Cinclidonemertes mooreae Crandall, 2010

Remarks

Established based on four specimens, up to 3.7 mm in length, collected from 19–25 m depth near Wauwermans Islands, Antarctica. With four eyes. The rhynchocoel is “composed of single fibres spaced apart from one another in a partially woven lattice” (Crandall 2010: 2412), a character state that cannot readily be interpreted as decisively homologous with that in Cratenemertea and/or Plectonemertidae . The cerebral organs are large, located behind the pre-cerebral septum, lying beside and beneath the brain, and thus conforming to those in Cratenemertea, but also in Proamphiporus Chernyshev & Polyakova, 2019 . The vascular plug is “broad and flat, lying tightly against ventral wall of rhynchocoel” (Crandall 2010: 2421), but one of the original figures (Crandall 2010, fig. 12) depicts it as if there are two vascular plugs, reminiscent of the character state in Oerstediina . The taxonomic placement of the family Cinclidonemertidae Crandall, 2010, the genus Cinclidonemertes Crandall, 2010, and C. mooreae among Monostilifera thus requires further scrutiny.