Six new species referred to four new genera and one new species of Porcellidium belonging to the family Porcellidiidae (Harpacticoida: Copepoda) are described from Kioloa, a locality on the southern coast of New South Wales, Australia. Characteristic features defining the following new genera are given together with descriptions of new species: Brevifrons n.gen., B. faviolatum n.sp., Kioloaria n.gen., K. sesquimaculata n.sp., Murramia n.gen., M. magna n.sp., M. bicincta n.sp., Tectacingulum n.gen., T. tumidum n.sp. and T. nigrum n.sp. A new species of Porcellidium, P. londonii n.sp., is described and referred to the 'Fimbriatum' group. The structure and taxonomic significance of the hyaline fringe and male antennule are discussed together with other characters that have been used to define new genera.