Abstract
A restudy of the rhynchonellide brachiopod genus Aetheia confirms that a single long-ranging species is present in New Zealand Cenozoic rocks. Aetheia gualteri (Morris) i.s preserved in a wide variety of sediments ranging from Mid Eocene to Early Miocene (Bortonian to Altonian local stages). The population structure, life habit, and biotic relations of Aetheia gualteri arc discussed.