Aquilonastra O’Loughlin, 2004 (in O’Loughlin and Waters, 2004)

Aquilonastra O’Loughlin, in O’Loughlin and Waters, 2004: 5 (key to genus), 13–15, tables 1, 2.— O’Loughlin and Rowe, 2005: 181.— Saba and Fujita, 2006: 270.— Byrne, 2006: 244, 245, 248, 250, 251.— O’Loughlin and Rowe, 2006: 257–287 (key to species).— O’Loughlin, 2009: 204, fig. 1.— O’Loughlin and Mackenzie, 2013: 177–180, figs 1, 2. — O’Loughlin and Bribiesca-Contreras, 2015: 33–46, figs 1–8 (revised key to species).

Diagnosis (from O’Loughlin and Bribiesca-Contreras, 2015). Rays 5, or 5–8 in fissiparous species; inter-radial margin deeply incurved, form stellate; rays discrete, broad at base, tapering, rounded distally; flat actinally, convex abactinally; abactinal plates in longitudinal series, not perpendicular to margin; papulate areas extensive; papulae predominantly single, large, in longitudinal series along sides of rays; abactinal plates with glassy convexities; abactinal spinelets and actinal spines predominantly fine, glassy, conical or sacciform or splay-pointed sacciform, in bands or tufts, numerous (10–40 per plate); actinal plates in longitudinal, sometimes oblique,series;superambulacral plates present for all of ray, sometimes for part of ray or absent in paedomorphic species; superactinal plates present.

Remarks. We have not further revised the morphological diagnosis of genus Aquilonastra to accord with variations observed here, such as a shallow incurved junction of rays in two of the species below and the absence of superambulacral plates in one of the species below. We anticipate a necessary extensive revision when adequate genetic data become available.