MARIONINA GEORGIANA (MICHAELSEN, 1888)

(FIG. 9D)

Pachydrilus georgianus Michaelsen, 1888: 65–66, pl. II, fig. 7a, b.

Marionia georgiana – Michaelsen, 1889b: 29.

Marionina georgiana – Michaelsen in Pfeffer, 1890: 511; Beddard, 1895: 332; Michaelsen, 1900: 76; Nielsen & Christensen, 1959: 109; Brinkhurst & Jamieson, 1971: 662; Rota et al., 2008: 425–433, figs 2–6; Schmelz & Collado, 2008: 12–18, figs 1–13.

Pachydrilus (Marionina) georgiana – Černosvitov, 1937: 293.

Christensenia georgiana – Dózsa-Farkas & Convey, 1997: 483–484, fig. 9; partim.

Christensenidrilus georgiana [sic] – Dózsa-Farkas & Convey, 1998: 292; partim.

Non Marionina georgiana – Michaelsen, 1905a: 15–17, pl. I, fig. 2; Michaelsen, 1905b: 5; Stephenson, 1932: 241.

Type material studied: Lectotype CeNak V428 and paralectotypes CeNak V428 2, 5–17, in alcohol. Loc. South Georgia Island.

Type locality: South Georgia Island, near the German station 1882–1883, 54.533 S, 36.017 W, at low water mark, from slate debris, algal weeds and sponge canals, Febuary 1883 .

Additions to Michaelsen’s original description and recent redescriptions of types: Paired clusters of perikarya on prostomial nerves and at ventral ends of circumoesophageal connectives. Ventral nerve cord with small subbuccal bulb (Fig. 9D); see Marionina discussion above. Developing male cells enveloped in testis sac, distally frayed, releasing free-floating cysts, parts of which extend into X and XII in seminal vesicle.

Remarks: This species was thoroughly redescribed by Rota et al. (2008) and Schmelz & Collado (2008), but neither described the subbuccal bulb (which we could not make out in most specimens) and neither considered the male cells enveloped in a testis sac but both mention the large seminal vesicle.