Two hundred eleven species in 149 genera and 42 families of polychaetous annelids are named. Most come from the Weddell Sea Quadrant. One family, Helmetophoridae, is new. Three genera, Helmetophorus in Helmetophoridae, Flabelliseta in Flabelligeridae, and Emaga in Ampharetidae, are new. Twenty-one species are new: Eunoe brunnea and Eunoe spica in Polynoidae; Eulalia pachycirra and Nipponophyllum antarcticum in Phyllodocidae; Helmetophorus rankini in Helmetophoridae; Apistobranchus glacierae in Apistobranchidae; Laonice weddellia in Spionidae; Caulleriella antarctica and Chaetozone pinguis in Cirratulidae; Flabelliseta incrusta, Ilyphagus antarcticus, and Ilyphagus cristata in Flabelligeridae; Asclerocheilus nigrocirrus in Scalibregmidae; Ammotrypane setigera in Opheliidae; Myriochele scotiae in Oweniidae; Emaga laevis, Glyphanostomum scotiarum, and Parampharete weddellia in Ampharetidae; and Euchone heteroseta, Euchone scotiarum, and Jasmineira regularis in Sabellidae. One subspecies, Pseudoscalibregma bransfieldia collaris in Scalibregmidae, is new. One name, Praxillella monroi in Maldanidae, is new. Seven combinations are new: Haploscoloplos minutus in Orbiniidae; Aricidea simplex in Paraonidae; Fauveliopsis brevis in Fauveliopsidae; Asclerocheilus aciculatus and Pseudoscalibregma bransfieldia in Scalibregmidae; Eusamythella sexdentata in Ampharetidae; and Axionice spinigera in Terebellidae. The following species have their accounts emended or their illustrations added: Brada bransfieldia and Bradabyssa papillata in Flabelligeridae; Fauveliopsis challengeriae in Fauveliopsidae; Kebuita minuta, Pseudoscalibregma bransfieldia, and Sclerocheilus antarcticus in Scalibregmidae; and Travisia antarctica in Opheliidae.
