Faubel A 1976 (citation)- description and illustration, p 217-220 from eulittoral Sylt, also a Retronectes sp.
Ehlers U 1985 (citation)- "Organisation der Statocyste von Retronectes (Catenulida, Plathelminthes)." Species
included Retronectes cf. sterreri, and Retronectes sp.