Two new genera of the pelagic family Yndolaciidae (Polychaeta) from the Arctic Ocean with an addition to the description of Yndolacia lopadorrhynchoides Støp-Bowitz

Until recently, the pelagic family Yndolaciidae was considered to include a single genus and species Yndolacia lopadorrhynchoides Støp-Bowitz, 1987 from the Gulf of Guinea. Yndolaciella polarsterni gen. et sp. nov. and Paryndolacia tomopteroides gen. et sp. nov. are described from the deep sea of the Arctic Ocean. Additions and refining of the diagnoses of the genus Yndolacia and the family are given. The absence of cephalic tentacles, a weakly developed brain, simple biramous parapodia with equal rami, similar cirri without cirrophores, a superficial position of the nervous system, the presence of two nerve cords and the lack of ganglionic swellings are assumed to constitute ancestral characters of the family. Some resemblance of the family to Tomopteridae is noted. It is supposed that fossil polychaete Eotomopteris aldridgei Briggs & Clarkson, 1987 belongs to Yndolaciidae.