Nausithoe marginata Kölliker, 1853

(Fig. 9)

Nausithoe marginata K̂lliker, 1853: 323.

Holotype not known, possibly not extant.

Material examined: ZMH C9774 and 9776 (11 specimens from France and Italy, no information on depth), NMNH 57649 (more than 30 specimens from Puerto Rico 1975, no information on depth) and photo from underwater photographer, Linda Ianniello (SE Florida, USA 2020, depth: 6–12 m) .

Diagnosis: medusa—isodome bell with no mouth lips nor manubrium; polyp—solitary with 8 cusps per whorl.

Description: Based on original description and Jarms (1990). Adult medusa 4–5 mm in diameter, 2 mm of this the central disc; rhopalia with statoliths and no ocellus; marginal lappets triangular; mouth without lips; tentacles shorter than total body length; transparent umbrella; gonads elongated. Polyp solitary; more than 5 mm in total length; aperture 0.6–0.8 mm in diameter; 5 to 10 whorls of cusps with 8 cusps each.

Type locality: Messina, Italy (shallow waters).

Distribution: Mediterranean and new report for Puerto Rico.

Remarks: Examined specimens were extremely damaged. Very delicate umbrella, transparent, with high dome. Gastrovascular cavity with 12 short gastric filaments in total (4 clusters in each quadrant) and no manubrium (mouth opens directly to the cavity). Eight white oblong gonads. Total diameter up to 3 mm.