type Gasteracantha cicatricosa C. L. Koch, 1844; gender feminine

N.B.: Simon, 1885d: 35 considered Isoxya a replacement name of Isacantha Simon, 1864 (described as subgenus of Gasteracantha, preoccupied in Coleoptera by Hope, 1833), but none of the species listed by Simon, 1864: 286 in Isacantha are later considered to belong to Isoxya, therefore Isacantha is regarded as a synonym of Gasteracantha (see there); Isoxya was removed from the synonymy of Gasteracantha Sundevall, 1833 by Benoit, 1962a: 14 (contra Simon, 1895a: 845); not a senior synonym of Afracantha Dahl, 1914, Hypsacantha Dahl, 1914 or Togacantha Dahl, 1914 (Emerit, 1974: 28-31, contra Benoit, 1962a: 14).

Transferred to other genera:
Isoxya camerunensis (Thorell, 1899) -- see Afracantha
Isoxya crucimaculata (Dahl, 1914) -- see Hypsacantha
Isoxya galeata Simon, 1887 -- see Aetrocantha
Isoxya nordviei (Strand, 1913) -- see Togacantha

In synonymy:
Isoxya cicatrella (Strand, 1907) = Isoxya tabulata (Thorell, 1859) (Dahl, 1914: 255, sub Gasteracantha).
Isoxya hildebrandti (Karsch, 1878) = Isoxya cicatricosa (C. L. Koch, 1844) (Dahl, 1914: 256, sub Gasteracantha).
Isoxya kibonotensis (Tullgren, 1910) = Isoxya tabulata (Thorell, 1859) (Dahl, 1914: 255, sub Gasteracantha).
Isoxya maculosa (Lenz, 1886) = Isoxya reuteri (Lenz, 1886) (Dahl, 1914: 255, sub Gasteracantha).
Isoxya modesta (Thorell, 1859) = Isoxya tabulata (Thorell, 1859) (Dahl, 1914: 255, sub Gasteracantha).
Isoxya momboensis (Tullgren, 1910) = Isoxya tabulata (Thorell, 1859) (Dahl, 1914: 255, sub Gasteracantha).
Isoxya penizoides Simon, 1887 = Isoxya kochi (O. Pickard-Cambridge, 1877) (Hormiga et al., 2023: 808).
Isoxya proba (O. Pickard-Cambridge, 1879) = Isoxya cicatricosa (C. L. Koch, 1844) (Strand, 1908g: 433, sub Gasteracantha hildebrandti).
Isoxya purpurea (Simon, 1884) = Isoxya mucronata (Walckenaer, 1841) (Dahl, 1914: 255, sub Gasteracantha).
Isoxya pygmaea (Bösenberg & Lenz, 1895) = Isoxya cicatricosa (C. L. Koch, 1844) (Dahl, 1914: 256, sub Gasteracantha).
Isoxya rogersi (O. Pickard-Cambridge, 1879, T from Gasteracantha) = Isoxya semiflava Simon, 1887 (Benoit, 1962a: 29).
Isoxya sanguinipes (Strand, 1906) = Isoxya cicatricosa (C. L. Koch, 1844) (Dahl, 1914: 256, sub Gasteracantha).
Isoxya testudinaria benina (Strand, 1913, T from Gasteracantha) = Isoxya testudinaria (Simon, 1901) (Benoit, 1962a: 31).
Isoxya tuberifera (Dahl, 1914, T from Gasteracantha) = Isoxya cicatricosa (C. L. Koch, 1844) (Benoit, 1962a: 38).
Isoxya tuberosa (Thorell, 1859) = Isoxya mucronata (Walckenaer, 1841) (Dahl, 1914: 255, sub Gasteracantha).
Isoxya wealii (O. Pickard-Cambridge, 1879) = Isoxya cicatricosa (C. L. Koch, 1844) (Dahl, 1914: 256, sub Gasteracantha).

Isoxya basilewskyi Benoit & Emerit, 1975: 324, f. 4-6 (Dmf).

