New Zealand foliose red algae belonging to the family Halymeniaceae were examined with a focus on species that have been placed in the genera Halymenia and Cryptonemia. Phylogenetic analyses of plastid-encoded rbcL and morphological observations were undertaken. Samples from northern New Zealand, referred to as Halymenia latifolia, were compared genetically with H. latifolia from its type locality in France. The New Zealand material was clearly separate from the genus Halymenia and from H. latifolia, and was found to be closely related to Halymenia abyssicola from Mexico. The new genus Amalthea is described to accommodate the New Zealand taxon. Samples referred to Cryptonemia sp. from New Zealand formed a well-supported clade with Cryptonemia rotunda from Korea and Japan. This clade was distinct from the clade containing the generitype Cryptonemia lomation from France and other species of Cryptonemia. We propose a new genus Galene to include three species from New Zealand, two of which are described as new here and transfer Cryptonemia rotunda to this new genus.