Moore's diagnosis is short but he identifies three characters for his genus: "The body is much elongated; anteriorly elytra and dorsal cirri alternate in the usual manner, but in the middle and posterior region all segments bear elytra only; a large free nuchal plate overlaps the prostomium dorsally."
Moore, J.P. (1905). New species of Polychaeta from the North Pacific, chiefly from Alaskan waters. Proceedings of the Academy of Natural Sciences of Philadelphia. 57: 525-554, plates XXXIV-XXXVI. available online athttp://biodiversitylibrary.org/page/26293556