A new species of giant (Eunicidae, Polychaeta, Annelida) from the east coast of Australia.

A new giant species is described from New South Wales, Australia. differs from described Australian species and is most similar to (Pallas, 1788), Izuka, 1912, and Ehlers, 1868. The unique combination of features that characterizes the new species is irregular articulated prostomial appendages; antennae reaching back beyond chaetiger 4; branchiae starting at chaetiger 10, initially button-shaped and distinctly longer than notopodial cirri where best developed; dorsal fleshy knobs on anterior chaetal lobes; notopodial cirri pendulous, abrupt tapering from inflated bases; bidentate compound falcigerous chaetae with both teeth directed laterally, distal tooth much shorter than proximal tooth in median and posterior chaetigers; and dark bidentate subacicular hooks starting at chaetiger 58, tapering to a small head with both teeth directed distally, and proximal tooth much larger than minute and spur-like distal tooth. This new species lives in sandy sediments in coastal waters 1-8 m deep. It is highly mobile and not easy to collect, which may explain why it was not described before.