H.J.Marchant & R.Perrin (1986: 210, figs 6, 7)
Takahashi (1981a: 9, pl. 6, fig. 21, as “sp. no. 15”)
Cells solitary. Lorica conical, c. 17 µm long including the pedicel, 8 µm diameter. Lorica chamber c. 10 µm long. Longitudinal costae 7–11, spirally arranged at the posterior end of lorica, interwoven with a variable in number of transverse costae; anterior transverse costa joins the longitudinal costae at the junction of the first and second costal strips of the longitudinal costae; all costal strips of the lorica chamber 3.2 µm long. Pedicel to 15 µm long, comprising thickened apparently flattened costal strips 1.5–3.6 µm long and c. 0.13 µm thick that also form part of the posterior end of the lorica chamber. Intact protoplasts not seen.
Burton Lake (tidal lagoon in the Vestfold Hills), East Antarctica (Marchant & Perrin, 1986); at the bottom of the sea-ice in Lützow-Holm Bay (Takahashi, 1981a, as “sp. no. 15”).
Marchant & Perrin (1986) noted that Spiraloecion superficially resembles some species of Acanthoecopsis. However, the number of costae and details of costal strip arrangement and morphology separate the two genera.