During the expeditions ANT XIII/3 (1996) and ANT XV/3 (1998) to the Weddell Sea, a number of
polynoid specimens resembling Harmothoe spinosa Kinberg, 1856 were collected. Due to contra-
dictory information in the literature regarding the differentiating characters of H. spinosa and other
related species, the type material of the former and of 27 nominal, similar species had to be examined
in order to allow the correct identification of the specimens from the Weddell Sea. As a result of this
study the validity of H. spinosa is confirmed, but this species has not been recorded in the Antarctic or
Subantarctic region. Of the 27 similar species only nine are considered valid and redescribed herein,
i.e. H. exanthema (Grube, 1858), H. fuligineum* (Baird, 1865), H. fullo* (Grube, 1878), H.
antarctica* (McIntosh, 1885), H. magellanica* (McIntosh, 1885), H. crosetensis (McIntosh, 1885), H.
acuminata* Willey, 1902, Antarctinoe gen. nov. ferox* (Baird, 1865), and A. spicoides* (Hartmann-
Schröder, 1986), with Antarctinoe being a new genus established herein. Species marked by an asterisk
were also present in the collection of polynoids from the Weddell Sea. All records and geographical
ranges given in the literature for H. spinosa and the other species not confirmed herein remain