Tetranemertes bifrost sp. nov. A–C external appearance in life of individuals CBdT0062 (A), CB057_18_01 (B), and CB057_18_07 (C) showing variation in color D ventral view of anterior end of individual SMCP0366 showing cephalic furrow (arrowhead) E, F close up views of head in dorsal (E) and ventral (F) view of individual CB057_18_01 showing distribution of pigment, eyes, and the cephalic furrow (arrowhead on F) G anterior end of individual CB057_18_03 compressed under a glass slide to show number and distribution of eyes H, I stylets of individuals CB057_18_01 (H) and CB057_18_04 (I). Note the sculpted stylets, and the difference in basis shape (forked or rounded posteriorly). Abbreviations: cg — cerebral ganglion, pb — proboscis. Scale bars: 5 mm (A–C); 1 mm (D); 0.5 mm (E–G); 25 μm (H, I).