, 68A-C (m).
Gayenna americana Ramírez, 2014: 228, f. 156C-F (m).

Gayenna alticola Mello-Leitão, 1926b: 6 (Df; preoccupied by Simon, 1896, see Sanogasta alticola).
Gayenna brasiliensis Roewer, 1951: 445 (replacement name).

Gayenna chrysophila Mello-Leitão, 1926b: 6, f. 3-4 (Dmf).

Anyphaena furcata Keyserling, 1879: 326, pl. 4, f. 23 (Df).
Abuzaida furcata Keyserling, 1891: 133.
Gayenna furcata Mello-Leitão, 1925a: 456.

Gayenna ignava Banks, 1898b: 224, pl. 13, f. 34 (Df).

Monapia moreirae Mello-Leitão, 1915a: 137 (Dmf).
Gayenna moreirae Mello-Leitão, 1925a: 457.

Gayenna orizaba Banks, 1898b: 223, pl. 13, f. 37 (Df).

Gayenna sigillum Mello-Leitão, 1941d: 194 (Dj; N.B.: probably a junior synonym of Oxysoma saccatum, per Ramírez, 2003: 225).

Anyphaena trivittata Bertkau, 1880a: 44, pl. 1, f. 12 (Df).
Gayenna trivittata Keyserling, 1891: 142.

Anyphaena vittata Keyserling, 1881c: 294, pl. 11, f. 15 (Df).
Gayenna vittata Keyserling, 1891: 142.