Placogorgiaatlantica Wright & Studer, 1889; SM Wright and Studer 1889 (= Pseudothesea Kükenthal, 1919).

Colonies usually branched laterally in one plane; main stem generally long; primary branches with tendency to curve upwards; primary branches tend to run parallel with main stem, tips button-shaped, prominent swellings. Polyp height moderately low, on all sides of branches; especially dense at branch tips. Calyces truncated, cone shaped, armed with spindles (thorn scales). With crown (collaret) and points arrangement (= operculum of Paramuricidae): each of eight points composed of two-three pointed, convergent spindles in triangular arrangement above collaret of spinous rods, latter forming spiny transverse ring; fairly large triangular space free from sclerites between each point, situated in tentacle base. Thorn scales of calyx typically large, coarse, thick; wider than tall, each with broad, abundantly branched basal root (broad, flat), and a (usually) short, stout, more or less laciniated but usually strong, blunt spine; these sclerites overlap like roof tiles. Coenenchymal sclerites diverse spindles, simple, branched, often flattened, occasionally with one or more projections. Outer coenenchyme with long, often bent, sclerites (spindles), blunt points on both ends; at calyx base these form enclosing annular ring.