Approximately 1,800 specimens of hymenosomatids from 14 species belonging to 4 genera were examined. A new genus Halimena intermediate in character between the genera Halicarcinus and Elamena is established. Another new genus Cyclohombronia resolves nomenclatural difficulties with continuing to use Hombronia; both new genera are monotypic. The first male pleopod is figured wherever possible, as the form of this appendage is valuable in distinguishing species. Eleven species are endemic to NZ, and 8 of these are found intertidally throughout the country, apparently being tolerant of regional temperature variations.