Arcticacysta backmanii, Sangiorgi et al., 2009, p. 254–255, pl.1, figs.1–12, pl.2, figs.1–9, pl.3, figs.1–2.

Holotype: Sangiorgi et al., 2009, pl.1, figs.1–3.
Paratype: Plate 1, Fig. 4, 5, 6 (IODP 302, core 2A-45X, 49-50 cm, EF: K21/2)
Type strata: subunit 1/5 ACEX record (IODP 302)
Occurrence: throughout subunit 1/5 (198.70-195.61 mcd) of core of the ACEX record until samples get palynologically barren
Age: ?early Miocene.

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Original description: [Sangiorgi et al., 2009]:

Diagnosis:
a species of Arcticacysta with a wall ornamented with very low ridges (less than 0.2 µm) which connect to form a microreticulum (details in Plate 1, Fig. 6 and Plate 2, Fig. 9).
The archeopyle, when developed, is of type 3A3I (Plate 1, Figs. 1-5; Plate 2, Figs. 1-5), resulting from the loss of three apical (2’-4’) and three intercalaries (1a-3a).
The sulcus and the cingulum are not indicated, although orientation to the ventral surface is provided by the first apical plate, when clearly visible (Plate 1, Figs. 1-5, Figs 7-8; Plate 2, Figs. 1-5).

Dimensions:
Holotype length 59 µm (archeopyle developed), width 49 µm, Range of 20 specimens: length 36-62 µm, width 35-58 µm

Remarks:
Frequently specimens appear deformed (Plate 1, Figs. 1, 12; Plate 2, Fig. 6). Occasionally specimens are complete without any clear, visible archeopyle (e.g., Plate 1, Figs. 9, 12; Plate 3, Fig. 2). When preservation is bad, the cyst wall can result scabrate, and microreticulation is difficultly distinguishable.