Begins: After a detailed, comparative study of a large series of benthonic Polychaeta collected from the Yellow Sea, the East China Sea and the South China Sea, we found that specimens previously reported from the East China Sea as "Cossura coasta Kitamori" by Uschakov and Wu (1962) possess characters not only differing from those of the species but also of the genus. A re-examination of C. coasta Uschakov and Wu (not Kitamori) showed that each notopodia and neuropodia of the posterior region of the body is provided with an acicular seta. This character makes it different from the genus Cossura. On this basis we establish a new genus Heterocossura
