Chaetozone setosa Malmgren, 1867 is commonly recorded as present in soft sediments from the intertidal zone to the deep sea from many localities worldwide. The genus was not defined by Malmgren, 1867 in his description of
Chaetozone n. gen. and
setosa n. sp. Later authors (Day, 1967; Fauvel, 1927; Hartman, 1961) have attempted definitions using a variety of characters based largely on the occurrence, form and arrangement of the spine-like chaetae. The publication of a new species of
Chaetozone (Woodham and Chambers, 1994a) highlighted the need for a re-examination of the type species of the genus. Malmgren's type material has been examined and re-described, the genus defined, and a new species described from British waters.