Gasteracantha cicatricosa C. L. Koch, 1844: 54, f. 877 (Df).
Isacantha hildebrandti Karsch, 1878b: 313, pl. 8, f. 3 (Df) [urn:lsid:nmbe.ch:spidersp:062726].
Gasteracantha wealii O. Pickard-Cambridge, 1879c: 290, pl. 27, f. 20 (Dj) [urn:lsid:nmbe.ch:spidersp:062727].
Gasteracantha proba O. Pickard-Cambridge, 1879c: 291, pl. 27, f. 22 (Df) [urn:lsid:nmbe.ch:spidersp:062728].
Gasteracantha pygmaea Bösenberg & Lenz, 1895: 47, pl. 2, f. 29 (Dm) [urn:lsid:nmbe.ch:spidersp:062729].
Gasteracantha sanguinipes Strand, 1906b: 625 (Df) [urn:lsid:nmbe.ch:spidersp:062730].
Gasteracantha hildebrandti Strand, 1908g: 433 (Dm, S of Gasteracantha proba).
Gasteracantha (Isoxya) cicatricosa Dahl, 1914: 256 (S of Gasteracantha hildebrandti, G. pygmaea, G. sanguinipes and G. wealii).
Gasteracantha (Isoxya) tubifera Dahl, 1914: 256, f. 18 (Df) [urn:lsid:nmbe.ch:spidersp:062725].
Isoxya cicatricosa Benoit, 1962a: 38, f. 25bis (f, T from Gasteracantha, S of Gasteracantha tubifera).
Isoxya cicatricosa Emerit, 1973: 676, f. 2A-C, pl. IA, C (m).
Isoxya cicatricosa Benoit & Emerit, 1975: 327, f. 8a-b (m).
Isoxya cicatricosa Dippenaar-Schoeman et al., 2022e: 28, p. 27: 1 f., p. 28: 5 f. (f habitus).

Gasteracantha cowani Butler, 1883: 766, pl. 57, f. 5 (Dm).
Gasteracantha cowani Dahl, 1914: 255 (Df).
Isoxya cowani Emerit, 1974: 49, f. 7A, 11, 12A-C, 16A (mf, T from Gasteracantha).

Paraplectana kochii O. Pickard-Cambridge, 1877c: 35, pl. 7, f. 10 (Df; Australia is possibly mislabelled per Hormiga et al., 2023: 810).
Isoxia penizoides Simon, 1887a: 269 (Df) [urn:lsid:nmbe.ch:spidersp:016209].
Gasteracantha penizoides Simon, 1895a: 843, f. 892 (f).
Paraplectanoides kochi Simon, 1895a: 871.
Plectana penizoides Thorell, 1899: 64.
Gasteracantha penizoides Simon, 1907d: 302 (Dm).
Isoxya penizoides Benoit, 1962a: 20 (T from Gasteracantha).
Isoxya penizoides Emerit, 1982b: 162, pl. 1B.
Isoxya kochi Hormiga et al., 2023: 808 (T from Paraplectanoides, S of Isoxya penizoides).

Isoxya mahafalensis Emerit, 1974: 43, f. 7C, 8, 9A-C, 10A-C, 16B (Dmf).

Isoxya manangona Agnarsson et al., 2023: 5, f. 2-25 (Dmf).

Isoxya milloti Emerit, 1974: 55, f. 15, 16C (Df).

Isoxya mossamedensis Benoit, 1962a: 24, f. 17 (Df).
Isoxya mossamedensis Dippenaar-Schoeman et al., 2022e: 29, p. 27: 1 f., p. 29: 6 f. (f habitus).

Plectana mucronata Walckenaer, 1841: 156 (Df).
Gasteracantha tuberosa Thorell, 1859: 303 (Df) [urn:lsid:nmbe.ch:spidersp:062752].
Stanneoclavis tuberosa Karsch, 1879a: 330.
Gasteracantha purpurea Simon, 1884k: 19, pl. 1, f. 9 (Df) [urn:lsid:nmbe.ch:spidersp:062753].
Gasteracantha mucronata Dahl, 1914: 255 (S of Gasteracantha purpurea, G. tuberosa and Isoxia semiflava [revalidated by Benoit, 1962a: 29]).
Isoxya mucronata Benoit, 1962a: 27, f. 20 (f, T from Gasteracantha).
Isoxya mucronata Emerit, 1982b: 160, pl. 1C, f. 2 (Dm).
Isoxya mucronata Heinrichs & Barrion, 2004: 207, f. 581-582 (f).
Isoxya mucronata Dippenaar-Schoeman et al., 2022e: 30, 4 f. (f habitus).

