Fritillaria sargassi Lohmann 1896: 51–53, Pl. 8 Figs. 1, 8, 10, 12.
Fritillaria borealis f. sargassi: Lohmann 1905: 361, Pl. 12 Fig. 12. Lohmann & Bückmann 1926: 169. Tokioka 1940: 15; 1960: 355, 361–363, Fig. 1. Bückmann 1969: 8: Fig. 12b 2.
Fritillaria borealis f. ritteri: Lohmann & Bückmann 1926: 169. Tokioka 1940: 15.
Fritillaria borealis truncata sargassi + Fritillaria borealis truncata ritteri: Lohmann 1931: 140, 141. Tokioka 1940: 16. Fritillaria borealis sargassi: Fenaux 1993: 63, 70, 84; 1998: 303, 304.
Material examined. Eleven specimens (MDAFWU 2020 /384–394), St.205, January 2020.
Description. Trunk 1–1.5 mm long, roughly eight-shaped, with the well-elongated posterior part. Mouth with the prominent upper lip. Ciliated rings of the branchial passages are circular. The endostyle is short and the digestive tract axis is oblique. Gonads asymmetrically arranged; testis Y-shaped and the spherical ovary placed on the left branch. Tail short, with a broad fin and without amphichordal cells; tail musculature broad, especially in the proximal part, ending abruptly.
Global distribution. The Atlantic Ocean, Indian Ocean, Pacific Ocean, the Mediterranean Sea and Red Sea (Fenaux et al. 1998); Australian waters (Thompson 1948). Type locality: The equatorial stream to Cape Verde.