Sertularella subdichotoma Kirchenpauer 1884: 46, pl. 16 fig. 1; Hartlaub 1905: 629, figs V 3, W 3; Jäderholm 1905: 25, pl. 9 fig. 8; 1926: 6; Stepanjants 1979: 77, pl. 17 fig. 7.
Symplectoscyphus subdichotomus – Blanco 1967 a: 273, pl. 3 figs 6–8, 10 – 11, pl. 4 figs 1, 2; 1967 b: 118, pl. 4 figs 5–10; 1984: 34, pl. 29 figs 64–66; Vervoort 1972 a: 140, figs 44 b–d, 45; Millard 1977: 37, figs 11 d–f; Peña Cantero & García Carrascosa 1995: 81 –82, fig. 42 D.
Sertularella divaricata var. sub-dichotoma Jäderholm 1917: 9.
Sertularella johnstoni – Naumov & Stepanjants 1962: 82, fig. 6. Sertularella filiformis – Naumov & Stepanjants 1972: 40, fig. 36.
Ecology. Eurybathic species, found at depths between 3 and 750 m (Stepanjants 1979). On rocky, stony and sandy bottoms (Stepanjants 1979; Peña Cantero & García Carrascosa 1995). Basibiont of other hydroids (Vervoort 1972 a; Stepanjants 1979). Gonothecae: February, March and June (Vervoort 1972 a), April (Millard 1977), September to June (Stepanjants 1979) and December (Blanco 1984).
Distribution. Uncertain, because of the presence of a group of closely related species (Vervoort 1972 a). Sub-Antarctic waters: southern South-America (Kirchenpauer 1884; Jäderholm 1905; 1926; Hartlaub 1905; Blanco 1967 b; Vervoort 1972 a; Stepanjants 1979), Falkland Islands (Jäderholm 1905; Vervoort 1972 a), Kerguélen and Crozet (Millard 1977; Stepanjants 1979), between Possession and Cochons (Millard 1977) and Lena Bank (Stepanjants 1979). Antarctic waters: South Shetland Islands (Stepanjants 1979; Peña Cantero & García Carrascosa 1995), South Orkney Islands (Stepanjants 1979), Low Island (Blanco 1984) and the Weddell Sea (Blanco 1967 a).