Gasteracantha nigromutica Caporiacco, 1939a: 348 (Df).
Isoxya nigromutica Benoit, 1962a: 66 (T from Gasteracantha).

Gasteracantha reuteri Lenz, 1886: 382, pl. 10, f. 3 (Df).
Gasteracantha maculosa Lenz, 1886: 383, pl. 10, f. 4 (Df) [urn:lsid:nmbe.ch:spidersp:062754].
Isoxya reuteri Dahl, 1914: 255 (S of Gasteracantha maculosa).
Isoxya reuteri Benoit, 1962d: 373 (T from Gasteracantha).
Isoxya reuteri Emerit, 1974: 51, f. 7B, 13, 14A-C, 16D (f).

Gasteracantha rogersi O. Pickard-Cambridge, 1879c: 292, pl. 27, f. 23 (Dm) [urn:lsid:nmbe.ch:spidersp:062723].
Isoxia semiflava Simon, 1887a: 268, pl. 6, f. 2 (Df).
Isoxya semiflava Simon, 1895a: 843, f. 893 (f).
Isoxya semiflava Benoit, 1962a: 29, f. 22 (f, removed from S of Gasteracantha mucronata [rejecting Dahl, 1914: 255], S of Gasteracantha rogersi [removed from S of G. testudinaria, rejecting Lessert, 1930: 659]; rogersi is the older name, but Benoit chose semiflava as valid without explanation, this was accepted by Platnick).

Gasteracantha somalica Caporiacco, 1940c: 773, f. 2 (Df).
Isoxya somalica Benoit, 1962a: 67 (T from Gasteracantha).

Gasteracantha stuhlmanni Bösenberg & Lenz, 1895: 48, pl. 2, f. 30 (Df).
Isoxya stuhlmanni Benoit, 1962a: 34, f. 25 (f, T from Gasteracantha).
Isoxya stuhlmanni Dippenaar-Schoeman et al., 2022e: 31, 5 f. (f habitus).

Gasteracantha tabulata Thorell, 1859: 303 (Df).
Gasteracantha modesta Thorell, 1859: 303 (Dm) [urn:lsid:nmbe.ch:spidersp:062755].
Isoxia tabulata Pavesi, 1895a: 497.
Gasteracantha cicatrella Strand, 1907a: 537 (Df) [urn:lsid:nmbe.ch:spidersp:062756].
Gasteracantha kibonotensis Tullgren, 1910: 169 (Df) [urn:lsid:nmbe.ch:spidersp:062757].
Gasteracantha momboensis Tullgren, 1910: 170 (Df) [urn:lsid:nmbe.ch:spidersp:062758].
Gasteracantha tabulata Dahl, 1914: 255, f. 8 (f, S of Gasteracantha cicatrella, G. kibonotensis, G. modesta and G. momboensis).
Gasteracantha tabulata Lawrence, 1937: 234, f. 11 (mf).
Isoxya tabulata Benoit, 1962a: 36 (T from Gasteracantha).
Isoxya tabulata Emerit, 1973: 680, f. 3A-C, pl. IE-G (m).
Isoxya tabulata Benoit & Emerit, 1975: 327, f. 7a-b (m).
Isoxya tabulata Dippenaar-Schoeman et al., 2022e: 32, p. 32: 5 f., p. 33: 2 f. (f habitus).

Gasteracantha testudinaria Simon, 1901d: 20 (Df).
Gasteracantha testudinaria benina Strand, 1913a: 385 (Df) [urn:lsid:nmbe.ch:spidersp:062724].
Gasteraeantha (Isoxya) testudinaria Lessert, 1930: 659 (probable [junior] S of Gastheracantha rogersi, accepted by Roewer, 1942a: 938, rejected by Benoit, 1962a: 29, see Isoxya semiflava).
Isoxya testudinaria Benoit, 1962a: 31, f. 23 (f, T from Gasteracantha, S of Gasteracantha testudinaria benina).
Isoxya testudinaria Emerit, 1982b: 163, pl. 1D.

Isoxya yatesi Emerit, 1973: 683, f. 4 (Df).
Isoxya yatesi Dippenaar-Schoeman et al., 2022e: 34, 4 f. (f).