[introduction in part] This paper deals with a collection of polychaetes made between tide marks during April and September 1960 from the following places on the southern coast: Bentota, Hikkaduwa, Ahangama, Weligama, Dondra, Gandara and Tangalle. A few species that were collected previously from Galle Face, Mutwal, Beruwala (Western Province), Chilaw (North Western Province) and from the Ceylon Pearl Banks, Gulf of Mannar have also been included. In all 35 species are described of which five species and two varieties are new to science and eleven species and one variety are new to the fauna of Ceylon.