Placogorgia Studer, 1887

Horvath, Elizabeth Anne, 2019, A review of gorgonian coral species (Cnidaria, Octocorallia, Alcyonacea) held in the Santa Barbara Museum of Natural History research collection: focus on species from Scleraxonia, Holaxonia, Calcaxonia - Part II: Species of Holaxonia, families Gorgoniidae and Plexauridae, ZooKeys 860, pp. 67-182 : 67

Genus Placogorgia Studer, 1887

Placogorgia Studer, 1887: 56 [without species]. Wright and Studer 1889: 113. Nutting 1912: 83. Kükenthal 1919: 841; 1924: 209-210. Deichmann 1936: 141-142. Bayer 1956 a: F206; 1959b: 54-55. Grasshoff 1977 (pars): 26. Muzik 1979: 80-81.

? nec Placogorgia Nutting (part), 1910a: 76 [= Discogorgia Kükenthal].

Clematissa Studer, 1887: 106-107.

Pseudothesea Kükenthal, 1919: 843.

Discomuricea Gordon, 1926: 521.

Type species.

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

Diagnosis.

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.